OMB APPROVAL OMB Number: 3235-0570 Expires: January 31, 2017 Estimated average burden hours per response.....20.6 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM N-CSR CERTIFIED SHAREHOLDER REPORT OF REGISTERED MANAGEMENT INVESTMENT COMPANIES 		Investment Company Act file number 811-21108 Pioneer Series Trust X (Exact name of registrant as specified in charter) 60 State Street, Boston, MA 02109 (Address of principal executive offices) (ZIP code) Terrence J. Cullen, Pioneer Investment Management, Inc., 60 State Street, Boston, MA 02109 (Name and address of agent for service) Registrant's telephone number, including area code: (617) 742-7825 Date of fiscal year end: March 31 Date of reporting period: April 1, 2015 through September 30, 2015 Form N-CSR is to be used by management investment companies to file reports with the Commission not later than 10 days after the transmission to stockholders of any report that is required to be transmitted to stockholders under Rule 30e-1 under the Investment Company Act of 1940 (17 CFR 270.30e-1). The Commission may use the information provided on Form N-CSR in its regulatory, disclosure review, inspection, and policymaking roles. A registrant is required to disclose the information specified by Form N-CSR, and the Commission will make this information public. A registrant is not required to respond to the collection of information contained in Form N-CSR unless the Form displays a currently valid Office of Management and Budget ("OMB") control number. Please direct comments concerning the accuracy of the information collection burden estimate and any suggestions for reducing the burden to Secretary, Securities and Exchange Commission, 450 Fifth Street, NW, Washington, DC 20549-0609. The OMB has reviewed this collection of information under the clearance requirements of 44 U.S.C. ss. 3507. ITEM 1. REPORTS TO STOCKHOLDERS. Pioneer Dynamic Credit Fund -------------------------------------------------------------------------------- Semiannual Report | September 30, 2015 -------------------------------------------------------------------------------- Ticker Symbols: Class A RCRAX Class C RCRCX Class Y RCRYX [LOGO] PIONEER Investments(R) visit us: us.pioneerinvestments.com Table of Contents President's Letter 2 Portfolio Management Discussion 4 Portfolio Summary 9 Prices and Distributions 10 Performance Update 11 Comparing Ongoing Fund Expenses 14 Schedule of Investments 16 Financial Statements 54 Notes to Financial Statements 61 Approval of Investment Advisory Agreements 77 Trustees, Officers and Service Providers 82 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 1 President's Letter Dear Shareholder, Through the first three quarters of 2015, global markets experienced pockets of higher-than-average volatility due to significant cross-currents from different geographic regions. All year, investors focused on the Federal Reserve System's (the Fed's) deliberations over when to begin normalizing interest rates. However, while there were signs of gradual economic improvement in the U.S., economies abroad increasingly diverged. In June, for example, investors grew concerned about the debt crisis in Greece. That news, in turn, was followed by evidence of an economic slowdown in China, which only served to exacerbate existing worries about growth trends in the emerging markets, a segment of the global economy already being negatively impacted by slumping commodity prices, including the price of crude oil, which has been in near-steady decline for almost a year. Through September 30, 2015, the pockets of heightened market volatility alluded to above had resulted in the Standard & Poor's 500 Index turning in a negative (-5.27%) return over the first nine months of the year. However, the S&P 500 recovered nicely in October, returning 8.43% for the month, which boosted the index's year-to-date return into positive territory, at 2.71%. Despite the headwinds still vexing the global economy, our longer-term view of the U.S. economy has remained positive. Economic conditions in the U.S. have generally been constructive, based largely on improvements in employment statistics and an uptick in the housing sector, which has aided the consumer side of the economy, where household spending has been rising modestly. U.S. consumers also stand to benefit, potentially, from lower energy prices as the winter weather approaches. We continue to believe the U.S. economy remains on a slow, steady growth trend, and that it is unlikely to be disrupted by a slow pace of interest-rate normalization by the Fed. Pioneer Investments believes that investors in today's environment can potentially benefit from the consistent and disciplined investment approach we have used since our founding in 1928. We focus on identifying value across global markets using proprietary research, careful risk management, and a long-term perspective. Our ongoing goal is to produce compelling returns consistent with the stated objectives of our investment products, and with our shareowners' expectations. We believe our shareowners can benefit from the experience and tenure of our investment teams as well as the insights generated from our extensive research process. 2 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 As always, and particularly during times of market uncertainty, we encourage you to work with your financial advisor to develop an overall investment plan that addresses both your short- and long-term goals, and to implement such a plan in a disciplined manner. We greatly appreciate your trust in us in the past and look forward to continuing to serve you in the future. Sincerely, /s/Lisa M. Jones Lisa M. Jones President and CEO Pioneer Investment Management USA Inc. November 2, 2015 Any information in this shareowner report regarding market or economic trends or the factors influencing the Fund's historical or future performance are statements of opinion as of the date of this report. These statements should not be relied upon for any other purposes. Past performance is no guarantee of future results, and there is no guarantee that market forecasts discussed will be realized. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 3 Portfolio Management Discussion | 9/30/15 Most non-government-related sectors of the fixed-income market, including high-yielding corporate bonds, weakened in performance during the six-month period ended September 30, 2015, as global economic growth slowed and the prices of oil and other commodities dropped. In the following interview, Michael Temple, a senior vice president, portfolio manager, and Director of Fixed-Income Credit Research at Pioneer, discusses the factors that affected the performance of Pioneer Dynamic Credit Fund during the six-month period. Mr. Temple is responsible for the day-to-day management of the Fund, along with Thomas Swaney, a senior vice president, portfolio manager, and Head of Alternative Fixed Income at Pioneer*. Q How did the Fund perform during the six-month period ended September 30, 2015? A Pioneer Dynamic Credit Fund's Class A shares returned -1.27% at net asset value during the six-month period ended September 30, 2015, while the Fund's benchmark, the Bank of America Merrill Lynch (BofA ML) U.S. Dollar 3-Month LIBOR Index (the BofA ML Index), returned 0.14%. During the same period, the average return of the 277 mutual funds in Lipper's Alternative Credit Focus Funds category was -2.37%, and the average return of the 496 mutual funds in Morningstar's Non-Traditional Bond Funds category was -1.99%. Q How would you describe the investment environment in the fixed-income markets during the six-month period ended September 30, 2015? A Declining commodity prices, particularly of oil, and growing evidence of weakening in the global economy led to a difficult period for the more credit-sensitive areas of the fixed-income market over the six-month period ended September 30, 2015. The period began in April 2015, in the wake of a strong recovery in the credit-sensitive fixed-income sectors over the first quarter of the calendar year. The rebound occurred following a severe sell-off in late 2014 that was driven by a collapse in oil prices; the bounce-back was the result of better-than-expected economic growth data coupled with a recovery in the crude oil market. * Note to shareholders: Effective September 25, 2015, Thomas Swaney, Senior Vice President and Head of Alternative Fixed Income, U.S., at Pioneer, was added as a portfolio manager on the Fund, joining Michael Temple, Senior Vice President and Director of Fixed-Income Credit Research at Pioneer, who has been a portfolio manager on the Fund since its inception in 2011. Also effective September 25, 2015, Andrew Feltus and Chin Liu no longer serve as portfolio managers on the Fund. 4 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 During that early part of the calendar year, high-yielding corporate bonds, emerging markets debt, bank loans and investment-grade corporates all rallied, with energy-related bonds performing particularly well. However, just as the Fund's fiscal period got underway, the global economic outlook again soured, and the recovery in oil prices proved short-lived as worldwide energy production continued to grow -- even in the face of weaker demand. Oil prices again started falling, and the markets for high-yield corporate bonds, emerging markets debt and investment-grade corporates all weakened. Complicating matters further was the fact that the investment-grade credit market began to see a powerful wave of new-bond issuance, much of it directed towards funding corporate merger-and- acquisition programs, stock buybacks and other equity-friendly actions that did not necessarily favor the interests of bondholders. As a result, yield spreads -- or the differences between the yields of higher-rated debt (typically Treasuries) and lower-rated debt with similar maturities -- widened, and credit-linked securities underperformed. The high-yield corporate sector, which tends to have a relatively large exposure to the energy sector, and emerging markets bonds fared the worst during this timeframe, while investment-grade debt also underperformed. Bank loans and structured products such as asset-backed securities (ABS) and mortgage-backed securities (MBS) were less affected. Q How was the Fund positioned in that environment, and what were the effects of that positioning on the Fund's performance during the six-month period ended September 30, 2015? A Starting in 2014, we had been positioning the Fund for a less-favorable environment for credit-sensitive debt, and had been reducing the portfolio's exposure to such securities. In the first quarter of 2015, as energy-related securities rallied, we seized upon the opportunity to lock in some gains and began to cut back the Fund's energy exposure. We also cut back on investments in emerging markets debt and convertible bonds. In addition, we upgraded the overall credit quality of the Fund's holdings. In the high-yield portion of the portfolio, for example, we reduced exposure to the lower-quality CCC-rated and B-rated credit tiers, and made comparable moves within the Fund's allocation to convertible bonds. As we did this, we increased exposure to floating-rate bank loans, which we found attractive because of their higher ratings, the fact that they are secured debt instruments, and perhaps most importantly, because their floating-rate feature made them less sensitive to changes in interest rates. We also maintained a relatively large hedge position in the portfolio, hedging about one-half of the Fund's exposure to high-yield corporates. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 5 In general, the Fund's underperformance of its benchmark during the period was attributable to the weak performance of the portfolio's credit- sensitive holdings, given that most fixed-income sectors, other than government-debt-related asset classes, turned in negative performance over the full six months. However, our decisions to upgrade the Fund's credit quality during the period and to hedge a larger portion of the portfolio using derivatives, helped to limit the benchmark-relative underperformance, while enabling the Fund to outperform its Lipper and Morningstar peer group average returns. At the end of the period, by sector, the largest allocation in the Fund's total investment portfolio was to U.S. corporate bonds, at 36%, with roughly 21% of that allocated to high-yield bonds; this was followed by bank loans (24%), collateralized mortgages (15%) and international corporates (13%). Other notable allocations included insurance-linked securities issued by property-and-casualty insurers, which represented roughly 8% of the Fund's total investment portfolio at period end. Q Did the Fund use any derivative securities or contracts during the six-month period ended September 30, 2015? If so, how did those investments affect performance? A Yes, as noted earlier, we hedged a relatively large portion of the Fund's portfolio during the period, using a variety of derivatives in our hedging strategy, including Standard & Poor's (S&P) futures contracts, credit derivatives and volatility contracts. The hedging moves helped to buffer the effects of the weak performance by the credit-sensitive securities in the portfolio, and had a beneficial effect on the Fund's benchmark-relative returns. Q What factors affected the Fund's income-generation, or yield for shareholders, during the six-month period ended September 30, 2015? A The Fund's yield was basically unchanged during the period. However, we have adjusted our hedging methodology, which we believe could increase the Fund's potential to pay higher distributions to shareholders in the future. Q What is your current view of the credit markets, and how has that outlook affected your investment strategy, if at all? A In the near term, we believe credit-linked securities appear more attractive than they did earlier in 2015. As a result, we very recently have increased the portfolio's credit risk by a little bit, although we have maintained the overall up-in-quality positioning we implemented over the past few months, focusing on the higher-quality tiers within the high-yield corporate universe as well as other asset classes. At present, we are trying to take advantage of some of the attractive opportunities that have appeared as a result of the earlier sell-offs in the fixed-income markets. 6 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 Looking further down the road, we intend to remain generally cautious with regard to investments in the credit-sensitive markets, while maintaining the flexibility to take advantage of good investment opportunities as they emerge. Please refer to the Schedule of Investments on pages 16-53 for a full listing of Fund securities. All investments are subject to risk, including the possible loss of principal. Pioneer Dynamic Credit Fund has the ability to invest in a wide variety of debt securities. The Fund may invest in underlying funds, including ETFs. In addition to the Fund's operating expenses, you will indirectly bear the operating expenses of investments in any underlying funds. The Fund and some of the underlying funds utilize strategies that have a leveraging effect on the Fund, which increases the volatility of investment returns and subjects the Fund to magnified losses if the Fund's or an underlying fund's investments decline in value. The Fund and some of the underlying funds may use derivatives, such as options and futures, which can be illiquid, may disproportionately increase losses, and have a potentially large impact on Fund performance. The Fund may invest in inflation-linked securities. As inflationary expectations increase, inflation-linked securities may become more attractive, because they protect future interest payments against inflation. Conversely, as inflationary concerns decrease, inflation-linked securities will become less attractive and less valuable. The Fund may invest in credit default swaps, which may in some cases be illiquid, and they increase credit risk since the Fund has exposure to both the issuer of the referenced obligation and the counterparty to the credit default swap. The Fund may invest in floating-rate loans. The value of collateral, if any, securing a floating-rate loan can decline or may be insufficient to meet the issuer's obligations or may be difficult to liquidate. The Fund may invest in event-linked bonds. The return of principal and the payment of interest on event-linked bonds are contingent on the nonoccurrence of a pre-defined "trigger" event, such as a hurricane or an earthquake of a specific magnitude. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 7 The Fund may invest in zero coupon bonds and payment-in-kind securities, which may be more speculative and fluctuate more in value than other fixed income securities. The accrual of income from these securities are payable as taxable annual dividends to shareholders. Investments in equity securities are subject to price fluctuation. Investments in fixed-income securities involve interest rate, credit, inflation, and reinvestment risks. As interest rates rise, the value of fixed-income securities generally falls. The Fund may invest in mortgage-backed securities, which during times of fluctuating interest rates may increase or decrease more than other fixed-income securities. Mortgage-backed securities are also subject to pre-payments. Prepayment risk is the chance that an issuer may exercise its right to prepay its security, if falling interest rates prompt the issuer to do so. Forced to reinvest the unanticipated proceeds at lower interest rates, the Fund would experience a decline in income and lose the opportunity for additional price appreciation. High-yield bonds possess greater price volatility, illiquidity, and possibility of default. There is no assurance that these and other strategies used by the Fund or underlying funds will be successful. The Fund is not intended to outperform stocks and bonds during strong market rallies. These risks may increase share price volatility. Please see the prospectus for a more complete discussion of the Fund's risks. Before investing, consider the product's investment objectives, risks, charges and expenses. Contact your advisor or Pioneer Investments for a prospectus or summary prospectus containing this information. Read it carefully. Any information in this shareholder report regarding market or economic trends or the factors influencing the Fund's historical or future performance are statements of opinion as of the date of this report. Past performance is no guarantee of future results. 8 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 Portfolio Summary | 9/30/15 Portfolio Diversification* -------------------------------------------------------------------------------- (As a percentage of total investment portfolio) [THE FOLLOWING DATA WAS REPRESENTED AS A PIE CHART IN THE PRINTED MATERIAL] U.S. Corporate Bonds 36.4% Senior Secured Loans 23.6% Collateralized Mortgage Obligations 14.7% International Corporate Bonds 13.2% Asset Backed Securities 4.6% U.S. Government Securities 2.4% U.S. Preferred Stocks 1.4% Temporary Cash Investments 1.1% Convertible Corporate Bonds 1.0% Foreign Government Bonds 0.5% Convertible Preferred Stocks 0.5% U.S. Common Stocks 0.5% International Preferred Stocks 0.1% International Common Stocks 0.0%** * Includes investments in insurance linked securities totaling 8.1% of total investment portfolio. ** Amount rounds to less than 0.1%. 10 Largest Holdings -------------------------------------------------------------------------------- (As a percentage of total long-term holdings)*** 1. Fannie Mae, 3.5%, 5/1/44 1.37% ------------------------------------------------------------------------------------------------ 2. Verizon Communications, Inc., 4.15%, 3/15/24 0.65 ------------------------------------------------------------------------------------------------ 3. CD 2005-CD1 Commercial Mortgage Trust, Floating Rate Note, 7/15/44 0.62 ------------------------------------------------------------------------------------------------ 4. JPMorgan Chase & Co., Floating Rate Note, 8/29/49 0.61 ------------------------------------------------------------------------------------------------ 5. Gullane Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 1/22/17 0.58 ------------------------------------------------------------------------------------------------ 6. Versutus, Ltd., Series 2015-A, Variable Rate Notes, 12/31/17 0.57 ------------------------------------------------------------------------------------------------ 7. Pangaea Re, Series 2015-1, Principal at Risk Notes, 2/1/19 0.56 ------------------------------------------------------------------------------------------------ 8. Builders FirstSource, Inc., Initial Term Loan, 7/24/22 0.52 ------------------------------------------------------------------------------------------------ 9. Pangaea Re, Series 2015-2, Principal at Risk Notes, 11/30/19 0.52 ------------------------------------------------------------------------------------------------ 10. Credit Suisse First Boston Mortgage Securities Corp., Floating Rate Note, 8/15/38 0.51 ------------------------------------------------------------------------------------------------ *** This list excludes temporary cash investments and derivative instruments. The portfolio is actively managed, and current holdings may be different. The holdings listed should not be considered recommendations to buy or sell any security listed. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 9 Prices and Distributions | 9/30/15 Net Asset Value per Share -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- Class 9/30/15 3/31/15 -------------------------------------------------------------------------------- A $9.30 $9.54 -------------------------------------------------------------------------------- C $9.27 $9.51 -------------------------------------------------------------------------------- Y $9.33 $9.58 -------------------------------------------------------------------------------- Distributions per Share: 4/1/15-9/30/15 -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- Short-Term Long-Term Class Dividends Capital Gains Capital Gains -------------------------------------------------------------------------------- A $0.1200 $-- $-- -------------------------------------------------------------------------------- C $0.0858 $-- $-- -------------------------------------------------------------------------------- Y $0.1367 $-- $-- -------------------------------------------------------------------------------- The Bank of America Merrill Lynch U.S. Dollar 3-Month LIBOR Index is an unmanaged index that tracks the performance of a synthetic asset paying the London Interbank Offered Rate (LIBOR), with a constant 3-month average maturity. The index is based on the assumed purchase at par value of a synthetic instrument having exactly its stated maturity and with a coupon equal to that day's 3-month LIBOR rate. Index returns assume reinvestment of dividends and, unlike Fund returns, do not reflect any fees, expenses or sales charges. It is not possible to invest directly in an index. The index defined here pertains to the "Value of $10,000 Investment" and "Value of $5 Million Investment" charts on pages 11-13. 10 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 Performance Update | 9/30/15 Class A Shares Investment Returns -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $10,000 investment made in Class A shares of Pioneer Dynamic Credit Fund at public offering price during the periods shown, compared to that of the Bank of America (BofA) Merrill Lynch (ML) U.S. Dollar 3-Month LIBOR Index. Average Annual Total Returns (As of September 30, 2015) -------------------------------------------------------------------------------- BofA ML Net Public U.S. Dollar Asset Offering 3-Month Value Price LIBOR Period (NAV) (POP) Index -------------------------------------------------------------------------------- Life-of-Class (4/29/11) 2.53% 1.47% 0.31% 1 Year -2.66 -7.09 0.25 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated August 1, 2015) -------------------------------------------------------------------------------- Gross -------------------------------------------------------------------------------- 1.14% -------------------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment Pioneer Dynamic BofA ML U.S. Credit Fund Dollar 3-Month 4/11 $ 9,550 $10,000 9/11 $ 9,122 $10,009 9/12 $10,086 $10,058 9/13 $10,483 $10,090 9/14 $10,957 $10,114 9/15 $10,665 $10,140 Call 1-800-225-6292 or visit us.pioneerinvestments.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. NAV results represent the percent change in net asset value per share. Returns would have been lower had sales charges been reflected. POP returns reflect deduction of maximum 4.50% sales charge. All results are historical and assume the reinvestment of dividends and capital gains. Other share classes are available for which performance and expenses will differ. Performance results reflect any applicable expense waivers in effect during the periods shown. Without such waivers Fund performance would be lower. Waivers may not be in effect for all funds. Certain fee waivers are contractual through a specified period. Otherwise, fee waivers can be rescinded at any time. See the prospectus and financial statements for more information. The performance table and graph do not reflect the deduction of fees and taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 11 Performance Update | 9/30/15 Class C Shares Investment Returns -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $10,000 investment made in Class C shares of Pioneer Dynamic Credit Fund during the periods shown, compared to that of the Bank of America (BofA) Merrill Lynch (ML) U.S. Dollar 3-Month LIBOR Index. Average Annual Total Returns (As of September 30, 2015) -------------------------------------------------------------------------------- BofA ML U.S. Dollar 3-Month If If LIBOR Period Held Redeemed Index -------------------------------------------------------------------------------- Life-of-Class (4/29/11) 1.71% 1.71% 0.31% 1 Year -3.39 -3.39 0.25 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated August 1, 2015) -------------------------------------------------------------------------------- Gross -------------------------------------------------------------------------------- 1.90% -------------------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment Pioneer Dynamic BofA ML U.S. Credit Fund Dollar 3-Month 4/11 $10,000 $10,000 9/11 $ 9,517 $10,009 9/12 $10,434 $10,058 9/13 $10,753 $10,090 9/14 $11,156 $10,114 9/15 $10,778 $10,140 Call 1-800-225-6292 or visit us.pioneerinvestments.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. Class C shares held for less than one year are subject to a 1% contingent deferred sales charge (CDSC). "If Held" results represent the percent change in net asset value per share. Returns would have been lower had sales charges been reflected. All results are historical and assume the reinvestment of dividends and capital gains. Other share classes are available for which performance and expenses will differ. Performance results reflect any applicable expense waivers in effect during the periods shown. Without such waivers Fund performance would be lower. Waivers may not be in effect for all funds. Certain fee waivers are contractual through a specified period. Otherwise, fee waivers can be rescinded at any time. See the prospectus and financial statements for more information. The performance table and graph do not reflect the deduction of fees and taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. 12 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 Performance Update | 9/30/15 Class Y Shares Investment Returns -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $5 million investment made in Class Y shares of Pioneer Dynamic Credit Fund during the periods shown, compared to that of the Bank of America (BofA) Merrill Lynch (ML) U.S. Dollar 3-Month LIBOR Index. Average Annual Total Returns (As of September 30, 2015) -------------------------------------------------------------------------------- BofA ML Net U.S. Dollar Asset 3-Month Value LIBOR Period (NAV) Index -------------------------------------------------------------------------------- Life-of-Class (4/29/11) 2.90% 0.31% 1 Year -2.45 0.25 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated August 1, 2015) -------------------------------------------------------------------------------- Gross Net -------------------------------------------------------------------------------- 0.93% 0.85% -------------------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $5 Million Investment Pioneer Dynamic BofA ML U.S. Credit Fund Dollar 3-Month 4/11 $5,000,000 $5,000,000 9/11 $4,800,067 $5,004,742 9/12 $5,318,483 $5,028,849 9/13 $5,549,790 $5,044,939 9/14 $5,816,604 $5,057,112 9/15 $5,674,308 $5,069,978 Call 1-800-225-6292 or visit us.pioneerinvestments.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. Class Y shares are not subject to sales charges and are available for limited groups of eligible investors, including institutional investors. All results are historical and assume the reinvestment of dividends and capital gains. Other share classes are available for which performance and expenses will differ. Performance results reflect any applicable expense waivers in effect during the periods shown. Without such waivers Fund performance would be lower. Waivers may not be in effect for all funds. Certain fee waivers are contractual through a specified period. Otherwise, fee waivers can be rescinded at any time. See the prospectus and financial statements for more information. The net expense ratio reflects the contractual expense limitation currently in effect through August 1, 2017, for Class Y shares. There can be no assurance that Pioneer will extend the expense limitation beyond such time. Please see the prospectus for more information. The performance table and graph do not reflect the deduction of fees and taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 13 Comparing Ongoing Fund Expenses As a shareowner in the Fund, you incur two types of costs: (1) ongoing costs, including management fees, distribution and/or service (12b-1) fees, and other Fund expenses; and (2) transaction costs, including sales charges (loads) on purchase payments. This example is intended to help you understand your ongoing expenses (in dollars) of investing in the Fund and to compare these costs with the ongoing costs of investing in other mutual funds. The example is based on an invest- ment of $1,000 at the beginning of the Fund's latest six-month period and held throughout the six months. Using the Tables -------------------------------------------------------------------------------- Actual Expenses The first table below provides information about actual account values and actual expenses. You may use the information in this table, together with the amount you invested, to estimate the expenses that you paid over the period as follows: (1) Divide your account value by $1,000 Example: an $8,600 account value (divided by) $1,000 = 8.6 (2) Multiply the result in (1) above by the corresponding share class's number in the third row under the heading entitled "Expenses Paid During Period" to estimate the expenses you paid on your account during this period. Expenses Paid on a $1,000 Investment in Pioneer Dynamic Credit Fund Based on actual returns from April 1, 2015, through September 30, 2015. -------------------------------------------------------------------------------- Share Class A C Y -------------------------------------------------------------------------------- Beginning Account $1,000.00 $1,000.00 $1,000.00 Value on 4/1/15 -------------------------------------------------------------------------------- Ending Account Value $ 987.30 $ 983.70 $ 988.00 (after expenses) on 9/30/15 -------------------------------------------------------------------------------- Expenses Paid $ 5.83 $ 9.60 $ 4.24 During Period* -------------------------------------------------------------------------------- * Expenses are equal to the Fund's annualized net expense ratio of 1.17%,1.93, and 0.85% for Class A, Class C and Class Y shares, respectively, multiplied by the average account value over the period, multiplied by 183/365 (to reflect the one-half year period). 14 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 Hypothetical Example for Comparison Purposes The table below provides information about hypothetical account values and hypothetical expenses based on the Fund's actual expense ratio and an assumed rate of return of 5% per year before expenses, which is not the Fund's actual return. The hypothetical account values and expenses may not be used to estimate the actual ending account balance or expenses you paid for the period. You may use this information to compare the ongoing costs of investing in the Fund and other funds. To do so, compare this 5% hypothetical example with the 5% hypothetical examples that appear in the shareholder reports of the other funds. Please note that the expenses shown in the tables are meant to highlight your ongoing costs only and do not reflect any transaction costs, such as sales charges (loads) that are charged at the time of the transaction. Therefore, the table below is useful in comparing ongoing costs only and will not help you determine the relative total costs of owning different funds. In addition, if these transaction costs were included, your costs would have been higher. Expenses Paid on a $1,000 Investment in Pioneer Dynamic Credit Fund Based on a hypothetical 5% return per year before expenses, reflecting the period from April 1, 2015, through September 30, 2015. -------------------------------------------------------------------------------- Share Class A C Y -------------------------------------------------------------------------------- Beginning Account $1,000.00 $1,000.00 $1,000.00 Value on 4/1/15 -------------------------------------------------------------------------------- Ending Account Value $1,019.20 $1,015.39 $1,020.81 (after expenses) on 9/30/15 -------------------------------------------------------------------------------- Expenses Paid $ 5.92 $ 9.75 $ 4.31 During Period* -------------------------------------------------------------------------------- * Expenses are equal to the Fund's annualized net expense ratio of 1.17%,1.93, and 0.85% for Class A, Class C and Class Y shares, respectively, multiplied by the average account value over the period, multiplied by 183/365 (to reflect the one-half year period). Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 15 Schedule of Investments | 9/30/15 (unaudited) ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- CONVERTIBLE CORPORATE BONDS -- 1.0% ENERGY -- 0.0%+ Oil & Gas Equipment & Services -- 0.0%+ 20,000 Energy XXI, Ltd., 3.0%, 12/15/18 $ 1,850 --------------- Total Energy $ 1,850 ---------------------------------------------------------------------------------------------- MATERIALS -- 0.0%+ Diversified Metals & Mining -- 0.0%+ 122,892 Mirabela Nickel, Ltd., 9.5%, 6/24/19 (144A) (0.0% cash, 9.5% PIK) (PIK) $ 61,446 ---------------------------------------------------------------------------------------------- Steel -- 0.0%+ EURO 67,741 New World Resources NV, 4.0%, 10/7/20 (144A) (4.0% cash, 8.0% PIK) (PIK) (d) $ 15,126 --------------- Total Materials $ 76,572 ---------------------------------------------------------------------------------------------- CAPITAL GOODS -- 0.2% Electrical Components & Equipment -- 0.2% 1,000,000 SolarCity Corp., 1.625%, 11/1/19 (144A) $ 779,375 --------------- Total Capital Goods $ 779,375 ---------------------------------------------------------------------------------------------- CONSUMER DURABLES & APPAREL -- 0.2% Homebuilding -- 0.2% 700,000 KB Home, 1.375%, 2/1/19 $ 650,125 --------------- Total Consumer Durables & Apparel $ 650,125 ---------------------------------------------------------------------------------------------- PHARMACEUTICALS, BIOTECHNOLOGY & LIFE SCIENCES -- 0.1% Biotechnology -- 0.1% 593,000 PDL BioPharma, Inc., 4.0%, 2/1/18 $ 522,581 --------------- Total Pharmaceuticals, Biotechnology & Life Sciences $ 522,581 ---------------------------------------------------------------------------------------------- SEMICONDUCTORS & SEMICONDUCTOR EQUIPMENT -- 0.5% Semiconductor Equipment -- 0.2% 2,000,000 SunEdison, Inc., 2.625%, 6/1/23 (144A) $ 1,007,500 ---------------------------------------------------------------------------------------------- Semiconductors -- 0.3% 1,455,000 JinkoSolar Holding Co., Ltd., 4.0%, 2/1/19 (144A) $ 1,197,647 --------------- Total Semiconductors & Semiconductor Equipment $ 2,205,147 ---------------------------------------------------------------------------------------------- TOTAL CONVERTIBLE CORPORATE BONDS (Cost $5,051,322) $ 4,235,650 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 16 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- PREFERRED STOCKS -- 1.4% BANKS -- 0.3% Diversified Banks -- 0.3% 50,173 7.12 Citigroup, Inc., Floating Rate Note (Perpetual) $ 1,350,657 3,141 6.00 US Bancorp, Floating Rate Note (Perpetual) 82,703 --------------- $ 1,433,360 --------------- Total Banks $ 1,433,360 ---------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 0.8% Consumer Finance -- 0.4% 800 Ally Financial, Inc., 7.0% (Perpetual) (144A) $ 806,525 27,750 8.12 GMAC Capital Trust I, Floating Rate Note, 2/15/40 708,458 --------------- $ 1,514,983 ---------------------------------------------------------------------------------------------- Investment Banking & Brokerage -- 0.4% 66,707 6.38 Morgan Stanley, Floating Rate Note (Perpetual) $ 1,697,026 --------------- Total Diversified Financials $ 3,212,009 ---------------------------------------------------------------------------------------------- INSURANCE -- 0.1% Property & Casualty Insurance -- 0.1% 17,164 5.95 Aspen Insurance Holdings, Ltd., Floating Rate Note (Perpetual) $ 435,279 ---------------------------------------------------------------------------------------------- Reinsurance -- 0.0%+ 2,500 Lorenz Re, Ltd., Variable Rate Notes, (Perpetual)* (g) $ 6,250 --------------- Total Insurance $ 441,529 ---------------------------------------------------------------------------------------------- REAL ESTATE -- 0.1% Diversified REIT -- 0.1% 400 Firstar Realty LLC, 8.875% (Perpetual) (144A) $ 496,750 --------------- Total Real Estate $ 496,750 ---------------------------------------------------------------------------------------------- TELECOMMUNICATION SERVICES -- 0.0%+ Integrated Telecommunication Services -- 0.0%+ 4,400 Qwest Corp., 7.375%, 6/1/51 $ 112,244 --------------- Total Telecommunication Services $ 112,244 ---------------------------------------------------------------------------------------------- UTILITIES -- 0.1% Electric Utilities -- 0.1% 18,955 PPL Capital Funding, Inc., 5.9%, 4/30/73 $ 477,666 --------------- Total Utilities $ 477,666 ---------------------------------------------------------------------------------------------- TOTAL PREFERRED STOCKS (Cost $6,035,574) $ 6,173,558 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 17 Schedule of Investments | 9/30/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- CONVERTIBLE PREFERRED STOCKS -- 0.5% CONSUMER DURABLES & APPAREL -- 0.2% Home Furnishings -- 0.2% 13,100 Sealy Corp., 8.0%, 7/15/16 (4.0% cash, 4.0% PIK) (PIK) $ 1,156,819 --------------- Total Consumer Durables & Apparel $ 1,156,819 ---------------------------------------------------------------------------------------------- BANKS -- 0.3% Diversified Banks -- 0.3% 1,050 Wells Fargo & Co., 7.5% (Perpetual) $ 1,226,400 --------------- Total Banks $ 1,226,400 ---------------------------------------------------------------------------------------------- TOTAL CONVERTIBLE PREFERRED STOCKS (Cost $2,270,227) $ 2,383,219 ---------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------- Shares ---------------------------------------------------------------------------------------------- COMMON STOCKS -- 0.0%+ ENERGY -- 0.0%+ Oil & Gas Exploration & Production -- 0.0%+ 14,179 SandRidge Energy, Inc.* $ 3,828 --------------- Total Energy $ 3,828 ---------------------------------------------------------------------------------------------- CAPITAL GOODS -- 0.0%+ Industrial Machinery -- 0.0%+ 3,071 Liberty Tire Reclycling LLC (d) $ 31 --------------- Total Capital Goods $ 31 ---------------------------------------------------------------------------------------------- COMMERCIAL SERVICES & SUPPLIES -- 0.0%+ Diversified Support Services -- 0.0%+ 4 IAP Worldwide Services, Inc. $ 3,955 --------------- Total Commercial Services & Supplies $ 3,955 ---------------------------------------------------------------------------------------------- INSURANCE -- 0.0%+ Life & Health Insurance -- 0.0%+ 34,794 TopCo. Ltd. (d) $ 8,416 --------------- Total Insurance $ 8,416 ---------------------------------------------------------------------------------------------- TOTAL COMMON STOCKS (Cost $63,174) $ 16,230 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 18 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- ASSET BACKED SECURITIES -- 4.3% CONSUMER SERVICES -- 0.2% Hotels, Resorts & Cruise Lines -- 0.2% 137,288 Westgate Resorts 2012-2 LLC, 9.0%, 1/21/25 (144A) $ 138,061 572,239 Westgate Resorts 2014-1 LLC, 5.5%, 12/20/26 (144A) 571,524 --------------- $ 709,585 --------------- Total Consumer Services $ 709,585 ---------------------------------------------------------------------------------------------- BANKS -- 3.2% Thrifts & Mortgage Finance -- 3.2% 499,993 Axis Equipment Finance Receivables III LLC, 5.27%, 5/20/20 (144A) $ 502,085 2,754 Bayview Financial Mortgage Pass-Through Trust 2007-B, 6.407%, 8/28/37 (Step) 2,737 282,188 Bayview Opportunity Master Fund IIa Trust 2014-20NPL, 3.721%, 8/28/44 (Step) (144A) 282,982 883,931 3.72 Bayview Opportunity Master Fund Trust 2014-15RPL, Floating Rate Note, 10/28/19 (144A) 883,777 101,338 Bayview Opportunity Master Fund Trust IIIa 2014-12RPL, 3.6225%, 7/28/19 (Step) (144A) 100,764 650,007 3.14 Drug Royalty II LP 2, Floating Rate Note, 7/15/23 (144A) 658,115 700,000 Flagship Credit Auto Trust 2013-1, 5.38%, 7/15/20 719,545 248,243 7.78 GE Mortgage Services LLC, Floating Rate Note, 3/25/27 170,668 769,349 GLC Trust 2013-1, 3.0%, 7/15/21 (144A) 761,655 400,000 HLSS Servicer Advance Receivables Trust, 4.4584%, 1/15/48 (144A) 399,652 212,922 Icon Brand Holdings LLC, 4.352%, 1/25/43 (144A) 216,460 750,000 Leaf Receivables Funding 10 LLC, 5.21%, 7/15/21 (144A) 743,048 358,317 Leaf Receivables Funding 8 LLC, 5.5%, 9/15/20 (144A) 361,363 543,239 1.69 MortgageIT Trust 2005-1, Floating Rate Note, 2/25/35 486,000 349,497 1.99 MortgageIT Trust 2005-1, Floating Rate Note, 2/25/35 298,117 1,360,000 Nations Equipment Finance Funding I LLC, 5.5%, 5/20/21 (144A) 1,362,976 750,000 Navitas Equipment Receivables LLC 2013-1, 5.82%, 6/15/19 754,196 710,500 Navitas Equipment Receivables LLC 2015-1, 5.75%, 5/17/21 (144A) 717,594 The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 19 Schedule of Investments | 9/30/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 600,000 4.72 NCF Dealer Floorplan Master Trust, Floating Rate Note, 10/20/20 (144A) $ 600,000 213,689 Orange Lake Timeshare Trust 2012-A, 4.87%, 3/10/27 (144A) 221,702 500,000 Progreso Receivables Funding II LLC, 6.0%, 7/8/19 (144A) 505,209 235,397 RASC Series 2003-KS5 Trust, 4.96%, 7/25/33 (Step) 233,376 172,870 6.55 Security National Mortgage Loan Trust 2007-1, Floating Rate Note, 4/25/37 (144A) 173,985 1,200,000 3.46 Silver Bay Realty 2014-1 Trust, Floating Rate Note, 9/18/31 (144A) 1,154,290 450,000 SNAAC Auto Receivables Trust 2013-1, 4.56%, 4/15/20 (144A) 458,218 192,002 STORE Master Funding LLC, 4.16%, 3/20/43 (144A) 199,355 1,000,000 VOLT XXV LLC, 4.5%, 6/26/45 (Step) (144A) 982,211 --------------- $ 13,950,080 --------------- Total Banks $ 13,950,080 ---------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 0.9% Other Diversified Financial Services -- 0.5% 1,099,877 AXIS Equipment Finance Receivables II LLC, 4.94%, 7/20/18 (144A) $ 1,126,472 249,972 AXIS Equipment Finance Receivables II LLC, 6.41%, 10/22/18 (144A) 255,336 137,566 Sierra Timeshare 2011-3 Receivables Funding LLC, 9.31%, 7/20/28 (144A) 145,371 500,000 Springleaf Funding Trust 2013-A, 5.0%, 9/15/21 (144A) 501,648 --------------- $ 2,028,827 ---------------------------------------------------------------------------------------------- Asset Management & Custody Banks -- 0.4% 1,000,000 RMAT 2015-1 LLC, 5.0%, 7/27/20 (Step) (144A) $ 981,555 1,000,000 VOLT XXXVII LLC, 4.375%, 7/25/45 (Step) (144A) 987,929 --------------- $ 1,969,484 --------------- Total Diversified Financials $ 3,998,311 ---------------------------------------------------------------------------------------------- TOTAL ASSET BACKED SECURITIES (Cost $18,722,052) $ 18,657,976 ---------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- 13.4% MATERIALS -- 0.1% Forest Products -- 0.1% 180,000 TimberStar Trust I, 7.5296%, 10/15/36 (144A) $ 183,969 --------------- Total Materials $ 183,969 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 20 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- BANKS -- 12.9% Thrifts & Mortgage Finance -- 12.9% 350,000 A10 Securitization 2013-1 LLC, 4.7%, 11/17/25 (144A) $ 349,768 139,000 A10 Securitization 2013-1 LLC, 6.41%, 11/17/25 (144A) 138,849 1,400,000 3.60 ACRE Commercial Mortgage Trust 2014-FL2, Floating Rate Note, 8/15/31 (144A) 1,381,561 1,250,000 6.17 Banc of America Commercial Mortgage Trust 2007-5, Floating Rate Note, 2/10/51 1,282,170 153,377 2.11 Bear Stearns ALT-A Trust 2003-3, Floating Rate Note, 10/25/33 141,360 100,000 5.21 Bear Stearns Commercial Mortgage Securities Trust 2005-PWR7, Floating Rate Note, 2/11/41 99,920 1,600,000 5.29 Bear Stearns Commercial Mortgage Securities Trust 2005-TOP20, Floating Rate Note, 10/12/42 1,597,805 2,000,000 5.90 Bear Stearns Commercial Mortgage Securities Trust 2007-PWR16, Floating Rate Note, 6/11/40 2,029,098 500,000 2.79 Carefree Portfolio Trust 2014-CARE, Floating Rate Note, 11/15/29 (144A) 485,032 2,500,000 5.34 CD 2005-CD1 Commercial Mortgage Trust, Floating Rate Note, 7/15/44 2,497,212 1,000,000 4.80 CFCRE 2015-RUM Mortgage Trust, Floating Rate Note, 7/15/30 (144A) 1,000,719 44,323 5.81 CHL Mortgage Pass-Through Trust 2002-32, Floating Rate Note, 1/25/33 45,442 300,000 5.97 Citigroup Commercial Mortgage Trust 2006-C4, Floating Rate Note, 3/17/49 304,817 1,000,000 3.21 Citigroup Commercial Mortgage Trust 2014-GC23 REMICS, Floating Rate Note, 7/12/47 (144A) 655,260 48,387 Citigroup Mortgage Loan Trust, Inc., 6.75%, 9/25/34 53,135 715,000 5.96 COBALT CMBS Commercial Mortgage Trust 2007-C3, Floating Rate Note, 5/15/46 683,548 220,000 5.96 COBALT CMBS Commercial Mortgage Trust 2007-C3, Floating Rate Note, 5/15/46 198,558 1,200,000 5.57 COBALT Commercial Mortgage Trust 2007-C2, Floating Rate Note, 4/15/47 (144A) 1,206,557 1,000,000 5.99 COMM 2007-C9 Mortgage Trust, Floating Rate Note, 12/10/49 (144A) 949,831 100,000 4.86 COMM 2012-CCRE2 Mortgage Trust, Floating Rate Note, 8/17/45 (144A) 98,547 1,000,000 3.81 COMM 2015-CCRE23 Mortgage Trust, Floating Rate Note, 5/12/48 968,239 1,600,000 6.25 Commercial Mortgage Trust 2007-GG11, Floating Rate Note, 12/10/49 1,641,077 366,946 5.45 Credit Suisse First Boston Mortgage Securities Corp., Floating Rate Note, 6/25/33 251,943 1,150,000 5.10 Credit Suisse First Boston Mortgage Securities Corp., Floating Rate Note, 8/15/38 1,148,201 The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 21 Schedule of Investments | 9/30/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 2,050,000 5.10 Credit Suisse First Boston Mortgage Securities Corp., Floating Rate Note, 8/15/38 $ 2,053,178 1,100,000 0.00 CSMC Trust 2015-SAND, Floating Rate Note, 8/15/30 (144A) 1,100,040 113,538 5.46 DBUBS 2011-LC2 Mortgage Trust, Floating Rate Note, 7/12/44 (144A) 125,442 530,000 3.65 EQTY 2014-INNS Mortgage Trust, Floating Rate Note, 5/8/31 (144A) 524,491 277,838 4.95 EQTY 2014-MZ Mezzanine Trust, Floating Rate Note, 5/10/19 (144A) 274,743 820,000 3.49 GAHR Commercial Mortgage Trust 2015-NRF, Floating Rate Note, 12/15/34 (144A) 773,259 343,487 Global Mortgage Securitization, Ltd., 5.25%, 11/25/32 (144A) 317,564 164,446 Global Mortgage Securitization, Ltd., 5.25%, 11/25/32 (144A) 131,146 641,056 Global Mortgage Securitization, Ltd., 5.25%, 4/25/32 611,751 130,728 Global Mortgage Securitization, Ltd., 5.25%, 4/25/32 95,897 570,000 5.00 GMAT 2013-1 Trust, Floating Rate Note, 8/25/53 541,303 890,000 4.94 GS Mortgage Securities Corp., II Series 2005-GG4, Floating Rate Note, 7/10/39 863,324 1,000,000 GS Mortgage Securities Trust 14-NEW, 3.79%, 1/10/31 (144A) 973,254 1,000,000 5.74 GS Mortgage Securities Trust 2006-GG6, Floating Rate Note, 4/10/38 999,388 705,000 4.11 GS Mortgage Securities Trust 2014-GSFL, Floating Rate Note, 7/15/31 (144A) 699,727 151,154 Homeowner Assistance Program Reverse Mortgage Loan Trust 2013-RM1, 4.0%, 5/26/53 (144A) 149,076 1,400,000 JP Morgan Chase Commercial Mortgage Securities Trust 2006-CIBC16, 5.623%, 5/12/45 1,378,265 1,400,000 6.10 JP Morgan Chase Commercial Mortgage Securities Trust 2006-LDP7 REMICS, Floating Rate Note, 4/15/45 1,375,233 1,725,000 6.21 JP Morgan Chase Commercial Mortgage Securities Trust 2007-LDP12, Floating Rate Note, 2/15/51 1,747,834 1,850,000 6.43 JP Morgan Chase Commercial Mortgage Securities Trust 2014-CBM MZ, Floating Rate Note, 10/15/19 (144A) 1,852,312 1,100,000 3.70 JP Morgan Chase Commercial Mortgage Securities Trust 2014-FBLU REMICS, Floating Rate Note, 12/15/28 (144A) 1,099,294 The accompanying notes are an integral part of these financial statements. 22 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 764,449 4.25 La Hipotecaria Panamanian Mortgage Trust 2007-1, Floating Rate Note, 12/23/36 (144A) $ 749,160 1,200,000 5.35 LB-UBS Commercial Mortgage Trust 2005-C7, Floating Rate Note, 11/15/40 1,232,650 213,057 Merrill Lynch Mortgage Investors Trust Series 2006-AF1, 5.75%, 8/25/36 170,107 1,400,000 5.48 ML-CFC Commercial Mortgage Trust 2006-3, Floating Rate Note, 7/12/46 1,412,093 2,000,000 ML-CFC Commercial Mortgage Trust 2006-4, 5.239%, 12/12/49 2,008,206 1,800,000 5.57 Morgan Stanley Capital I Trust 2007-TOP25, Floating Rate Note, 11/12/49 1,832,798 1,500,000 5.19 NorthStar 2013-1, Floating Rate Note, 8/27/29 (144A) 1,515,000 1,000,000 ORES 2014-LV3 LLC, 6.0%, 3/27/24 1,000,000 1,171,000 4.81 PFP 2015-2, Ltd., Floating Rate Note, 7/14/34 (144A) 1,171,192 98,905 RCMC LLC, 5.62346%, 12/17/18 (144A) 100,654 1,277,152 1.50 RESI Finance LP 2003-D, Floating Rate Note, 12/10/35 (144A) 1,074,842 200,000 5.30 Springleaf Mortgage Loan Trust 2012-3, Floating Rate Note, 12/26/59 (144A) 200,409 250,000 5.58 Springleaf Mortgage Loan Trust 2013-1, Floating Rate Note, 6/25/58 (144A) 251,367 118,610 1.72 Structured Asset Mortgage Investments Trust 2003-AR1, Floating Rate Note, 10/19/33 109,598 1,600,000 5.56 Wachovia Bank Commercial Mortgage Trust Series 2005-C22, Floating Rate Note, 12/15/44 1,602,662 304,000 5.66 Wachovia Bank Commercial Mortgage Trust Series 2006-C24, Floating Rate Note, 3/15/45 305,229 1,500,000 5.63 Wachovia Bank Commercial Mortgage Trust Series 2006-C28, Floating Rate Note, 10/15/48 1,522,161 1,813,000 5.95 Wachovia Bank Commercial Mortgage Trust Series 2007-C34, Floating Rate Note, 5/15/46 1,876,094 1,500,000 3.71 Wells Fargo Commercial Mortgage Trust 2014-TISH, Floating Rate Note, 1/15/27 (144A) 1,460,817 50,000 5.27 WFRBS Commercial Mortgage Trust 2011-C4, Floating Rate Note, 6/17/44 (144A) 52,834 200,000 4.35 WFRBS Commercial Mortgage Trust 2013-C12, Floating Rate Note, 3/17/48 (144A) 187,664 --------------- $ 56,730,707 --------------- Total Banks $ 56,730,707 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 23 Schedule of Investments | 9/30/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 0.4% Other Diversified Financial Services -- 0.4% 1,300,000 5.21 Del Coronado Trust 2013-DEL MZ, Floating Rate Note, 3/15/18 (144A) $ 1,293,500 489,532 Monty Parent Issuer 1 LLC, 4.25%, 11/20/28 (144A) 489,524 143,888 Rialto Capital Management LLC, 2.85%, 5/15/24 (144A) 143,651 --------------- $ 1,926,675 --------------- Total Diversified Financials $ 1,926,675 ---------------------------------------------------------------------------------------------- GOVERNMENT -- 0.0%+ Government -- 0.0%+ 175,000 4.18 Federal Home Loan Mortgage Corp., Floating Rate Note, 5/25/45 (144A) $ 181,156 --------------- Total Government $ 181,156 ---------------------------------------------------------------------------------------------- TOTAL COLLATERALIZED MORTGAGE OBLIGATIONS (Cost $58,866,627) $ 59,022,507 ---------------------------------------------------------------------------------------------- CORPORATE BONDS -- 45.3% ENERGY -- 4.7% Oil & Gas Drilling -- 0.3% 1,950,000 Ensco Plc, 5.75%, 10/1/44 $ 1,348,992 ---------------------------------------------------------------------------------------------- Oil & Gas Equipment & Services -- 0.4% 330,000 Calfrac Holdings LP, 7.5%, 12/1/20 (144A) $ 206,250 355,000 Key Energy Services, Inc., 6.75%, 3/1/21 122,475 2,000,000 Weatherford International, Ltd. Bermuda, 5.95%, 4/15/42 1,390,422 --------------- $ 1,719,147 ---------------------------------------------------------------------------------------------- Oil & Gas Exploration & Production -- 1.5% 980,000 Bonanza Creek Energy, Inc., 5.75%, 2/1/23 $ 637,000 345,000 Bonanza Creek Energy, Inc., 6.75%, 4/15/21 240,638 865,000 EP Energy LLC, 6.375%, 6/15/23 638,474 1,190,000 Gulfport Energy Corp., 7.75%, 11/1/20 1,169,175 650,000 Legacy Reserves LP, 6.625%, 12/1/21 442,000 580,000 Memorial Production Partners LP, 6.875%, 8/1/22 353,800 515,000 Noble Energy, Inc., 5.625%, 5/1/21 518,090 665,000 Noble Energy, Inc., 5.875%, 6/1/22 663,746 1,075,000 RSP Permian, Inc., 6.625%, 10/1/22 1,032,000 1,285,000 Swift Energy Co., 7.875%, 3/1/22 340,525 675,000 WPX Energy, Inc., 7.5%, 8/1/20 617,625 --------------- $ 6,653,073 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 24 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- Oil & Gas Storage & Transportation -- 2.5% 2,000,000 Boardwalk Pipelines LP, 4.95%, 12/15/24 $ 1,852,526 373,000 Copano Energy LLC, 7.125%, 4/1/21 389,161 1,250,000 5.85 DCP Midstream LLC, Floating Rate Note, 5/21/43 (144A) 1,000,000 NOK 2,000,000 6.46 Golar LNG Partners LP, Floating Rate Note, 10/12/17 238,076 1,360,000 Kinder Morgan, Inc., Delaware, 5.55%, 6/1/45 1,129,664 1,450,000 ONEOK, Inc., 6.875%, 9/30/28 1,290,500 2,000,000 Sabine Pass Liquefaction LLC, 5.625%, 2/1/21 1,855,000 100,000 Sabine Pass LNG LP, 6.5%, 11/1/20 96,750 1,500,000 Sunoco Logistics Partners Operations LP, 3.45%, 1/15/23 1,304,012 555,000 Targa Resources Partners LP, 4.25%, 11/15/23 462,038 2,000,000 The Williams Companies, Inc., 5.75%, 6/24/44 1,381,346 --------------- $ 10,999,073 ---------------------------------------------------------------------------------------------- Coal & Consumable Fuels -- 0.0%+ 250,000 James River Coal Co., 7.875%, 4/1/19 (e) $ 25 --------------- Total Energy $ 20,720,310 ---------------------------------------------------------------------------------------------- MATERIALS -- 2.2% Commodity Chemicals -- 0.4% 1,405,000 Axiall Corp., 4.875%, 5/15/23 $ 1,180,200 565,000 Hexion, Inc., 8.875%, 2/1/18 452,000 --------------- $ 1,632,200 ---------------------------------------------------------------------------------------------- Specialty Chemicals -- 0.1% 600,000 INEOS Group Holdings SA, 5.875%, 2/15/19 (144A) $ 558,000 ---------------------------------------------------------------------------------------------- Metal & Glass Containers -- 0.4% 707,758 Ardagh Finance Holdings SA, 8.625%, (0.00% Cash, 8.625% PIK) 6/15/19 (144A) (PIK) $ 721,913 200,000 Beverage Packaging Holdings Luxembourg II SA, 5.625%, 12/15/16 (144A) 197,000 300,000 Beverage Packaging Holdings Luxembourg II SA, 6.0%, 6/15/17 (144A) 293,625 425,000 Reynolds Group Issuer, Inc., 8.25%, 2/15/21 423,938 330,000 Reynolds Group Issuer, Inc., 9.875%, 8/15/19 341,550 --------------- $ 1,978,026 ---------------------------------------------------------------------------------------------- Diversified Metals & Mining -- 0.4% 1,200,000 FMG Resources August 2006 Pty, Ltd., 9.75%, 3/1/22 (144A) $ 1,117,500 500,000 MMC Norilsk Nickel OJSC via MMC Finance, Ltd., 5.55%, 10/28/20 (144A) 495,080 --------------- $ 1,612,580 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 25 Schedule of Investments | 9/30/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- Steel -- 0.7% 1,000,000 Cliffs Natural Resources, Inc., 8.25%, 3/31/20 (144A) $ 880,000 200,000 Glencore Funding LLC, 4.125%, 5/30/23 (144A) 157,375 200,000 Metalloinvest Finance, Ltd., 5.625%, 4/17/20 (144A) 188,240 EURO 38,709 0.00 New World Resources NV, Floating Rate Note, 10/7/20 (d) 12,965 EURO 29,032 0.00 New World Resources NV, Floating Rate Note, 10/7/20 (d) 4,214 1,940,000 Reliance Steel & Aluminum Co., 4.5%, 4/15/23 1,851,703 --------------- $ 3,094,497 ---------------------------------------------------------------------------------------------- Paper Products -- 0.2% 1,110,000 Resolute Forest Products, Inc., 5.875%, 5/15/23 $ 826,950 --------------- Total Materials $ 9,702,253 ---------------------------------------------------------------------------------------------- CAPITAL GOODS -- 2.2% Building Products -- 0.8% 1,000,000 Gibraltar Industries, Inc., 6.25%, 2/1/21 $ 1,015,000 1,375,000 Griffon Corp., 5.25%, 3/1/22 1,307,969 1,000,000 Masco Corp., 4.45%, 4/1/25 1,012,500 --------------- $ 3,335,469 ---------------------------------------------------------------------------------------------- Construction & Engineering -- 0.5% 635,000 AECOM, 5.75%, 10/15/22 (144A) $ 638,575 1,205,000 Amsted Industries, Inc., 5.0%, 3/15/22 (144A) 1,186,925 500,000 Empresas ICA SAB de CV, 8.9%, 2/4/21 (144A) 251,250 --------------- $ 2,076,750 ---------------------------------------------------------------------------------------------- Industrial Conglomerates -- 0.1% 450,000 Magnesita Finance, Ltd., 8.625% (Perpetual) (144A) $ 294,750 400,000 Turkiye Sise ve Cam Fabrikalari AS, 4.25%, 5/9/20 (144A) 377,200 --------------- $ 671,950 ---------------------------------------------------------------------------------------------- Construction & Farm Machinery & Heavy Trucks -- 0.2% 400,000 Commercial Vehicle Group, Inc., 7.875%, 4/15/19 $ 407,000 350,000 Cummins, Inc., 5.65%, 3/1/98 374,025 --------------- $ 781,025 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 26 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- Industrial Machinery -- 0.5% 750,000 Cleaver-Brooks, Inc., 8.75%, 12/15/19 (144A) $ 708,750 1,235,000 EnPro Industries, Inc., 5.875%, 9/15/22 1,244,262 63,982 Liberty Tire Recycling LLC, 11.0%, 3/31/21 (0.0% cash, 11.0% PIK) (144A) (PIK) (d) 40,948 168,000 Xerium Technologies, Inc., 8.875%, 6/15/18 170,520 --------------- $ 2,164,480 ---------------------------------------------------------------------------------------------- Trading Companies & Distributors -- 0.1% 600,000 Aircastle, Ltd., 6.25%, 12/1/19 $ 643,500 --------------- Total Capital Goods $ 9,673,174 ---------------------------------------------------------------------------------------------- COMMERCIAL SERVICES & SUPPLIES -- 0.8% Commercial Printing -- 0.2% 1,210,000 Cenveo Corp., 6.0%, 8/1/19 (144A) $ 1,016,400 ---------------------------------------------------------------------------------------------- Environmental & Facilities Services -- 0.2% 865,000 Safway Group Holding LLC, 7.0%, 5/15/18 (144A) $ 885,544 ---------------------------------------------------------------------------------------------- Diversified Support Services -- 0.4% 930,000 Allegion US Holding Co., Inc., 5.75%, 10/1/21 $ 953,250 805,000 Transfield Services, Ltd., 8.375%, 5/15/20 (144A) 828,144 --------------- $ 1,781,394 --------------- Total Commercial Services & Supplies $ 3,683,338 ---------------------------------------------------------------------------------------------- TRANSPORTATION -- 2.0% Airlines -- 1.3% 464,229 Air Canada 2013-1 Class A Pass Through Trust, 4.125%, 11/15/26 (144A) $ 468,291 500,000 Air Canada 2013-1 Class C Pass Through Trust, 6.625%, 5/15/18 (144A) 518,700 1,478,549 American Airlines 2014-1 Class B Pass Through Trust, 4.375%, 10/1/22 1,478,549 7,919 Continental Airlines 1997-4 Class B Pass Through Trust, 6.9%, 1/2/17 8,142 49,861 Continental Airlines 2001-1 Class B Pass Through Trust, 7.373%, 12/15/15 49,985 900,000 Delta Air Lines 2010-2 Class B Pass Through Trust, 6.75%, 11/23/15 (144A) 911,250 540,000 Guanay Finance, Ltd., 6.0%, 12/15/20 (144A) 532,575 98,075 Hawaiian Airlines 2013-1 Class A Pass Through Certificates, 3.9%, 1/15/26 96,603 1,350,000 Intrepid Aviation Group Holdings LLC, 6.875%, 2/15/19 (144A) 1,215,000 374,821 US Airways 2013-1 Class A Pass Through Trust, 3.95%, 5/15/27 376,246 193,381 US Airways 2013-1 Class B Pass Through Trust, 5.375%, 11/15/21 199,666 --------------- $ 5,855,007 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 27 Schedule of Investments | 9/30/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- Marine -- 0.1% 600,000 Navios South American Logistics, Inc., 7.25%, 5/1/22 (144A) $ 540,000 ---------------------------------------------------------------------------------------------- Railroads -- 0.3% 1,070,000 Florida East Coast Holdings Corp., 6.75%, 5/1/19 (144A) $ 1,048,600 ---------------------------------------------------------------------------------------------- Trucking -- 0.3% 1,000,000 Jack Cooper Holdings Corp., 9.25%, 6/1/20 (144A) $ 900,000 325,000 Transnet SOC, Ltd., 4.0%, 7/26/22 (144A) 300,219 --------------- $ 1,200,219 ---------------------------------------------------------------------------------------------- Airport Services -- 0.0%+ 152,880 Aeropuertos Argentina 2000 SA, 10.75%, 12/1/20 (144A) $ 157,466 --------------- Total Transportation $ 8,801,292 ---------------------------------------------------------------------------------------------- AUTOMOBILES & COMPONENTS -- 0.4% Auto Parts & Equipment -- 0.4% 400,000 International Automotive Components Group SA, 9.125%, 6/1/18 (144A) $ 406,000 481,000 Pittsburgh Glass Works LLC, 8.0%, 11/15/18 (144A) 497,835 950,000 Stackpole International Intermediate, 7.75%, 10/15/21 (144A) 1,033,125 --------------- $ 1,936,960 --------------- Total Automobiles & Components $ 1,936,960 ---------------------------------------------------------------------------------------------- CONSUMER DURABLES & APPAREL -- 1.4% Homebuilding -- 1.2% 95,000 CalAtlantic Group, Inc., 5.375%, 10/1/22 $ 95,950 1,000,000 CalAtlantic Group, Inc., 6.25%, 12/15/21 1,067,500 765,000 DR Horton, Inc., 5.75%, 8/15/23 828,112 500,000 KB Home, 7.0%, 12/15/21 501,250 200,000 KB Home, Inc., 8.0%, 3/15/20 212,000 675,000 Lennar Corp., 4.5%, 6/15/19 682,425 890,000 MDC Holdings, Inc., 5.5%, 1/15/24 898,900 1,000,000 Taylor Morrison Communities, Inc., 5.875%, 4/15/23 1,000,000 --------------- $ 5,286,137 ---------------------------------------------------------------------------------------------- Household Appliances -- 0.1% 400,000 Arcelik AS, 5.0%, 4/3/23 (144A) $ 354,760 ---------------------------------------------------------------------------------------------- Textiles -- 0.1% 400,000 Springs Industries, Inc., 6.25%, 6/1/21 $ 396,000 --------------- Total Consumer Durables & Apparel $ 6,036,897 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 28 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- CONSUMER SERVICES -- 0.6% Casinos & Gaming -- 0.3% 800,000 Scientific Games International, Inc., 10.0%, 12/1/22 $ 698,000 750,000 Scientific Games International, Inc., 7.0%, 1/1/22 (144A) 738,750 --------------- $ 1,436,750 ---------------------------------------------------------------------------------------------- Specialized Consumer Services -- 0.3% 1,135,000 Sotheby's, 5.25%, 10/1/22 (144A) $ 1,049,875 --------------- Total Consumer Services $ 2,486,625 ---------------------------------------------------------------------------------------------- MEDIA -- 1.4% Broadcasting -- 0.7% 1,000,000 DIRECTV Holdings LLC, 5.15%, 3/15/42 $ 939,681 1,120,000 Gannett Co., Inc., 6.375%, 10/15/23 1,176,000 825,000 Quebecor Media, Inc., 5.75%, 1/15/23 812,625 --------------- $ 2,928,306 ---------------------------------------------------------------------------------------------- Cable & Satellite -- 0.7% 705,000 CCO Safari II LLC, 6.384%, 10/23/35 (144A) $ 713,282 250,000 Intelsat Jackson Holdings SA, 7.25%, 4/1/19 234,375 830,000 Sirius XM Radio, Inc., 4.625%, 5/15/23 (144A) 776,050 1,000,000 Virgin Media Secured Finance Plc, 5.25%, 1/15/26 (144A) 920,000 450,000 Virgin Media Secured Finance Plc, 5.375%, 4/15/21 (144A) 452,812 --------------- $ 3,096,519 ---------------------------------------------------------------------------------------------- Publishing -- 0.0%+ 100,000 MPL 2 Acquisition Canco, Inc., 9.875%, 8/15/18 (144A) $ 103,500 --------------- Total Media $ 6,128,325 ---------------------------------------------------------------------------------------------- RETAILING -- 1.1% Catalog Retail -- 0.3% 1,500,000 QVC, Inc., 4.45%, 2/15/25 $ 1,446,272 ---------------------------------------------------------------------------------------------- Department Stores -- 0.1% 525,000 Grupo Famsa SAB de CV, 7.25%, 6/1/20 (144A) $ 460,688 ---------------------------------------------------------------------------------------------- Computer & Electronics Retail -- 0.2% 930,000 Rent-A-Center, Inc., 6.625%, 11/15/20 $ 911,400 ---------------------------------------------------------------------------------------------- Specialty Stores -- 0.2% 600,000 Radio Systems Corp., 8.375%, 11/1/19 (144A) $ 629,250 ---------------------------------------------------------------------------------------------- Automotive Retail -- 0.3% 1,325,000 CST Brands, Inc., 5.0%, 5/1/23 $ 1,315,062 --------------- Total Retailing $ 4,762,672 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 29 Schedule of Investments | 9/30/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- FOOD & STAPLES RETAILING -- 0.5% Food Retail -- 0.5% 1,150,000 C&S Group Enterprises LLC, 5.375%, 7/15/22 (144A) $ 1,046,500 1,060,000 Darling Ingredients, Inc., 5.375%, 1/15/22 1,038,800 --------------- $ 2,085,300 --------------- Total Food & Staples Retailing $ 2,085,300 ---------------------------------------------------------------------------------------------- FOOD, BEVERAGE & TOBACCO -- 1.2% Agricultural Products -- 0.2% 800,000 Southern States Cooperative, Inc., 10.0%, 8/15/21 (144A) $ 704,000 ---------------------------------------------------------------------------------------------- Packaged Foods & Meats -- 0.8% 75,000 Agrokor dd, 8.875%, 2/1/20 (144A) $ 80,250 428,000 Chiquita Brands International, Inc., 7.875%, 2/1/21 454,750 400,000 Dole Food Co., Inc., 7.25%, 5/1/19 (144A) 399,000 300,000 FAGE Dairy Industry SA, 9.875%, 2/1/20 (144A) 312,000 1,105,000 Marfrig Holdings Europe BV, 6.875%, 6/24/19 (144A) 947,538 500,000 MHP SA, 8.25%, 4/2/20 (144A) 420,692 400,000 Minerva Luxembourg SA, 7.75%, 1/31/23 (144A) 350,000 550,000 Post Holdings, Inc., 7.375%, 2/15/22 558,250 200,000 Post Holdings, Inc., 7.75%, 3/15/24 (144A) 205,000 --------------- $ 3,727,480 ---------------------------------------------------------------------------------------------- Tobacco -- 0.2% 800,000 Alliance One International, Inc., 9.875%, 7/15/21 $ 684,000 --------------- Total Food, Beverage & Tobacco $ 5,115,480 ---------------------------------------------------------------------------------------------- HEALTH CARE EQUIPMENT & SERVICES -- 2.2% Health Care Supplies -- 0.0%+ 100,000 ConvaTec Healthcare E SA, 10.5%, 12/15/18 (144A) $ 103,250 100,000 Immucor, Inc., 11.125%, 8/15/19 103,000 --------------- $ 206,250 ---------------------------------------------------------------------------------------------- Health Care Distributors -- 0.4% 1,500,000 McKesson Corp., 4.883%, 3/15/44 $ 1,525,960 ---------------------------------------------------------------------------------------------- Health Care Services -- 0.3% 1,360,000 DaVita HealthCare Partners, Inc., 5.125%, 7/15/24 $ 1,335,520 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 30 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- Health Care Facilities -- 1.1% 545,000 Amsurg Corp., 5.625%, 7/15/22 $ 544,319 1,075,000 CHS, Inc., 8.0%, 11/15/19 1,118,672 1,000,000 HCA, Inc., 5.375%, 2/1/25 990,000 400,000 Kindred Healthcare, Inc., 6.375%, 4/15/22 397,000 1,480,000 Tenet Healthcare Corp., 4.375%, 10/1/21 1,443,000 265,000 Tenet Healthcare Corp., 4.5%, 4/1/21 261,025 --------------- $ 4,754,016 ---------------------------------------------------------------------------------------------- Managed Health Care -- 0.4% 1,815,000 WellCare Health Plans, Inc., 5.75%, 11/15/20 $ 1,887,600 ---------------------------------------------------------------------------------------------- Health Care Technology -- 0.0%+ 175,000 MedAssets, Inc., 8.0%, 11/15/18 $ 178,500 --------------- Total Health Care Equipment & Services $ 9,887,846 ---------------------------------------------------------------------------------------------- PHARMACEUTICALS, BIOTECHNOLOGY & LIFE SCIENCES -- 0.7% Biotechnology -- 0.4% 1,500,000 Amgen, Inc., 5.375%, 5/15/43 $ 1,599,264 ---------------------------------------------------------------------------------------------- Pharmaceuticals -- 0.3% 705,000 DPx Holdings BV, 7.5%, 2/1/22 (144A) $ 712,050 875,000 Endo Finance LLC, 5.375%, 1/15/23 (144A) 841,094 --------------- $ 1,553,144 --------------- Total Pharmaceuticals, Biotechnology & Life Sciences $ 3,152,408 ---------------------------------------------------------------------------------------------- BANKS -- 2.6% Diversified Banks -- 2.2% 800,000 6.38 Banco Santander SA, Floating Rate Note (Perpetual) $ 747,000 400,000 Bank of America Corp., 6.11%, 1/29/37 460,096 800,000 6.50 Bank of America Corp., Floating Rate Note, 10/23/49 816,000 925,000 6.25 Bank of America Corp., Floating Rate Note, 9/29/49 904,188 1,500,000 5.90 Citigroup, Inc., Floating Rate Note (Perpetual) 1,462,500 640,000 5.95 Citigroup, Inc., Floating Rate Note (Perpetual) 621,200 1,900,000 6.62 Credit Agricole SA, Floating Rate Note (Perpetual) (144A) 1,826,375 525,000 Intesa Sanpaolo S.p.A., 6.5%, 2/24/21 (144A) 606,360 500,000 Macquarie Bank, Ltd., 6.625%, 4/7/21 (144A) 560,444 425,000 4.00 Oversea-Chinese Banking Corp., Ltd., Floating Rate Note, 10/15/24 (144A) 435,153 1,150,000 5.88 Wells Fargo & Co., Floating Rate Note (Perpetual) 1,177,312 --------------- $ 9,616,628 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 31 Schedule of Investments | 9/30/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- Regional Banks -- 0.2% 250,000 HSBC Bank USA NA New York NY, 6.0%, 8/9/17 $ 268,710 625,000 6.75 The PNC Financial Services Group, Inc., Floating Rate Note (Perpetual) 678,125 --------------- $ 946,835 ---------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- 0.2% 1,000,000 Provident Funding Associates LP, 6.75%, 6/15/21 (144A) $ 947,500 --------------- Total Banks $ 11,510,963 ---------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 4.8% Other Diversified Financial Services -- 1.5% 1,665,000 Carlyle Holdings II Finance LLC, 5.625%, 3/30/43 (144A) $ 1,754,306 1,000,000 Fixed Income Trust Series 2013-A, 10/15/97 (Step) (144A) (c) (d) 708,297 2,360,000 6.75 JPMorgan Chase & Co., Floating Rate Note, 8/29/49 2,457,350 500,000 SUAM Finance BV, 4.875%, 4/17/24 (144A) 500,000 1,030,000 Summit Midstream Holdings LLC, 7.5%, 7/1/21 988,800 100,000 0.00 Tiers Trust, Floating Rate Note, 10/15/97 (144A) (c) (d) 92,770 --------------- $ 6,501,523 ---------------------------------------------------------------------------------------------- Specialized Finance -- 0.9% 500,000 Cantor Fitzgerald LP, 7.875%, 10/15/19 (144A) $ 549,366 1,375,000 Fly Leasing, Ltd., 6.375%, 10/15/21 1,388,750 720,000 Nationstar Mortgage LLC, 6.5%, 6/1/22 574,200 725,000 Nationstar Mortgage LLC, 6.5%, 7/1/21 601,750 700,000 Oxford Finance LLC, 7.25%, 1/15/18 (144A) 712,250 --------------- $ 3,826,316 ---------------------------------------------------------------------------------------------- Consumer Finance -- 0.4% 1,000,000 Ally Financial, Inc., 4.625%, 5/19/22 $ 983,750 66,670 Tarjeta Naranja SA, 9.0%, 1/28/17 (144A) 66,357 1,035,000 TMX Finance LLC, 8.5%, 9/15/18 (144A) 815,062 --------------- $ 1,865,169 ---------------------------------------------------------------------------------------------- Asset Management & Custody Banks -- 1.4% 915,000 Affiliated Managers Group, Inc., 4.25%, 2/15/24 $ 930,474 300,000 Blackstone Holdings Finance Co., LLC, 5.0%, 6/15/44 (144A) 305,974 750,000 Blackstone Holdings Finance Co., LLC, 6.25%, 8/15/42 (144A) 912,867 500,000 JBS Investment Management, Ltd., 7.25%, 4/3/24 481,250 1,500,000 KKR Group Finance Co., II LLC, 5.5%, 2/1/43 (144A) 1,568,746 The accompanying notes are an integral part of these financial statements. 32 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- Asset Management & Custody Banks -- (continued) 1,250,000 Legg Mason, Inc., 3.95%, 7/15/24 $ 1,253,629 500,000 Legg Mason, Inc., 5.625%, 1/15/44 517,492 --------------- $ 5,970,432 ---------------------------------------------------------------------------------------------- Investment Banking & Brokerage -- 0.6% 750,000 Morgan Stanley, 4.1%, 5/22/23 $ 759,085 250,000 Morgan Stanley, 4.875%, 11/1/22 266,357 300,000 The Goldman Sachs Group, Inc., 6.45%, 5/1/36 350,224 225,000 The Goldman Sachs Group, Inc., 6.75%, 10/1/37 268,407 1,050,000 UBS AG, 7.625%, 8/17/22 1,208,011 --------------- $ 2,852,084 --------------- Total Diversified Financials $ 21,015,524 ---------------------------------------------------------------------------------------------- INSURANCE -- 8.0% Life & Health Insurance -- 0.7% 500,000 Fidelity & Guaranty Life Holdings, Inc., 6.375%, 4/1/21 (144A) $ 520,000 1,500,000 5.88 Prudential Financial, Inc., Floating Rate Note, 9/15/42 1,586,250 GBP 202,103 TIG FINCO Plc, 8.75%, 4/2/20 280,332 GBP 35,665 0.00 TIG FINCO Plc, Floating Rate Note, 3/2/20 (144A) 56,145 615,000 5.65 Voya Financial, Inc., Floating Rate Note, 5/15/53 619,920 --------------- $ 3,062,647 ---------------------------------------------------------------------------------------------- Reinsurance -- 7.3% 2,501,147 Altair Re, Variable Rate Notes, 6/30/16 (g) $ 175,581 1,000,000 Altair Re, Variable Rate Notes, 6/30/17(g) 1,043,000 500,000 Arlington Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 8/31/16 (g) 513,600 250,000 3.47 Atlas IX Capital, Ltd., Floating Rate Note, 1/17/19 (Cat Bond) (144A) 254,425 500,000 Berwick Segregated Account (Kane SAC Ltd.), Variable Rate Note, 1/22/16 (g) 517,700 750,000 4.37 Blue Danube II, Ltd., Floating Rate Note, 5/23/18 (Cat Bond) (144A) 756,375 1,000,000 6.86 Caelus Re, Ltd., Floating Rate Note, 4/7/17 (Cat Bond) (144A) 1,033,000 1,500,000 Carnoustie Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 2/19/16 (g) 1,636,050 250,000 4.48 Citrus Re, Ltd., Floating Rate Note, 4/18/17 (Cat Bond) (144A) 251,800 350,000 4.30 Citrus Re, Ltd., Floating Rate Note, 4/24/17 (Cat Bond) (144A) 352,800 400,000 Clarendon Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 6/15/16 (g) 393,480 250,000 0.00 Compass Re II, Ltd., Floating Rate Note, 12/8/15 (Cat Bond) 247,050 The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 33 Schedule of Investments | 9/30/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- Reinsurance -- (continued) 250,000 9.06 East Lane Re V, Ltd., Floating Rate Note, 3/16/16 (Cat Bond) (144A) $ 257,950 1,050,525 Exeter Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 1/7/16 (g) 1,123,431 1,050,000 Fairfield Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 2/2/16 (g) 1,027,110 1,000,000 7.41 Galileo Re, Ltd., Floating Rate Note, 1/9/19 (Cat Bond) (144A) 1,019,700 600,000 6.69 Gator Re, Ltd., Floating Rate Note, 1/9/17 (Cat Bond) (144A) 554,400 250,000 2.21 Golden State Re II, Ltd., Floating Rate Note, 1/8/19 (Cat Bond) (144A) 248,575 2,100,000 Gullane Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 1/22/17 (g) 2,303,070 294,350 Hereford Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 1/7/16 (g) 338,090 250,000 4.57 Ibis Re II, Ltd., Floating Rate Note, 6/28/16 (Cat Bond) (144A) 255,800 650,000 4.77 Kilimanjaro Re, Ltd., Floating Rate Note, 4/30/18 (Cat Bond) (144A) 653,835 350,000 4.52 Kilimanjaro Re, Ltd., Floating Rate Note, 4/30/18 (Cat Bond) (144A) 347,585 250,000 Lorenz Re, Ltd., Variable Rate Notes, 3/31/18 (g) 264,525 533,600 Muirfield Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 1/12/16 (g) 585,786 500,000 11.88 Mythen Re, Ltd., Series 2012-2 Class A, Floating Rate Note, 11/10/16 (Cat Bond) (144A) 518,750 2,000,000 Pangaea Re, Series 2015-1, Principal at Risk Notes, 2/1/19 (g) 2,258,600 2,000,000 Pangaea Re, Series 2015-2, Principal at Risk Notes, 11/30/19 (g) 2,065,800 2,000,000 Pangaea Re., Variable Rate Notes, 7/1/18 (g) 36,000 1,503,871 PI-4, Series C -- 2014, (Kane SAC Ltd.), Variable Rate Notes, 7/7/16 (g) 1,506,728 700,000 Prestwick Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 7/1/16 (g) 733,600 800,000 4.54 Residential Reinsurance 2012, Ltd., Floating Rate Note, 12/6/16 (Cat Bond) (144A) 813,760 500,000 10.03 Residential Reinsurance 2012, Ltd., Floating Rate Note, 6/6/16 (Cat Bond) (144A) 528,100 1,000,000 3.51 Sanders Re, Ltd., Floating Rate Note, 5/5/17 (Cat Bond) (144A) 1,003,500 500,000 3.87 Sanders Re, Ltd., Floating Rate Note, 6/7/17 (Cat Bond) (144A) 505,900 1,433 Sector Re V, Ltd., Variable Rate Notes, 12/1/18 (144A) (g) 6,124 500,000 Sector Re V, Ltd., Variable Rate Notes, 12/1/19 (144A) (g) 557,400 The accompanying notes are an integral part of these financial statements. 34 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- Reinsurance -- (continued) 1,205 Sector Re V, Ltd., Variable Rate Notes, 3/30/19 (144A) (g) $ 28,219 400,000 Silverton Re, Ltd., Variable Rate Notes, 9/16/16 (144A) (g) 8,000 800,000 Silverton Re, Ltd., Variable Rate Notes, 9/18/17 (144A) (g) 904,000 1,200,000 St. Andrews Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 1/22/16 (g) 1,251,360 550,600 Troon Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 1/12/16 (g) 589,417 2,000,000 Versutus Ltd., Series 2015-A, Variable Rate Notes, 12/31/2017 (g) 2,260,000 250,000 2.86 Vita Capital V, Ltd., Floating Rate Note, 1/15/17 (Cat Bond) (144A) 252,450 250,000 2.52 Vitality Re V, Ltd., Floating Rate Note, 1/7/19 (Cat Bond) (144A) 252,025 --------------- $ 32,234,451 --------------- Total Insurance $ 35,297,098 ---------------------------------------------------------------------------------------------- REAL ESTATE -- 0.6% Specialized REIT -- 0.6% 1,165,918 AAF Holdings LLC, 12.0%, 7/1/19 (144A) (12.0% cash, 0.0% PIK) (PIK) $ 1,148,429 1,000,000 DuPont Fabros Technology LP, 5.875%, 9/15/21 1,025,000 500,000 Iron Mountain, Inc., 5.75%, 8/15/24 482,500 --------------- $ 2,655,929 --------------- Total Real Estate $ 2,655,929 ---------------------------------------------------------------------------------------------- SOFTWARE & SERVICES -- 0.7% Internet Software & Services -- 0.4% 1,150,000 Bankrate, Inc., 6.125%, 8/15/18 (144A) $ 1,121,250 705,000 j2 Global, Inc., 8.0%, 8/1/20 750,825 --------------- $ 1,872,075 ---------------------------------------------------------------------------------------------- Data Processing & Outsourced Services -- 0.2% 1,000,000 Cardtronics, Inc., 5.125%, 8/1/22 $ 960,000 ---------------------------------------------------------------------------------------------- Application Software -- 0.1% 200,000 Igloo Holdings Corp., 8.25%, 12/15/17 (8.25% Cash, 9.00% PIK) (144A) (PIK) $ 200,500 --------------- Total Software & Services $ 3,032,575 ---------------------------------------------------------------------------------------------- TECHNOLOGY HARDWARE & EQUIPMENT -- 1.3% Computer Hardware Storage & Peripherals -- 0.6% 1,160,000 NCR Corp., 6.375%, 12/15/23 $ 1,136,800 900,000 Seagate HDD Cayman, 4.75%, 1/1/25 863,965 885,000 Seagate HDD Cayman, 4.75%, 6/1/23 873,446 --------------- $ 2,874,211 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 35 Schedule of Investments | 9/30/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- Electronic Components -- 0.4% EURO 300,000 Belden, Inc., 5.5%, 4/15/23 $ 321,538 1,360,000 Belden, Inc., 5.5%, 9/1/22 (144A) 1,315,800 --------------- $ 1,637,338 ---------------------------------------------------------------------------------------------- Electronic Manufacturing Services -- 0.3% 585,000 Flextronics International, Ltd., 4.625%, 2/15/20 $ 602,550 695,000 Flextronics International, Ltd., 5.0%, 2/15/23 695,000 --------------- $ 1,297,550 --------------- Total Technology Hardware & Equipment $ 5,809,099 ---------------------------------------------------------------------------------------------- SEMICONDUCTORS & SEMICONDUCTOR EQUIPMENT -- 0.3% Semiconductor Equipment -- 0.2% 1,000,000 Entegris, Inc., 6.0%, 4/1/22 (144A) $ 1,015,000 ---------------------------------------------------------------------------------------------- Semiconductors -- 0.1% 320,000 Advanced Micro Devices, Inc., 7.5%, 8/15/22 $ 204,800 --------------- Total Semiconductors & Semiconductor Equipment $ 1,219,800 ---------------------------------------------------------------------------------------------- TELECOMMUNICATION SERVICES -- 3.5% Integrated Telecommunication Services -- 2.1% 2,000,000 AT&T, Inc., 3.9%, 3/11/24 $ 2,033,876 500,000 CenturyLink, Inc., 5.8%, 3/15/22 427,500 150,000 CenturyLink, Inc., 7.6%, 9/15/39 113,625 1,300,000 CenturyLink, Inc., 7.65%, 3/15/42 994,500 90,000 Frontier Communications Corp., 10.5%, 9/15/22 (144A) 87,750 250,000 Frontier Communications Corp., 7.625%, 4/15/24 208,750 500,000 Frontier Communications Corp., 8.75%, 4/15/22 445,265 90,000 Frontier Communications Corp., 8.875%, 9/15/20 (144A) 88,200 200,000 Frontier Communications Corp., 9.0%, 8/15/31 165,000 2,500,000 Verizon Communications, Inc., 4.15%, 3/15/24 2,585,950 576,000 Verizon Communications, Inc., 5.012%, 8/21/54 524,243 576,000 Verizon Communications, Inc., 6.55%, 9/15/43 680,512 1,305,000 Windstream Corp., 7.5%, 6/1/22 985,275 --------------- $ 9,340,446 ---------------------------------------------------------------------------------------------- Wireless Telecommunication Services -- 1.4% 1,000,000 Altice Financing SA, 6.625%, 2/15/23 (144A) $ 961,875 2,225,000 Sprint Corp., 7.125%, 6/15/24 1,712,360 1,000,000 Sprint Corp., 7.25%, 9/15/21 818,750 1,500,000 T-Mobile USA, Inc., 6.625%, 4/1/23 1,485,000 300,000 Unison Ground Lease Funding LLC, 5.78%, 3/16/43 (144A) 299,862 The accompanying notes are an integral part of these financial statements. 36 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- Wireless Telecommunication Services -- (continued) 200,000 VimpelCom Holdings BV, 7.5043%, 3/1/22 (144A) $ 200,500 400,000 WCP Issuer llc, 6.657%, 8/15/20 (144A) 414,804 --------------- $ 5,893,151 --------------- Total Telecommunication Services $ 15,233,597 ---------------------------------------------------------------------------------------------- UTILITIES -- 2.1% Electric Utilities -- 1.3% 1,000,000 5.25 Electricite de France SA, Floating Rate Note (Perpetual) (144A) $ 962,500 150,000 Enel Finance International NV, 5.125%, 10/7/19 (144A) 164,913 1,190,000 8.13 Enel S.p.A., Floating Rate Note, 9/24/73 (144A) 1,365,192 75,000 6.25 Southern California Edison Co., Floating Rate Note (Perpetual) 83,438 525,000 Talen Energy Supply LLC, 4.6%, 12/15/21 436,012 1,880,000 Talen Energy Supply LLC, 4.625%, 7/15/19 (144A) 1,710,800 1,165,000 TerraForm Power, 9.75%, 8/15/22 (144A) 934,912 --------------- $ 5,657,767 ---------------------------------------------------------------------------------------------- Gas Utilities -- 0.1% 300,000 DCP Midstream Operating LP, 5.6%, 4/1/44 $ 242,810 300,000 Transportadora de Gas del Peru SA, 4.25%, 4/30/28 (144A) 280,875 --------------- $ 523,685 ---------------------------------------------------------------------------------------------- Independent Power Producers & Energy Traders -- 0.7% 100,000 Inkia Energy, Ltd., 8.375%, 4/4/21 (144A) $ 103,750 1,000,000 Instituto Costarricense de Electricidad, 6.375%, 5/15/43 (144A) 800,000 650,000 InterGen NV, 7.0%, 6/30/23 (144A) 552,500 500,000 NRG Energy, Inc., 6.25%, 5/1/24 441,250 900,000 NRG Energy, Inc., 7.625%, 1/15/18 945,000 200,000 NRG Energy, Inc., 8.25%, 9/1/20 205,400 --------------- $ 3,047,900 --------------- Total Utilities $ 9,229,352 ---------------------------------------------------------------------------------------------- TOTAL CORPORATE BONDS (Cost $208,918,640) $ 199,176,817 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 37 Schedule of Investments | 9/30/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- 2.2% 5,256,972 Fannie Mae, 3.5%, 5/1/44 $ 5,490,132 1,032,512 Fannie Mae, 4.0%, 5/1/44 1,102,085 467,385 Fannie Mae, 4.0%, 9/1/43 503,071 941,026 Fannie Mae, 4.5%, 9/1/39 1,022,920 715,859 Fannie Mae, 4.5%, 9/1/40 776,527 703,614 Federal Home Loan Mortgage Corp., 4.5%, 6/1/41 763,194 --------------- $ 9,657,929 ---------------------------------------------------------------------------------------------- TOTAL U.S. GOVERNMENT AND AGENCY OBLIGATIONS (Cost $9,364,713) $ 9,657,929 ---------------------------------------------------------------------------------------------- FOREIGN GOVERNMENT BONDS -- 0.5% 1,700,000 Commonwealth of the Bahamas, 5.75%, 1/16/24 (144A) $ 1,824,100 405,000 Kenya Government International Bond, 5.875%, 6/24/19 (144A) 387,650 --------------- $ 2,211,750 ---------------------------------------------------------------------------------------------- TOTAL FOREIGN GOVERNMENT BONDS (Cost $2,102,490) $ 2,211,750 ---------------------------------------------------------------------------------------------- SENIOR FLOATING RATE LOAN INTERESTS -- 21.3%** ENERGY -- 0.8% Oil & Gas Drilling -- 0.1% 50,343 5.75 Offshore Group Investment, Ltd., Term Loan, 3/28/19 $ 16,068 204,879 4.50 Pacific Drilling SA, Term Loan, 6/3/18 122,757 287,100 3.75 Paragon Offshore Finance, Term Loan, 7/16/21 112,448 --------------- $ 251,273 ---------------------------------------------------------------------------------------------- Integrated Oil & Gas -- 0.3% 1,026,327 5.25 ExGen Renewables I LLC, Term Loan, 2/5/21 $ 1,034,024 12,927 4.50 Glenn Pool Oil & Gas Trust, Term Loan, 5/2/16 12,895 835,125 4.00 Seadrill Operating LP, Initial Term Loan, 2/14/21 512,767 --------------- $ 1,559,686 ---------------------------------------------------------------------------------------------- Oil & Gas Exploration & Production -- 0.0%+ 176,667 3.50 EP Energy LLC, Tranche B-3 Loan, 5/24/18 $ 164,006 ---------------------------------------------------------------------------------------------- Oil & Gas Refining & Marketing -- 0.4% 1,080,649 4.25 Pilot Travel Centers LLC, Initial Tranche B, 9/30/21 $ 1,086,987 498,731 4.25 Western Refining, Inc., Term Loan 2013, 11/12/20 496,160 --------------- $ 1,583,147 --------------- Total Energy $ 3,558,112 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 38 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- MATERIALS -- 1.7% Commodity Chemicals -- 0.3% 570,688 4.75 Eco Services Operations, Initial Term Loan, 10/8/21 $ 567,834 736,875 5.00 Nexeo Solutions LLC, Term Loan B3, 9/9/17 706,479 --------------- $ 1,274,313 ---------------------------------------------------------------------------------------------- Specialty Chemicals -- 0.6% 1,424,799 4.50 MacDermid, Inc., Tranche B Term Loan (First Lien), 6/7/20 $ 1,382,946 680,750 4.00 PQ Corp., 2014 Term Loan, 8/7/17 679,687 171,486 2.75 WR Grace & Co-Conn, Delayed Draw Term Loan, 1/23/21 170,629 476,534 2.75 WR Grace & Co-Conn, U.S. Term Loan, 1/23/21 474,151 --------------- $ 2,707,413 ---------------------------------------------------------------------------------------------- Paper Packaging -- 0.1% 23,802 4.50 Coveris Holdings SA, USD Term Loan, 4/14/19 $ 23,846 246,250 4.25 Multi Packaging Solutions, Inc., Initial Dollar Tranche B Term, 9/30/20 244,095 --------------- $ 267,941 ---------------------------------------------------------------------------------------------- Aluminum -- 0.1% 540,375 5.50 TurboCombustor Technology, Inc., Initial Term Loan, 10/18/20 $ 526,866 ---------------------------------------------------------------------------------------------- Diversified Metals & Mining -- 0.1% 544,810 3.75 Fortescue Metals Group, Ltd., Bank Loan, 6/30/19 $ 448,106 ---------------------------------------------------------------------------------------------- Steel -- 0.2% 346,500 7.50 Essar Steel Algoma Inc., Initial Term Loan, 8/9/19 $ 276,622 572,050 4.50 TMS International Corp., Term B Loan, 10/2/20 569,429 --------------- $ 846,051 ---------------------------------------------------------------------------------------------- Paper Products -- 0.3% 1,083,645 6.50 Wausau Paper Corp., Term Loan, 7/20/20 $ 1,085,677 502,388 5.81 Appvion, Inc., Term Commitment, 6/28/19 472,559 --------------- $ 1,558,236 --------------- Total Materials $ 7,628,926 ---------------------------------------------------------------------------------------------- CAPITAL GOODS -- 2.0% Metal & Glass Containers -- 0.1% 327,838 4.75 Pro Mach Group, Inc., Dollar Term Loan, 10/22/21 $ 329,272 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 39 Schedule of Investments | 9/30/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- Aerospace & Defense -- 0.7% 785,905 4.00 Accudyne Industries Borrower SCA, Refinancing Term Loan, 12/13/19 $ 630,944 687,677 3.75 DigitalGlobe, Inc., Term Loan, 1/25/20 784,808 787,396 6.25 DynCorp International, Inc., Term Loan, 7/7/16 798,810 815,805 7.02 TASC, Inc., New Term Loan (First Lien), 5/23/20 788,852 211,726 5.75 The SI Organization, Inc., Term Loan (First Lien), 11/19/19 211,991 --------------- $ 3,215,405 ---------------------------------------------------------------------------------------------- Building Products -- 0.8% 2,081,129 6.00 Builders FirstSource, Inc., Initial Term Loan, 7/24/22 $ 2,071,048 989,981 5.50 Ultima Intermediate Sarl, Term Loan B (First Lien), 7/2/20 998,643 259,245 4.25 Unifrax Corp., New Term B Loan, 12/31/19 257,733 --------------- $ 3,327,424 ---------------------------------------------------------------------------------------------- Electrical Components & Equipment -- 0.0%+ 45,858 6.00 WireCo WorldGroup, Inc., Term Loan, 2/15/17 $ 45,944 ---------------------------------------------------------------------------------------------- Industrial Conglomerates -- 0.0%+ 17,764 5.00 Kloeckner Pentaplast Of America, 1st Lien Term Loan, 4/22/20 $ 17,842 41,569 5.00 Kloeckner Pentaplast Of America, 1st Lien Term Loan, 4/22/20 41,750 --------------- $ 59,592 ---------------------------------------------------------------------------------------------- Industrial Machinery -- 0.4% 379,556 4.25 Gardner Denver, Inc., Initial Dollar Term Loan, 7/30/20 $ 360,314 813,699 6.00 NN, Inc., Term Loan, 8/27/21 815,733 625,039 5.25 Tank Holding Corp., Initial Term Loan, 7/9/19 624,064 --------------- $ 1,800,111 --------------- Total Capital Goods $ 8,777,748 ---------------------------------------------------------------------------------------------- COMMERCIAL SERVICES & SUPPLIES -- 0.8% Environmental & Facilities Services -- 0.7% 479,116 5.50 Wastequip LLC, Term Loan, 8/9/19 $ 478,118 687,117 4.00 WCA Waste Corp., Term Loan, 3/23/18 684,218 1,901,341 5.00 Wheelabrator, Term B Loan, 10/15/21 1,866,484 84,291 5.00 Wheelabrator, Term C Loan, 10/15/21 82,746 --------------- $ 3,111,566 ---------------------------------------------------------------------------------------------- Diversified Support Services -- 0.0%+ 28,403 5.24 IAP Worldwide Services, Inc., Term Loan, 7/18/19 $ 28,545 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 40 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- Security & Alarm Services -- 0.1% 52,012 4.00 Garda World Security Corp., Term B Delayed Draw Loan, 11/8/20 $ 51,281 203,321 4.00 Garda World Security Corp., Term B Loan, 11/1/20 200,462 --------------- $ 251,743 --------------- Total Commercial Services & Supplies $ 3,391,854 ---------------------------------------------------------------------------------------------- TRANSPORTATION -- 0.9% Air Freight & Logistics -- 0.1% 171,063 6.75 Ozburn-Hessey Holding Co., LLC, Term Loan, 5/23/19 $ 170,742 691,206 5.25 Syncreon Group BV, Term Loan, 9/26/20 555,269 --------------- $ 726,011 ---------------------------------------------------------------------------------------------- Airlines -- 0.5% 343,875 3.25 American Airlines, Inc., 2015 Term Loan (New), 6/27/20 $ 341,618 175,000 3.50 American Airlines, Inc., 2015 Term Loan, 10/10/21 174,344 170,188 3.25 Delta Air Lines, Inc., 2014 Term B-1 Loan, 10/18/18 170,121 243,750 3.25 United Airlines, Inc., Class B Term Loan, 4/1/19 243,674 606,375 3.50 US Airways, Inc., Tranche B-1 Term Loan (Consenting), 5/23/19 604,606 520,625 3.00 US Airways, Inc., Tranche B-2 Term Loan (Consenting), 11/23/16 519,812 --------------- $ 2,054,175 ---------------------------------------------------------------------------------------------- Marine -- 0.3% 498,721 7.50 Commercial Barge Line Co., Initial Term Loan (First Lien), 9/22/19 $ 494,981 874,860 5.25 Navios Maritime Partners LP, Term Loan, 6/27/18 874,587 --------------- $ 1,369,568 --------------- Total Transportation $ 4,149,754 ---------------------------------------------------------------------------------------------- AUTOMOBILES & COMPONENTS -- 1.6% Auto Parts & Equipment -- 0.8% 551,860 3.50 Allison Transmission, Inc., Term B-3 Loan, 8/23/19 $ 552,895 641,875 4.00 Cooper Standard Intermediate Holdco 2 LLC, Term Loan, 3/28/21 638,987 1,393,457 3.75 MPG Holdco I, Inc., Initial Term Loan, 10/20/21 1,392,089 1,042,136 4.00 Tower Automotive Holdings USA LLC, Initial Term Loan (2014), 4/23/20 1,033,017 --------------- $ 3,616,988 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 41 Schedule of Investments | 9/30/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- Automobile Manufacturers -- 0.8% 1,994,625 3.25 Chrysler Group LLC, Tranche B Term Loan, 12/29/18 $ 1,980,164 1,215,984 6.00 Crown Group llc, Term Loan (First Lien), 9/30/20 1,212,184 --------------- $ 3,192,348 --------------- Total Automobiles & Components $ 6,809,336 ---------------------------------------------------------------------------------------------- CONSUMER DURABLES & APPAREL -- 0.1% Housewares & Specialties -- 0.0%+ 184,585 5.50 World Kitchen LLC, U.S. Term Loan, 3/4/19 $ 185,278 ---------------------------------------------------------------------------------------------- Leisure Products -- 0.1% 400,857 3.75 Bombardier Recreational Products, Inc., Term B-2 Loan, 1/30/19 $ 401,294 --------------- Total Consumer Durables & Apparel $ 586,572 ---------------------------------------------------------------------------------------------- CONSUMER SERVICES -- 1.4% Casinos & Gaming -- 0.4% 1,612,813 6.00 Scientific Games, Initial Term B-2, 10/1/21 $ 1,596,080 ---------------------------------------------------------------------------------------------- Leisure Facilities -- 0.2% 907,921 5.50 L.A. Fitness International, LLC, Tranche B Term Loan (First Lien), 4/25/20 $ 869,334 ---------------------------------------------------------------------------------------------- Restaurants -- 0.2% 402,386 4.00 Landry's, Inc., B Term Loan, 4/24/18 $ 403,015 557,578 4.00 NPC International, Inc., Term Loan, 12/28/18 553,629 --------------- $ 956,644 ---------------------------------------------------------------------------------------------- Education Services -- 0.4% 783,197 3.75 Bright Horizons Family Solutions, Inc., Term B Loan, 1/14/20 $ 785,070 124,688 4.00 Houghton Mifflin Harcourt Publishers, Inc., Term Loan, 5/11/21 123,285 1,036,654 5.00 Laureate Education, Inc., New Series 2018 Extended Term Loan, 6/16/18 925,214 --------------- $ 1,833,569 ---------------------------------------------------------------------------------------------- Specialized Consumer Services -- 0.2% 498,737 5.25 Genex Holdings, Inc., Term B Loan (First Lien), 5/22/21 $ 498,737 312,263 5.00 Prime Security Services Borrower LLC, (aka Protection 1 Security Solutions) Term B Loan (First Lien), 6/19/21 312,692 --------------- $ 811,429 --------------- Total Consumer Services $ 6,067,056 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 42 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- MEDIA -- 1.7% Advertising -- 0.3% 498,053 6.75 Affinion Group, Inc., Tranche B Term Loan, 4/30/18 $ 903,572 956,794 4.50 Consolidated Precision Products, Inc., 1st Lien Term Loan, 12/28/19 494,815 194,622 4.50 Crossmark Holdings, Inc., Term Loan (First Lien), 12/20/19 171,592 --------------- $ 1,569,979 ---------------------------------------------------------------------------------------------- Broadcasting -- 0.2% 498,306 3.75 Gray Television, Inc., Term Loan (First Lien), 6/10/21 $ 497,735 233,710 3.25 Quebecor Media, Inc., Facility B-1 Tranche, 8/17/20 228,451 --------------- $ 726,186 ---------------------------------------------------------------------------------------------- Cable & Satellite -- 0.7% 488,750 3.00 Charter Communications Operating LLC, Term F Loan, 1/1/21 $ 483,295 289,851 3.75 Intelsat Jackson Holdings SA, Tranche B-2 Term Loan, 6/30/19 283,257 994,975 6.75 MediArena Acquisition BV, Dollar Term B Loan (First Lien), 8/6/21 970,722 599,966 3.50 Telesat Canada, U.S. Term B Loan, 3/28/19 597,091 587,872 3.50 Ziggo BV, (USD) Tranche B-3 Term Loan, 1/15/22 579,299 --------------- $ 2,913,664 ---------------------------------------------------------------------------------------------- Movies & Entertainment -- 0.0%+ 201,722 3.75 Rovi Solutions Corp., Term B Loan, 7/2/21 $ 198,444 ---------------------------------------------------------------------------------------------- Publishing -- 0.5% 250,000 7.00 Cengage Learning Acquisitions Inc, Term Loan, 3/6/20 $ 249,188 1,866,750 6.25 McGraw-Hill School Education Holdings llc, Term B Loan, 12/18/19 1,872,584 --------------- $ 2,121,772 --------------- Total Media $ 7,530,045 ---------------------------------------------------------------------------------------------- RETAILING -- 0.7% Home Improvement Retail -- 0.3% 1,232,582 4.50 Apex Tool Group LLC, Term Loan, 2/1/20 $ 1,206,005 ---------------------------------------------------------------------------------------------- Specialty Stores -- 0.1% 498,750 4.25 PetSmart, Inc., Tranche B-1 Loan, 3/10/22 $ 498,698 ---------------------------------------------------------------------------------------------- Automotive Retail -- 0.3% 1,359,375 5.25 CWGS Group LLC, Term Loan, 2/20/20 $ 1,361,924 --------------- Total Retailing $ 3,066,627 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 43 Schedule of Investments | 9/30/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- FOOD & STAPLES RETAILING -- 0.4% Food Distributors -- 0.1% 244,582 4.26 Del Monte Foods Consumer Products, Inc., Term Loan (First Lien), 11/26/20 $ 232,353 ---------------------------------------------------------------------------------------------- Food Retail -- 0.3% 887,705 5.38 Albertsons LLC, Term B-2 Loan, 3/21/19 $ 889,016 495,497 4.75 New Albertson's, Inc., Term Loan (First Lien), 6/24/21 495,436 --------------- $ 1,384,452 --------------- Total Food & Staples Retailing $ 1,616,805 ---------------------------------------------------------------------------------------------- FOOD, BEVERAGE & TOBACCO -- 0.4% Packaged Foods & Meats -- 0.4% 738,689 4.50 Boulder Brands USA, Inc., Term Loan, 7/9/20 $ 727,300 940,500 4.50 Shearer's Foods, LLC, Term Loan (First Lien), 6/19/21 936,385 --------------- $ 1,663,685 --------------- Total Food, Beverage & Tobacco $ 1,663,685 ---------------------------------------------------------------------------------------------- HOUSEHOLD & PERSONAL PRODUCTS -- 0.6% Household Products -- 0.2% 638,116 4.02 SRAM LLC, Term Loan (First Lien), 4/10/20 $ 621,365 ---------------------------------------------------------------------------------------------- Personal Products -- 0.4% 591,000 4.25 Atrium Innovations, Inc., Term Loan, 1/29/21 $ 564,405 648,359 4.75 Federal-Mogul Corp., Tranche C Term, 4/15/21 618,372 750,000 3.50 NBTY, Inc., Term B-2 Loan, 10/1/17 746,812 --------------- $ 1,929,589 --------------- Total Household & Personal Products $ 2,550,954 ---------------------------------------------------------------------------------------------- HEALTH CARE EQUIPMENT & SERVICES -- 2.4% Health Care Equipment -- 0.2% 911,125 4.50 Accellent, Inc., Initial Term Loan (First Lien), 2/21/21 $ 910,442 ---------------------------------------------------------------------------------------------- Health Care Supplies -- 0.1% 576,384 5.00 Immucor, Inc., Term B-2 Loan, 8/19/18 $ 573,982 ---------------------------------------------------------------------------------------------- Health Care Services -- 1.1% 845,635 4.25 Alliance HealthCare Services, Inc., Initial Term Loan, 6/3/19 $ 842,993 487,281 6.25 BioScrip, Inc., Initial Term B Loan, 7/31/20 458,044 292,369 6.50 BioScrip, Inc., Term Loan, 7/31/20 274,827 62,705 3.50 DaVita HealthCare Partners, Inc., Tranche B Loan (First Lien), 6/19/21 62,795 291,620 4.00 Envision Healthcare Corp., Initial Term Loan, 5/25/18 292,015 The accompanying notes are an integral part of these financial statements. 44 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- Health Care Services -- (continued) 132,691 7.75 inVentiv Health, Inc., Term B-3 Loan, 5/15/18 $ 132,580 1,144,192 4.25 National Mentor Holdings, Inc., Tranche B Term Loan, 1/31/21 1,142,405 86,916 8.00 Rural, Term Loan, 6/30/18 87,351 984,849 4.50 Truven Health Analytics, Inc., New Tranche B Term Loan, 6/6/19 978,989 736,355 4.25 US Renal Care, Inc., Tranche B-2 Term Loan (First Lien), 7/3/19 735,894 --------------- $ 5,007,893 ---------------------------------------------------------------------------------------------- Health Care Facilities -- 0.7% 120,738 3.08 CHS, Incremental 2019 Term G Loan, 12/31/19 $ 120,813 222,155 4.00 CHS, Incremental 2021 Term H Loan, 1/27/21 222,617 598,462 4.50 IASIS Healthcare LLC, Term B-2 Loan, 5/3/18 599,833 486,356 4.25 Kindred Healthcare, Inc., Tranche B Loan (First Lien), 4/10/21 485,943 1,090,403 5.25 RegionalCare Hospital Partners, Inc., Term Loan (First Lien), 4/21/19 1,084,269 20,527 3.75 Select Medical Corp., Series E Tranche B Term Loan, 6/1/18 20,505 488,750 6.75 Steward Health Care System LLC, Term Loan, 4/10/20 488,292 --------------- $ 3,022,272 ---------------------------------------------------------------------------------------------- Managed Health Care -- 0.0%+ 24,057 9.75 MMM Holdings, Inc., Term Loan, 10/9/17 $ 18,043 17,489 9.75 MSO of Puerto Rico, Inc., MSO Term Loan, 12/12/17 13,117 --------------- $ 31,160 ---------------------------------------------------------------------------------------------- Health Care Technology -- 0.3% 99,750 4.25 ConvaTec, Inc., Dollar Term Loan, 12/22/16 $ 99,750 769,989 3.75 Emdeon, Inc., Term B-2 Loan, 11/2/18 768,705 318,842 4.00 MedAssets, Inc., Term B Loan, 12/13/19 318,141 --------------- $ 1,186,596 --------------- Total Health Care Equipment & Services $ 10,732,345 ---------------------------------------------------------------------------------------------- PHARMACEUTICALS, BIOTECHNOLOGY & LIFE SCIENCES -- 1.1% Biotechnology -- 0.4% 922,688 3.50 Alkermes, Inc., 2019 Term Loan, 9/25/19 $ 682,950 682,665 7.00 Lantheus Medical Imaging, Initial Term Loan, 6/25/22 876,553 --------------- $ 1,559,503 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 45 Schedule of Investments | 9/30/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- Pharmaceuticals -- 0.7% 686,651 5.50 Akorn, Inc., Term Loan B, 11/13/20 $ 685,506 98,500 3.20 Grifols Worldwide Operations USA, Inc., U.S. Tranche B Term Loam, 4/1/21 98,633 444,375 4.25 JLL, Initial Dollar Term Loan, 1/23/21 438,709 889,143 3.51 Prestige Brands, Inc., Term B-3 Loan, 9/3/21 890,162 298,478 3.75 Valeant Pharmaceuticals International, Inc., Series C-2 Tranche B Term Loan, 12/11/19 294,448 728,520 3.75 Valeant Pharmaceuticals International, Inc., Series E1 Tranche B Term Loan, 8/5/20 718,958 --------------- $ 3,126,416 --------------- Total Pharmaceuticals, Biotechnology & Life Sciences $ 4,685,919 ---------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 0.9% Other Diversified Financial Services -- 0.6% 696,495 3.50 Fly Funding II Sarl, Term Loan, 8/9/18 $ 694,101 708,688 5.00 Livingston International, Inc., Initial Term B-1 Loan (First Lien), 4/18/19 689,199 994,962 4.50 Nord Anglia Education, Initial Term Loan, 3/31/21 981,281 78,745 5.25 WorldPay, Facility B2A Term Loan, 8/6/17 79,041 --------------- $ 2,443,622 ---------------------------------------------------------------------------------------------- Specialized Finance -- 0.2% 909,490 4.25 Mirror BidCo Corp., New Incremental Term Loan, 12/18/19 $ 909,490 ---------------------------------------------------------------------------------------------- Investment Banking & Brokerage -- 0.1% 473,813 4.00 Concentra, Inc., Tranche B Term Loan (First Lien), 5/8/22 $ 473,513 --------------- Total Diversified Financials $ 3,826,625 ---------------------------------------------------------------------------------------------- INSURANCE -- 0.2% Property & Casualty Insurance -- 0.2% 906,964 5.75 Confie Seguros Holding II Co., Term B Loan (First Lien), 11/9/18 $ 909,231 --------------- Total Insurance $ 909,231 ---------------------------------------------------------------------------------------------- REAL ESTATE -- 0.6% Retail REIT -- 0.4% 1,650,065 4.25 DTZ U.S. Borrower LLC, (DTZ AUS Holdco PTY, Ltd.) 2015-1 Additional Term Loan (First Lien), 11/4/21 $ 1,636,401 ---------------------------------------------------------------------------------------------- Real Estate Services -- 0.2% 1,126,426 4.50 Altisource Solutions Sarl, Term B Loan, 12/9/20 $ 1,002,519 --------------- Total Real Estate $ 2,638,920 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 46 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- SOFTWARE & SERVICES -- 1.6% Internet Software & Services -- 0.1% 498,739 6.00 Vocus, Inc., Tranche B Loan (First Lien), 5/23/21 $ 495,207 ---------------------------------------------------------------------------------------------- IT Consulting & Other Services -- 0.3% 1,267,200 5.75 Evergreen Skills Lux Sarl, Initial Term Loan (First Lien), 4/23/21 $ 1,146,816 113,275 4.50 PSAV Presentation Services, Tranche B Term Loan (First Lien), 1/24/21 112,992 --------------- $ 1,259,808 ---------------------------------------------------------------------------------------------- Data Processing & Outsourced Services -- 0.2% 750,000 3.70 First Data Corp., 2018 New Dollar Term Loan, 3/24/18 $ 744,668 ---------------------------------------------------------------------------------------------- Application Software -- 0.5% 745,869 4.50 Epiq Systems, Inc., Term Loan, 8/27/20 $ 585,524 586,992 7.50 Serena Software, Inc., Term Loan, 4/10/20 771,625 771,023 6.25 STG-Fairway Acquisitions, Inc., Term Loan (First Lien), 3/4/19 746,801 --------------- $ 2,103,950 ---------------------------------------------------------------------------------------------- Systems Software -- 0.3% 1,240,625 5.75 AVG Technologies N.V., Term Loan, 10/15/20 $ 1,248,379 ---------------------------------------------------------------------------------------------- Home Entertainment Software -- 0.2% 1,180,469 5.25 Micro Focus International, Term Loan B, 10/7/21 $ 1,182,068 --------------- Total Software & Services $ 7,034,080 ---------------------------------------------------------------------------------------------- TECHNOLOGY HARDWARE & EQUIPMENT -- 0.2% Communications Equipment -- 0.0%+ 109,659 3.25 Commscope, Inc., Tranche 4 Term Loan, 1/14/18 $ 109,590 ---------------------------------------------------------------------------------------------- Electronic Equipment Manufacturers -- 0.0%+ 405 4.50 Sensus USA, Inc., Term Loan (First Lien), 5/9/17 $ 404 ---------------------------------------------------------------------------------------------- Electronic Components -- 0.2% 292,950 6.25 FCI -- Fidji Luxembourg Bc4 Sarl , Term Loan, 12/19/20 $ 292,950 572,400 3.50 Generac Power Systems, Inc., Term Loan B, 5/31/20 559,693 --------------- $ 852,643 --------------- Total Technology Hardware & Equipment $ 962,637 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 47 Schedule of Investments | 9/30/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- SEMICONDUCTORS & SEMICONDUCTOR EQUIPMENT -- 0.0%+ Semiconductors -- 0.0%+ 155,398 3.25 Microsemi Corp., Term Loan (First Lien), 3/14/21 $ 154,970 --------------- Total Semiconductors & Semiconductor Equipment $ 154,970 ---------------------------------------------------------------------------------------------- TELECOMMUNICATION SERVICES -- 0.8% Integrated Telecommunication Services -- 0.6% 1,400,000 0.00 Level 3 Financing, Inc., Tranche B-II 2022 Term Loan, 5/31/22 (f) $ 1,392,416 531,924 4.75 Securus Technologies Holdings, Inc., Initial Term Loan (First Lien), 4/30/20 477,004 490,493 3.50 Virgin Media Investment Holdings, Ltd., Term Facility, 6/30/23 525,085 366,334 3.25 West Corp., B-10 Term Loan (First Lien), 6/30/18 362,814 --------------- $ 2,757,319 ---------------------------------------------------------------------------------------------- Wireless Telecommunication Services -- 0.2% 647,209 3.00 Crown Castle International Corp., Tranche B-2 Term Loan (First Lien), 1/31/21 $ 646,421 --------------- Total Telecommunication Services $ 3,403,740 ---------------------------------------------------------------------------------------------- UTILITIES -- 0.4% Electric Utilities -- 0.3% 1,320,790 4.75 Atlantic Power LP, Term Loan, 2/20/21 $ 1,318,314 522,963 3.00 Calpine Construction Finance Co. LP, Term B-1 Loan, 5/3/20 510,760 --------------- $ 1,829,074 ---------------------------------------------------------------------------------------------- Independent Power Producers & Energy Traders -- 0.1% 210,024 3.75 NSG Holdings LLC, New Term Loan, 12/11/19 $ 208,449 --------------- Total Utilities $ 2,037,523 ---------------------------------------------------------------------------------------------- TOTAL SENIOR FLOATING RATE LOAN INTERESTS (Cost $95,480,516) $ 93,783,464 ---------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 48 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 ---------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------- TEMPORARY CASH INVESTMENTS -- 1.0% Repurchase Agreements -- 0.4% 425,000 $425,000 Bank of Nova Scotia, 0.12%, dated 9/30/15 plus accrued interest on 10/1/15 collateralized by the following: $287,378 Federal National Mortgage Association, 3.0-4.5%, 3/1/35-3/1/45 $146,124 Freddie Mac Giant, 3.5-4.0%, 10/1/44-9/1/45 $ 425,000 1,430,000 $1,430,000 RBC Capital Markets, Inc., 0.10%, dated 9/30/15 plus accrued interest on 10/1/15 collateralized by the following: $11,356 Federal Home Loan Mortgage Corp., 2.229-2.476%, 3/1/43-5/1/45 $1,447,244 Federal National Mortgage Association (ARM), 2.310-4.866%, 9/1/33-6/1/41 $ 1,430,000 --------------- $ 1,855,000 ---------------------------------------------------------------------------------------------- Commercial Paper -- 0.6% 1,100,000 Mondelez International, Inc., Commercial Paper, 10/1/15 (c) $ 1,099,992 1,100,000 Prudential Funding LLC, Discount Commercial Paper, 10/1/15 (c) 1,099,996 390,000 Societe Generale SA, Commercial Paper, 10/1/15 (c) 390,000 --------------- $ 2,589,988 ---------------------------------------------------------------------------------------------- TOTAL TEMPORARY CASH INVESTMENTS (Cost $4,445,000) $ 4,444,988 ---------------------------------------------------------------------------------------------- TOTAL INVESTMENT IN SECURITIES -- 90.9% (Cost $411,320,335) (a) $ 399,764,088 ---------------------------------------------------------------------------------------------- OTHER ASSETS & LIABILITIES -- 9.1% $ 39,919,196 ---------------------------------------------------------------------------------------------- TOTAL NET ASSETS -- 100.0% $ 439,683,284 ============================================================================================== * Non-income producing security. + Rounds to less than 0.1%. REIT Real Estate Investment Trust. (Step) Bond issued with an initial coupon rate which converts to a higher rate at a later date. (Cat Bond) Catastrophe or event linked bond. At September 30, 2015 the value of these securities amounted to $10,107,780 or 2.3% of total net assets. See Notes to Financial Statements -- 1H. (Perpetual) Security with no stated maturity date. REMICS Real Estate Mortgage Investment Conduits. (PIK) Represents a pay in kind security. (144A) Security is exempt from registration under Rule 144A of the Securities Act of 1933. Such securities may be resold normally to qualified institutional buyers in a transaction exempt from registration. At September 30, 2015, the value of these securities amounted to $116,836,395 or 26.6% of total net assets. The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 49 Schedule of Investments | 9/30/15 (unaudited) (continued) ** Senior floating rate loan interests in which the Fund invests generally pay interest at rates that are periodically redetermined by reference to a base lending rate plus a premium. These base lending rates are generally (i) the lending rate offered by one or more major European banks, such as LIBOR (London InterBank Offered Rate), (ii) the prime rate offered by one or more major United States banks, (iii) the rate of a certificate of deposit or (iv) other base lending rates used by commercial lenders. The rate shown is the coupon rate at period end. (a) At September 30, 2015, the net unrealized depreciation on investments based on cost for federal income tax purposes of $412,960,296 was as follows: Aggregate gross unrealized appreciation for all investments in which there is an excess of value over tax cost $ 3,838,107 Aggregate gross unrealized depreciation for all investments in which there is an excess of tax cost over value (17,034,315) ------------ Net unrealized depreciation $(13,196,208) ============ (b) Debt obligation with a variable interest rate. Rate shown is rate at end of period. (c) Security issued with a zero coupon. Income is recognized through accretion of discount. (d) Security is valued using fair value methods (other than prices supplied by independent pricing services). See Notes to Financial Statement -- Note 1A. (e) Security is in default. (f) Rate to be determined. (g) Structured reinsurance investment. At September 30, 2015, the value of these securities amounted to $22,132,921 or 5.0% of total net assets. See Notes To Financial Statements -- Note 1H. Purchases and sales of securities (excluding temporary cash investments) for the six months ended September 30, 2015 aggregated $81,308,533 and $152,860,370, respectively. Principal amounts are denominated in U.S. Dollars unless otherwise noted: EURO Euro GBP British Pound Sterling NOK Norwegian Krone CREDIT DEFAULT SWAP AGREEMENTS - SELL PROTECTION --------------------------------------------------------------------------------------------------------------------- Net Premiums Unrealized Notional Obligation Credit Expiration Paid Appreciation Principal ($)(1) Counterparty Entity/Index Coupon Rating(2) Date (Received) (Depreciation) --------------------------------------------------------------------------------------------------------------------- 7,000,000 J.P. Morgan American Axle & 5.00% B+ 12/20/17 $ (7,499) $ 31,535 Securities LLC Manufacturing Co., 10,480,000 Morgan Diamond Offshore 1.00% BBB+ 12/20/19 (74,553) (188,342) Stanley Capital Drilling Co. Services LLC --------------------------------------------------------------------------------------------------------------------- $(82,052) $(156,807) ===================================================================================================================== (1) The notional amount is the maximum amount that a seller of credit protection would be obligated to pay upon occurrence of a credit event. (2) Based on Standard & Poor's rating of the issuer or weighted average of all the underlying securities of the index. The accompanying notes are an integral part of these financial statements. 50 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 Various inputs are used in determining the value of the Fund's investments. These inputs are summarized in the three broad levels listed below. Level 1 - quoted prices in active markets for identical securities. Level 2 - other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk, etc.) See Notes to Financial Statements -- Notes 1A. Level 3 - significant unobservable inputs (including the Fund's own assumptions in determining fair value of investments) See Notes to Financial Statements -- Notes 1A. The following is a summary of the inputs used as of September 30, 2015, in valuing the Fund's investments: ---------------------------------------------------------------------------------------------------- Level 1 Level 2 Level 3 Total ---------------------------------------------------------------------------------------------------- Convertible Corporate Bonds Materials Steel $ -- $ -- $15,126 $ 15,126 All Other Convertible Corporate Bonds -- 4,220,524 -- 4,220,524 Preferred Stocks Diversified Financials Consumer Finance 708,458 806,525 -- 1,514,983 Insurance Reinsurance -- -- 6,250 6,250 Real Estate Diversified REIT 496,750 -- 496,750 All Other Preferred Stocks 4,155,575 -- -- 4,155,575 Convertible Preferred Stocks Consumer Durables & Apparel Home Furnishings -- 1,156,819 -- 1,156,819 Banks Diversified Banks -- 1,226,400 -- 1,226,400 Common Stocks Energy Oil & Gas Exploration & Production 3,828 -- -- 3,828 Capital Goods Industrial Machinery -- -- 31 31 Commercial Services & Supplies Diversified Support Services -- 3,955 -- 3,955 Insurance Life & Health Insurance -- -- 8,416 8,416 Asset Backed Securities -- 18,657,976 -- 18,657,976 Collateralized Mortgage Obligations -- 59,022,507 -- 59,022,507 Corporate Bonds Materials Steel -- 477,901 17,179 495,080 Capital Goods Industrial Machinery -- 2,123,532 40,948 2,164,480 Diversified Financials Other Diversified Financial Services -- 5,700,456 801,067 6,501,523 The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 51 Schedule of Investments | 9/30/15 (unaudited) (continued) -------------------------------------------------------------------------------------------------- Level 1 Level 2 Level 3 Total -------------------------------------------------------------------------------------------------- Insurance Reinsurance $ -- $ 10,107,780 $ 22,126,671 $ 32,234,451 All Other Corporate Bonds -- 157,781,283 -- 157,781,283 U.S. Government and Agency Obligations -- 9,657,929 -- 9,657,929 Foreign Government Bonds -- 2,211,750 -- 2,211,750 Municipal Bonds -- -- -- -- Senior Floating Rate Loan Interests -- 93,783,464 -- 93,783,464 Repurchase Agreement -- 1,855,000 -- 1,855,000 Commercial Paper -- 2,589,988 -- 2,589,988 -------------------------------------------------------------------------------------------------- Total $ 4,867,861 $371,880,539 $ 23,015,688 $399,764,088 ================================================================================================== Other Financial Instruments Net unrealized depreciation on swap contracts $ -- $ (156,807) $ -- $ (156,807) Net unrealized appreciation on forward foreign currency contracts -- 5,064 -- 5,064 -------------------------------------------------------------------------------------------------- Total $ -- $ (151,743) $ -- $ (151,743) ================================================================================================== The following is a summary of fund valuation of certain fund's assets and liabilities as of September 30, 2015. ------------------------------------------------------------------------------------------------- Level 1 Level 2 Level 3 Total ------------------------------------------------------------------------------------------------- Assets: Foreign currencies, at value (cost $36,420) $ -- $ 87,111 $ -- $ 87,111 Swap collateral -- 146,253 -- 146,253 Variation margin for swap contracts -- 743 -- 743 Liabilities: Swap collateral -- (145,510) -- (145,510) ------------------------------------------------------------------------------------------------- Total $ -- $ 88,597 $ -- $ 88,597 ================================================================================================= The accompanying notes are an integral part of these financial statements. 52 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 Following is a reconciliation of assets using significant unobservable inputs (Level 3): ---------------------------------------------------------------------------------------------------- Convertible Corporate Preferred Common Corporate Bonds Stocks Stocks Bonds Total ---------------------------------------------------------------------------------------------------- Balance as of 3/31/15 $18,194 $ 2,494,900 $ 31 $24,273,166 $26,786,291 Realized gain (loss)(1) -- -- -- (2,512) (2,512) Change in unrealized appreciation (depreciation)(2) (3,068) (308,250) 149 (2,934,689) (3,245,858) Purchases -- -- 8,267 3,579,517 3,587,784 Sales -- -- -- (4,110,017) (4,110,017) Transfers in to Level 3* -- -- -- -- -- Transfers out of Level 3* -- -- -- -- -- Transfers in and out of Level 3 activity -- $ (2,180,400) -- 2,180,400 -- ---------------------------------------------------------------------------------------------------- Balance as of 9/30/15 $15,126 $ 6,250 $8,447 $22,985,865 $23,015,688 ==================================================================================================== (1) Realized gain (loss) on these securities is included in the net realized gain (loss) from investments in the Statement of Operations. (2) Unrealized appreciation (depreciation) on these securities is included in the change in unrealized appreciation (depreciation) on investments in the Statement of Operations. * Transfers are calculated on the beginning of period values. During the six months ended September 30, 2015, there were no transfers between Levels 1, 2 and 3. Net change in unrealized appreciation (depreciation) of investments still held as of 9/30/15 $(3,159,717) =========== The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 53 Statement of Assets and Liabilities | 9/30/15 (unaudited) ASSETS: Investment in securities (cost $411,320,335) $399,764,088 Cash 24,109,253 Foreign currencies, at value (cost $36,420) 87,111 Swap collateral 146,253 Receivables -- Investment securities sold 13,937,370 Fund shares sold 928,350 Interest 3,639,504 Dividends 34,885 Due from Pioneer Investment Management, Inc. 32,989 Variation margin on swap contracts 743 Net unrealized appreciation on forward foreign currency contracts 5,064 Other assets 52,743 ---------------------------------------------------------------------------------------- Total assets $442,738,353 ======================================================================================== LIABILITIES: Payables -- Investment securities purchased $ 669,842 Fund shares repurchased 1,556,433 Distributions 199,606 Trustee fees 1,340 Swap collateral 145,510 Net unrealized depreciation on swap contracts 156,807 Swap contracts, premiums received 82,052 Due to affiliates 118,380 Accrued expenses 125,099 ---------------------------------------------------------------------------------------- Total liabilities $ 3,055,069 ======================================================================================== NET ASSETS: Paid-in capital $483,688,351 Undistributed net investment income 3,939,212 Accumulated net realized loss on investments, foreign currency transactions, swap contracts and futures contracts (36,213,862) Net unrealized depreciation on investments (11,556,247) Net unrealized depreciation on forward foreign currency contracts and other assets and liabilities denominated in foreign currencies (17,363) Net unrealized depreciation on swap contracts (156,807) ---------------------------------------------------------------------------------------- Total net assets $439,683,284 ======================================================================================== NET ASSET VALUE PER SHARE: (No par value, unlimited number of shares authorized) Class A (based on $65,879,207/7,087,597 shares) $ 9.30 Class C (based on $56,719,040/6,121,324 shares) $ 9.27 Class Y (based on $317,085,037/33,979,955 shares) $ 9.33 MAXIMUM OFFERING PRICE: Class A ($9.30 (divided by) 95.5%) $ 9.74 ======================================================================================== The accompanying notes are an integral part of these financial statements. 54 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 Statement of Operations (unaudited) For the Six Months Ended 9/30/15 INVESTMENT INCOME: Interest $ 12,815,925 Dividends 346,192 ------------------------------------------------------------------------------------------------ Total investment income $ 13,162,117 ------------------------------------------------------------------------------------------------ EXPENSES: Management fees $ 1,765,706 Transfer agent fees and expenses Class A 6,916 Class C 3,608 Class Y 2,307 Class Z* 27 Distribution fees Class A 100,470 Class C 316,003 Shareholder communications expense 239,495 Administrative expense 81,614 Custodian fees 48,247 Registration fees 64,426 Professional fees 36,296 Printing expense 14,681 Fees and expenses of nonaffiliated Trustees 12,815 Pricing expense 28,478 Miscellaneous 36,002 ------------------------------------------------------------------------------------------------ Total expenses $ 2,757,091 Less fees waived and expenses reimbursed by Pioneer Investment Management, Inc. (145,225) ------------------------------------------------------------------------------------------------ Net expenses $ 2,611,866 ------------------------------------------------------------------------------------------------ Net investment income $ 10,550,251 ------------------------------------------------------------------------------------------------ * Class Z shares converted to Class Y shares on August 7, 2015. REALIZED AND UNREALIZED GAIN (LOSS) ON INVESTMENTS, FUTURES CONTRACTS, SWAP CONTRACTS AND FOREIGN CURRENCY TRANSACTIONS: Net realized gain (loss) on: Investments $(10,146,793) Swap contracts (591,427) Futures contracts (77,067) Forward foreign currency contracts and other assets and liabilities denominated in foreign currencies 83,807 $(10,731,480) ------------------------------------------------------------------------------------------------ Change in net unrealized appreciation (depreciation) on: Investments $ (7,437,575) Futures contracts 349,068 Swap contracts 1,999,300 Forward foreign currency contracts and other assets and liabilities denominated in foreign currencies (124,835) $ (5,214,042) ------------------------------------------------------------------------------------------------ Net realized and unrealized loss on investments, futures contracts, swap contracts and foreign currency transactions $(15,945,522) ------------------------------------------------------------------------------------------------ Net decrease in net assets resulting from operations $ (5,395,271) ================================================================================================ The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 55 Statements of Changes in Net Assets ------------------------------------------------------------------------------------------------- Six Months Ended 9/30/15 Year Ended (unaudited) 3/31/15 ------------------------------------------------------------------------------------------------- FROM OPERATIONS: Net investment income $ 10,550,251 $ 27,983,787 Net realized loss on investments, futures contracts, swap contracts and foreign currency transactions (10,731,480) (20,634,227) Change in net unrealized appreciation (depreciation) on investments, futures contracts, swap contracts, and foreign currency transactions (5,214,042) (17,767,905) ------------------------------------------------------------------------------------------------- Net decrease in net assets resulting from operations $ (5,395,271) $ (10,418,345) ------------------------------------------------------------------------------------------------- DISTRIBUTIONS TO SHAREOWNERS: Net investment income: Class A ($0.12 and $0.33 per share, respectively) $ (1,017,988) $ (4,962,455) Class C ($0.09 and $0.26 per share, respectively) (574,547) (2,322,800) Class Y ($0.14 and $0.36 per share, respectively) (5,179,728) (17,280,907) Class Z* ($0.09 and $0.33 per share, respectively) (1,754) (55,741) ------------------------------------------------------------------------------------------------- Total distributions to shareowners $ (6,774,017) $ (24,621,903) ------------------------------------------------------------------------------------------------- FROM FUND SHARE TRANSACTIONS: Net proceeds from sale of shares $ 39,749,747 $ 479,298,606 Reinvestment of distributions 5,499,605 20,074,632 Cost of shares repurchased (153,954,143) (555,768,538) ------------------------------------------------------------------------------------------------- Net decrease in net assets resulting from Fund share transactions $ (108,704,791) $ (56,395,300) ------------------------------------------------------------------------------------------------- Net decrease in net assets $ (120,874,079) $ (91,435,548) NET ASSETS: Beginning of period 560,557,363 651,992,911 ------------------------------------------------------------------------------------------------- End of period $ 439,683,284 $ 560,557,363 ------------------------------------------------------------------------------------------------- Undistributed net investment income $ 3,939,212 $ 162,978 ================================================================================================= * Class Z shares converted to Class Y shares on August 7, 2015. The accompanying notes are an integral part of these financial statements. 56 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 ----------------------------------------------------------------------------------------------- Six Months Six Months Ended Ended 9/30/15 9/30/15 Year Ended Year Ended Shares Amount 3/31/15 3/31/15 (unaudited) (unaudited) Shares Amount ----------------------------------------------------------------------------------------------- Class A Shares sold 815,748 $ 7,688,805 10,733,797 $ 106,058,161 Reinvestment of distributions 99,556 942,161 469,156 4,575,600 Less shares repurchased (3,515,780) (33,286,421) (17,713,478) (172,921,032) ----------------------------------------------------------------------------------------------- Net decrease (2,600,476) $ (24,655,455) (6,510,525) $ (62,287,271) =============================================================================================== Class C Shares sold 221,214 $ 2,088,918 2,714,172 $ 26,737,821 Reinvestment of distributions 52,952 499,389 207,145 2,006,684 Less shares repurchased (1,597,797) (15,120,297) (4,701,719) (45,380,077) ----------------------------------------------------------------------------------------------- Net decrease (1,323,631) $ (12,531,990) (1,780,402) $ (16,635,572) =============================================================================================== Class Y Shares sold 3,144,045 $ 29,968,477 34,889,481 $ 345,939,487 Reinvestment of distributions 427,086 4,056,469 1,377,859 13,442,959 Less shares repurchased (11,073,993) (105,359,124) (34,372,056) (332,894,266) ----------------------------------------------------------------------------------------------- Net increase (decrease) (7,502,862) $ (71,334,178) 1,895,284 $ 26,488,180 =============================================================================================== Class Z* Shares sold 375 $ 3,547 56,381 $ 563,137 Reinvestment of distributions 168 1,586 4,946 49,389 Less shares repurchased (20,094) (188,301) (457,902) (4,573,163) ----------------------------------------------------------------------------------------------- Net decrease (19,551) $ (183,168) (396,575) $ (3,960,637) =============================================================================================== * Class Z shares converted to Class Y shares on August 7, 2015. The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 57 Financial Highlights -------------------------------------------------------------------------------------------------------------------------- Six Months Ended Year Year Year 9/30/15 Ended Ended Ended 4/29/11 (unaudited) 3/31/15 3/31/14 3/31/13 to 3/31/12 -------------------------------------------------------------------------------------------------------------------------- Class A Net asset value, beginning of period $ 9.54 $ 9.94 $ 10.04 $ 9.63 $ 10.00 -------------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income (loss) $ 0.20 $ 0.40 $ 0.41 $ 0.51 $ 0.39 Net realized and unrealized gain (loss) on investments (0.32) (0.47) (0.12) 0.45 (0.36) -------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ (0.12) $ (0.07) $ 0.29 $ 0.96 $ 0.03 -------------------------------------------------------------------------------------------------------------------------- Distribution to shareowners: Net investment income $ (0.12) $ (0.33) $ (0.37) $ (0.55) $ (0.40) Net realized gain -- -- (0.02) -- -- -------------------------------------------------------------------------------------------------------------------------- Total distributions $ (0.12) $ (0.33) $ (0.39) $ (0.55) $ (0.40) -------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ (0.24) $ (0.40) $ (0.09) $ 0.41 $ (0.37) -------------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 9.30 $ 9.54 $ 9.94 $ 10.04 $ 9.63 ========================================================================================================================== Total return* (1.27)% (0.71)% 2.95% 10.24% 0.38%(a) Ratio of net expenses to average net assets 1.17%** 1.14% 1.19% 1.20% 1.20%** Ratio of net investment income (loss) to average net assets 4.04%** 3.76% 3.89% 5.05% 4.87%** Portfolio turnover rate 35%** 81% 95% 30% 17% Net assets, end of period (in thousands) $65,879 $92,376 $161,097 $47,233 $ 7,365 Ratios with no waiver of fees and assumption of expenses by the Adviser and no reduction for fees paid indirectly: Total expenses to average net assets 1.17%** 1.14% 1.19% 1.48% 1.66%** Net investment income (loss) to average net assets 4.04%** 3.76% 3.89% 4.77% 4.41%** ========================================================================================================================== * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions, the complete redemption of the investment at net asset value at the end of each period and no sales charges. Total return would be reduced if sales charges were taken into account. ** Annualized. (a) Not annualized. The accompanying notes are an integral part of these financial statements. 58 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 ------------------------------------------------------------------------------------------------------------------------- Six Months Ended Year Year Year 9/30/15 Ended Ended Ended 4/29/11 (unaudited) 3/31/15 3/31/14 3/31/13 to 3/31/12 ------------------------------------------------------------------------------------------------------------------------- Class C Net asset value, beginning of period $ 9.51 $ 9.92 $ 10.02 $ 9.61 $ 10.00 ------------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income (loss) $ 0.16 $ 0.31 $ 0.34 $ 0.44 $ 0.34 Net realized and unrealized gain (loss) on investments (0.31) (0.46) (0.13) 0.45 (0.40) ------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ (0.15) $ (0.15) $ 0.21 $ 0.89 $ (0.06) ------------------------------------------------------------------------------------------------------------------------- Distribution to shareowners: Net investment income $ (0.09) $ (0.26) $ (0.29) $ (0.48) $ (0.33) Net realized gain -- -- (0.02) -- -- ------------------------------------------------------------------------------------------------------------------------- Total distributions $ (0.09) $ (0.26) $ (0.31) $ (0.48) $ (0.33) ------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ (0.24) $ (0.41) $ (0.10) $ 0.41 $ (0.39) ------------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 9.27 $ 9.51 $ 9.92 $ 10.02 $ 9.61 ========================================================================================================================= Total return* (1.63)% (1.58)% 2.19% 9.44% (0.47)%(a) Ratio of net expenses to average net assets 1.93%** 1.90% 1.93% 1.95% 1.98%** Ratio of net investment income (loss) to average net assets 3.30%** 3.04% 3.18% 4.29% 4.07%** Portfolio turnover rate 35%** 81% 95% 30% 17% Net assets, end of period (in thousands) $56,719 $70,793 $91,491 $28,796 $ 4,501 Ratios with no waiver of fees and assumption of expenses by the Adviser and no reduction for fees paid indirectly: Total expenses to average net assets 1.93%** 1.90% 1.93% 2.23% 2.46%** Net investment income (loss) to average net assets 3.30%** 3.04% 3.18% 4.01% 3.59%** ========================================================================================================================= * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions, the complete redemption of the investment at net asset value at the end of each period and no sales charges. Total return would be reduced if sales charges were taken into account. ** Annualized. (a) Not annualized. The accompanying notes are an integral part of these financial statements. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 59 Financial Highlights (continued) -------------------------------------------------------------------------------------------------------------------------- Six Months Ended Year Year Year 9/30/15 Ended Ended Ended 4/29/11 (unaudited) 3/31/15 3/31/14 3/31/13 to 3/31/12 -------------------------------------------------------------------------------------------------------------------------- Class Y Net asset value, beginning of period $ 9.58 $ 9.98 $ 10.08 $ 9.66 $ 10.00 -------------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income (loss) $ 0.22 $ 0.41 $ 0.44 $ 0.55 $ 0.42 Net realized and unrealized gain (loss) on investments (0.33) $ (0.45) (0.12) 0.45 (0.34) -------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ (0.11) $ (0.04) $ 0.32 $ 1.00 $ 0.08 -------------------------------------------------------------------------------------------------------------------------- Distribution to shareowners: Net investment income $ (0.14) $ (0.36) $ (0.40) $ (0.58) $ (0.42) Net realized gain -- -- (0.02) -- -- -------------------------------------------------------------------------------------------------------------------------- Total distributions $ (0.14) $ (0.36) $ (0.42) $ (0.58) $ (0.42) -------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ (0.25) $ (0.40) $ (0.10) $ 0.42 $ (0.34) -------------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 9.33 $ 9.58 $ 9.98 $ 10.08 $ 9.66 ========================================================================================================================== Total return* (1.20)% (0.43)% 3.24% 10.69% 0.95%(a) Ratio of net expenses to average net assets 0.85%** 0.85% 0.85% 0.85% 0.85%** Ratio of net investment income (loss) to average net assets 4.37%** 4.10% 4.24% 5.52% 5.48%** Portfolio turnover rate 35%** 81% 95% 30% 17% Net assets, end of period (in thousands) $317,085 $397,203 $395,245 $131,013 $41,606 Ratios with no waiver of fees and assumption of expenses by the Adviser and no reduction for fees paid indirectly: Total expenses to average net assets 0.93%** 0.93% 0.97% 1.21% 1.30%** Net investment income (loss) to average net assets 4.29%** 4.02% 4.12% 5.16% 5.03%** ========================================================================================================================== * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions, the complete redemption of the investment at net asset value at the end of each period. ** Annualized. (a) Not annualized. The accompanying notes are an integral part of these financial statements. 60 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 Notes to Financial Statements |9/30/15 (unaudited) 1. Organization and Significant Accounting Policies Pioneer Dynamic Credit Fund (formerly known as Pioneer Absolute Return Credit Fund) (the Fund) is one of three portfolios comprising Pioneer Series Trust X, a Delaware statutory trust. The Fund is registered under the Investment Company Act of 1940 as a diversified, open-end management investment company. The investment objective of the Fund is to seek a high level of current income. Capital appreciation is a secondary objective. The Fund offers three classes of shares designated as Class A, Class C and Class Y shares. Class A, Class C and Class Y shares commenced operations on April 29, 2011. Class Z shares were converted to Class Y shares on August 7, 2015. Each class of shares represents an interest in the same portfolio of investments of the Fund and has identical rights (based on relative net asset values) to assets and liquidation proceeds. Share classes can bear different rates of class-specific fees and expenses, such as transfer agent and distribution fees. Differences in class-specific fees and expenses will result in differences in net investment income and, therefore, the payment of different dividends from net investment income earned by each class. The Amended and Restated Declaration of Trust of the Fund gives the Board the flexibility to specify either per-share voting or dollar-weighted voting when submitting matters for shareholder approval. Under per-share voting, each share of a class of the Fund is entitled to one vote. Under dollar-weighted voting, a shareholder's voting power is determined not by the number of shares owned, but by the dollar value of the shares on the record date. Each share class has exclusive voting rights with respect to matters affecting only that class, including with respect to the distribution plan for that class. There is no distribution plan for Class Y shares. The Fund's financial statements have been prepared in conformity with U.S. generally accepted accounting principles that require the management of the Fund to, among other things, make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of income, expenses and gains and losses on investments during the reporting period. Actual results could differ from those estimates. The following is a summary of significant accounting policies followed by the Fund in the preparation of its financial statements: A. Security Valuation Security transactions are recorded as of trade date. The net asset value of the Fund is computed once daily, on each day the New York Stock Exchange (NYSE) is open, as of the close of regular trading on the NYSE. Fixed income Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 61 securities are valued at prices supplied by independent pricing services, which consider such factors as market prices, market events, quotations from one or more brokers, Treasury spreads, yields, maturities and ratings. Valuations may be supplemented by dealers and other sources, as required. Senior floating rate loan interests (senior loans) are valued in accordance with guidelines established by the Board of Trustees at the mean between the last available bid and asked prices from one or more brokers or dealers as obtained from Loan Pricing Corporation, an independent pricing service. If price information is not available from Loan Pricing Corporation, or if the price information is deemed to be unreliable, price information will be obtained from an alternative loan interest pricing service. If no reliable price quotes are available from either the primary or alternative pricing service, broker quotes will be solicited. Shares of money market mutual funds are valued at such funds' net asset value. Event- linked bonds are valued at the bid price obtained from an independent third party pricing service. Other insurance-linked securities may be valued at the bid price obtained from an independent pricing service, or through a third party using a pricing matrix, insurance industry valuation models, or other fair value method or techniques to provide an estimated value of the instrument. Cash may include overnight time deposits at approved financial institutions. Securities or senior loans interests for which independent pricing services are unable to supply prices or for which market prices and/or quotations are not readily available or are considered to be unreliable are valued by a fair valuation team comprised of certain personnel of Pioneer Investment Management, Inc. (PIM), the Fund's investment adviser, pursuant to procedures adopted by the Fund's Board of Trustees. PIMs fair valuation team uses fair value methods approved by the Valuation Committee of the Board of Trustees. Inputs used when applying fair value methods to value a security may include credit ratings, the financial condition of the company, current market conditions and comparable securities. The Fund may use fair value methods if it is determined that a significant event has occurred after the close of the exchange or market on which the security trades and prior to the determination of the Fund's net asset value. Examples of a significant event might include political or economic news, corporate restructurings, natural disasters, terrorist activity or trading halts. Thus, the valuation of the Fund's securities may differ significantly from exchange prices and such differences could be material. PIM's fair valuation team is responsible for monitoring developments that may impact fair valued securities and for discussing and assessing fair values on an ongoing basis, and at least quarterly, with the Valuation Committee of the Board of Trustees. At September 30, 2015, there were eight securities that were valued using fair value methods (in addition to securities valued using prices supplied by independent pricing services, broker dealers or using a third party insurance industry pricing model) representing 0.2% of net assets. 62 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 B. Investment Income and Transactions Principal amounts of mortgage-backed securities are adjusted for monthly paydowns. Premiums and discounts related to certain mortgage-backed securities are amortized or accreted in proportion to the monthly paydowns. All discounts/premiums on purchase prices of debt securities are accreted/- amortized for financial reporting purposes over the life of the respective securities, and such accretion/amortization is included in interest income. Dividend income is recorded on the ex-dividend date, except that certain dividends from foreign securities where the ex-dividend date may have passed are recorded as soon as the Fund becomes aware of the ex-dividend data in the exercise of reasonable diligence. Interest income, including interest on income bearing cash accounts, is recorded on the accrual basis, net of unrecoverable foreign taxes withheld at the applicable country rates. Gains and losses on sales of investments are calculated on the identified cost method for both financial reporting and federal income tax purposes. C. Foreign Currency Translation The books and records of the Fund are maintained in U.S. dollars. Amounts denominated in foreign currencies are translated into U.S. dollars using current exchange rates. Net realized gains and losses on foreign currency transactions, if any, represent, among other things, the net realized gains and losses on foreign currency contracts, disposition of foreign currencies and the difference between the amount of income accrued and the U.S. dollars actually received. Further, the effects of changes in foreign currency exchange rates on investments are not segregated in the statement of operations from the effects of changes in the market price of those securities but are included with the net realized and unrealized appreciation or depreciation on investments. D. Forward Foreign Currency Contracts The Fund may enter into forward foreign currency contracts (contracts) for the purchase or sale of a specific foreign currency at a fixed price on a future date. All contracts are marked to market daily at the applicable exchange rates, and any resulting unrealized appreciation or depreciation are recorded in the Fund's financial statements. The Fund records realized gains and losses at the time a contract is offset by entry into a closing transaction or extinguished by delivery of the currency. Risks may arise upon entering into these contracts from the potential inability of counterparties to meet the terms of the contract and from unanticipated movements in the value of foreign currencies relative to the U.S. dollar (see Note 6). Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 63 E. Federal Income Taxes It is the Fund's policy to comply with the requirements of the Internal Revenue Code applicable to regulated investment companies and to distribute all of its net taxable income and net realized capital gains, if any, to its shareowners. Therefore, no provision for federal income taxes is required. As of March 31, 2015, the Fund had not accrued any interest or penalties with respect to uncertain tax positions, which, if applicable, would be recorded as an income tax expense in the Statement of Operations. Tax returns filed within the prior three years are subject to examination by Federal and State tax authorities. The amount and character of income and capital gain distributions to share- owners are determined in accordance with federal income tax rules, which may differ from U.S. generally accepted accounting principles. Distributions in excess of net investment income or net realized gains are temporary overdistributions for financial statement purposes resulting from differences in the recognition or classification of income or distributions for financial statement and tax purposes. Capital accounts within the financial statements are adjusted for permanent book/tax differences to reflect tax character, but are not adjusted for temporary differences. The tax character of current year distributions payable will be determined at the end of the current taxable year. The tax character of distributions paid during the year ended March 31, 2015 was as follows: -------------------------------------------------------------------------------- 2015 -------------------------------------------------------------------------------- Distributions paid from: Ordinary income $24,621,903 -------------------------------------------------------------------------------- Total $24,621,903 -------------------------------------------------------------------------------- The following shows components of distributable earnings on a federal income tax basis at March 31, 2015. -------------------------------------------------------------------------------- 2015 -------------------------------------------------------------------------------- Undistributed ordinary income $ 299,325 Capital loss carryforward (25,870,315) Dividend Payable (247,626) Unrealized depreciation (6,017,163) -------------------------------------------------------------------------------- Total $ (31,835,779) -------------------------------------------------------------------------------- The difference between book-basis and tax-basis net unrealized depreciation is attributable to the tax adjustments relating to catastrophe bonds and credit default swaps, the mark-to-market of forward currency, option and futures contracts, and adjustments relating to interest accruals on preferred stock and defaulted bonds. 64 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 F. Fund Shares The Fund records sales and repurchases of its shares as of trade date. Pioneer Funds Distributor, Inc. (PFD), the principal underwriter for the Fund and a wholly owned indirect subsidiary of UniCredit S.p.A. (UniCredit), earned $4,099 in underwriting commissions on the sale of Class A shares during the six months ended September 30, 2015. G. Class Allocations Income, common expenses, and realized and unrealized gains and losses are calculated at the Fund level and allocated daily to each class of shares based on its respective percentage of adjusted net assets at the beginning of the day. Distribution fees are calculated based on the average daily net asset value attributable to Class A and Class C shares of the Fund, respectively (see Note 4). Class Y shares do not pay distribution fees. All expenses and fees paid to the transfer agent, Pioneer Investment Management Shareholder Services, Inc. (PIMSS), for its services are allocated among the classes of shares based on the number of accounts in each class and the ratable allocation of related out-of-pocket expenses (see Note 3). The Fund declares as daily dividends substantially all of its net investment income. All dividends are paid on a monthly basis. Short-term capital gain distributions, if any, may be declared with the daily dividends. Distributions to shareowners are recorded as of the ex-dividend date. Distributions paid by the Fund with respect to each class of shares are calculated in the same manner and at the same time except that net investment income dividends to Class A, Class C and Class Y shares can reflect different transfer agent and distribution expense rates. H. Risks When interest rates rise, the prices of fixed-income securities in the Fund will generally fall. Conversely, when interest rates fall, the prices of fixed-income securities in the Fund will generally rise. Investments in the Fund are subject to possible loss due to the financial failure of issuers of underlying securities and the issuers' inability to meet their debt obligations. The Fund's prospectus contains unaudited information regarding the Fund's principal risks. Please refer to that document when considering the Fund's principal risks. The Fund invests in event-linked bonds. Event-linked bonds are floating rate debt obligations for which the return of principal and the payment of interest are contingent on the non-occurrence of a pre-defined "trigger" event, such as a hurricane or an earthquake of a specific magnitude. The trigger event's magnitude may be based on losses to a company or industry, industry indexes or readings of scientific instruments, or may be based on specified Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 65 actual losses. If a trigger event, as defined within the terms of an event-linked bond occurs, the Fund may lose a portion or all of its accrued interest and/or principal invested in such event-linked bond. The Fund is entitled to receive principal and interest payments so long as no trigger event occurs of the description and magnitude specified by the instrument. In addition to the specified trigger events, event-linked bonds may expose the Fund to other risks, including but not limited to issuer (credit) default, adverse regulatory or jurisdictional interpretations and adverse tax consequences. In addition to event-linked bonds, the Fund also may invest in other insurance-linked securities ("ILS"). The Fund's investments in ILS may include special purpose vehicles ("SPVs") or similar instruments structured to comprise a portion of a reinsurer's catastrophe-oriented business, known as quota share instruments (sometimes referred to as reinsurance sidecars), or to provide reinsurance relating to specific risks to insurance or reinsurance companies through a collateralized instrument, known as collateralized reinsurance. Structured reinsurance investments which also may include industry loss warranties ("ILWs"), are subject to the same risks as event-linked bonds. In addition, because quota share instruments represent an interest in a basket of underlying reinsurance contracts, the Fund has limited transparency into the individual underlying contracts and therefore must rely upon the risk assessment and sound underwriting practices of the issuer. Accordingly, it may be more difficult for PIM to fully evaluate the underlying risk profile of the Fund's investment in quota share instruments and therefore place the Fund's assets at greater risk of loss than if PIM had more complete information. These securities may be difficult to purchase, sell or unwind and may be difficult to value. I. Futures Contracts The Fund may enter into futures transactions in order to attempt to hedge against changes in interest rates, securities prices and currency exchange rates or to seek to increase total return. Futures contracts are types of derivatives. All futures contracts entered into by the Fund are traded on a futures exchange. Upon entering into a futures contract, the Fund is required to deposit with a broker an amount of cash or securities equal to the minimum "initial margin" requirements of the associated futures exchange. Subsequent payments for futures contracts ("variation margin") are paid or received by the Fund, depending on the daily fluctuation in the value of the contracts, and are recorded by the Fund as unrealized appreciation or depreciation. When the contract is closed, the Fund realizes a gain or loss equal to the difference between the opening and closing value of the contract as well as any fluctuation in foreign currency exchange rates where applicable. Futures contracts are subject to market risk, interest rate risk and currency exchange rate risk. Changes in value of the contracts may not directly correlate to the 66 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 changes in value of the underlying securities. The average value of contracts open during the six months ended September 30, 2015 was $(35,014,717). There were no open futures contracts outstanding at September 30, 2015. J. Repurchase Agreements Repurchase agreements are arrangements under which the Fund purchases securities from a broker-dealer or a bank, called the counterparty, upon the agreement of the counterparty to repurchase the securities from the Fund at a later date, and at a specific price, which is typically higher than the purchase price paid by the Fund. The securities purchased serve as the Fund's collateral for the obligation of the counterparty to repurchase the securities. The value of the collateral, including accrued interest, is required to be equal to or in excess of the repurchase price. The collateral for all repurchase agreements is held in safekeeping in the customer-only account of the Fund's custodian or a subcustodian of the Fund. The Fund's investment adviser, PIM is responsible for determining that the value of the collateral remains at least equal to the repurchase price. In the event of a default by the counterparty, the Fund is entitled to sell the securities, but the Fund may not be able to sell them for the price at which they were purchased, thus causing a loss to the Fund. Additionally, if the counterparty becomes insolvent, there is some risk that the Fund will not have a right to the securities, or the immediate right to sell the securities. K. Credit Default Swap Agreements A credit default swap is a contract between a buyer of protection and a seller of protection against a pre-defined credit event. The Fund may sell or buy credit default swap contracts to seek to increase the Fund's income, or to attempt to hedge the risk of default on portfolio securities. A credit default swap index is used to hedge risk or take a position on a basket of credit entities or indices. As a seller of protection, the Fund would be required to pay the notional (or other agreed-upon) value of the referenced debt obligation to the counterparty in the event of a default by a U.S. or foreign corporate issuer of a debt obligation, which would likely result in a loss to the Fund. In return, the Fund would receive from the counterparty a periodic stream of payments during the term of the contract provided that no event of default occurred. The maximum exposure of loss to the seller would be the notional value of the credit default swaps outstanding. If no default occurs, the Fund would keep the stream of payments and would have no payment obligation. The Fund may also buy credit default swap contracts in order to hedge against the risk of default of debt securities, in which case the Fund would function as the counterparty referenced above. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 67 When the Fund enters into a credit default swap contract, the protection buyer makes an upfront or periodic payment to the protection seller in exchange for the right to receive a contingent payment. An upfront payment made by the Fund, as the protection buyer, is recorded as an asset in the Statement of Assets and Liabilities. Periodic payments received or paid by the Fund are recorded as realized gains or losses in the Statement of Operations. Credit default swap contracts are marked-to-market daily using valuations supplied by independent sources and the change in value, if any, is recorded as unrealized appreciation or depreciation in the Statement of Assets and Liabilities. Payments received or made as a result of a credit event or upon termination of the contract are recognized, net of the appropriate amount of the upfront payment, as realized gains or losses in the Statement of Operations. Credit default swap contracts involving the sale of protection may involve greater risks than if the Fund had invested in the referenced debt instrument directly. Credit default swap contracts are subject to general market risk, liquidity risk, counterparty risk and credit risk. If the Fund is a protection buyer and no credit event occurs, it will lose its investment. If the Fund is a protection seller and a credit event occurs, the value of the referenced debt instrument received by the Fund, together with the periodic payments received, may be less than the amount the Fund pays to the protection buyer, resulting in a loss to the Fund. Certain swap contracts that are cleared through a central clearinghouse are referred to as centrally cleared swaps. All payments made or received by the Fund are pursuant to a centrally cleared swap contract with the central clearing party rather than the original counterparty. Upon entering into a centrally cleared swap contract, the Fund is required to make an initial margin deposit, either in cash or in securities. The daily change in value on open centrally cleared contracts is recorded as variation margin on centrally cleared swaps on the Statement of Assets and Liabilities. Open credit default swap contracts at September 30, 2015 are listed in the Schedule of Investments. The average value of swap contracts open during the six months ended September 30, 2015 was $(6,639,143). L. Purchased Options The Fund may purchase put and call options to seek increase total return. Purchased call and put options entitle the Fund to buy and sell a specified number of shares or units of a particular security, currency or index at a specified price at a specific date or within a specific period of time. Upon the purchase of a call or put option, the premium paid by the Fund is included in the Statement of Assets and Liabilities as an investment. All premiums are 68 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 marked-to-market daily, and any unrealized gains or losses are recorded in the Fund's financial statements. As the purchaser of an index option, the Fund has the right to receive a cash payment equal to any depreciation in the value of the index below the strike price of the option (in the case of a put) or equal to any appreciation in the value of the index over the strike price of the option (in the case of a call) as of the valuation date of the option. Premiums paid for purchased calls and put options which have expired are treated as realized losses on investments in the Statement of Operations. Upon the exercise or closing of a purchased put option, the premium is offset against the proceeds on the sale of the underlying security or financial instrument in order to determine the realized gain or loss on investments. Upon the exercise or closing of a purchased call option, the premium is added to the cost of the security or financial instrument. The risk associated with purchasing options is limited to the premium originally paid. The average value of purchased options open for the six months ended September 30, 2015 was $44,911. There were no open purchased options outstanding at September 30, 2015. 2. Management Agreement PIM, a wholly owned indirect subsidiary of UniCredit, manages the Fund's portfolio. Management fees are calculated daily at the annual rate equal to 0.70% of the Fund's average daily net assets up to $1 billion and 0.65% on assets over $1 billion. For the six months ended September 30, 2015, the effective management fee (excluding waivers and/or assumption of expenses) was equivalent to 0.70% of the Fund's average daily net assets. PIM has contractually agreed to limit ordinary operating expenses to the extent required to reduce Fund expenses to 0.85% of the average daily net assets attributable to Class Y shares. Fees waived and expenses reimbursed during the six months ended September 30, 2015 are reflected on the Statement of Operations. This expense limitation is in effect through August 1, 2017. There can be no assurance that PIM will extend the expense limitation agreement for a class of shares beyond the date referred to above. In addition, under the management and administration agreements, certain other services and costs, including accounting, regulatory reporting, and insurance premiums, are paid by the Fund as administrative reimbursements. Included in "Due to affiliates" reflected on the Statement of Assets and Liabilities is $16,502 in management fees, administrative costs and certain other reimbursements payable to PIM at September 30, 2015. 3. Transfer Agent Prior to November 2, 2015, PIMSS, a wholly owned indirect subsidiary of UniCredit, provided substantially all transfer agent and shareowner services to the Fund at negotiated rates. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 69 In addition, the Fund reimbursed PIMSS for out-of-pocket expenses incurred by PIMSS related to shareholder communications activities such as proxy and statement mailings, outgoing phone calls and omnibus relationship contracts. For the six months ended September 30, 2015, such out-of-pocket expenses by class of shares were as follows: ------------------------------------------------------------------------------- Shareholder Communications: ------------------------------------------------------------------------------- Class A $ 29,461 Class C 27,047 Class Y 182,857 Class Z 130 ------------------------------------------------------------------------------- Total $239,495 =============================================================================== Included in "Due to affiliates" reflected on the Statement of Assets and Liabilities is $97,874 in transfer agent fees and out-of-pocket reimbursements payable to PIMSS at September 30, 2015. Effective November 2, 2015, Boston Financial Data Services serves as the transfer agent to the Fund at negotiated rates. 4. Distribution Plan The Fund has adopted a Distribution Plan pursuant to Rule 12b-1 of the Investment Company Act of 1940 with respect to its Class A and Class C shares. Pursuant to the Plan, the Fund pays PFD 0.25% of the average daily net assets attributable to Class A shares as compensation for personal services and/or account maintenance services or distribution services with regard to Class A shares. Pursuant to the Plan, the Fund also pays PFD 1.00% of the average daily net assets attributable to Class C shares. The fee for Class C shares consists of a 0.25% service fee and a 0.75% distribution fee paid as compensation for personal services and/or account maintenance services or distribution services with regard to Class C shares. Included in "Due to affiliates" reflected on the Statement of Assets and Liabilities is $4,004 in distribution fees payable to PFD at September 30, 2015. In addition, redemptions of each class of shares (except Class Y shares) may be subject to a contingent deferred sales charge (CDSC). A CDSC of 1.00% may be imposed on redemptions of certain net asset value purchases of Class A shares within 12 months of purchase. Redemptions of Class C shares within 12 months of purchase are subject to a CDSC of 1.00%, based on the lower of cost or market value of shares being redeemed. Shares purchased as part of an exchange remain subject to any CDSC that applied to the original purchase of those shares. There is no CDSC for Class Y shares. Proceeds from the CDSCs are paid to PFD. For the six months ended September 30, 2015, CDSCs in the amount of $4,432 were paid to PFD. 70 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 5. Expense Offset Arrangements The Fund has entered into certain expense offset arrangements with PIMSS which may result in a reduction in the Fund's total expenses due to interest earned on cash held by PIMSS. For the six months ended September 30, 2015, the Fund's expenses were not reduced under such arrangements. 6. Forward Foreign Currency Contracts At September 30, 2015, the Fund had entered into various forward foreign currency contracts that obligate the Fund to deliver or take delivery of currencies at specified future maturity dates. Alternatively, prior to the settlement date of a forward foreign currency contract, the Fund may close out such contract by entering into an offsetting contract. The average value of contracts open during the six months ended September 30, 2015 was $(1,475,998). As of September 30, 2015, outstanding forward foreign currency contracts were as follows: --------------------------------------------------------------------------------------------- In Net Currency Currency Exchange Settlement Unrealized Sold Deliver Purchased for Counterparty Date Appreciation --------------------------------------------------------------------------------------------- GBP (British (227,167) USD 347,772 Citibank 11/3/15 $4,394 Pound Sterling) EUR (Euro) (199,821) USD 223,831 Brown Brothers 10/23/15 670 Harriman And Co. --------------------------------------------------------------------------------------------- Total $5,064 ============================================================================================= 7. Assets and Liabilities Offsetting The Fund has entered into an International Swaps and Derivatives Association, Inc. Master Agreement ("ISDA Master Agreement") or similar agreement with substantially all its derivative counterparties. An ISDA Master Agreement is a bilateral agreement between the Fund and a counterparty that governs the trading of certain OTC derivatives and typically contains, among other things, close-out and set-off provisions which apply upon the occurrence of event of a default and/or termination event as defined under the relevant ISDA Master Agreement. The ISDA Master Agreement may also give a party the right to terminate all transactions traded under such agreement if, among other things, there is deterioration in the credit quality of the other party. Upon an event of default or a termination of the ISDA Master Agreement, the non-defaulting party has the right to close out all transactions under such agreement and to net amounts owed under each transaction to determine one net amount payable by one party to the other. The right to close out and net payments across all transactions under the ISDA Master Agreement could result in a reduction of the Fund's credit risk to its counterparty equal to any amounts Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 71 payable by the Fund under the applicable transactions, if any. However, the Fund's right to setoff may be restricted or prohibited by the bankruptcy or insolvency laws of the particular jurisdiction to which a specific ISDA counter- party is subject. The collateral requirements for derivatives transactions under an ISDA Master Agreement are governed by a credit support annex to the ISDA Master Agreement. Collateral requirements are generally determined at the close of business each day and are typically based on changes in market values for each transaction under an ISDA Master Agreement and netted into one amount for such agreement. Generally, the amount of collateral due from or to a counterparty is subject to threshold (a "minimum transfer amount") before a transfer is required, which may vary by counterparty. Collateral pledged for the benefit of the Fund and/or counterparty is held in segregated accounts by the Fund's custodian and cannot be sold, re-pledged, assigned or otherwise used while pledged. Cash that has been segregated to cover the Fund's collateral obligations, if any, will be reported separately in the Statement of Assets and Liabilities as "Futures collateral", "Swap Collateral" or "Deposit with broker." Securities pledged by the Fund as collateral, if any, are identified as such in the Schedule of Investments. Financial instruments subject to an enforceable master netting agreement such as an ISDA Master Agreement have been offset on the Statement of Assets and Liabilities. The following charts show gross assets and liabilities of the Fund as of September 30, 2015. --------------------------------------------------------------------------------------------------- Derivative Assets Derivatives Non-Cash Cash Net Amount Subject to Master Available for Collateral Collateral of Derivative Counterparty Netting Agreement Offset Received (a) Received (a) Assets (b) --------------------------------------------------------------------------------------------------- JP Morgan $31,535 $ -- $ -- $ (31,535) $ -- Morgan Stanley -- -- -- -- -- Capital Services LLC Citibank 4,394 -- -- -- 4,394 Brown Brothers Harriman and Co. 670 -- -- -- 670 --------------------------------------------------------------------------------------------------- $36,599 $ -- $ -- $ (31,535) $ 5,064 =================================================================================================== -------------------------------------------------------------------------------------------------------- Derivative Liabilities Derivatives Non-Cash Cash Net Amount Subject to Master Available for Collateral Collateral of Derivative Counterparty Netting Agreement Offset Pledged (a) Pledged (a) Assets (c) -------------------------------------------------------------------------------------------------------- JP Morgan $ -- $ -- $ -- $146,253 $146,253 Morgan Stanley 188,342 -- -- -- 188,342 Capital Services LLC Citibank -- -- -- -- -- Brown Brothers Harriman and Co. -- -- -- -- -- -------------------------------------------------------------------------------------------------------- $ 188,342 $ -- $ -- $146,253 $334,595 ======================================================================================================== (a) The amount presented here may be less than the total amount of collateral received/pledged as the net amount of derivative assets and liabilities cannot be less than $0. 72 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 (b) Represents the net amount due from the counterparty in the event of default. (c) Represents the net amount payable to the counterparty in the event of default. 8. Additional Disclosures about Derivative Instruments and Hedging Activities: The Fund's use of derivatives subjects it to the following risks: Interest rate risk relates to the fluctuations in the value of interest-bearing securities due to changes in the prevailing levels of market interest rates. Credit risk relates to the ability of the issuer of a financial instrument to make further principal or interest payments on an obligation or commitment that it has to the Fund. Foreign exchange rate risk relates to fluctuations in the value of an asset or liability due to changes in currency exchange rates. Equity risk relates to the fluctuations in the value of financial instruments as a result of changes in market prices (other than those arising from interest rate risk or foreign exchange risk), whether caused by factors specific to an individual investment, its issuer, or all factors affecting all instruments traded in a market or market segment. Commodity risk relates to the risk that the value of a commodity or commodity index will fluctuate based on increases or decreases in the commodities market and factors specific to a particular industry or commodity. The fair value of open derivative instruments (not considered to be hedging instruments for accounting disclosure purposes) by risk exposure at September 30, 2015 was as follows: ---------------------------------------------------------------------------------------------------------- Statement of Assets and Interest Credit Foreign Exchange Equity Commodity Liabilities Caption Rate Risk Risk Rate Risk Risk Risk ---------------------------------------------------------------------------------------------------------- Assets Net unrealized appreciation of forward foreign currency contracts -- -- 5,064 -- -- ---------------------------------------------------------------------------------------------------------- Total Value -- -- 5,064 -- -- Liabilities Net unrealized depreciation on swap contracts -- (156,807) -- -- -- ---------------------------------------------------------------------------------------------------------- Total Value -- (156,807) -- -- -- ========================================================================================================== * Reflects unrealized appreciation/depreciation of futures contracts (see Note 1I). The current day's variation margin is disclosed on the Statement of Assets and Liabilities. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 73 The effect of derivative instruments (not considered to be hedging instruments for accounting disclosure purposes) on the Statement of Operations by risk exposure at September 30, 2015 was as follows: ---------------------------------------------------------------------------------------------- Statement of Operations Interest Rate Credit Foreign Exchange Equity Commodity Caption Risk Risk Rate Risk Risk Risk ---------------------------------------------------------------------------------------------- Net realized gain (loss) on Swap contracts -- (591,427) -- -- -- Futures contracts (77,067) -- -- -- -- Forward foreign currency contracts and other assets and liabilities denominated in foreign currencies -- -- 29,805 -- -- ---------------------------------------------------------------------------------------------- Total Value (77,067) (591,427) 29,805 -- -- ============================================================================================== Change in net unrealized appreciation (depreciation) on Swap contracts -- 1,999,300 -- -- -- Futures contracts 349,068 Forward foreign currency contracts and other assets and liabilities denominated in foreign currencies -- -- (102,720) -- -- ---------------------------------------------------------------------------------------------- Total Value 349,068 1,999,300 (102,720) -- -- ============================================================================================== 9. Bridge Loan Commitments As of September 30, 2015, the Fund had one bridge loan commitment of $1,015,000, which could be extended at the option of the borrower, pursuant to the following loan agreement: ------------------------------------------------------------------------------------- Unrealized Loan Principal Cost Value Appreciation ------------------------------------------------------------------------------------- Charter Communications 1,015,000 $1,015,000 $1,015,000 $ -- Operating Co., Bridge Loan ------------------------------------------------------------------------------------- Total $ -- ===================================================================================== 10. Line of Credit Facility The Fund, along with certain other funds in the Pioneer Family of Funds (the Funds), participates in a committed, unsecured revolving line of credit facility. Borrowings are used solely for temporary or emergency purposes. The Fund may borrow up to the lesser of the amount available under the facility or the limits set for borrowing by the Fund's prospectus and the 1940 Act. The credit facility in effect until June 9, 2015 was in the amount of $215 million. As of June 9, 2015, the facility is in the amount of $240 million. Under such facility, depending on the type of loan, interest on borrowings is payable at the London Interbank Offered Rate (LIBOR) plus 0.85% on an annualized basis, or the alternate base rate, which is the greater of (a) the facility's administrative agent's daily announced prime rate on the borrowing date, (b) 2% plus the 74 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 federal funds rate on the borrowing date and (c) 2% plus the overnight eurodollar rate on the borrowing date. The Funds pay an annual commitment fee to participate in the credit facility. The commitment fee is allocated among participating Funds based on an allocation schedule set forth in the credit agreement. For the six months ended September 30, 2015, the Fund had no borrowings under the credit facility. 11. Conversion of Class Z shares As of the close of business on August 7, 2015 (the "Conversion Date"), all outstanding Class Z shares of the Pioneer funds were converted to Class Y shares. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 75 ADDITIONAL INFORMATION Pioneer Investment Management, Inc. (the "Adviser"), each fund's investment adviser, is currently an indirect, wholly owned subsidiary of UniCredit S.p.A. ("UniCredit"). On November 11, 2015, UniCredit announced that it signed a binding master agreement with Banco Santander and affiliates of Warburg Pincus and General Atlantic (the "Private Equity Firms") with respect to Pioneer Investments ("Pioneer") and Santander Asset Management ("SAM") (the "Transaction"). The Transaction, as described in the UniCredit announcement, will establish a holding company, with the name Pioneer Investments, to be owned by UniCredit (50%) and the Private Equity Firms (50% between them). The holding company will control Pioneer's U.S. operations, including the Adviser. The holding company also will own 66.7% of Pioneer's and SAM's combined operations outside the U.S., while Banco Santander will own directly the remaining 33.3% stake. The closing of the Transaction is expected to happen in 2016, subject to certain regulatory and other approvals, and other conditions. Under the Investment Company Act of 1940, completion of the Transaction will cause each fund's current investment advisory agreement with the Adviser to terminate. Accordingly, each fund's Board of Trustees will be asked to approve a new investment advisory agreement. If approved by the Board, each fund's new investment advisory agreement will be submitted to the shareholders of the fund for their approval. 76 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 Approval of Investment Advisory Agreement Pioneer Investment Management, Inc. (PIM) serves as the investment adviser to Pioneer Dynamic Credit Fund (the Fund) pursuant to an investment advisory agreement between PIM and the Fund. In order for PIM to remain the investment adviser of the Fund, the Trustees of the Fund must determine annually whether to renew the investment advisory agreement for the Fund. The contract review process began in January 2015 as the Trustees of the Fund agreed on, among other things, an overall approach and timeline for the process. Contract review materials were provided to the Trustees in March 2015 and July 2015. Supplemental contract review materials were provided to the Trustees in September 2015. In addition, the Trustees reviewed and discussed the Fund's performance at regularly scheduled meetings throughout the year and took into account other information related to the Fund provided to the Trustees at regularly scheduled meetings in connection with the review of the Fund's investment advisory agreement. In March 2015, the Trustees, among other things, discussed the memorandum provided by Fund counsel that summarized the legal standards and other considerations that are relevant to the Trustees in their deliberations regarding the renewal of the investment advisory agreement, and reviewed and discussed the qualifications of the investment management teams, as well as the level of investment by the Fund's portfolio managers in the Fund. In July 2015, the Trustees, among other things, reviewed the Fund's management fee and total expense ratios, the financial statements of PIM and its parent companies, the profitability analyses provided by PIM, and possible economies of scale. The Trustees also reviewed the profitability of the institutional business of PIM and PIM's affiliate, Pioneer Institutional Asset Management, Inc. (together with PIM, "Pioneer"), as compared to that of PIM's fund management business, and considered the differences between the fees and expenses of the Fund and the fees and expenses of Pioneer's institutional accounts, as well as the different services provided by PIM to the Fund and by Pioneer to the institutional accounts. The Trustees further considered contract review materials in September 2015. At a meeting held on September 15, 2015, based on their evaluation of the information provided by PIM and third parties, the Trustees of the Fund, including the Independent Trustees voting separately, unanimously approved the renewal of the investment advisory agreement for another year. In approving the renewal of the investment advisory agreement, the Trustees considered various factors that they determined were relevant, including the factors described below. The Trustees did not identify any single factor as the controlling factor in determining to approve the renewal of the agreement. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 77 Nature, Extent and Quality of Services The Trustees considered the nature, extent and quality of the services that had been provided by PIM to the Fund, taking into account the investment objective and strategy of the Fund. The Trustees also reviewed PIM's investment approach for the Fund and its research process. The Trustees considered the resources of PIM and the personnel of PIM who provide investment management services to the Fund. They also reviewed the amount of non-Fund assets managed by the portfolio managers of the Fund. The Trustees considered the non-investment resources and personnel of PIM involved in PIM's services to the Fund, including PIM's compliance and legal resources and personnel. The Trustees noted the substantial attention and high priority given by PIM's senior management to the Pioneer fund complex. The Trustees considered that PIM supervises and monitors the performance of the Fund's service providers and provides the Fund with personnel (including Fund officers) and other resources that are necessary for the Fund's business management and operations. The Trustees also considered that, as administrator, PIM is responsible for the administration of the Fund's business and other affairs. The Trustees considered the fees paid to PIM for the provision of administration services. Based on these considerations, the Trustees concluded that the nature, extent and quality of services that had been provided by PIM to the Fund were satisfactory and consistent with the terms of the investment advisory agreement. Performance of the Fund In considering the Fund's performance, the Trustees regularly review and discuss throughout the year data prepared by PIM and information comparing the Fund's performance with the performance of its peer group of funds as classified by each of Morningstar, Inc. (Morningstar) and Lipper, and with the performance of the Fund's benchmark index. They also discuss the Fund's performance with PIM on a regular basis. The Trustees' regular reviews and discussions were factored into the Trustees' deliberations concerning the renewal of the advisory agreement. The Trustees indicated that the Fund's performance, when considered in connection with the various other factors, was consistent with the renewal of the investment advisory agreement. Management Fee and Expenses The Trustees considered information showing the fees and expenses of the Fund in comparison to the management fees and expense ratios of its peer group of funds as classified by Morningstar and also to the expense ratios of a peer group of funds selected on the basis of criteria determined by the Independent Trustees for this purpose using data provided by Strategic Insight 78 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 Mutual Fund Research and Consulting, LLC (Strategic Insight), an independent third party. In all quintile rankings referred to below, first quintile is most favorable to the Fund's shareowners. The Trustees considered that the Fund's management fee for the most recent fiscal year was in the third quintile relative to the management fees paid by other funds in its Morningstar peer group for the comparable period. The Trustees also considered the breakpoint in the management fee schedule and the reduced fee rate above a certain asset level. The Trustees considered that the expense ratio of the Fund's Class A shares the most recent fiscal year was in the third quintile relative to its Morningstar peer group and in the third quintile relative its Strategic Insight peer group, in each case for the comparable period. The Trustees considered that the expense ratio of the Fund's Class Y shares for the most recent fiscal year was in the second quintile relative to its Morningstar peer group and in the second quintile relative its Strategic Insight peer group, in each case for the comparable period. The Trustees noted that PIM was waiving fees and/or reimbursing expenses in order to limit the ordinary operating expenses of the Fund. The Trustees considered the impact of transfer agency, sub-transfer agency, and other non-management fee expenses on the expense ratios of the Fund. The Trustees noted that they separately review the Fund's transfer agency, sub-transfer agency and intermediary arrangements. The Trustees reviewed management fees charged by Pioneer to institutional and other clients, including publicly offered European funds sponsored by affiliates of Pioneer, unaffiliated U.S. registered investment companies (in a sub-advisory capacity), and unaffiliated foreign and domestic separate accounts. The Trustees also considered PIM's costs in providing services to the Fund and Pioneer's costs in providing services to the other clients and considered the differences in management fees and profit margins for Fund and non-Fund services. In evaluating the fees associated with Pioneer's client accounts, the Trustees took into account the respective demands, resources and complexity associated with the Fund and client accounts. The Trustees noted that, in some instances, the fee rates for those clients were lower than the management fee for the Fund and considered that, under the investment advisory agreement with the Fund, PIM performs additional services for the Fund that it does not provide to those other clients or services that are broader in scope, including oversight of the Fund's other service providers and activities related to compliance and the extensive regulatory and tax regimes to which the Fund is subject. The Trustees also considered the different entrepreneurial risks associated with PIM's management of the Fund and Pioneer's management of the other client accounts. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 79 The Trustees concluded that the management fee payable by the Fund to PIM was reasonable in relation to the nature and quality of the services provided by PIM to the Fund. Profitability The Trustees considered information provided by PIM regarding the profitability of PIM with respect to the advisory services provided by PIM to the Fund, including the methodology used by PIM in allocating certain of its costs to the management of the Fund. The Trustees also considered PIM's profit margin in connection with the overall operation of the Fund. They further reviewed the financial results realized by PIM and its affiliates from non-fund businesses. The Trustees considered PIM's profit margins with respect to the Fund in comparison to the limited industry data available and noted that the profitability of any adviser was affected by numerous factors, including its organizational structure and method for allocating expenses. The Trustees concluded that PIM's profitability with respect to the management of the Fund was not unreasonable. Economies of Scale The Trustees considered PIM's views relating to economies of scale in connection with the Pioneer Funds as fund assets grow and the extent to which any such economies of scale are shared with funds and fund shareholders. The Trustees noted the breakpoint in the management fee schedule. The Trustees recognize that economies of scale are difficult to identify and quantify, and that, among other factors that may be relevant, are the following: fee levels, expense subsidization, investment by PIM in research and analytical capabilities and PIM's commitment and resource allocation to the Fund. The Trustees noted that profitability also may be an indicator of the availability of any economies of scale, although profitability may vary for other reasons including reductions in expenses. The Trustees concluded that economies of scale, if any, were being appropriately shared with the Funds. Other Benefits The Trustees considered the other benefits to PIM from its relationship with the Fund. The Trustees considered the character and amount of fees paid by the Fund, other than under the investment advisory agreement, for services provided by PIM and its affiliates. The Trustees further considered the revenues and profitability of PIM's businesses other than the fund business. Pioneer is the principal U.S. asset management business of Pioneer Global Asset Management, the worldwide asset management business of UniCredit Group, which manages over $150 billion in assets (including the Funds). Pioneer and the Funds receive reciprocal intangible benefits from the relationship, including mutual brand recognition and, for the Funds, direct 80 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 and indirect access to the resources of a large global asset manager. The Trustees concluded that any such benefits received by Pioneer as a result of its relationship with the Funds were reasonable and their consideration of the advisory agreement between the Fund and PIM and the fees thereunder were unaffected by Pioneer's possible receipt of any such intangible benefits. Conclusion After consideration of the factors described above as well as other factors, the Trustees, including all of the Independent Trustees, concluded that the investment advisory agreement between PIM and the Fund, including the fees payable thereunder, was fair and reasonable and voted to approve the proposed renewal of the investment advisory agreement for the Fund. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 81 Trustees, Officers and Service Providers Trustees Advisory Trustee Thomas J. Perna, Chairman Lorraine H. Monchak* David R. Bock Benjamin M. Friedman Officers Margaret B.W. Graham Lisa M. Jones, President and Chief Marguerite A. Piret Executive Officer Fred J. Ricciardi Mark E. Bradley, Treasurer and Kenneth J. Taubes Chief Financial Officer Christopher J. Kelley, Secretary and Chief Legal Officer Investment Adviser and Administrator Pioneer Investment Management, Inc. Custodian and Sub-Administrator Brown Brothers Harriman & Co. Principal Underwriter Pioneer Funds Distributor, Inc. Legal Counsel Morgan, Lewis & Bockius LLP Transfer Agent Boston Financial Data Services, Inc. Proxy Voting Policies and Procedures of the Fund are available without charge, upon request, by calling our toll free number (1-800-225-6292). Information regarding how the Fund voted proxies relating to portfolio securities during the most recent 12-month period ended June 30 is publicly available to shareowners at us.pioneerinvestments.com. This information is also available on the Securities and Exchange Commission's web site at www.sec.gov. * Ms. Monchak is a non-voting Advisory Trustee. 82 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 This page for your notes. Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 83 This page for your notes. 84 Pioneer Dynamic Credit Fund | Semiannual Report | 9/30/15 How to Contact Pioneer We are pleased to offer a variety of convenient ways for you to contact us for assistance or information. Call us for: -------------------------------------------------------------------------------- Account Information, including existing accounts, new accounts, prospectuses, applications and service forms 1-800-225-6292 FactFone(SM) for automated fund yields, prices, account information and transactions 1-800-225-4321 Retirement plans information 1-800-622-0176 Write to us: -------------------------------------------------------------------------------- PIMSS, Inc. P.O. Box 55014 Boston, Massachusetts 02205-5014 Our toll-free fax 1-800-225-4240 Our internet e-mail address ask.pioneer@pioneerinvestments.com (for general questions about Pioneer only) Visit our web site: us.pioneerinvestments.com This report must be preceded or accompanied by a prospectus. The Fund files a complete schedule of investments with the Securities and Exchange Commission for the first and third quarters for each fiscal year on Form N-Q. Shareholders may view the filed Form N-Q by visiting the Commission's web site at www.sec.gov. The filed form may also be viewed and copied at the Commission's Public Reference Room in Washington, DC. Information regarding the operations of the Public Reference Room may be obtained by calling 1-800-SEC-0330. [LOGO] PIONEER Investments(R) Pioneer Investment Management, Inc. 60 State Street Boston, MA 02109 us.pioneerinvestments.com Securities offered through Pioneer Funds Distributor, Inc. 60 State Street, Boston, MA 02109 Underwriter of Pioneer Mutual Funds, Member SIPC (C) 2015 Pioneer Investments 25266-04-1115 Pioneer Fundamental Growth Fund -------------------------------------------------------------------------------- Semiannual Report | September 30, 2015 -------------------------------------------------------------------------------- Ticker Symbols: Class A PIGFX Class C FUNCX Class K PFGKX Class R PFGRX Class Y FUNYX [LOGO] PIONEER Investments(R) visit us: us.pioneerinvestments.com Table of Contents President's Letter 2 Portfolio Management Discussion 4 Portfolio Summary 9 Prices and Distributions 10 Performance Update 11 Comparing Ongoing Fund Expenses 16 Schedule of Investments 18 Financial Statements 22 Notes to Financial Statements 31 Approval of Investment Advisory Agreement 39 Trustees, Officers and Service Providers 44 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 1 President's Letter Dear Shareholder, Through the first three quarters of 2015, global markets experienced pockets of higher-than-average volatility due to significant cross-currents from different geographic regions. All year, investors focused on the Federal Reserve System's (the Fed's) deliberations over when to begin normalizing interest rates. However, while there were signs of gradual economic improvement in the U.S., economies abroad increasingly diverged. In June, for example, investors grew concerned about the debt crisis in Greece. That news, in turn, was followed by evidence of an economic slowdown in China, which only served to exacerbate existing worries about growth trends in the emerging markets, a segment of the global economy already being negatively impacted by slumping commodity prices, including the price of crude oil, which has been in near-steady decline for almost a year. Through September 30, 2015, the pockets of heightened market volatility alluded to above had resulted in the Standard & Poor's 500 Index turning in a negative (-5.27%) return over the first nine months of the year. However, the S&P 500 recovered nicely in October, returning 8.43% for the month, which boosted the index's year-to-date return into positive territory, at 2.71%. Despite the headwinds still vexing the global economy, our longer-term view of the U.S. economy has remained positive. Economic conditions in the U.S. have generally been constructive, based largely on improvements in employment statistics and an uptick in the housing sector, which has aided the consumer side of the economy, where household spending has been rising modestly. U.S. consumers also stand to benefit, potentially, from lower energy prices as the winter weather approaches. We continue to believe the U.S. economy remains on a slow, steady growth trend, and that it is unlikely to be disrupted by a slow pace of interest-rate normalization by the Fed. Pioneer Investments believes that investors in today's environment can potentially benefit from the consistent and disciplined investment approach we have used since our founding in 1928. We focus on identifying value across global markets using proprietary research, careful risk management, and a long-term perspective. Our ongoing goal is to produce compelling returns consistent with the stated objectives of our investment products, and with our shareowners' expectations. We believe our shareowners can benefit from the experience and tenure of our investment teams as well as the insights generated from our extensive research process. 2 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 As always, and particularly during times of market uncertainty, we encourage you to work with your financial advisor to develop an overall investment plan that addresses both your short- and long-term goals, and to implement such a plan in a disciplined manner. We greatly appreciate your trust in us in the past and look forward to continuing to serve you in the future. Sincerely, /s/ Lisa M. Jones Lisa M. Jones President and CEO Pioneer Investment Management USA Inc. November 2, 2015 Any information in this shareowner report regarding market or economic trends or the factors influencing the Fund's historical or future performance are statements of opinion as of the date of this report. These statements should not be relied upon for any other purposes. Past performance is no guarantee of future results, and there is no guarantee that market forecasts discussed will be realized. Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 3 Portfolio Management Discussion | 9/30/15 The U.S stock market grew volatile in the latter weeks of the six-month period ended September 30, 2015, as investors became concerned about the possibility that weakness in the global economy could become a drag on the domestic economy. Led by sharp declines in energy, materials and industrials stocks, most stock market averages declined for the full six-month period. In the following interview, Andrew Acheson and Paul Cloonan discuss the factors that affected the performance of Pioneer Fundamental Growth Fund during the six months. Mr. Acheson and Mr. Cloonan, both senior vice presidents and portfolio managers at Pioneer, are responsible for the day-to-day management of the Fund. Q How did the Fund perform during the six-month period ended September 30, 2015? A Pioneer Fundamental Growth Fund's Class A shares returned -3.31% at net asset value during the six-month period ended September 30, 2015, while the Fund's benchmark, the Russell 1000 Growth Index (the Russell index), returned -5.18%. During the same period, the average return of the 686 mutual funds in Lipper's Large Cap Growth Funds category was -5.71%, and the average return of the 1,716 mutual funds in Morningstar's Large Growth Funds category was -6.23%. Q How would you describe the investment environment for domestic stocks during the six-month period ended September 30, 2015? A The backdrop for investing in U.S. stocks remained favorable as the period began in April 2015, with most sectors continuing to appreciate. However, growing concerns among investors that market volatility could increase led to a sharp correction in equity prices, beginning in August, when stock market indices began tumbling. The initial catalyst for the change in the market's direction was the announcement by the Chinese government that it was devaluing the Chinese currency, the yuan. While the announcement itself might not have been considered very significant, it proved to have a more major impact on world markets, including the U.S. market, for several reasons. First of all, it marked the first change in the value of the yuan outside of its trading band on world currency markets in several years, and it triggered a wider re-appraisal of the relative values of assets. Second, it accelerated the pace of declines in the values of the already devaluating currencies of many Latin American and Asian countries. Third, together with falling prices of 4 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 commodities, most notably oil and raw materials, the yuan devaluation raised concerns that commodity-dependent countries and industries would have less access to the credit and equity markets. Close on the heels of the Chinese announcement, the Greek sovereign-debt problem re-surfaced and once again focused attention on economic conditions in Europe. Although the European economy had appeared to be improving, concerns grew about how Germany and other exporting nations would be affected by weakening demand from China and the emerging markets. The U.S. economy appeared to be the strongest over the period, as gross domestic product (GDP) growth had accelerated to an annual 3.7% rate in the second calendar quarter. In addition, steady new-job creation and a reviving housing industry led to growing consumer confidence, which particularly benefited domestically oriented companies. However, the energy and materials sectors felt the effects of falling commodity prices. That, in turn, weakened demand in the industrials sector. Problems in those sectors, combined with fears of potential contagion effects of the global economic weakening on the United States, led to the increased volatility in the domestic equity market. The consumer discretionary sector, which is more oriented to domestic than to global economic issues, was the only Russell Index sector to produce positive results for the six-month period. All other sectors in the Russell Index posted negative returns, with energy, materials and industrials stocks the weakest performers. Q What were the principal factors affecting the Fund's performance relative to the benchmark Russell Index during the six-month period ended September 30, 2015? A The Fund's absolute return was negative over the period, which was disappointing, but benchmark-relative returns were positive. The Fund's benchmark-relative outperformance was driven by stock selection, which was strong in every sector versus the Russell Index. Sector allocation results, on the other hand, were a negative factor in the Fund's benchmark-relative performance, but not enough to offset the positive effects of security selection. Our traditional emphasis on allocating the portfolio's assets among stocks of what we view as higher-quality companies with strong balance sheets and sustainable business models proved to be an advantage for the Fund during a difficult period for equities in general. That was especially true in the latter months of the six-month period, when the market became more volatile and increasing numbers of investors sought out higher-quality equities. Stock selection results relative to the benchmark were particularly good for the Fund in the consumer discretionary and information technology sectors. In consumer discretionary, the top-performing holding in the Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 5 portfolio was coffee chain Starbucks. Although it has become a global company, Starbucks remains most heavily dependent on the domestic economy, where it has successfully grown its same-shop revenues as it has expanded both its beverage and food offerings. In information technology, two strong performers in the portfolio during the period were software company Microsoft and financial transaction processor MasterCard. Microsoft, after performing poorly early in 2015, rebounded as investors were buoyed by the belief that the company's new Windows 10 computer operating system would help it recover from the lingering effects of the disappointing Windows 8 system rollout. MasterCard, a high-quality company with predictable growth dynamics, produced solid performance over the six-month period as it benefited from the increased use of credit- and debit-card transactions in place of check- writing and cash transactions. Among other sectors, while the last six months were a weak period for most industrials stocks, the Fund's position in Precision Castparts performed well as the company's share price regained some of its lost value, a turnaround owing in part to its pending acquisition by Berkshire Hathaway, the firm headed by renowned investor Warren Buffet. Also, the Fund's position in tobacco company Reynolds American, a relatively recent addition to the portfolio in the consumer staples sector, produced strong results over the period. We had initiated a position in Reynolds American even before it had completed its acquisition of Lorillard, another tobacco company that was an existing Fund holding. We think the tobacco industry as a whole has stabilized after experiencing some sales declines and we feel that consolidation within the group will lead to greater efficiencies and increased pricing power. On the negative side, with the exception of Precision Castparts, several of the Fund's other holdings in the industrials sector were notable detractors from benchmark-relative performance during the period, including shares of United Technologies, 3M and Cummins. All three companies saw demand for their products slow because of slumping global economic activity. The effects were exacerbated by the weakening currencies of many emerging markets nations, which eroded the value of the companies' sales in those countries. In addition, while the Fund's overall selection results in the information technology sector were positive over the six months, the portfolio's position in Qualcomm proved to be a noteworthy exception, as the company's semiconductor chip design business felt the effects of increased competition and greater pricing pressures. In consumer discretionary, despite good overall benchmark-relative performance in the sector, the Fund's position in media company Time Warner was a detractor from relative returns. As new competition for advertising spending surfaced 6 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 from internet-based content providers and social media websites, investors became concerned about the effects those new advertising options would have on the revenues of traditional media platforms like Time Warner's. However, we believe the trends have been evolving over a period of years, which has afforded companies such as Time Warner time to adapt. Meanwhile, Time Warner's media content properties, including Warner Brothers Studios and its sports networks, are proving to be highly successful. Q What noteworthy changes did you make in the Fund's portfolio during the six-month period ended September 30, 2015? A The most notable change was our decision in September to liquidate the Fund's position in Praxair, a materials company specializing in producing gases for industrial uses. The company's performance was hurt by its emerging markets exposure, particularly in Brazil, where the economy has entered into a severe recession. Q Did the Fund have any exposure to derivative securities during the six- month period ended September 30, 2015? A No, the Fund had no investments in any derivative securities during the period. Q What is your investment outlook? A While the domestic equity market has entered a more volatile period -- which we predicted in the Fund's last report six months ago -- we think there remains the potential for equities to produce positive results over the next 12 months, despite the many uncertainties which exist. We believe diverging monetary policies of central banks around the globe -- that is, expected tightening actions by the U.S. Federal Reserve System while other central banks are becoming more accommodative -- are likely to create more imbalances in world currency markets. In the wake of the market correction that began in August, most investors have become more bearish and have positioned their portfolios somewhat defensively in order to protect against the possibility that the global economic slowdown may lead to less growth in the United States. Despite the obvious dangers presented by slowing growth in China and the emerging markets in general, mounting credit problems in Brazil and threats of economic disruption because of violence in the Middle East, we think investors have become too pessimistic. We believe threats to the Chinese economy have been overstated, and that prospects for a re-acceleration of economic growth in China have improved. Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 7 Domestically, corporate earnings growth is relatively low, in part because of the challenges faced by companies selling to overseas markets. However, U.S. growth trends, including improvements in new-job creation and a reviving housing industry, appear sustainable, and we believe the economic expansion will continue. While cheaper commodity prices may have hurt companies in some sectors, like energy, they can have a beneficial impact on consumer spending while also lending support to the profit margins of companies in other sectors by lowering their energy and input costs. We continue to believe that our traditional emphasis on purchasing shares of what we view as higher-quality, financially strong companies has the Fund's portfolio well positioned for an uncertain, volatile market environment. As always, we have emphasized owning companies with solid balance sheets and the ability to generate sustained, high returns on incremental capital. We think these types of investments are especially well suited for periods of market stress. Please refer to the Schedule of Investments on pages 18-21 for a full listing of Fund securities. Investing in foreign and/or emerging markets securities involves risks relating to interest rates, currency exchange rates, economic, and political conditions. The Fund invests in a limited number of securities and, as a result, the Fund's performance may be more volatile than the performance of other funds holding more securities. At times, the Fund's investments may represent industries or industry sectors that are interrelated or have common risks, making the Fund more susceptible to any economic, political, or regulatory developments or other risks affecting those industries and sectors. These risks may increase share price volatility. Before investing, consider the product's investment objectives, risks, charges and expenses. Contact your advisor or Pioneer Investments for a prospectus or summary prospectus containing this information. Read it carefully. Any information in this shareholder report regarding market or economic trends or the factors influencing the Fund's historical or future performance are statements of opinion as of the date of this report. Past performance is no guarantee of future results. 8 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 Portfolio Summary | 9/30/15 Portfolio Diversification -------------------------------------------------------------------------------- (As a percentage of total investment portfolio) [THE FOLLOWING DATA WAS REPRESENTED AS A PIE CHART IN THE PRINTED MATERIAL] U.S. Common Stocks 97.2% International Common Stocks 2.8% Sector Distribution -------------------------------------------------------------------------------- (As a percentage of equity holdings) [THE FOLLOWING DATA WAS REPRESENTED AS A PIE CHART IN THE PRINTED MATERIAL] Information Technology 26.8% Consumer Discretionary 20.2% Health Care 19.9% Consumer Staples 13.4% Industrials 9.5% Materials 4.0% Financials 3.3% Energy 2.9% 10 Largest Holdings -------------------------------------------------------------------------------- (As a percentage of equity holdings)* 1. Apple, Inc. 5.84% -------------------------------------------------------------------------------- 2. Microsoft Corp. 4.78 -------------------------------------------------------------------------------- 3. MasterCard, Inc. 4.49 -------------------------------------------------------------------------------- 4. The Home Depot, Inc. 4.26 -------------------------------------------------------------------------------- 5. CVS Health Corp. 3.95 -------------------------------------------------------------------------------- 6. Gilead Sciences, Inc. 3.74 -------------------------------------------------------------------------------- 7. The Walt Disney Co. 3.73 -------------------------------------------------------------------------------- 8. Starbucks Corp. 3.67 -------------------------------------------------------------------------------- 9. Celgene Corp. 3.58 -------------------------------------------------------------------------------- 10. Thermo Fisher Scientific, Inc. 3.30 -------------------------------------------------------------------------------- * This list excludes temporary cash investments and derivative instruments. The portfolio is actively managed, and current holdings may be different. The holdings listed should not be considered recommendations to buy or sell any securities listed. Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 9 Prices and Distributions | 9/30/15 Net Asset Value per Share -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- Class 9/30/15 3/31/15 -------------------------------------------------------------------------------- A $18.43 $19.06 -------------------------------------------------------------------------------- C $17.16 $17.81 -------------------------------------------------------------------------------- K $18.46 $19.05 -------------------------------------------------------------------------------- R $18.21 $18.86 -------------------------------------------------------------------------------- Y $18.59 $19.20 -------------------------------------------------------------------------------- Distributions per Share: 4/1/15-9/30/15 -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- Short-Term Long-Term Class Dividends Capital Gains Capital Gains -------------------------------------------------------------------------------- A $- $- $- -------------------------------------------------------------------------------- C $- $- $- -------------------------------------------------------------------------------- K $- $- $- -------------------------------------------------------------------------------- R $- $- $- -------------------------------------------------------------------------------- Y $- $- $- -------------------------------------------------------------------------------- The Russell 1000 Growth Index is an unmanaged index that measures the performance of large-cap U.S. growth stocks. Index returns assume reinvestment of dividends and, unlike Fund returns, do not reflect any fees, expenses or sales charges. It is not possible to invest directly in an index. The index defined here pertains to the "Value of $10,000 Investment" and "Value of $5 Million Investment" charts on pages 11-15. 10 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 Performance Update | 9/30/15 Class A Shares Investment Returns -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $10,000 investment made in Class A shares of Pioneer Fundamental Growth Fund at public offering price during the periods shown, compared to that of the Russell 1000 Growth Index. Average Annual Total Returns (As of September 30, 2015) -------------------------------------------------------------------------------- Net Public Russell Asset Offering 1000 Value Price Growth Period (NAV) (POP) Index -------------------------------------------------------------------------------- 10 Years 8.36% 7.72% 8.09% -------------------------------------------------------------------------------- 5 Years 14.77 13.42 14.47 -------------------------------------------------------------------------------- 1 Year 5.31 -0.76 3.17% -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated August 1, 2015) -------------------------------------------------------------------------------- Gross Net -------------------------------------------------------------------------------- 1.13% 1.09% -------------------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment Pioneer Fundamental Russell 1000 Growth Fund Growth Index 9/05 $ 9,425 $10,000 9/06 $ 9,854 $10,604 9/07 $11,474 $12,656 9/08 $ 9,677 $10,013 9/09 $ 9,738 $ 9,828 9/10 $10,567 $11,071 9/11 $11,138 $11,490 9/12 $14,352 $14,843 9/13 $16,712 $17,704 9/14 $19,982 $21,094 9/15 $21,043 $21,764 Call 1-800-225-6292 or visit us.pioneerinvestments.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. NAV results represent the percent change in net asset value per share. Returns would have been lower had sales charges been reflected. POP returns reflect deduction of maximum 5.75% sales charge. All results are historical and assume the reinvestment of dividends and capital gains. Other share classes are available for which performance and expenses will differ. Performance results reflect any applicable expense waivers in effect during the periods shown. Without such waivers Fund performance would be lower. Waivers may not be in effect for all funds. Certain fee waivers are contractual through a specified period. Otherwise, fee waivers can be rescinded at any time. See the prospectus and financial statements for more information. The net expense ratio reflects the contractual expense limitation currently in effect through August 1, 2016, for Class A shares. There can be no assurance that Pioneer will extend the expense limitation beyond such time. Please see the prospectus and financial statements for more information. The performance table and graph do not reflect the deduction of fees and taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 11 Performance Update | 9/30/15 Class C Shares Investment Returns -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $10,000 investment made in Class C shares of Pioneer Fundamental Growth Fund during the periods shown, compared to that of the Russell 1000 Growth Index. Average Annual Total Returns (As of September 30, 2015) -------------------------------------------------------------------------------- Russell 1000 If If Growth Period Held Redeemed Index -------------------------------------------------------------------------------- Life-of-Class 12/15/2005 7.44% 7.44% 7.72% 5 Years 13.92 13.92 14.47 1 Year 4.60 4.60 3.17 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated August 1, 2015) -------------------------------------------------------------------------------- Gross -------------------------------------------------------------------------------- 1.79% -------------------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment Pioneer Fundamental Russell 1000 Growth Fund Growth Index 12/05 $10,000 $10,000 9/06 $10,331 $10,297 9/07 $11,936 $12,290 9/08 $ 9,978 $ 9,724 9/09 $ 9,963 $ 9,544 9/10 $10,719 $10,751 9/11 $11,217 $11,158 9/12 $14,335 $14,414 9/13 $16,572 $17,192 9/14 $19,665 $20,484 9/15 $20,569 $21,134 Call 1-800-225-6292 or visit us.pioneerinvestments.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. Class C shares held for less than one year are also subject to a 1% contingent deferred sales charge (CDSC). "If Held" results represent the percent change in net asset value per share. Returns would have been lower had sales charges been reflected. All results are historical and assume the reinvestment of dividends and capital gains. Other share classes are available for which performance and expenses will differ. Performance results reflect any applicable expense waivers in effect during the periods shown. Without such waivers Fund performance would be lower. Waivers may not be in effect for all funds. Certain fee waivers are contractual through a specified period. Otherwise, fee waivers can be rescinded at any time. See the prospectus and financial statements for more information. The performance table and graph do not reflect the deduction of fees and taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. 12 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 Performance Update | 9/30/15 Class K Shares Investment Returns -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $10,000 investment made in Class K shares of Pioneer Fundamental Growth Fund during the periods shown, compared to that of the Russell 1000 Growth Index. Average Annual Total Returns (As of September 30, 2015) -------------------------------------------------------------------------------- Net Russell Asset 1000 Value Growth Period (NAV) Index -------------------------------------------------------------------------------- 10 Years 8.49% 8.09% 5 Years 15.03 14.47 1 Year 5.81 3.17 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated August 1, 2015) -------------------------------------------------------------------------------- Gross -------------------------------------------------------------------------------- 0.69% -------------------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment Pioneer Fundamental Russell 1000 Growth Fund Growth Index 9/05 $10,000 $10,000 9/06 $10,453 $10,604 9/07 $12,172 $12,656 9/08 $10,266 $10,013 9/09 $10,330 $ 9,828 9/10 $11,210 $11,071 9/11 $11,816 $11,490 9/12 $15,225 $14,843 9/13 $17,789 $17,704 9/14 $21,342 $21,094 9/15 $22,581 $21,764 Call 1-800-225-6292 or visit us.pioneerinvestments.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. The performance shown for Class K shares for the period prior to the commencement of operations of Class K shares on December 20, 2012, is the net asset value performance of the Fund's Class A shares, which has not been restated to reflect any differences in expenses, including Rule 12b-1 fees applicable to Class A shares. Since fees for Class A shares generally are higher than those of Class K shares, the performance of Class K shares prior to their inception would have been higher than the performance shown. For the period beginning December 20, 2012, the actual performance of Class K shares is reflected. Class K shares are not subject to sales charges and are available for limited groups of eligible investors, including institutional investors. All results are historical and assume the reinvestment of dividends and capital gains. Other share classes are available for which performance and expenses will differ. Performance results reflect any applicable expense waivers in effect during the periods shown. Without such waivers Fund performance would be lower. Waivers may not be in effect for all funds. Certain fee waivers are contractual through a specified period. Otherwise, fee waivers can be rescinded at any time. See the prospectus and financial statements for more information. The performance table and graph do not reflect the deduction of fees and taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 13 Performance Update | 9/30/15 Class R Shares Investment Returns -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $10,000 investment made in Class R shares of Pioneer Fundamental Growth Fund during the periods shown, compared to that of the Russell 1000 Growth Index. Average Annual Total Returns (As of September 30, 2015) -------------------------------------------------------------------------------- Net Russell Asset 1000 Value Growth Period (NAV) Index -------------------------------------------------------------------------------- 10 Years 8.25% 8.09% 5 Years 14.54 14.47 1 Year 4.98 3.17 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated August 1, 2015) -------------------------------------------------------------------------------- Gross Net -------------------------------------------------------------------------------- 1.52% 1.40% -------------------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment Pioneer Fundamental Russell 1000 Growth Fund Growth Index 9/05 $10,000 $10,000 9/06 $10,453 $10,604 9/07 $12,172 $12,656 9/08 $10,266 $10,013 9/09 $10,330 $ 9,828 9/10 $11,210 $11,071 9/11 $11,816 $11,490 9/12 $15,202 $14,843 9/13 $17,651 $17,704 9/14 $21,047 $21,094 9/15 $22,096 $21,764 Call 1-800-225-6292 or visit us.pioneerinvestments.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. The performance shown for Class R shares for the period prior to the commencement of operations of Class R shares on April 2, 2012, is based on the performance of Class A shares, reduced to reflect the higher distribution and service fees of Class R shares. For the period beginning April 2, 2012, the actual performance of Class R shares is reflected. Class R shares are not subject to sales charges and are available for limited groups of eligible investors, including institutional investors. All results are historical and assume the reinvestment of dividends and capital gains. Other share classes are available for which performance and expenses will differ. Performance results reflect any applicable expense waivers in effect during the periods shown. Without such waivers Fund performance would be lower. Waivers may not be in effect for all funds. Certain fee waivers are contractual through a specified period. Otherwise, fee waivers can be rescinded at any time. See the prospectus and financial statements for more information. The net expense ratio reflects the contractual expense limitation currently in effect through August 1, 2016, for Class R shares. There can be no assurance that Pioneer will extend the expense limitation beyond such time. Please see the prospectus and financial statements for more information. The performance table and graph do not reflect the deduction of fees and taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. 14 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 Performance Update | 9/30/15 Class Y Shares Investment Returns -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $5 million investment made in Class Y shares of Pioneer Fundamental Growth Fund during the periods shown, compared to that of the Russell 1000 Growth Index. Average Annual Total Returns (As of September 30, 2015) -------------------------------------------------------------------------------- Net Russell Asset 1000 Value Growth Period (NAV) Index -------------------------------------------------------------------------------- 10 Years 8.61% 8.09% 5 Years 15.17 14.47 1 Year 5.66 3.17 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated August 1, 2015) -------------------------------------------------------------------------------- Gross -------------------------------------------------------------------------------- 0.80% -------------------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $5 Million Investment Pioneer Fundamental Russell 1000 Growth Fund Growth Index 9/05 $ 5,000,000 $ 5,000,000 9/06 $ 5,226,479 $ 5,301,791 9/07 $ 6,085,873 $ 6,327,905 9/08 $ 5,132,803 $ 5,006,740 9/09 $ 5,180,007 $ 4,913,965 9/10 $ 5,635,728 $ 5,535,666 9/11 $ 5,973,980 $ 5,744,825 9/12 $ 7,720,604 $ 7,421,634 9/13 $ 9,014,671 $ 8,852,130 9/14 $10,807,791 $10,547,098 9/15 $11,419,999 $10,881,803 Call 1-800-225-6292 or visit us.pioneerinvestments.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. The performance shown for Class Y shares for the period prior to the commencement of operations of Class Y shares on April 8, 2009, is the net asset value performance of the Fund's Class A shares, which has not been restated to reflect any differences in expenses, including Rule 12b-1 fees applicable to Class A shares. Since fees for Class A shares generally are higher than those of Class Y shares, the performance of Class Y shares prior to their inception would have been higher than the performance shown. For the period beginning April 8, 2009, the actual performance of Class Y shares is reflected. Class Y shares are not subject to sales charges and are available for limited groups of eligible investors, including institutional investors. All results are historical and assume the reinvestment of dividends and capital gains. Other share classes are available for which performance and expenses will differ. Performance results reflect any applicable expense waivers in effect during the periods shown. Without such waivers Fund performance would be lower. Waivers may not be in effect for all funds. Certain fee waivers are contractual through a specified period. Otherwise, fee waivers can be rescinded at any time. See the prospectus and financial statements for more information. The performance table and graph do not reflect the deduction of fees and taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 15 Comparing Ongoing Fund Expenses As a shareowner in the Fund, you incur two types of costs: (1) ongoing costs, including management fees, distribution and/or service (12b-1) fees, and other Fund expenses; and (2) transaction costs, including sales charges (loads) on purchase payments. This example is intended to help you understand your ongoing expenses (in dollars) of investing in the Fund and to compare these costs with the ongoing costs of investing in other mutual funds. The example is based on an investment of $1,000 at the beginning of the Fund's latest six-month period and held throughout the six months. Using the Tables -------------------------------------------------------------------------------- Actual Expenses The first table below provides information about actual account values and actual expenses. You may use the information in this table, together with the amount you invested, to estimate the expenses that you paid over the period as follows: (1) Divide your account value by $1,000 Example: an $8,600 account value (divided by) $1,000 = 8.6 (2) Multiply the result in (1) above by the corresponding share class's number in the third row under the heading entitled "Expenses Paid During Period" to estimate the expenses you paid on your account during this period. Expenses Paid on a $1,000 Investment in Pioneer Fundamental Growth Fund Based on actual returns from April 1, 2015 through September 30, 2015. ---------------------------------------------------------------------------------- Share Class A C K R Y ---------------------------------------------------------------------------------- Beginning Account $1,000.00 $1,000.00 $1,000.00 $1,000.00 $ 1,000.00 Value on 4/1/15 ---------------------------------------------------------------------------------- Ending Account $ 966.90 $ 963.50 $ 969,00 $ 965.50 $ 968.20 Value (after expenses) on 9/30/15 ---------------------------------------------------------------------------------- Expenses Paid $ 5.37 $ 8.76 $ 3.31 $ 6.90 $ 3.90 During Period* ---------------------------------------------------------------------------------- * Expenses are equal to the Fund's annualized expense ratio of 1.09%, 1.78%, 0.67%, 1.40% and 0.79% for Class A, Class C, Class K, Class R, and Class Y shares, respectively, multiplied by the average account value over the period, multiplied by 183/365 (to reflect the one-half year period). 16 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 Hypothetical Example for Comparison Purposes The table below provides information about hypothetical account values and hypothetical expenses based on the Fund's actual expense ratio and an assumed rate of return of 5% per year before expenses, which is not the Fund's actual return. The hypothetical account values and expenses may not be used to estimate the actual ending account balance or expenses you paid for the period. You may use this information to compare the ongoing costs of investing in the Fund and other funds. To do so, compare this 5% hypothetical example with the 5% hypothetical examples that appear in the shareholder reports of the other funds. Please note that the expenses shown in the tables are meant to highlight your ongoing costs only and do not reflect any transaction costs, such as sales charges (loads) that are charged at the time of the transaction. Therefore, the table below is useful in comparing ongoing costs only and will not help you determine the relative total costs of owning different funds. In addition, if these transaction costs were included, your costs would have been higher. Expenses Paid on a $1,000 Investment in Pioneer Fundamental Growth Fund Based on a hypothetical 5% per year return before expenses, reflecting the period from April 1, 2015 through September 30, 2015. -------------------------------------------------------------------------------- Share Class A C K R Y -------------------------------------------------------------------------------- Beginning Account $1,000.00 $1,000.00 $1,000.00 $1,000.00 $1,000.00 Value on 4/1/15 -------------------------------------------------------------------------------- Ending Account $1,019.60 $1,016.14 $1,021.71 $1,018.05 $1,021.11 Value (after expenses) on 9/30/15 -------------------------------------------------------------------------------- Expenses Paid $ 5.52 $ 9.00 $ 3.40 $ 7.08 $ 4.00 During Period* -------------------------------------------------------------------------------- * Expenses are equal to the Fund's annualized expense ratio of 1.09%, 1.78%, 0.67%, 1.40% and 0.79% for Class A, Class C, Class K, Class R, and Class Y shares, respectively, multiplied by the average account value over the period, multiplied by 183/365 (to reflect the one-half year period). Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 17 Schedule of Investments | 9/30/15 (unaudited) ------------------------------------------------------------------------------------------- Shares Value ------------------------------------------------------------------------------------------- COMMON STOCKS -- 97.7% ENERGY -- 2.9% Oil & Gas Equipment & Services -- 2.0% 768,958 Schlumberger, Ltd. $ 53,035,033 ------------------------------------------------------------------------------------------- Oil & Gas Exploration & Production -- 0.9% 1,138,729 Cabot Oil & Gas Corp. $ 24,892,616 -------------- Total Energy $ 77,927,649 ------------------------------------------------------------------------------------------- MATERIALS -- 4.0% Fertilizers & Agricultural Chemicals -- 0.9% 266,484 Monsanto Co. $ 22,741,745 ------------------------------------------------------------------------------------------- Specialty Chemicals -- 3.1% 445,828 Ecolab, Inc. $ 48,916,248 324,450 International Flavors & Fragrances, Inc. 33,502,707 -------------- $ 82,418,955 -------------- Total Materials $ 105,160,700 ------------------------------------------------------------------------------------------- CAPITAL GOODS -- 7.7% Aerospace & Defense -- 3.3% 200,049 Precision Castparts Corp. $ 45,953,256 473,145 United Technologies Corp. 42,105,174 -------------- $ 88,058,430 ------------------------------------------------------------------------------------------- Industrial Conglomerates -- 3.1% 590,639 3M Co. $ 83,734,891 ------------------------------------------------------------------------------------------- Construction & Farm Machinery & Heavy Trucks -- 1.3% 311,747 Cummins, Inc. $ 33,849,489 -------------- Total Capital Goods $ 205,642,810 ------------------------------------------------------------------------------------------- TRANSPORTATION -- 1.6% Air Freight & Logistics -- 1.6% 442,906 United Parcel Service, Inc. (Class B) $ 43,710,393 -------------- Total Transportation $ 43,710,393 ------------------------------------------------------------------------------------------- CONSUMER DURABLES & APPAREL -- 1.6% Footwear -- 1.6% 351,993 NIKE, Inc. (Class B) $ 43,284,579 -------------- Total Consumer Durables & Apparel $ 43,284,579 ------------------------------------------------------------------------------------------- CONSUMER SERVICES -- 3.6% Restaurants -- 3.6% 1,677,171 Starbucks Corp. $ 95,330,400 -------------- Total Consumer Services $ 95,330,400 ------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 18 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 ------------------------------------------------------------------------------------------- Shares Value ------------------------------------------------------------------------------------------- MEDIA -- 6.0% Movies & Entertainment -- 6.0% 947,201 The Walt Disney Co. $ 96,803,942 907,471 Time Warner, Inc. 62,388,631 -------------- $ 159,192,573 -------------- Total Media $ 159,192,573 ------------------------------------------------------------------------------------------- RETAILING -- 8.6% Apparel Retail -- 2.7% 1,464,786 Ross Stores, Inc. $ 70,998,177 ------------------------------------------------------------------------------------------- Home Improvement Retail -- 4.1% 957,886 The Home Depot, Inc. $ 110,626,254 ------------------------------------------------------------------------------------------- Automotive Retail -- 1.8% 191,376 O'Reilly Automotive, Inc.* $ 47,844,000 -------------- Total Retailing $ 229,468,431 ------------------------------------------------------------------------------------------- FOOD & STAPLES RETAILING -- 3.9% Drug Retail -- 3.9% 1,062,335 CVS Health Corp. $ 102,494,081 -------------- Total Food & Staples Retailing $ 102,494,081 ------------------------------------------------------------------------------------------- FOOD, BEVERAGE & TOBACCO -- 6.1% Soft Drinks -- 3.2% 889,216 PepsiCo., Inc. $ 83,853,069 ------------------------------------------------------------------------------------------- Tobacco -- 2.9% 1,758,267 Reynolds American, Inc. $ 77,838,480 -------------- Total Food, Beverage & Tobacco $ 161,691,549 ------------------------------------------------------------------------------------------- HOUSEHOLD & PERSONAL PRODUCTS -- 3.2% Household Products -- 2.0% 842,941 Colgate-Palmolive Co. $ 53,493,036 ------------------------------------------------------------------------------------------- Personal Products -- 1.2% 401,046 The Estee Lauder Companies, Inc. $ 32,356,391 -------------- Total Household & Personal Products $ 85,849,427 ------------------------------------------------------------------------------------------- HEALTH CARE EQUIPMENT & SERVICES -- 4.2% Health Care Equipment -- 2.0% 799,011 Medtronic PLC $ 53,485,796 ------------------------------------------------------------------------------------------- Health Care Services -- 2.2% 715,302 Express Scripts Holding Co.* $ 57,910,850 -------------- Total Health Care Equipment & Services $ 111,396,646 ------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 19 Schedule of Investments | 9/30/15 (unaudited) (continued) ------------------------------------------------------------------------------------------- Shares Value ------------------------------------------------------------------------------------------- PHARMACEUTICALS, BIOTECHNOLOGY & LIFE SCIENCES -- 15.3% Biotechnology -- 7.8% 860,327 Celgene Corp.* $ 93,061,572 989,465 Gilead Sciences, Inc.* 97,155,568 158,207 Vertex Pharmaceuticals, Inc.* 16,475,677 -------------- $ 206,692,817 ------------------------------------------------------------------------------------------- Pharmaceuticals -- 4.3% 262,737 Allergan plc $ 71,414,544 453,753 Johnson & Johnson 42,357,843 -------------- $ 113,772,387 ------------------------------------------------------------------------------------------- Life Sciences Tools & Services -- 3.2% 701,062 Thermo Fisher Scientific, Inc. $ 85,725,861 -------------- Total Pharmaceuticals, Biotechnology & Life Sciences $ 406,191,065 ------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 2.8% Specialized Finance -- 2.8% 315,990 Intercontinental Exchange, Inc. $ 74,254,490 -------------- Total Diversified Financials $ 74,254,490 ------------------------------------------------------------------------------------------- SOFTWARE & SERVICES -- 16.2% Internet Software & Services -- 5.7% 120,934 Google, Inc. (Class A)* $ 77,200,638 120,814 Google, Inc. (Class C) 73,505,654 -------------- $ 150,706,292 ------------------------------------------------------------------------------------------- IT Consulting & Other Services -- 1.4% 607,565 Cognizant Technology Solutions Corp.* $ 38,039,645 ------------------------------------------------------------------------------------------- Data Processing & Outsourced Services -- 4.4% 1,294,752 MasterCard, Inc. $ 116,683,050 ------------------------------------------------------------------------------------------- Systems Software -- 4.7% 2,808,063 Microsoft Corp. $ 124,284,868 -------------- Total Software & Services $ 429,713,855 ------------------------------------------------------------------------------------------- TECHNOLOGY HARDWARE & EQUIPMENT -- 8.9% Communications Equipment -- 1.3% 644,702 Qualcomm, Inc. $ 34,639,838 ------------------------------------------------------------------------------------------- Computer Storage & Peripherals -- 7.6% 1,374,645 Apple, Inc. $ 151,623,344 2,135,644 EMC Corp. 51,597,159 -------------- $ 203,220,503 -------------- Total Technology Hardware & Equipment $ 237,860,341 ------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 20 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 ------------------------------------------------------------------------------------------- Shares Value ------------------------------------------------------------------------------------------- SEMICONDUCTORS & SEMICONDUCTOR EQUIPMENT -- 1.1% Semiconductors -- 1.1% 509,847 Analog Devices, Inc. $ 28,760,470 -------------- Total Semiconductors & Semiconductor Equipment $ 28,760,470 ------------------------------------------------------------------------------------------- TOTAL COMMON STOCKS (Cost $2,080,215,634) $2,597,929,459 ------------------------------------------------------------------------------------------- TOTAL INVESTMENT IN SECURITIES -- 97.7% (Cost $2,080,215,634) (a) $2,597,929,459 ------------------------------------------------------------------------------------------- OTHER ASSETS & LIABILITIES -- 2.3% $ 61,278,887 ------------------------------------------------------------------------------------------- TOTAL NET ASSETS -- 100.0% $2,659,208,346 =========================================================================================== * Non-income producing security. (a) At September 30, 2015, the net unrealized appreciation on investments based on cost for federal income tax purposes of $2,081,794,080 was as follows: Aggregate gross unrealized appreciation for all investments in which there is an excess of value over tax cost $ 574,683,609 Aggregate gross unrealized depreciation for all investments in which there is an excess of tax cost over value (58,548,230) -------------- Net unrealized appreciation $ 516,135,379 ============== Purchases and sales of securities (excluding temporary cash investments) for the six months ended September 30, 2015 aggregated $470,324,820 and $94,487,990, respectively. Various inputs are used in determining the value of the Fund's investments. These inputs are summarized in the three broad levels listed below. Level 1 - quoted prices in active markets for identical securities. Level 2 - other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk, etc.) See Notes to Financial Statements -- Note 1A. Level 3 - significant unobservable inputs (including the Fund's own assumptions in determining fair value of investments) See Notes to Financial Statements -- Note 1A. The following is a summary of the inputs used as of September 30, 2015, in valuing the Fund's investments: -------------------------------------------------------------------------------- Level 1 Level 2 Level 3 Total -------------------------------------------------------------------------------- Common Stocks $2,597,929,459 $-- $-- $2,597,929,459 -------------------------------------------------------------------------------- Total $2,597,929,459 $-- $-- $2,597,929,459 -------------------------------------------------------------------------------- During the six months ended September 30, 2015, there were no transfers between Levels 1, 2 and 3. The accompanying notes are an integral part of these financial statements. Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 21 Statement of Assets and Liabilities | 9/30/15 (unaudited) ASSETS: Investment in securities (cost $2,080,215,634) $2,597,929,459 Cash 82,688,121 Receivables -- Investment securities sold 1,669,995 Fund shares sold 7,300,149 Dividends 2,045,247 Due to Pioneer Investment Management, Inc. 63,017 Other Assets 114,492 -------------------------------------------------------------------------------- Total assets $2,691,810,480 -------------------------------------------------------------------------------- LIABILITIES: Payables -- Investment securities purchased $ 27,293,653 Fund shares repurchased 4,516,159 Due to affiliates 691,405 Accrued expenses 100,917 -------------------------------------------------------------------------------- Total liabilities $ 32,602,134 -------------------------------------------------------------------------------- NET ASSETS: Paid-in capital $2,020,556,950 Undistributed net investment income 9,248,491 Accumulated net realized gain on investments 111,689,080 Net unrealized appreciation on investments 517,713,825 -------------------------------------------------------------------------------- Total net assets $2,659,208,346 -------------------------------------------------------------------------------- NET ASSET VALUE PER SHARE: (No par value, unlimited number of shares authorized) Class A (based on $816,533,867/44,309,083 shares) $ 18.43 Class C (based on $264,003,821/15,386,353 shares) $ 17.16 Class K (based on $104,266,242/5,648,697 shares) $ 18.46 Class R (based on $45,590,012/2,503,562 shares) $ 18.21 Class Y (based on $1,428,814,404/76,864,815 shares) $ 18.59 MAXIMUM OFFERING PRICE: Class A ($18.43 (divided by) 94.25%) $ 19.55 ================================================================================ The accompanying notes are an integral part of these financial statements. 22 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 Statement of Operations (unaudited) For the Six Months Ended 9/30/15 INVESTMENT INCOME: Dividends $ 19,519,232 Interest 12,269 -------------------------------------------------------------------------------------------------- Total investment income $ 19,531,501 -------------------------------------------------------------------------------------------------- EXPENSES: Management fees $ 8,203,058 Transfer agent fees Class A 132,659 Class C 22,546 Class K 27 Class R 5,381 Class Y 5,246 Class Z* 251 Distribution fees Class A 1,034,797 Class C 1,312,390 Class R 104,406 Shareholder communications expense 1,715,420 Administrative expense 387,042 Custodian fees 16,092 Registration fees 73,563 Professional fees 56,386 Printing expense 11,752 Fees and expenses of nonaffiliated Trustees 57,416 Miscellaneous 22,323 -------------------------------------------------------------------------------------------------- Total operating expenses $ 13,160,755 Less fees waived and expenses reimbursed by Pioneer Investment Management, Inc. (86,534) -------------------------------------------------------------------------------------------------- Net operating expenses $ 13,074,221 -------------------------------------------------------------------------------------------------- Net investment income $ 6,457,280 -------------------------------------------------------------------------------------------------- REALIZED AND UNREALIZED GAIN (LOSS) ON INVESTMENTS: Net realized gain on investments $ 14,762,465 Change in net unrealized depreciation on investments $ (116,274,609) -------------------------------------------------------------------------------------------------- Net realized and unrealized loss on investments $ (101,512,144) -------------------------------------------------------------------------------------------------- Net decrease in net assets resulting from operations $ (95,054,864) ================================================================================================== * Class Z shares converted to Class Y shares on August 7, 2015. The accompanying notes are an integral part of these financial statements. Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 23 Statements of Changes in Net Assets ------------------------------------------------------------------------------------------------ Six Months Ended 9/30/15 Year Ended (unaudited) 3/31/15 ------------------------------------------------------------------------------------------------ FROM OPERATIONS: Net investment income $ 6,457,280 $ 9,125,781 Net realized gain on investments 14,762,465 125,298,386 Change in net unrealized appreciation (depreciation) on investments (116,274,609) 181,601,642 ------------------------------------------------------------------------------------------------ Net increase (decrease) in net assets resulting from operations $ (95,054,864) $ 316,025,809 ------------------------------------------------------------------------------------------------ DISTRIBUTIONS TO SHAREOWNERS: Net investment income: Class A ($0.00 and $0.05 per share, respectively) $ -- $ (1,878,797) Class K ($0.00 and $0.12 per share, respectively) -- (269,640) Class Y ($0.00 and $0.10 per share, respectively) -- (5,956,917) Class Z ($0.00 and $0.08 per share, respectively)** -- (11,941) Net realized gain: Class A ($0.00 and $0.47 per share, respectively) -- (17,853,702) Class B ($0.00 and $0.00 per share, respectively)* -- -- Class C ($0.00 and $0.47 per share, respectively) -- (5,512,482) Class K ($0.00 and $0.47 per share, respectively) -- (1,078,395) Class R ($0.00 and $0.47 per share, respectively) -- (835,064) Class Y ($0.00 and $0.47 per share, respectively) -- (26,141,183) Class Z ($0.00 and $0.47 per share, respectively)** -- (65,055) ------------------------------------------------------------------------------------------------ Total distributions to shareowners $ -- $ (59,603,176) ------------------------------------------------------------------------------------------------ FROM FUND SHARE TRANSACTIONS: Net proceeds from sale or exchange of shares $ 605,762,007 $ 991,290,489 Reinvestment of distributions -- 52,453,024 Cost of shares repurchased (296,233,076) (593,937,145) ------------------------------------------------------------------------------------------------ Net increase in net assets resulting from Fund share transactions $ 309,528,931 $ 449,806,368 ------------------------------------------------------------------------------------------------ Net increase in net assets $ 214,474,067 $ 706,229,001 NET ASSETS: Beginning of period 2,444,734,279 1,738,505,278 ------------------------------------------------------------------------------------------------ End of period $ 2,659,208,346 $ 2,444,734,279 ------------------------------------------------------------------------------------------------ Undistributed net investment income $ 9,248,491 $ 2,791,211 ------------------------------------------------------------------------------------------------ * Class B shares converted to Class A shares on November 10, 2014. ** Class Z shares converted to Class Y shares on August 7, 2015. The accompanying notes are an integral part of these financial statements. 24 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 ----------------------------------------------------------------------------------------- Six Months Six Months Ended Ended 9/30/15 9/30/15 Year Ended Year Ended Shares Amount 3/31/15 3/31/15 (unaudited) (unaudited) Shares Amount ----------------------------------------------------------------------------------------- Class A Shares sold 7,765,536 $ 149,792,756 15,036,362 $ 274,201,233 Reinvestment of distributions -- -- 937,391 17,489,419 Less shares repurchased (5,258,383) (101,557,269) (12,861,620) (231,236,932) ----------------------------------------------------------------------------------------- Net increase 2,507,153 $ 48,235,487 3,112,133 $ 60,453,720 ========================================================================================= Class B* Shares sold or exchanged -- $ -- 36,067 $ 587,911 Reinvestment of distributions -- -- -- -- Less shares repurchased -- -- (237,960) (4,042,482) ----------------------------------------------------------------------------------------- Net decrease -- $ -- (201,893) $ (3,454,571) ========================================================================================= Class C Shares sold 2,619,990 $ 47,228,231 4,493,019 $ 77,274,336 Reinvestment of distributions -- -- 246,472 4,293,542 Less shares repurchased (1,082,029) (19,496,845) (2,038,629) (34,334,848) ----------------------------------------------------------------------------------------- Net increase 1,537,961 $ 27,731,386 2,700,862 $ 47,233,030 ========================================================================================= Class K Shares sold 1,470,977 $ 28,387,388 3,621,619 $ 67,520,968 Reinvestment of distributions -- -- 72,149 1,348,035 Less shares repurchased (917,655) (17,895,735) (491,338) (8,895,211) ----------------------------------------------------------------------------------------- Net increase 553,322 $ 10,491,653 3,202,430 $ 59,973,792 ========================================================================================= Class R Shares sold 734,026 $ 14,051,846 1,235,064 $ 22,131,079 Reinvestment of distributions -- -- 38,654 712,401 Less shares repurchased (207,158) (3,979,840) (1,763,621) (31,500,220) ----------------------------------------------------------------------------------------- Net increase (decrease) 526,868 $ 10,072,006 (489,903) $ (8,656,740) ========================================================================================= Class Y Shares sold 18,605,196 $ 363,674,583 29,577,154 $ 547,481,140 Reinvestment of distributions -- -- 1,516,299 28,532,632 Less shares repurchased (7,567,395) (146,965,206) (15,515,618) (283,571,107) ----------------------------------------------------------------------------------------- Net increase 11,037,801 $ 216,709,377 15,577,835 $ 292,442,665 ========================================================================================= Class Z** Shares sold 136,233 $ 2,627,203 115,242 $ 2,093,822 Reinvestment of distributions -- -- 4,127 76,995 Less shares repurchased (320,712) (6,338,181) (19,275) (356,345) ----------------------------------------------------------------------------------------- Net increase (decrease) (184,479) $ (3,710,978) 100,094 $ 1,814,472 ========================================================================================= * Class B shares converted to Class A shares on November 10, 2014. ** Class Z shares converted to Class Y shares on August 7, 2015. The accompanying notes are an integral part of these financial statements. Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 25 Financial Highlights ------------------------------------------------------------------------------------------------------------------------------------ Six Months Ended Year Year Year Year Year 9/30/15 Ended Ended Ended Ended Ended (unaudited) 3/31/15 3/31/14 3/31/13 3/31/12 3/31/11 ------------------------------------------------------------------------------------------------------------------------------------ Class A Net asset value, beginning of period $ 19.06 $ 16.66 $ 14.33 $ 13.23 $ 11.86 $ 10.96 ------------------------------------------------------------------------------------------------------------------------------------ Increase (decrease) from investment operations: Net investment income (loss) $ 0.03 $ 0.06 $ 0.06 $ 0.07 $ 0.02 $ 0.03 Net realized and unrealized gain (loss) on investments (0.66) 2.86 2.95 1.20 1.68 1.17 ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) from investment operations $ (0.63) $ 2.92 $ 3.01 $ 1.27 $ 1.70 $ 1.20 ------------------------------------------------------------------------------------------------------------------------------------ Distribution to shareowners: Net investment income $ -- $ (0.05) $ (0.06) $ (0.06) $ (0.03) $ (0.02) Net realized gain -- (0.47) (0.62) (0.11) (0.30) (0.28) ------------------------------------------------------------------------------------------------------------------------------------ Total distributions $ -- $ (0.52) $ (0.68) $ (0.17) $ (0.33) $ (0.30) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) in net asset value $ (0.63) $ 2.40 $ 2.33 $ 1.10 $ 1.37 $ 0.90 ------------------------------------------------------------------------------------------------------------------------------------ Net asset value, end of period $ 18.43 $ 19.06 $ 16.66 $ 14.33 $ 13.23 $ 11.86 ==================================================================================================================================== Total return* (3.31)% 17.60% 21.16% 9.64% 14.84% 11.23% Ratio of net expenses plus interest expense to average net assets 1.09%** 1.09% 1.08% 1.09% 1.19% 1.25% Ratio of net investment income (loss) to average net assets 0.38%** 0.38% 0.46% 0.54% 0.28% 0.25% Portfolio turnover rate 7%** 12% 21% 28% 16% 18% Net assets, end of period (in thousands) $ 816,534 $796,689 $644,527 $436,682 $346,987 $123,305 Ratios with no waiver of fees and assumption of expenses by the Adviser and no reduction for fees paid indirectly: Total expenses plus interest expense to average net assets 1.11%** 1.13% 1.13% 1.20% 1.19% 1.28% Net investment income (loss) to average net assets 0.36%** 0.34% 0.41% 0.43% 0.28% 0.22% ==================================================================================================================================== * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions, the complete redemption of the investment at net asset value at the end of each period and no sales charges. Total return would be reduced if sales charges were taken into account. ** Annualized. The accompanying notes are an integral part of these financial statements. 26 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 ------------------------------------------------------------------------------------------------------------------------------------ Six Months Ended Year Year Year Year Year 9/30/15 Ended Ended Ended Ended Ended (unaudited) 3/31/15 3/31/14 3/31/13 3/31/12 3/31/11 ------------------------------------------------------------------------------------------------------------------------------------ Class C Net asset value, beginning of period $ 17.81 $ 15.66 $ 13.55 $ 12.57 $ 11.34 $ 10.56 ------------------------------------------------------------------------------------------------------------------------------------ Increase (decrease) from investment operations: Net investment income (loss) $ (0.02) $ (0.03) $ (0.04) $ (0.02)(a) $ (0.04) $ (0.05)(a) Net realized and unrealized gain (loss) on investments (0.63) 2.65 2.77 1.12 1.57 1.11 ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) from investment operations $ (0.65) $ 2.62 $ 2.73 $ 1.10 $ 1.53 $ 1.06 ------------------------------------------------------------------------------------------------------------------------------------ Distribution to shareowners: Net investment income $ -- $ -- $ -- $ (0.01) $ -- $ -- Net realized gain -- (0.47) (0.62) (0.11) (0.30) (0.28) ------------------------------------------------------------------------------------------------------------------------------------ Total distributions $ -- $ (0.47) $ (0.62) $ (0.12) $ (0.30) $ (0.28) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) in net asset value $ (0.65) $ 2.15 $ 2.11 $ 0.98 $ 1.23 $ 0.78 ------------------------------------------------------------------------------------------------------------------------------------ Net asset value, end of period $ 17.16 $ 17.81 $ 15.66 $ 13.55 $ 12.57 $ 11.34 ==================================================================================================================================== Total return* (3.65)% 16.81% 20.29% 8.77% 13.98% 10.33% Ratio of net expenses plus interest expense to average net assets 1.78%** 1.79% 1.83% 1.91% 1.96% 2.03% Ratio of net investment income (loss) to average net assets (0.31)%** (0.32)% (0.28)% (0.23)% (0.50)% (0.52)% Portfolio turnover rate 7%** 12% 21% 28% 16% 18% Net assets, end of period (in thousands) $ 264,004 $ 246,593 $ 174,565 $89,299 $ 33,880 $ 15,149 ==================================================================================================================================== (a) The amount shown for a share outstanding does not correspond with the aggregate gain on investments for the period due to the timing of sales and repurchases of shares in relation to fluctuating fair values of the investments of the Fund. * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions, the complete redemption of the investment at net asset value at the end of each period and no sales charges. Total return would be reduced if sales charges were taken into account. ** Annualized. The accompanying notes are an integral part of these financial statements. Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 27 Financial Highlights (continued) ------------------------------------------------------------------------------------------------------------------------------------ Six Months Ended Year Year 9/30/15 Ended Ended 12/20/12 to (unaudited) 3/31/15 3/31/14 3/31/13 ------------------------------------------------------------------------------------------------------------------------------------ Class K Net asset value, beginning of period $ 19.05 $ 16.64 $ 14.30 $ 13.37 ------------------------------------------------------------------------------------------------------------------------------------ Increase (decrease) from investment operations: Net investment income (loss) $ 0.08 $ 0.16 $ 0.06 $ 0.03 Net realized and unrealized gain (loss) on investments (0.67) 2.84 3.01 1.00 ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) from investment operations $ (0.59) $ 3.00 $ 3.07 $ 1.03 ------------------------------------------------------------------------------------------------------------------------------------ Distribution to shareowners: Net investment income $ -- $ (0.12) $ (0.11) $ (0.10) Net realized gain -- (0.47) (0.62) -- ------------------------------------------------------------------------------------------------------------------------------------ Total distributions $ -- $ (0.59) $ (0.73) $ (0.10) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) in net asset value $ (0.59) $ 2.41 $ 2.34 $ 0.93 ------------------------------------------------------------------------------------------------------------------------------------ Net asset value, end of period $ 18.46 $ 19.05 $ 16.64 $ 14.30 ==================================================================================================================================== Total return* (3.10)% 18.11% 21.61% 7.77%(a)(b) Ratio of net expenses plus interest expense to average net assets 0.67%** 0.69% 0.71% 0.77%** Ratio of net investment income (loss) to average net assets 0.80%** 0.81% 0.85% 0.77%** Portfolio turnover rate 7%** 12% 21% 28% Net assets, end of period (in thousands) $ 104,266 $97,063 $31,501 $ 11 ==================================================================================================================================== (a) If the Fund had not recognized gains in settlement of class action lawsuits during the year ended March 31, 2013, the total return would have been 7.74%. (b) Not annualized. * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions, the complete redemption of the investment at net asset value at the end of each period and no sales charges. Total return would be reduced if sales charges were taken into account. ** Annualized. The accompanying notes are an integral part of these financial statements. 28 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 ------------------------------------------------------------------------------------------------------------------------------------ Six Months Ended Year Year 9/30/15 Ended Ended 4/2/12 to (unaudited) 3/31/15 3/31/14 3/31/13 ------------------------------------------------------------------------------------------------------------------------------------ Class R Net asset value, beginning of period $ 18.86 $ 16.50 $ 14.25 $ 13.34 ------------------------------------------------------------------------------------------------------------------------------------ Increase (decrease) from investment operations: Net investment income (loss) $ 0.02 $ (0.00)(a) $ 0.01 $ 0.06 Net realized and unrealized gain (loss) on investments (0.67) 2.83 2.94 1.05 ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) from investment operations $ (0.65) $ 2.83 $ 2.95 $ 1.11 ------------------------------------------------------------------------------------------------------------------------------------ Distribution to shareowners: Net investment income $ -- $ -- $ (0.08) $ (0.09) Net realized gain -- (0.47) (0.62) (0.11) ------------------------------------------------------------------------------------------------------------------------------------ Total distributions $ -- $ (0.47) $ (0.70) $ (0.20) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) in net asset value $ (0.65) $ 2.36 $ 2.25 $ 0.91 ------------------------------------------------------------------------------------------------------------------------------------ Net asset value, end of period $ 18.21 $ 18.86 $ 16.50 $ 14.25 ==================================================================================================================================== Total return* (3.45)% 17.23% 20.84% 8.42%(b)(c) Ratio of net expenses plus interest expense to average net assets 1.40%** 1.40% 1.39% 1.40%** Ratio of net investment income (loss) to average net assets 0.08%** 0.05% 0.18% 0.27%** Portfolio turnover rate 7%** 12% 21% 28% Net assets, end of period (in thousands) $ 45,590 $ 37,285 $40,703 $ 2,437 Ratios with no waiver of fees and assumption of expenses by the Adviser and no reduction for fees paid indirectly: Total expenses plus interest expense to average net assets 1.46%** 1.52% 1.39% 1.45%** Net investment income (loss) to average net assets 0.02%** (0.07)% 0.18% 0.21%** ==================================================================================================================================== (a) Amount rounds to less than $0.01 or $(0.01) per share. (b) If the Fund had not recognized gains in settlement of class action lawsuits during the year ended March 31, 2013, the total return would have been 8.41%. (c) Not annualized. * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions, the complete redemption of the investment at net asset value at the end of each period and no sales charges. Total return would be reduced if sales charges were taken into account. ** Annualized. The accompanying notes are an integral part of these financial statements. Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 29 Financial Highlights (continued) ------------------------------------------------------------------------------------------------------------------------------------ Six Months Ended Year Year Year Year Year 9/30/15 Ended Ended Ended Ended Ended (unaudited) 3/31/15 3/31/14 3/31/13 3/31/12 3/31/11 ------------------------------------------------------------------------------------------------------------------------------------ Class Y Net asset value, beginning of period $ 19.20 $ 16.77 $ 14.41 $ 13.30 $ 11.91 $ 10.99 ------------------------------------------------------------------------------------------------------------------------------------ Increase (decrease) from investment operations: Net investment income (loss) $ 0.06 $ 0.10 $ 0.10 $ 0.10 $ 0.07 $ 0.08 Net realized and unrealized gain (loss) on investments (0.67) 2.90 2.97 1.22 1.69 1.19 ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) from investment operations $ (0.61) $ 3.00 $ 3.07 $ 1.32 $ 1.76 $ 1.27 ------------------------------------------------------------------------------------------------------------------------------------ Distribution to shareowners: Net investment income $ -- $ (0.10) $ (0.09) $ (0.10) $ (0.07) $ (0.07) Net realized gain -- (0.47) (0.62) (0.11) (0.30) (0.28) ------------------------------------------------------------------------------------------------------------------------------------ Total distributions $ -- $ (0.57) $ (0.71) $ (0.21) $ (0.37) $ (0.35) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) in net asset value $ (0.61) $ 2.43 $ 2.36 $ 1.11 $ 1.39 $ 0.92 ------------------------------------------------------------------------------------------------------------------------------------ Net asset value, end of period $ 18.59 $ 19.20 $ 16.77 $ 14.41 $ 13.30 $ 11.91 ==================================================================================================================================== Total return* (3.18)% 17.98% 21.44% 9.99%(a) 15.29% 11.84% Ratio of net expenses plus interest expense to average net assets 0.79%** 0.80% 0.82% 0.81% 0.78% 0.78% Ratio of net investment income (loss) to average net assets 0.69%** 0.68% 0.72% 0.85% 0.67% 0.72% Portfolio turnover rate 7%** 12% 21% 28% 16% 18% Net assets, end of period (in thousands) $ 1,428,814 $1,263,594 $842,680 $558,383 $403,490 $226,409 ==================================================================================================================================== (a) If the Fund had not recognized gains in settlement of class action lawsuits during the year ended March 31, 2013, the total return would have been 9.96%. * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions, the complete redemption of the investment at net asset value at the end of each period and no sales charges. Total return would be reduced if sales charges were taken into account. ** Annualized. The accompanying notes are an integral part of these financial statements. 30 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 Notes to Financial Statements | 9/30/15 (unaudited) 1. Organization and Significant Accounting Policies Pioneer Fundamental Growth Fund (the Fund) is a series of Pioneer Series Trust X, a Delaware statutory trust. The Fund is registered under the Investment Company Act of 1940 as a diversified, open-end management investment company. The Fund's investment objective is to seek long-term capital growth. The Fund offers five classes of shares designated as Class A, Class C, Class K, Class R and Class Y shares. Class Y shares were first publicly offered on April 7, 2009. Class R shares were first publicly offered on April 2, 2012. Class K shares were first publicly offered on December 20, 2012. The Fund ceased to offer Class B shares on November 10, 2014. Class B shares were converted to Class A shares as of the close of business on November 10, 2014. The Fund ceased to offer Class Z shares on August 7, 2015. Class Z shares were converted to Class Y shares as of the close of business on August 7, 2015. Each class of shares represents an interest in the same portfolio of investments of the Fund and has identical rights (based on relative net asset values) to assets and liquidation proceeds. Share classes can bear different rates of class-specific fees and expenses such as transfer agent and distribution fees. Differences in class-specific fees and expenses will result in differences in net investment income and, therefore, the payment of different dividends from net investment income earned by each class. The Amended and Restated Declaration of Trust of the Fund gives the Board the flexibility to specify either per share voting or dollar-weighted voting when submitting matters for shareholder approval. Under per share voting, each share of a class of the Fund is entitled to one vote. Under dollar-weighted voting, a shareholder's voting power is determined not by the number of shares owned, but by the dollar value of the shares on the record date. Each share class has exclusive voting rights with respect to matters affecting only that class, including with respect to the distribution plan for that class. There is no distribution plan for Class K or Class Y shares. The Fund's financial statements have been prepared in conformity with U.S. generally accepted accounting principles that require the management of the Fund to, among other things, make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of income, expenses and gains and losses on investments during the reporting period. Actual results could differ from those estimates. The following is a summary of significant accounting policies followed by the Fund in the preparation of its financial statements: Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 31 A. Security Valuation Security transactions are recorded as of trade date. The net asset value of the Fund is computed once daily, on each day the New York Stock Exchange (NYSE) is open, as of the close of regular trading on the NYSE. In computing the net asset value, securities that have traded on an exchange are valued at the last sale price on the principal exchange where they are traded. Securities that have not traded on the date of valuation, or securities for which sale prices are not available, generally are valued at the mean between the last bid and asked prices. Shares of money market mutual funds are valued at such funds' net asset value. Cash may include overnight time deposits at approved financial institutions. Trading in foreign securities is substantially completed each day at various times prior to the close of the NYSE. The values of such securities used in computing the net asset value of the Fund's shares are determined as of such times. Securities for which independent pricing services are unable to supply prices or for which market prices and/or quotations are not readily available or are considered to be unreliable are valued by a fair valuation team comprised of certain personnel of Pioneer Investment Management, Inc. (PIM), the Fund's investment adviser, pursuant to procedures adopted by the Fund's Board of Trustees. PIM's fair valuation team uses fair valued methods approved by the Valuation Committee of the Board of Trustees. Inputs used when applying fair value methods to value a security may include credit ratings, the financial condition of the company, current market conditions and comparable securities. The Fund may use fair value methods if it is determined that a significant event has occurred after the close of the exchange or market on which the security trades and prior to the determination of the Fund's net asset value. Examples of a significant event might include political or economic news, corporate restructurings, natural disasters, terrorist activity or trading halts. Thus, the valuation of the Fund's securities may differ significantly from exchange prices and such differences could be material. PIM's fair valuation team is responsible for monitoring developments that may impact fair valued securities and for discussing and assessing fair values on an ongoing basis, and at least quarterly, with the Valuation Committee. At September 30, 2015, there were no securities that were valued using fair value methods (other than securities that were valued using prices supplied by independent pricing services or broker-dealers). 32 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 B. Investment Income and Transactions Dividend income is recorded on the ex-dividend date, except that certain dividends from foreign securities where the ex-dividend date may have passed are recorded as soon as the Fund becomes aware of the ex-dividend data in the exercise of reasonable diligence. Interest income, including interest on income bearing cash accounts, is recorded on the accrual basis. Dividend and interest income are reported net of unrecoverable foreign taxes withheld at the applicable country rates. Gains and losses on sales of investments are calculated on the identified cost method for both financial reporting and federal income tax purposes. C. Federal Income Taxes It is the Fund's policy to comply with the requirements of the Internal Revenue Code applicable to regulated investment companies and to distribute all of its net taxable income and net realized capital gains, if any, to its shareowners. Therefore, no provision for federal income taxes is required. As of March 31, 2015, the Fund did not accrue any interest or penalties with respect to uncertain tax positions, which, if applicable, would be recorded as an income tax expense in the Statement of Operations. Tax returns filed within the prior three years remain subject to examination by Federal and State tax authorities. The amount and character of income and capital gain distributions to shareowners are determined in accordance with federal income tax rules, which may differ from U.S. generally accepted accounting principles. Distributions in excess of net investment income or net realized gains are temporary overdistributions for financial statement purposes resulting from differences in the recognition or classification of income or distributions for financial statement and tax purposes. Capital accounts within the financial statements are adjusted for permanent book/tax differences to reflect tax character, but are not adjusted for temporary differences. The tax character of current year distributions payable will be determined at the end of the current taxable year. The tax character of distributions paid during the years ended March 31, 2015 and March 31, 2014 were as follows: -------------------------------------------------------------------------- 2015 -------------------------------------------------------------------------- Distributions paid from: Ordinary income $ 8,706,828 Long-term capital gain 50,896,348 -------------------------------------------------------------------------- Total $59,603,176 ========================================================================== Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 33 The following shows the components of distributable earnings on a federal income tax basis at March 31, 2015: -------------------------------------------------------------------------- 2015 -------------------------------------------------------------------------- Distributable earnings: Undistributed ordinary income $ 4,329,640 Undistributed long-term capital gain 96,966,632 Net unrealized appreciation 632,409,988 -------------------------------------------------------------------------- Total $733,706,260 ========================================================================== The difference between book-basis and tax-basis net unrealized appreciation is attributable to the tax deferral of losses on wash sales. D. Fund Shares The Fund records sales and repurchases of its shares as of trade date. Pioneer Funds Distributor, Inc. (PFD) is the principal underwriter for the Fund and a wholly-owned indirect subsidiary of UniCredit S.p.A. (UniCredit), earned $105,439 in underwriting commissions on the sale of Class A shares during the six months ended September 30, 2015. E. Class Allocations Income, common expenses and realized and unrealized gains and losses are calculated at the Fund level and allocated daily to each class of shares based on its respective percentage of adjusted net assets at the beginning of the day. Distribution fees are calculated based on the average daily net asset value attributable to Class A, Class C and Class R shares of the Fund, respectively (see Note 4). Class Y shares do not pay distribution fees. All expenses and fees paid to the transfer agent, Pioneer Investment Management Shareholder Services, Inc. (PIMSS), for its services are allocated among the classes of shares based on the number of accounts in each class and the ratable allocation of related out-of-pocket expenses (see Note 3). Distributions to shareowners are recorded as of the ex-dividend date. Distributions paid by the Fund with respect to each class of shares are calculated in the same manner and at the same time, except that net investment income dividends to Class A, Class C, Class R and Class Y shares can reflect different transfer agent and distribution expense rates. F. Risks At times, the Fund's investments may represent industries or industry sectors that are interrelated or have common risks, making the Fund more susceptible to any economic, political, or regulatory developments or other risks affecting those industries and sectors. The Fund's prospectus contains unaudited information regarding the Fund's principal risks. Please refer to that document when considering the Fund's principal risks. 34 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 G. Repurchase Agreements Repurchase agreements are arrangements under which the Fund purchases securities from a broker-dealer or a bank, called the counterparty, upon the agreement of the counterparty to repurchase the securities from the Fund at a later date, and at a specific price, which is typically higher than the purchase price paid by the Fund. The securities purchased serve as the Fund's collateral for the obligation of the counterparty to repurchase the securities. The value of the collateral, including accrued interest, is required to be equal to or in excess of the repurchase price. The collateral for all repurchase agreements is held in safekeeping in the customer-only account of the Fund's custodian or a subcustodian of the Fund. The Fund's investment adviser, PIM is responsible for determining that the value of the collateral remains at least equal to the repurchase price. In the event of a default by the counterparty, the Fund is entitled to sell the securities, but the Fund may not be able to sell them for the price at which they were purchased, thus causing a loss to the Fund. Additionally, if the counterparty becomes insolvent, there is some risk that the Fund will not have a right to the securities, or the immediate right to sell the securities. 2. Management Agreement PIM, a wholly-owned indirect subsidiary of UniCredit, manages the Fund's portfolio. Management fees are calculated daily at the annual rate of 0.65% of the Fund's average daily net assets up to $1 billion and 0.60% on assets over $1 billion. For the six months ended September 30, 2015, the effective management fee (excluding waivers and/or assumption of expenses) was equivalent to 0.62% of the Fund's average daily net assets. PIM has contractually agreed to limit ordinary operating expenses to the extent required to reduce Fund expenses to 1.09%, 1.40% and 0.83% of the average daily net assets attributable to Class A, Class R, and Class Y, respectively. Class C and Class K shares do not have an expense limitation. Fees waived and expenses reimbursed during the six months ended September 31, 2015 are reflected on the Statement of Operations. These expense limitations are in effect through August 1, 2017. There can be no assurance that PIM will extend the expense limitation agreement for a class of shares beyond the date referred to above. In addition, under the management and administration agreements, certain other services and costs, including accounting, regulatory reporting and insurance premiums, are paid by the Fund as administrative reimbursements. Included in "Due to affiliates" reflected on the Statement of Assets and Liabilities is $86,077 in management fees, administrative costs and certain other reimbursements payable to PIM at September 31, 2015. Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 35 3. Transfer Agent Prior to November 2, 2015 PIMSS, a wholly owned indirect subsidiary of UniCredit, provided substantially all transfer agent and shareowner services to the Fund at negotiated rates. In addition, the Fund reimbursed PIMSS for out-of-pocket expenses incurred by PIMSS related to shareholder communications activities such as proxy and statement mailings, outgoing phone calls and omnibus relationship contracts. For the six months ended September 30, 2015, such out-of-pocket expenses by class of shares were as follows: -------------------------------------------------------------------------------- Shareholder Communications: -------------------------------------------------------------------------------- Class A $ 663,000 Class C 126,877 Class K 963 Class R 55,985 Class Y 866,574 Class Z 2,021 -------------------------------------------------------------------------------- Total $1,715,420 ================================================================================ Included in "Due from affiliates" reflected on the Statement of Assets and Liabilities is $579,064 in transfer agent fees and out-of-pocket reimbursements payable to PIMSS at September 30, 2015. Effective November 2, 2015, Boston Financial Data Services serves as the transfer agent to the fund at negotiated rates. 4. Distribution and Service Plans The Fund has adopted a Distribution Plan pursuant to Rule 12b-1 of the Investment Company Act of 1940 with respect to its Class A, Class C and Class R shares. Pursuant to the Plan, the Fund pays PFD 0.25% of the average daily net assets attributable to Class A shares as compensation for personal services and/or account maintenance services or distribution services with regard to Class A shares. Pursuant to the Plan, the Fund also pays PFD 1.00% of the average daily net assets attributable to Class C shares. The fee for Class C shares consists of a 0.25% service fee and a 0.75% distribution fee paid as compensation for personal services and/or account maintenance services or distribution services with regard to Class C shares. Pursuant to the Plan, the Fund further pays PFD 0.50% of the average daily net assets attributable to Class R shares for distribution services. Included in "Due to affiliates" reflected on the Statement of Assets and Liabilities is $26,264 in distribution fees payable to PFD at September 30, 2015. The Fund also has adopted a separate service plan for Class R shares (Service Plan). The Service Plan authorizes the Fund to pay securities dealers, plan administrators or other service organizations that agree to provide certain 36 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 services to retirement plans or plan participants holding shares of the Fund a service fee of up to 0.25% of the Fund's average daily net assets attributable to Class R shares held by such plans. In addition, redemptions of each class of shares (except Class K, Class R and Class Y shares) may be subject to a contingent deferred sales charge (CDSC). A CDSC of 1.00% may be imposed on redemptions of certain net asset value purchases of Class A shares within 12 months of purchase. Redemptions of Class C shares within 12 months of purchase are subject to a CDSC of 1.00%, based on the lower of cost or market value of shares being redeemed. Shares purchased as part of an exchange remain subject to any CDSC that applied to the original purchase of those shares. There is no CDSC for Class K, Class R or Class Y shares. Proceeds from the CDSCs are paid to PFD. For the six months ended September 30, 2015, CDSCs in the amount of $17,881 were paid to PFD. 5. Expense Offset Arrangements The Fund has entered into certain expense offset arrangements with PIMSS which may result in a reduction in the Fund's total expenses due to interest earned on cash held by PIMSS. For the six months ended September 30, 2015, the Fund's expenses were not reduced under such arrangements. 6. Line of Credit Facility The Fund, along with certain other funds in the Pioneer Family of Funds (the Funds), participates in a committed, unsecured revolving line of credit facility. Borrowings are used solely for temporary or emergency purposes. The Fund may borrow up to the lesser of the amount available under the facility or the limits set for borrowing by the Fund's prospectus and the 1940 Act. The credit facility in effect until June 9, 2015, was in the amount of $215 million. As of June 9, 2015, the facility is in the amount of $240 million. Under such facility, depending on the type of loan, interest on borrowings is payable at the London Interbank Offered Rate (LIBOR) plus 0.85% on an annualized basis, or the Alternate Base Rate, which is the greater of (a) the facility's administrative agent's daily announced prime rate on the borrowing date, (b) 2% plus the Federal Funds Rate on the borrowing date and (c) 2% plus the overnight Eurodollar rate on the borrowing date. The Funds pay an annual commitment fee to participate in a credit facility. The commitment fee is allocated among participating Funds based on an allocation schedule set forth in the credit agreement. For the six months ended September 30, 2015, the Fund had no borrowings under the credit facility. 7. Conversion of Class Z Shares As of the close of business on August 7, 2015 (the "Conversion Date"), all outstanding Class Z shares of the Fund were converted to Class Y shares. Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 37 Additional Information Pioneer Investment Management, Inc. (the "Adviser"), each fund's investment adviser, is currently an indirect, wholly owned subsidiary of UniCredit S.p.A. ("UniCredit"). On November 11, 2015, UniCredit announced that it signed a binding master agreement with Banco Santander and affiliates of Warburg Pincus and General Atlantic (the "Private Equity Firms") with respect to Pioneer Investments ("Pioneer") and Santander Asset Management ("SAM") (the "Transaction"). The Transaction, as described in the UniCredit announcement, will establish a holding company, with the name Pioneer Investments, to be owned by UniCredit (50%) and the Private Equity Firms (50% between them). The holding company will control Pioneer's U.S. operations, including the Adviser. The holding company also will own 66.7% of Pioneer's and SAM's combined operations outside the U.S., while Banco Santander will own directly the remaining 33.3% stake. The closing of the Transaction is expected to happen in 2016, subject to certain regulatory and other approvals, and other conditions. Under the Investment Company Act of 1940, completion of the Transaction will cause each fund's current investment advisory agreement with the Adviser to terminate. Accordingly, each fund's Board of Trustees will be asked to approve a new investment advisory agreement. If approved by the Board, each fund's new investment advisory agreement will be submitted to the shareholders of the fund for their approval. 38 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 Approval of Investment Advisory Agreement Pioneer Investment Management, Inc. (PIM) serves as the investment adviser to Pioneer Fundamental Growth Fund (the Fund) pursuant to an investment advisory agreement between PIM and the Fund. In order for PIM to remain the investment adviser of the Fund, the Trustees of the Fund must determine annually whether to renew the investment advisory agreement for the Fund. The contract review process began in January 2015 as the Trustees of the Fund agreed on, among other things, an overall approach and timeline for the process. Contract review materials were provided to the Trustees in March 2015 and July 2015. Supplemental contract review materials were provided to the Trustees in September 2015. In addition, the Trustees reviewed and discussed the Fund's performance at regularly scheduled meetings throughout the year and took into account other information related to the Fund provided to the Trustees at regularly scheduled meetings in connection with the review of the Fund's investment advisory agreement. In March 2015, the Trustees, among other things, discussed the memorandum provided by Fund counsel that summarized the legal standards and other considerations that are relevant to the Trustees in their deliberations regarding the renewal of the investment advisory agreement, and reviewed and discussed the qualifications of the investment management teams, as well as the level of investment by the Fund's portfolio managers in the Fund. In July 2015, the Trustees, among other things, reviewed the Fund's management fee and total expense ratios, the financial statements of PIM and its parent companies, the profitability analyses provided by PIM, and possible economies of scale. The Trustees also reviewed the profitability of the institutional business of PIM and PIM's affiliate, Pioneer Institutional Asset Management, Inc. (together with PIM, "Pioneer"), as compared to that of PIM's fund management business, and considered the differences between the fees and expenses of the Fund and the fees and expenses of Pioneer's institutional accounts, as well as the different services provided by PIM to the Fund and by Pioneer to the institutional accounts. The Trustees further considered contract review materials in September 2015. At a meeting held on September 15, 2015, based on their evaluation of the information provided by PIM and third parties, the Trustees of the Fund, including the Independent Trustees voting separately, unanimously approved the renewal of the investment advisory agreement for another year. In approving the renewal of the investment advisory agreement, the Trustees considered various factors that they determined were relevant, including the factors described below. The Trustees did not identify any single factor as the controlling factor in determining to approve the renewal of the agreement. Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 39 Nature, Extent and Quality of Services The Trustees considered the nature, extent and quality of the services that had been provided by PIM to the Fund, taking into account the investment objective and strategy of the Fund. The Trustees also reviewed PIM's investment approach for the Fund and its research process. The Trustees considered the resources of PIM and the personnel of PIM who provide investment management services to the Fund. They also reviewed the amount of non-Fund assets managed by the portfolio managers of the Fund. The Trustees considered the non-investment resources and personnel of PIM involved in PIM's services to the Fund, including PIM's compliance and legal resources and personnel. The Trustees noted the substantial attention and high priority given by PIM's senior management to the Pioneer fund complex. The Trustees considered that PIM supervises and monitors the performance of the Fund's service providers and provides the Fund with personnel (including Fund officers) and other resources that are necessary for the Fund's business management and operations. The Trustees also considered that, as administrator, PIM is responsible for the administration of the Fund's business and other affairs. The Trustees considered the fees paid to PIM for the provision of administration services. Based on these considerations, the Trustees concluded that the nature, extent and quality of services that had been provided by PIM to the Fund were satisfactory and consistent with the terms of the investment advisory agreement. Performance of the Fund In considering the Fund's performance, the Trustees regularly review and discuss throughout the year data prepared by PIM and information comparing the Fund's performance with the performance of its peer group of funds as classified by each of Morningstar, Inc. (Morningstar) and Lipper, and with the performance of the Fund's benchmark index. They also discuss the Fund's performance with PIM on a regular basis. The Trustees' regular reviews and discussions were factored into the Trustees' deliberations concerning the renewal of the advisory agreement. The Trustees indicated that the Fund's performance, when considered in connection with the various other factors, was consistent with the renewal of the investment advisory agreement. Management Fee and Expenses The Trustees considered information showing the fees and expenses of the Fund in comparison to the management fees and expense ratios of its peer group of funds as classified by Morningstar and also to the expense ratios of a peer group of funds selected on the basis of criteria determined by the Independent Trustees for this purpose using data provided by Strategic Insight 40 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 Mutual Fund Research and Consulting, LLC (Strategic Insight), an independent third party. In all quintile rankings referred to below, first quintile is most favorable to the Fund's shareowners. The Trustees considered that the Fund's management fee for the most recent fiscal year was in the second quintile relative to the management fees paid by other funds in its Morningstar peer group for the comparable period. The Trustees also considered the breakpoint in the management fee schedule and the reduced fee rate above a certain asset level. The Trustees considered that the expense ratio of the Fund's Class A shares for the most recent fiscal year was in the third quintile relative to its Morningstar peer group and in the second quintile relative its Strategic Insight peer group, in each case for the comparable period. The Trustees considered that the expense ratio of the Fund's Class Y shares for the most recent fiscal year was in the third quintile relative to its Morningstar peer group and in the second quintile relative its Strategic Insight peer group, in each case for the comparable period. The Trustees considered the impact of transfer agency, sub-transfer agency, and other non-management fee expenses on the expense ratios of the Fund. The Trustees noted that they separately review the Fund's transfer agency, sub-transfer agency and intermediary arrangements. The Trustees reviewed management fees charged by Pioneer to institutional and other clients, including publicly offered European funds sponsored by affiliates of Pioneer, unaffiliated U.S. registered investment companies (in a sub-advisory capacity), and unaffiliated foreign and domestic separate accounts. The Trustees also considered PIM's costs in providing services to the Fund and Pioneer's costs in providing services to the other clients and considered the differences in management fees and profit margins for Fund and non-Fund services. In evaluating the fees associated with Pioneer's client accounts, the Trustees took into account the respective demands, resources and complexity associated with the Fund and client accounts. The Trustees noted that, in some instances, the fee rates for those clients were lower than the management fee for the Fund and considered that, under the investment advisory agreement with the Fund, PIM performs additional services for the Fund that it does not provide to those other clients or services that are broader in scope, including oversight of the Fund's other service providers and activities related to compliance and the extensive regulatory and tax regimes to which the Fund is subject. The Trustees also considered the different entrepreneurial risks associated with PIM's management of the Fund and Pioneer's management of the other client accounts. The Trustees concluded that the management fee payable by the Fund to PIM was reasonable in relation to the nature and quality of the services provided by PIM to the Fund. Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 41 Profitability The Trustees considered information provided by PIM regarding the profitability of PIM with respect to the advisory services provided by PIM to the Fund, including the methodology used by PIM in allocating certain of its costs to the management of the Fund. The Trustees also considered PIM's profit margin in connection with the overall operation of the Fund. They further reviewed the financial results realized by PIM and its affiliates from non-fund businesses. The Trustees considered PIM's profit margins with respect to the Fund in comparison to the limited industry data available and noted that the profitability of any adviser was affected by numerous factors, including its organizational structure and method for allocating expenses. The Trustees concluded that PIM's profitability with respect to the management of the Fund was not unreasonable. Economies of Scale The Trustees considered PIM's views relating to economies of scale in connection with the Pioneer Funds as fund assets grow and the extent to which any such economies of scale are shared with funds and fund shareholders. The Trustees noted the breakpoint in the management fee schedule. The Trustees recognize that economies of scale are difficult to identify and quantify, and that, among other factors that may be relevant, are the following: fee levels, expense subsidization, investment by PIM in research and analytical capabilities and PIM's commitment and resource allocation to the Fund. The Trustees noted that profitability also may be an indicator of the availability of any economies of scale, although profitability may vary for other reasons including reductions in expenses. The Trustees concluded that economies of scale, if any, were being appropriately shared with the Funds. Other Benefits The Trustees considered the other benefits to PIM from its relationship with the Fund. The Trustees considered the character and amount of fees paid by the Fund, other than under the investment advisory agreement, for services provided by PIM and its affiliates. The Trustees further considered the revenues and profitability of PIM's businesses other than the fund business. Pioneer is the principal U.S. asset management business of Pioneer Global Asset Management, the worldwide asset management business of UniCredit Group, which manages over $150 billion in assets (including the Funds). Pioneer and the Funds receive reciprocal intangible benefits from the relationship, including mutual brand recognition and, for the Funds, direct and indirect access to the resources of a large global asset manager. The Trustees concluded that any such benefits received by Pioneer as a result of its relationship with the Funds were reasonable and their consideration of the advisory agreement between the Fund and PIM and the fees thereunder were unaffected by Pioneer's possible receipt of any such intangible benefits. 42 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 Conclusion After consideration of the factors described above as well as other factors, the Trustees, including all of the Independent Trustees, concluded that the investment advisory agreement between PIM and the Fund, including the fees payable thereunder, was fair and reasonable and voted to approve the proposed renewal of the investment advisory agreement for the Fund. Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 43 Trustees, Officers and Service Providers Trustees Advisory Trustee Thomas J. Perna, Chairman Lorraine H. Monchak* David R. Bock Benjamin M. Friedman Officers Margaret B.W. Graham Lisa M. Jones, President and Chief Marguerite A. Piret Executive Officer Fred J. Ricciardi Mark E. Bradley, Treasurer and Kenneth J. Taubes Chief Financial Officer Christopher J. Kelley, Secretary and Chief Legal Officer Investment Adviser and Administrator Pioneer Investment Management, Inc. Custodian and Sub-Administrator Brown Brothers Harriman & Co. Principal Underwriter Pioneer Funds Distributor, Inc. Legal Counsel Morgan, Lewis & Bockius LLP Transfer Agent Boston Financial Data Services, Inc. Proxy Voting Policies and Procedures of the Fund are available without charge, upon request, by calling our toll free number (1-800-225-6292). Information regarding how the Fund voted proxies relating to portfolio securities during the most recent 12-month period ended June 30 is publicly available to shareowners at us.pioneerinvestments.com. This information is also available on the Securities and Exchange Commission's web site at www.sec.gov. * Ms. Monchak is a non-voting Advisory Trustee. 44 Pioneer Fundamental Growth Fund | Semiannual Report | 9/30/15 How to Contact Pioneer We are pleased to offer a variety of convenient ways for you to contact us for assistance or information. Call us for: -------------------------------------------------------------------------------- Account Information, including existing accounts, new accounts, prospectuses, applications and service forms 1-800-225-6292 FactFone(SM) for automated fund yields, prices, account information and transactions 1-800-225-4321 Retirement plans information 1-800-622-0176 Write to us: -------------------------------------------------------------------------------- PIMSS, Inc. P.O. Box 55014 Boston, Massachusetts 02205-5014 Our toll-free fax 1-800-225-4240 Our internet e-mail address ask.pioneer@pioneerinvestments.com (for general questions about Pioneer only) Visit our web site: us.pioneerinvestments.com This report must be preceded or accompanied by a prospectus. The Fund files a complete schedule of investments with the Securities and Exchange Commission for the first and third quarters for each fiscal year on Form N-Q. Shareholders may view the filed Form N-Q by visiting the Commission's web site at http://www.sec.gov. The filed form may also be viewed and copied at the Commission's Public Reference Room in Washington, DC. Information regarding the operations of the Public Reference Room may be obtained by calling 1-800-SEC-0330. [LOGO] PIONEER Investments(R) Pioneer Investment Management, Inc. 60 State Street Boston, MA 02109 us.pioneerinvestments.com Securities offered through Pioneer Funds Distributor, Inc. 60 State Street, Boston, MA 02109 Underwriter of Pioneer Mutual Funds, Member SIPC (C) 2015 Pioneer Investments 19434-09-1115 Pioneer Multi-Asset Ultrashort Income Fund -------------------------------------------------------------------------------- Semiannual Report | September 30, 2015 -------------------------------------------------------------------------------- Ticker Symbols: Class A MAFRX Class C MCFRX Class C2 MAUCX Class K MAUKX Class Y MYFRX [LOGO] PIONEER Investments(R) visit us: us.pioneerinvestments.com Table of Contents President's Letter 2 Portfolio Management Discussion 4 Portfolio Summary 10 Prices and Distributions 11 Performance Update 12 Comparing Ongoing Fund Expenses 17 Schedule of Investments 19 Financial Statements 94 Notes to Financial Statements 103 Approval of Investment Advisory Agreement 113 Trustees, Officers and Service Providers 118 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 1 President's Letter Dear Shareowner, Through the first three quarters of 2015, global markets experienced pockets of higher-than-average volatility due to significant cross-currents from different geographic regions. All year, investors focused on the Federal Reserve System's (the Fed's) deliberations over when to begin normalizing interest rates. However, while there were signs of gradual economic improvement in the U.S., economies abroad increasingly diverged. In June, for example, investors grew concerned about the debt crisis in Greece. That news, in turn, was followed by evidence of an economic slowdown in China, which only served to exacerbate existing worries about growth trends in the emerging markets, a segment of the global economy already being negatively impacted by slumping commodity prices, including the price of crude oil, which has been in near-steady decline for almost a year. Through September 30, 2015, the pockets of heightened market volatility alluded to above had resulted in the Standard & Poor's 500 Index turning in a negative (-5.27%) return over the first nine months of the year. However, the S&P 500 recovered nicely in October, returning 8.43% for the month, which boosted the index's year-to-date return into positive territory, at 2.71%. Despite the headwinds still vexing the global economy, our longer-term view of the U.S. economy has remained positive. Economic conditions in the U.S. have generally been constructive, based largely on improvements in employment statistics and an uptick in the housing sector, which has aided the consumer side of the economy, where household spending has been rising modestly. U.S. consumers also stand to benefit, potentially, from lower energy prices as the winter weather approaches. We continue to believe the U.S. economy remains on a slow, steady growth trend, and that it is unlikely to be disrupted by a slow pace of interest-rate normalization by the Fed. Pioneer Investments believes that investors in today's environment can potentially benefit from the consistent and disciplined investment approach we have used since our founding in 1928. We focus on identifying value across global markets using proprietary research, careful risk management, and a long-term perspective. Our ongoing goal is to produce compelling returns consistent with the stated objectives of our investment products, and with our shareowners' expectations. We believe our shareowners can benefit from the experience and tenure of our investment teams as well as the insights generated from our extensive research process. 2 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 As always, and particularly during times of market uncertainty, we encourage you to work with your financial advisor to develop an overall investment plan that addresses both your short- and long-term goals, and to implement such a plan in a disciplined manner. We greatly appreciate your trust in us in the past and look forward to continuing to serve you in the future. Sincerely, /s/Lisa M. Jones Lisa M. Jones President and CEO Pioneer Investment Management USA Inc. November 2, 2015 Any information in this shareowner report regarding market or economic trends or the factors influencing the Fund's historical or future performance are statements of opinion as of the date of this report. These statements should not be relied upon for any other purposes. Past performance is no guarantee of future results, and there is no guarantee that market forecasts discussed will be realized. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 3 Portfolio Management Discussion | 9/30/15 In the following interview, portfolio managers Charles Melchreit, Seth Roman and Jonathan Sharkey discuss the factors that influenced Pioneer Multi-Asset Ultrashort Income Fund's performance during the six-month period ended September 30, 2015. Mr. Melchreit, Director of Investment-Grade Management, a senior vice president and a portfolio manager at Pioneer, Mr. Roman, a vice president and a portfolio manager at Pioneer, and Mr. Sharkey, a senior vice president and a portfolio manager at Pioneer, are responsible for the day-to-day management of the Fund. Q How did the Fund perform during the six-month period ended September 30, 2015? A Pioneer Multi-Asset Ultrashort Income Fund's Class A shares returned 0.30% at net asset value during the six-month period ended September 30, 2015, while the Fund's benchmark, the Bank of America Merrill Lynch 3-Month U.S. Dollar LIBOR Index (the BofA ML Index), returned 0.14%. During the same period, the average return of the 119 mutual funds in Lipper's Ultrashort Obligations Funds category was -0.05%, and the average return of the 155 mutual funds in Morningstar's Ultrashort Bond category was -0.04%. Q Can you describe the market environment for fixed-income investors over the six-month period ended September 30, 2015? A The second calendar quarter of 2015, which was also the first three months of the Fund's semiannual reporting period, saw the U.S. economy resume its upward trajectory, following a winter in which growth was constrained by severe weather, and labor disruptions at West Coast shipping terminals. Nonetheless, the U.S. Federal Reserve System (the Fed) continued to display patience with respect to implementing any shift towards less-accommodative monetary policy (that is, raising interest rates), as economic growth overseas remained tenuous and global investor sentiment was further undermined by the threat of debt-riddled Greece exiting the euro zone. In addition, a strong U.S. dollar combined with low energy prices served to dampen inflationary pressures on the domestic front. As the period progressed, slowing economic growth in China increasingly dominated financial headlines, and the August devaluation of that nation's currency, the yuan, raised the possibility of further global currency devaluations and spurred dramatic spikes in both equity and fixed-income market volatility. The U.S. economy remained the leading source of growth among developed economies, with strengthening observed in key areas such as employment and housing, while consumers benefited from a further 4 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 drop in energy prices, led by the plummeting price of oil, which started declining in late 2014, briefly recovered at the beginning of 2015, and began falling again throughout the rest of the six-month period. Against a backdrop of elevated geopolitical uncertainty combined with a lack of upward price pressure at home, expectations were further pushed back with respect to the timing of the Fed's first hike in short-term interest rates. U.S. Treasury yields generally rose during the six months ended September 30, 2015, and the yield curve steepened. To illustrate, the two-year Treasury yield rose from 0.56% to 0.64% over the six months; the five-year Treasury yield finished the period unchanged, at 1.37%; the 10-year Treasury yield rose from 1.94% to 2.06%; and the 30-year Treasury yield rose from 2.54% to 2.86%. While the period saw some widening of credit spreads, price declines on shorter-maturity securities were generally modest. (Credit spreads are commonly defined as the differences in yield between Treasuries and other types of fixed-income securities with similar maturities.) Q Can you review your principal strategies in managing the Fund during the six-month period ended September 30, 2015? A During the period we continued to maintain a portfolio which seeks to provide income, while also seeking to provide protection to shareholders' principal against a rise in market interest rates. Our strategy entailed investing the Fund's assets in a wide range of mostly high-quality, floating-rate securities as well as fixed-rate instruments with very short remaining maturities. At period end, well over 90% of the Fund's invested assets were allocated either to floating-rate issues with interest rates tied to a short-term reference rate such as LIBOR (London InterBank Offered Rate), or fixed-rate issues with less than one year remaining to maturity. Unlike many other floating-rate vehicles, the Fund's investments are typically focused primarily on investment-grade asset classes. At the same time, we did seek to have the Fund's performance benefit from credit spreads - or the incremental yield available from issues that trade at a yield premium to Treasuries - during the period. In doing so, we sought at all times to maintain the portfolio's broadly diversified* exposure to a number of different spread sectors. (Spread sectors represent non-governmental fixed-income investments with higher yields - at greater risk - than governmental investments.) The Fund's largest weighting during the period was in the securitized sectors, including asset-backed securities (ABS), along with residential and commercial mortgage-backed securities (RMBS and CMBS). * Diversification does not assure a profit nor protect against loss. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 5 Q How did your investment strategies affect the Fund's performance during the six-month period ended September 30, 2015? A The leading positive contributor to the Fund's relative returns over the six-month period was the portfolio's allocation to event-linked securities, or "catastrophe" bonds, issued by insurance companies seeking to mitigate the risk of having to pay claims after a natural disaster. In addition to providing incremental income, catastrophe bonds have a very low correlation to other areas of the bond market, and we therefore view the asset class as a valuable source of diversification. Moreover, we have been careful to diversify the Fund's holdings within the catastrophe bond sector according to both peril (for example, hurricanes, floods, earthquakes), and geographic region. The Fund's allocations to ABS, RMBS and CMBS also contributed to relative performance during the period, as housing and consumer fundamentals remained on an upward trend in the U.S., and those securities provided incremental income. Within ABS, we have emphasized credit card-backed receivables in recent months, as the fundamentals there have been supported by consumers' restraint in borrowing. Conversely, we have minimized the Fund's exposure to subprime auto loans in view of some deterioration in underwriting standards in that sector. While our primary investment focus in the Fund's portfolio is on investment-grade sectors, we also include below-investment-grade asset categories where we believe the incremental income provides an attractive tradeoff between risk and reward. In that vein, the Fund's position in floating-rate, leveraged bank loans was a modest positive contributor to relative performance during the period, based on the attractive coupon income offered by the asset class, which helped offset the price erosion experienced in the second half of the period as oil and other commodities came under renewed pricing pressure. In addition, we have taken care to avoid undue concentration on energy-related credits within the loan market, while focusing the Fund's energy-related holdings on asset-rich companies that we view as providing a "margin of safety" when it comes to loan principal amounts ultimately being repaid. On the downside, the Fund's allocation to investment-grade corporates detracted modestly from relative performance, as credit-sensitive fixed- income sectors softened over the period due to the news coming out of China as well as global growth concerns. With that said, corporate bond issuers have continued to be supported by generally strong profitability and cash-rich balance sheets. Our investment focus within investment-grade corporates has been on two- to three-year floating-rate issues within the financials sector. The portfolio also has allocations to fixed-rate issues with maturities of 15 months or less, with a focus on U.S. bank issuers, as we find 6 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 U.S. banks compelling because of their strengthened capital structures and lower earnings volatility in the wake of reforms following the financial crisis of several years ago. While we manage the Fund with a focus on total return, as always, we are mindful that many investors view the Fund as a source of liquidity in their portfolios. As such, we continued to maintain significant liquidity in the portfolio. With a relatively flat money market yield curve, we have been focusing on purchasing very short-term issues with maturities between one day and one week in order to maintain the requisite liquidity in the Fund's portfolio. Given the sharp increase in volatility in both equity and fixed- income markets as the six-month period progressed, we are pleased that the Fund's net asset value remained relatively stable, as Class A shares experienced a modest decline from $10.00 to $9.97 between April 1, 2015, and September 30, 2015. Q Can you discuss the factors that affected the Fund's income-generation (or yield), either positively or negatively, during the six-month period ended September 30, 2015? A The Fund's yield/income generation was fairly stable throughout the six- month period, as the Fund's portfolio was invested principally in short-term fixed-income instruments across a broad range of spread sectors that trade at a yield advantage versus U.S. Treasuries. Q Did you use any derivative strategies in managing the Fund during the six- month period ended September 30, 2015? A No. The Fund had no exposure to derivatives during the period. Q What is your assessment of the current investment climate for the Fund heading into the final months of 2015? A With continued modest economic growth and low inflation in the United States, we expect that conditions will remain supportive of credit-sector fundamentals. In recent quarters, spreads versus Treasuries have become somewhat more attractive, and we are seeking to selectively add to the Fund's exposure to the credit-sensitive areas of the market, while maintaining a portfolio bias toward higher-quality securities. In all cases, we are being careful not to assume any risk for which the Fund is not adequately compensated. While the portfolio's sector allocations will shift around the margins to reflect our view of relative risk and reward, the Fund continues to be broadly diversified with respect to its allocation across asset categories. Within the Fund's allocation to investment-grade corporates, we are maintaining a preference for U.S. financials, which have seen significant balance-sheet strengthening along with lower risk profiles in the wake of recent regulatory initiatives. In contrast, we are being cautious with respect Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 7 to issuers in the industrials sector, which has seen an increase in leverage driven by measures perceived as friendly to equity stakeholders, such as share buybacks as well as mergers and acquisitions. In all investment environments, however, we will continue to seek to provide shareholders with higher income than cash vehicles while striving to provide protection against any future rise in market interest rates. (Please note that the Fund is not a money market fund.) Please refer to the Schedule of Investments on pages 19-93 for a full listing of Fund securities. All investments are subject to risk, including the possible loss of principal. Pioneer Multi-Asset Ultrashort Income Fund ("The Fund") has the ability to invest in a wide variety of debt securities. The Fund may invest in underlying funds (including ETFs). In addition to the Fund's operating expenses, you will indirectly bear the operating expenses of investments in any underlying funds. The Fund and some of the underlying funds may utilize strategies that have a leveraging effect on the Fund, which increases the volatility of investment returns and subjects the Fund to magnified losses if the Fund's or an underlying fund's investments decline in value. The Fund and some of the underlying funds may use derivatives, such as options and futures, which can be illiquid, may disproportionately increase losses, and have a potentially large impact on Fund performance. The Fund may invest in inflation-linked securities. As inflationary expectations increase, inflation-linked securities may become more attractive, because they protect future interest payments against inflation. Conversely, as inflationary concerns decrease, inflation-linked securities will become less attractive and less valuable. The Fund may invest in credit default swaps, which may in some cases be illiquid, and they increase credit risk since the Fund has exposure to both the issuer of the referenced obligation and the counterparty to the credit default swap. The Fund may invest in subordinated securities which may be disproportionately adversely affected by a default or even a perceived decline in creditworthiness of the issuer. The Fund may invest in floating-rate loans. The value of collateral, if any, securing a floating-rate loan can decline or may be insufficient to meet the issuer's obligations or may be difficult to liquidate. The Fund may invest in event-linked bonds. The return of principal and the payment of interest on event-linked bonds are contingent on the non-occurrence of a pre-defined "trigger" event, such as a hurricane or an earthquake of a specific magnitude. 8 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 The Fund may invest in zero-coupon bonds and payment-in-kind securities, which may be more speculative and fluctuate more in value than other fixed income securities. The accrual of income from these securities are payable as taxable annual dividends to shareholders. Investments in equity securities are subject to price fluctuation. International investments are subject to special risks including currency fluctuations, social, economic and political uncertainties, which could increase volatility. These risks are magnified in emerging markets. Investments in fixed-income securities involve interest rate, credit, inflation, and reinvestment risks. As interest rates rise, the value of fixed income securities generally falls. The Fund may invest in mortgage-backed securities, which during times of fluctuating interest rates may increase or decrease more than other fixed-income securities. Mortgage-backed securities are also subject to pre-payments. Prepayment risk is the chance that an issuer may exercise its right to prepay its security, if falling interest rates prompt the issuer to do so. Forced to reinvest the unanticipated proceeds at lower interest rates, the Fund would experience a decline in income and lose the opportunity for additional price appreciation. High yield bonds possess greater price volatility, illiquidity, and possibility of default. There may be insufficient or illiquid collateral securing the floating rate loans held within the Fund. This may reduce the future redemption or recovery value of such loans. The Fund may have disadvantaged access to confidential information that could be used to assess a loan issuer, as Pioneer normally seeks to avoid receiving material, non-public information. Pioneer Multi-Asset Ultrashort Income Fund is not a money market fund. These risks may increase share price volatility. There is no assurance that these and other strategies used by the Fund or underlying funds will be successful. Please see the prospectus for a more complete discussion of the Fund's risks. Before investing, consider the product's investment objectives, risks, charges and expenses. Contact your advisor or Pioneer Investments for a prospectus or summary prospectus containing this information. Read it carefully. Any information in this shareholder report regarding market or economic trends or the factors influencing the Fund's historical or future performance are statements of opinion as of the date of this report. Past performance is no guarantee of future results. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 9 Portfolio Summary | 9/30/15 Portfolio Diversification* -------------------------------------------------------------------------------- (As a percentage of total investment portfolio) [THE FOLLOWING DATA WAS REPRESENTED AS A PIE CHART IN THE PRINTED MATERIAL] Collateralized Mortgage Obligations 28.6% Asset Backed Securities 24.5% U.S. Corporate Bonds 20.5% International Corporate Bonds 9.4% U.S. Government Securities 6.8% Senior Secured Loans 6.6% Temporary Cash Investment 3.3% Municipal Bonds 0.3% * Includes investments in Insurance Linked Securities totaling 4.5% of total investment portfolio. 10 Largest Holdings -------------------------------------------------------------------------------- (As a percentage of total long-term holdings)** 1. U.S. Treasury Note, Floating Rate Note, 4/30/17 1.46% ---------------------------------------------------------------------------------------------- 2. Societe Generale SA, Commercial Paper, 10/1/15 0.75 ---------------------------------------------------------------------------------------------- 3. U.S. Treasury Note, Floating Rate Note, 4/30/16 0.74 ---------------------------------------------------------------------------------------------- 4. U.S. Treasury Note, Floating Rate Note, 10/31/16 0.74 ---------------------------------------------------------------------------------------------- 5. U.S. Treasury Note, Floating Rate Note, 7/31/17 0.73 ---------------------------------------------------------------------------------------------- 6. U.S. Treasury Note, Floating Rate Note, 1/31/17 0.73 ---------------------------------------------------------------------------------------------- 7. U.S. Treasury Note, Floating Rate Note, 7/31/16 0.49 ---------------------------------------------------------------------------------------------- 8. Federal National Mortgage Association, Floating Rate Note, 2/25/38 0.48 ---------------------------------------------------------------------------------------------- 9. World Financial Network Credit Card Master Trust, Floating Rate Note, 12/16/19 0.38 ---------------------------------------------------------------------------------------------- 10. Federal Farm Credit Banks, Floating Rate Note, 6/20/16 0.36 ---------------------------------------------------------------------------------------------- ** This list excludes temporary cash investments and derivative instruments. The portfolio is actively managed and current holdings may be different. The holdings listed should not be considered recommendations to buy or sell any security listed. 10 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 Prices and Distributions | 9/30/15 Net Asset Value per Share -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- Class 9/30/15 3/31/15 -------------------------------------------------------------------------------- A $9.97 $10.00 -------------------------------------------------------------------------------- C $9.96 $ 9.99 -------------------------------------------------------------------------------- C2 $9.95 $ 9.99 -------------------------------------------------------------------------------- K $9.98 $10.01 -------------------------------------------------------------------------------- Y $9.97 $10.01 -------------------------------------------------------------------------------- Distributions per Share: 4/1/15-9/30/15 -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- Short-Term Long-Term Class Dividends Capital Gains Capital Gains -------------------------------------------------------------------------------- A $0.0595 $ $ -------------------------------------------------------------------------------- C $0.0451 $ $ -------------------------------------------------------------------------------- C2 $0.0448 $ $ -------------------------------------------------------------------------------- K $0.0714 $ $ -------------------------------------------------------------------------------- Y $0.0667 $ $ -------------------------------------------------------------------------------- The Bank of America Merrill Lynch U.S. Dollar 3-Month LIBOR Index is an unmanaged index that tracks the performance of a synthetic asset paying the London Interbank Offered Rate (LIBOR), with a constant 3-month average maturity. The index is based on the assumed purchase at par value of a synthetic instrument having exactly its stated maturity and with a coupon equal to that day's 3-month LIBOR rate. Index returns assume reinvestment of dividends and, unlike Fund returns, do not reflect any fees, expenses or sales charges. It is not possible to invest directly in an index. The index defined here pertains to the "Value of $10,000 Investment" and "Value of $5 Million Investment" charts on pages 12-16. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 11 Performance Update | 9/30/15 Class A Shares Investment Returns -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $10,000 investment made in Class A shares of Pioneer Multi-Asset Ultrashort Income Fund at public offering price during the periods shown, compared to that of the Bank of America (BofA) Merrill Lynch (ML) U.S. Dollar 3-Month LIBOR Index. Average Annual Total Returns (As of September 30, 2015) -------------------------------------------------------------------------------- BofA ML Net Public U.S. Dollar Asset Offering 3-Month Value Price LIBOR Period (NAV) (POP) Index -------------------------------------------------------------------------------- Life-of-Class (4/29/11) 1.22% 0.63% 0.31% 1 Year 0.52 -2.01 0.25 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated August 1, 2015) -------------------------------------------------------------------------------- Gross -------------------------------------------------------------------------------- 0.63% -------------------------------------------------------------------------------- Value of $10,000 Investment [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Pioneer Multi-Asset BofA ML U.S. Dollar Ultrashort Income Fund 3-Month LIBOR Index 4/11 $ 9,750 $ 10,000 9/11 $ 9,756 $ 10,009 9/12 $ 10,037 $ 10,058 9/13 $ 10,124 $ 10,090 9/14 $ 10,228 $ 10,114 9/15 $ 10,282 $ 10,140 Call 1-800-225-6292 or visit us.pioneerinvestments.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. NAV results represent the percent change in net asset value per share. Returns would have been lower had sales charges been reflected. POP returns reflect deduction of maximum 2.50% sales charge. All results are historical and assume the reinvestment of dividends and capital gains. Other share classes are available for which performance and expenses will differ. Performance results reflect any applicable expense waivers in effect during the periods shown. Without such waivers Fund performance would be lower. Waivers may not be in effect for all funds. Certain fee waivers are contractual through a specified period. Otherwise, fee waivers can be rescinded at any time. See the prospectus and financial statements for more information. The performance table and graph do not reflect the deduction of fees and taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. 12 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 Performance Update | 9/30/15 Class C Shares Investment Returns -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $10,000 investment made in Class C shares of Pioneer Multi-Asset Ultrashort Income Fund during the periods shown, compared to that of the Bank of America (BofA) Merrill Lynch (ML) U.S. Dollar 3-Month LIBOR Index. Average Annual Total Returns (As of September 30, 2015) -------------------------------------------------------------------------------- BofA ML U.S. Dollar 3-Month If If LIBOR Period Held Redeemed Index -------------------------------------------------------------------------------- Life-of-Class (4/29/11) 0.78% 0.78% 0.31% 1 Year 0.23 0.23 0.25 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated August 1, 2015) -------------------------------------------------------------------------------- Gross -------------------------------------------------------------------------------- 0.94% -------------------------------------------------------------------------------- Value of $10,000 Investment [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Pioneer Multi-Asset BofA ML U.S. Dollar Ultrashort Income Fund 3-Month LIBOR Index 4/11 $ 10,000 $ 10,000 9/11 $ 9,975 $ 10,009 9/12 $ 10,191 $ 10,058 9/13 $ 10,252 $ 10,090 9/14 $ 10,325 $ 10,114 9/15 $ 10,349 $ 10,140 Call 1-800-225-6292 or visit us.pioneerinvestments.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. "If Held" results represent the percent change in net asset value per share. Returns would have been lower had sales charges been reflected. All results are historical and assume the reinvestment of dividends and capital gains. Other share classes are available for which performance and expenses will differ. Performance results reflect any applicable expense waivers in effect during the periods shown. Without such waivers Fund performance would be lower. Waivers may not be in effect for all funds. Certain fee waivers are contractual through a specified period. Otherwise, fee waivers can be rescinded at any time. See the prospectus and financial statements for more information. The performance table and graph do not reflect the deduction of fees and taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 13 Performance Update | 9/30/15 Class C2 Shares Investment Returns -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $10,000 investment made in Class C2 shares of Pioneer Multi-Asset Ultrashort Income Fund during the periods shown, compared to that of the Bank of America (BofA) Merrill Lynch (ML) U.S. Dollar 3-Month LIBOR Index. Average Annual Total Returns (As of September 30, 2015) -------------------------------------------------------------------------------- BofA ML U.S. Dollar 3-Month If If LIBOR Period Held Redeemed Index -------------------------------------------------------------------------------- Life-of-Class (4/29/11) 0.75% 0.75% 0.31% 1 Year 0.11 0.11 0.25 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated August 1, 2015) -------------------------------------------------------------------------------- Gross -------------------------------------------------------------------------------- 0.95% -------------------------------------------------------------------------------- Value of $10,000 Investment [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Pioneer Multi-Asset BofA ML U.S. Dollar Ultrashort Income Fund 3-Month LIBOR Index 4/11 $ 10,000 $ 10,000 9/11 $ 9,975 $ 10,009 9/12 $ 10,191 $ 10,058 9/13 $ 10,250 $ 10,090 9/14 $ 10,324 $ 10,114 9/15 $ 10,336 $ 10,140 Call 1-800-225-6292 or visit us.pioneerinvestments.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. Class C2 shares held for less than 1 year are subject to a 1% contingent deferred sales charge (CDSC). "If Held" results represent the percentage change in net asset value per share. Returns would have been lower had sales charges been reflected. All results are historical and assume the reinvestment of dividends and capital gains. Other share classes are available for which performance and expenses will differ. The performance shown for periods prior to the commencement of operations of Class C2 shares on August 1, 2013, is the net asset value performance of the Fund's Class C shares, which has not been restated to reflect any differences in expenses. For the period beginning August 1, 2013, the actual performance of Class C2 shares is reflected. Performance results reflect any applicable expense waivers in effect during the periods shown. Without such waivers Fund performance would be lower. Waivers may not be in effect for all funds. Certain fee waivers are contractual through a specified period. Otherwise, fee waivers can be rescinded at any time. See the prospectus and financial statements for more information. The performance table and graph do not reflect the deduction of fees and taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. 14 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 Performance Update | 9/30/15 Class K Shares Investment Returns -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $10,000 investment made in Class K shares of Pioneer Multi-Asset Ultrashort Income Fund during the periods shown, compared to that of the Bank of America (BofA) Merrill Lynch (ML) U.S. Dollar 3-Month LIBOR Index. Average Annual Total Returns (As of September 30, 2015) -------------------------------------------------------------------------------- BofA ML Net U.S. Dollar Asset 3-Month Value LIBOR Period (NAV) Index -------------------------------------------------------------------------------- Life-of-Class (4/29/11) 1.38% 0.31% 1 Year 0.74 0.25 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated August 1, 2015) -------------------------------------------------------------------------------- Gross -------------------------------------------------------------------------------- 0.41% -------------------------------------------------------------------------------- Value of $10,000 Investment [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Pioneer Multi-Asset BofA ML U.S. Dollar Ultrashort Income Fund 3-Month LIBOR Index 4/11 $ 10,000 $ 10,000 9/11 $ 10,010 $ 10,009 9/12 $ 10,298 $ 10,058 9/13 $ 10,416 $ 10,090 9/14 $ 10,546 $ 10,114 9/15 $ 10,624 $ 10,140 Call 1-800-225-6292 or visit us.pioneerinvestments.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. The performance shown for Class K shares for the period prior to the commencement of operations of Class K shares on December 20, 2012, is the net asset value performance of the Fund's Class A shares, which has not been restated to reflect any differences in expenses, including Rule 12b-1 fees applicable to Class A shares. Since fees for Class A shares generally are higher than those of Class K shares, the performance of Class K shares prior to their inception would have been higher than the performance shown. For the period beginning on December 20, 2012, the actual performance of Class K shares is reflected. Class K shares are not subject to sales charges and are available for limited groups of eligible investors, including institutional investors. All results are historical and assume the reinvestment of dividends and capital gains. Other share classes are available for which performance and expenses will differ. Performance results reflect any applicable expense waivers in effect during the periods shown. Without such waivers Fund performance would be lower. Waivers may not be in effect for all funds. Certain fee waivers are contractual through a specified period. Otherwise, fee waivers can be rescinded at any time. See the prospectus and financial statements for more information. The performance table and graph do not reflect the deduction of fees and taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 15 Performance Update | 9/30/15 Class Y Shares Investment Returns -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $5 million investment made in Class Y shares of Pioneer Multi-Asset Ultrashort Income Fund during the periods shown, compared to that of the Bank of America (BofA) Merrill Lynch (ML) U.S. Dollar 3-Month LIBOR Index. Average Annual Total Returns (As of September 30, 2015) -------------------------------------------------------------------------------- BofA ML Net U.S. Dollar Asset 3-Month Value LIBOR Period (NAV) Index -------------------------------------------------------------------------------- Life-of-Class (4/29/11) 1.40% 0.31% 1 Year 0.57 0.25 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated August 1, 2015) -------------------------------------------------------------------------------- Gross -------------------------------------------------------------------------------- 0.51% -------------------------------------------------------------------------------- Value of $5 Million Investment [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Pioneer Multi-Asset BofA ML U.S. Dollar Ultrashort Income Fund 3-Month LIBOR Index 4/11 $ 5,000,000 $ 5,000,000 9/11 $ 5,008,825 $ 5,004,742 9/12 $ 5,169,696 $ 5,028,849 9/13 $ 5,224,861 $ 5,044,939 9/14 $ 5,286,365 $ 5,057,112 9/15 $ 5,316,328 $ 5,069,978 Call 1-800-225-6292 or visit us.pioneerinvestments.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. Class Y shares are not subject to sales charges and are available for limited groups of eligible investors, including institutional investors. All results are historical and assume the reinvestment of dividends and capital gains. Other share classes are available for which performance and expenses will differ. Performance results reflect any applicable expense waivers in effect during the periods shown. Without such waivers Fund performance would be lower. Waivers may not be in effect for all funds. Certain fee waivers are contractual through a specified period. Otherwise, fee waivers can be rescinded at any time. See the prospectus and financial statements for more information. The performance table and graph do not reflect the deduction of fees and taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. 16 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 Comparing Ongoing Fund Expenses As a shareowner in the Fund, you incur two types of costs: (1) ongoing costs, including management fees, distribution and/or service (12b-1) fees, and other Fund expenses; and (2) transaction costs, including sales charges (loads) on purchase payments. This example is intended to help you understand your ongoing expenses (in dollars) of investing in the Fund and to compare these costs with the ongoing costs of investing in other mutual funds. The example is based on an investment of $1,000 at the beginning of the Fund's latest six-month period and held throughout the six months. Using the Tables -------------------------------------------------------------------------------- Actual Expenses The first table below provides information about actual account values and actual expenses. You may use the information in this table, together with the amount you invested, to estimate the expenses that you paid over the period as follows: (1) Divide your account value by $1,000 Example: an $8,600 account value (divided by) $1,000 = 8.6 (2) Multiply the result in (1) above by the corresponding share class's number in the third row under the heading entitled "Expenses Paid During Period" to estimate the expenses you paid on your account during this period. Expenses Paid on a $1,000 Investment in Pioneer Multi-Asset Ultrashort Income Fund Based on actual returns from April 1, 2015, through September 30, 2015. -------------------------------------------------------------------------------- Share Class A C C2 K Y -------------------------------------------------------------------------------- Beginning Account Value on 4/1/15 $1,000.00 $1,000.00 $1,000.00 $1,000.00 $1,000.00 -------------------------------------------------------------------------------- Ending Account Value (after expenses) on 9/30/15 $1,003.00 $1,001.50 $1,000.50 $1,004.10 $1,002.70 -------------------------------------------------------------------------------- Expenses Paid During Period* $ 3.16 $ 4.72 $ 4.71 $ 2.06 $ 2.51 -------------------------------------------------------------------------------- * Expenses are equal to the Fund's annualized expense ratio of 0.63%, 0.94%, 0.94%, 0.41%, and 0.50% for class A, C, C2, K, and Y shares respectively, multiplied by the average account value over the period, multiplied by 183/365 (to reflect the one-half year period). Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 17 Hypothetical Example for Comparison Purposes The table below provides information about hypothetical account values and hypothetical expenses based on the Fund's actual expense ratio and an assumed rate of return of 5% per year before expenses, which is not the Fund's actual return. The hypothetical account values and expenses may not be used to estimate the actual ending account balance or expenses you paid for the period. You may use this information to compare the ongoing costs of investing in the Fund and other funds. To do so, compare this 5% hypothetical example with the 5% hypothetical examples that appear in the shareholder reports of the other funds. Please note that the expenses shown in the tables are meant to highlight your ongoing costs only and do not reflect any transaction costs, such as sales charges (loads) that are charged at the time of the transaction. Therefore, the table below is useful in comparing ongoing costs only and will not help you determine the relative total costs of owning different funds. In addition, if these transaction costs were included, your costs would have been higher. Expenses Paid on a $1,000 Investment in Pioneer Multi-Asset Ultrashort Income Fund Based on a hypothetical 5% return per year before expenses, reflecting the period from April 1, 2015, through September 30, 2015. -------------------------------------------------------------------------------- Share Class A C C2 K Y -------------------------------------------------------------------------------- Beginning Account Value on 4/1/15 $1,000.00 $1,000.00 $1,000.00 $1,000.00 $1,000.00 -------------------------------------------------------------------------------- Ending Account Value (after expenses) on 9/30/15 $1,021.91 $1,020.36 $1,020.36 $1,023.01 $1,022.56 -------------------------------------------------------------------------------- Expenses Paid During Period* $ 3.19 $ 4.76 $ 4.76 $ 2.08 $ 2.54 -------------------------------------------------------------------------------- * Expenses are equal to the Fund's annualized expense ratio of 0.63%, 0.94%, 0.94%, 0.41% and 0.50% for class A, C, C2, K, and Y shares respectively, multiplied by the average account value over the period, multiplied by 183/365 (to reflect the one-half year period). 18 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 Schedule of Investments | 9/30/15 (unaudited) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- ASSET BACKED SECURITIES -- 24.6% ENERGY -- 0.3% Oil & Gas Exploration & Production -- 0.3% 4,219,417 GCAT 2015-2, 3.75%, 7/25/20 (Step) (144A) $ 4,219,214 3,000,000 1.72 NCF Dealer Floorplan Master Trust, Floating Rate Note, 10/20/20 (144A) 2,999,998 1,673,075 Oscar US Funding Trust 2014-1, 1.0%, 8/15/17 (144A) 1,674,521 --------------- $ 8,893,733 --------------- Total Energy $ 8,893,733 --------------------------------------------------------------------------------------------------------- MATERIALS -- 0.1% Steel -- 0.1% 2,450,000 0.67 First NLC Trust 2005-2, Floating Rate Note, 9/25/35 $ 2,401,662 --------------- Total Materials $ 2,401,662 --------------------------------------------------------------------------------------------------------- TRANSPORTATION -- 0.0%+ Trucking -- 0.0%+ 882,781 0.60 Hertz Fleet Lease Funding LP, Floating Rate Note, 4/10/28 (144A) $ 881,243 --------------------------------------------------------------------------------------------------------- Marine Ports & Services -- 0.0%+ 720,299 Global Container Assets 2013-1, Ltd., 2.2%, 11/6/28 (144A) $ 719,927 --------------- Total Transportation $ 1,601,170 --------------------------------------------------------------------------------------------------------- CONSUMER DURABLES & APPAREL -- 0.0%+ Homebuilding -- 0.0%+ 283,300 1.09 Manufactured Housing Contract Trust Pass-Through Certificates Series 2001-1, Floating Rate Note, 4/20/32 $ 282,841 --------------- Total Consumer Durables & Apparel $ 282,841 --------------------------------------------------------------------------------------------------------- CONSUMER SERVICES -- 0.1% Hotels, Resorts & Cruise Lines -- 0.1% 205,933 Westgate Resorts 2012-2 LLC, 9.0%, 1/21/25 (144A) $ 207,092 3,128,517 Westgate Resorts 2012-A LLC, 3.75%, 8/20/25 (144A) 3,159,456 71,530 Westgate Resorts 2014-1 LLC, 2.15%, 12/20/26 (144A) 71,038 78,258 Westgate Resorts LLC, 2.5%, 3/20/25 (144A) 78,308 --------------- $ 3,515,894 --------------- Total Consumer Services $ 3,515,894 --------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 19 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- HEALTH CARE EQUIPMENT & SERVICES -- 0.1% Health Care Distributors -- 0.1% 2,500,000 0.91 Oscar US Funding Trust II, Floating Rate Note, 2/15/18 (144A) $ 2,500,000 --------------- Total Health Care Equipment & Services $ 2,500,000 --------------------------------------------------------------------------------------------------------- BANKS -- 15.9% Diversified Banks -- 0.0%+ 68,425 0.60 KeyCorp Student Loan Trust 2004-A, Floating Rate Note, 10/28/41 $ 67,759 --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- 15.9% 1,269,872 0.44 321 Henderson Receivables I LLC, Floating Rate Note, 11/15/40 (144A) $ 1,214,997 3,216,644 0.41 321 Henderson Receivables I LLC, Floating Rate Note, 12/15/41 (144A) 3,153,045 658,792 0.56 321 Henderson Receivables I LLC, Floating Rate Note, 9/15/45 (144A) 651,917 3,291,495 0.41 321 Henderson Receivables II LLC, Floating Rate Note, 9/15/41 (144A) 3,199,511 1,502,040 0.94 ABFC 2005-HE2 Trust, Floating Rate Note, 6/25/35 1,485,424 674,368 0.81 ABFC 2005-WF1 Trust, Floating Rate Note, 12/25/34 670,920 777,323 0.52 ACAS CLO 2007-1, Ltd., Floating Rate Note, 4/20/21 769,096 891,123 0.60 Accredited Mortgage Loan Trust 2005-2, Floating Rate Note, 7/25/35 878,691 2,917,797 0.39 ACE Securities Corp Home Equity Loan Trust Series 2006-ASAP2, Floating Rate Note, 3/25/36 2,865,136 39,150 6.50 ACE Securities Corp. Manufactured Housing Trust Series 2003-MH1, Floating Rate Note, 8/15/30 (144A) 39,180 417,777 1.29 Aegis Asset Backed Securities Trust Mortgage Pass- Through Ctfs Series 2004-3, Floating Rate Note, 9/25/34 412,943 1,082,896 1.15 Aegis Asset Backed Securities Trust Mortgage Pass-Through Certificates Series 2004-2, Floating Rate Note, 6/25/34 1,075,884 1,092,942 1.29 Aegis Asset Backed Securities Trust Mortgage Pass-Through Certificates Series 2004-4, Floating Rate Note, 10/25/34 1,081,239 330,176 0.56 Aegis Asset Backed Securities Trust Mortgage Pass-Through Ctfs Ser 2005-4, Floating Rate Note, 10/25/35 324,986 4,500,000 American Credit Acceptance Receivables Trust 2015-3 Class A, 9/12/19 (144A) 4,499,698 2,600,000 0.49 American Express Credit Account Master Trust, Floating Rate Note, 1/15/20 2,600,125 1,500,000 1.60 American Homes 4 Rent 2014-SFR1, Floating Rate Note, 6/17/31 1,471,090 The accompanying notes are an integral part of these financial statements. 20 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 2,125,000 0.60 AmeriCredit Automobile Receivables Trust 2015-2, Floating Rate Note, 9/10/18 $ 2,125,793 48,195 0.62 Ameriquest Mortgage Securities Inc Asset-Backed Pass-Through Ctfs Ser 2005-R5, Floating Rate Note, 7/25/35 48,075 440,778 0.53 Ameriquest Mortgage Securities, Inc., Asset Backed Pass-Through Ctfs Series 2005-R11, Floating Rate Note, 1/25/36 432,644 241,559 3.95 Ameriquest Mortgage Securities, Inc., Asset-Backed Pass-Through Ctfs Series 03-AR3, Floating Rate Note, 6/25/33 245,609 4,769,259 0.80 Ameriquest Mortgage Securities, Inc., Asset-Backed Pass-Through Ctfs Series 2004-R11, Floating Rate Note, 11/25/34 4,747,201 982,905 0.87 Ameriquest Mortgage Securities, Inc., Asset-Backed Pass-Through Ctfs Series 2005-R1, Floating Rate Note, 3/25/35 980,461 1,000,000 1.74 Apidos Quattro CDO, Floating Rate Note, 1/20/19 (144A) 992,211 1,152,502 0.51 ARI Fleet Lease Trust 2012-B, Floating Rate Note, 1/15/21 (144A) 1,150,536 582,710 ARI Fleet Lease Trust 2013-A, 0.92%, 7/15/21 (144A) 582,547 1,787,015 ARI Fleet Lease Trust 2014-A, 0.81%, 11/15/22 (144A) 1,786,602 188,216 0.87 Asset Backed Securities Corp Home Equity Loan Trust Series 2005-HE2, Floating Rate Note, 2/25/35 188,019 392,137 0.90 Asset Backed Securities Corp Home Equity Loan Trust Series 2005-HE3, Floating Rate Note, 4/25/35 387,476 949,578 0.39 Asset Backed Securities Corp Home Equity Loan Trust Series AEG 2006-HE1, Floating Rate Note, 1/25/36 906,704 989,019 0.70 Asset Backed Securities Corp Home Equity Loan Trust Series OOMC 2005-HE6, Floating Rate Note, 7/25/35 981,536 1,108,347 0.81 Asset-Backed Pass-Through Certificates Series 2004-R2, Floating Rate Note, 4/25/34 1,088,518 1,126,693 Bank of The West Auto Trust 2014-1, 0.69%, 7/17/17 (144A) 1,126,458 1,100,000 0.56 Barclays Dryrock Issuance Trust, Floating Rate Note, 12/16/19 1,097,549 1,800,000 0.54 Barclays Dryrock Issuance Trust, Floating Rate Note, 3/16/20 1,797,336 45,284 Bayview Financial Acquisition Trust, 6.205%, 5/28/37 (Step) 47,570 785,377 0.87 Bayview Financial Mortgage Pass-Through Trust 2004-A, Floating Rate Note, 2/28/44 782,358 3,004,022 0.69 Bayview Financial Mortgage Pass-Through Trust 2005-C, Floating Rate Note, 6/28/44 2,980,645 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 21 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 730,584 0.49 Bayview Financial Mortgage Pass-Through Trust 2006-B, Floating Rate Note, 4/28/36 $ 718,599 571,169 0.46 Bayview Financial Mortgage Pass-Through Trust 2006-B, Floating Rate Note, 4/28/36 561,799 1,001,318 0.64 Bayview Financial Mortgage Pass-Through Trust Series 2005-B, Floating Rate Note, 4/28/39 994,351 907,909 3.72 Bayview Opportunity Master Fund IIa Trust 2014-20NPL, 3.721%, 8/28/44 (Step) (144A) (e) 910,464 496,558 Bayview Opportunity Master Fund Trust IIIa 2014-12RPL, 3.6225%, 7/28/19 (Step) (144A) 493,745 1,565,213 0.69 Bear Stearns Asset Backed Securities I Trust 2005-FR1, Floating Rate Note, 6/25/35 1,558,273 783,852 0.96 Bear Stearns Asset Backed Securities I Trust 2005-HE9, Floating Rate Note, 10/25/35 779,143 796,776 1.39 Bear Stearns Asset Backed Securities Trust 2004-2, Floating Rate Note, 8/25/34 796,609 248,064 0.76 Bear Stearns Asset Backed Securities Trust 2004-SD3, Floating Rate Note, 9/25/34 243,632 66,771 0.59 Bear Stearns Asset Backed Securities Trust 2005-SD1, Floating Rate Note, 8/25/43 65,759 1,376,795 0.66 Bear Stearns Asset Backed Securities Trust 2005-SD2, Floating Rate Note, 3/25/35 1,366,686 594,408 0.59 Bear Stearns Asset Backed Securities Trust 2005-SD2, Floating Rate Note, 3/25/35 589,311 532,838 0.47 Bear Stearns Asset Backed Securities Trust 2006-1, Floating Rate Note, 2/25/36 531,534 2,178,785 0.57 Bear Stearns Asset Backed Securities Trust 2006-SD2, Floating Rate Note, 6/25/36 2,129,399 830,160 1.19 Bear Stearns Structured Products Trust 2007-EMX1, Floating Rate Note, 3/25/37 (144A) 819,801 2,895,000 0.69 Cabela's Credit Card Master Note Trust, Floating Rate Note, 6/15/20 (144A) 2,893,503 1,000,000 0.49 Capital One Multi-Asset Execution Trust, Floating Rate Note, 11/15/19 998,903 1,213,005 CarMax Auto Owner Trust 2013-3, 0.97%, 4/16/18 1,213,383 2,500,000 0.49 CarMax Auto Owner Trust 2015-2, Floating Rate Note, 6/15/18 2,497,628 3,500,000 Carnow Auto Receivables Trust 2015-1, 1.69%, 1/15/20 (144A) 3,499,999 1,148,835 0.93 Carrington Mortgage Loan Trust Series 2005-NC1, Floating Rate Note, 2/26/35 1,148,429 16,073 0.60 Carrington Mortgage Loan Trust Series 2005-NC4, Floating Rate Note, 9/25/35 16,012 1,668,891 0.37 Carrington Mortgage Loan Trust Series 2006-OPT1, Floating Rate Note, 12/25/35 1,618,901 The accompanying notes are an integral part of these financial statements. 22 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 2,274,450 Cazenovia Creek Funding I LLC, 2.0%, 12/10/23 (144A) $ 2,278,317 1,514,845 Cazenovia Creek Funding I LLC, 2.773%, 12/10/23 (144A) 1,517,981 1,315,238 CCG Receivables Trust 2014-1, 1.06%, 11/14/21 (144A) 1,312,787 2,750,000 CCG Receivables Trust 2015-1, 0.55%, 9/14/16 (144A) 2,750,230 136,620 CCG Receivables Truste 2013-1, 1.05%, 4/14/20 (144A) 136,618 5,220,000 1.55 Cent CLO 16 LP, Floating Rate Note, 8/1/24 (144A) 5,204,714 372,006 3.65 Centex Home Equity Loan Trust 2003-A, Floating Rate Note, 3/25/33 371,427 313,022 Chase Funding Trust Series 2004-2, 5.323%, 2/26/35 316,943 200,000 0.46 Chase Issuance Trust, Floating Rate Note, 12/16/19 199,332 7,750,000 0.45 Chase Issuance Trust, Floating Rate Note, 5/15/19 7,740,064 2,500,000 CIT Equipment Collateral 2014-VT1, 0.86%, 5/22/17 (144A) 2,500,345 1,465,285 Citi Held For Asset Issuance 2015-PM1, 1.85%, 12/15/21 (144A) 1,468,199 55,801 0.68 Citigroup Global Markets Mortgage Securities VII, Inc., Floating Rate Note, 3/25/28 55,324 1,747,858 0.39 Citigroup Mortgage Loan Trust 2006-SHL1, Floating Rate Note, 11/27/45 (144A) 1,693,321 1,307,325 1.02 Citigroup Mortgage Loan Trust Series 2004-OPT1 Asset Backed Pass-Through Certifi, Floating Rate Note, 10/25/34 1,306,210 228,793 1.21 Citigroup Mortgage Loan Trust, Inc., Floating Rate Note, 11/25/34 215,159 3,724,759 0.95 Citigroup Mortgage Loan Trust, Inc., Floating Rate Note, 5/25/35 (144A) 3,705,644 750,000 CNH Equipment Trust 2013-B, 0.99%, 11/15/18 748,862 2,300,000 2.10 Colony American Homes 2014-1, Floating Rate Note, 5/19/31 (144A) 2,248,275 4,000,000 Conn's Receivables Funding 2015-A LLC, 4.565%, 9/15/20 (144A) 4,000,000 206,505 1.71 Conseco Finance Home Equity Loan Trust 2002-C, Floating Rate Note, 4/15/32 202,442 4,272 Conseco Financial Corp., 7.05%, 1/15/19 4,367 1,617,995 Consumer Credit Origination Loan Trust 2015-1, 2.82%, 3/15/21 (144A) 1,624,446 2,026,162 1.03 Countrywide Asset-Backed Certificates, Floating Rate Note, 10/25/34 2,018,926 221,846 0.78 Countrywide Asset-Backed Certificates, Floating Rate Note, 11/25/35 219,518 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 23 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 1,656,429 1.09 Countrywide Asset-Backed Certificates, Floating Rate Note, 3/25/35 $ 1,642,255 10,134 0.96 Countrywide Asset-Backed Certificates, Floating Rate Note, 5/25/35 10,129 34,607 1.01 Countrywide Asset-Backed Certificates, Floating Rate Note, 5/25/35 34,584 171,873 0.87 Countrywide Asset-Backed Certificates, Floating Rate Note, 6/25/33 (144A) 166,451 36,745 1.09 Countrywide Asset-Backed Certificates, Floating Rate Note, 6/25/33 (144A) 35,407 1,550,862 CPS Auto Receivables Trust 2015-B, 1.65%, 11/15/19 1,542,600 441,162 Credit Acceptance Auto Loan Trust 2013-1, 1.21%, 10/15/20 (144A) 441,266 129,973 0.46 Credit Suisse Mortgage Capital Certificates, Floating Rate Note, 10/27/36 (144A) 127,994 549,112 0.85 Credit-Based Asset Servicing and Securitization LLC, Floating Rate Note, 7/25/34 547,820 4,121,610 0.50 Credit-Based Asset Servicing and Securitization LLC, Floating Rate Note, 7/25/36 4,077,875 4,114,690 1.24 CWABS Asset-Backed Certificates Trust 2004-7, Floating Rate Note, 12/25/34 4,092,779 547 Delta Funding Home Equity Loan Trust 1997-2, 7.04%, 6/25/27 550 1,603,351 3.14 Drug Royalty II LP 2, Floating Rate Note, 7/15/23 (144A) 1,623,351 1,146,992 DT Auto Owner Trust 2015-1, 1.06%, 9/17/18 (144A) 1,146,282 2,053,955 DT Auto Owner Trust 2015-2, 1.24%, 9/17/18 (144A) 2,052,431 2,832,566 1.09 Ellington Loan Acquisition Trust 2007-1, Floating Rate Note, 5/26/37 (144A) 2,796,171 327,534 1.09 Ellington Loan Acquisition Trust 2007-2, Floating Rate Note, 5/26/37 (144A) 326,799 14,400 0.66 Encore Credit Receivables Trust 2005-3, Floating Rate Note, 10/25/35 14,395 2,600,000 Enterprise Fleet Financing LLC, 1.59%, 2/22/21 (144A) 2,608,169 18,544 EquiVantage Home Equity Loan Trust 1997-1, 8.05%, 3/25/28 (Step) 18,430 1,000,000 Exeter Automobile Receivables Trust 2012-2, 3.06%, 7/16/18 (144A) 1,003,269 1,000,000 Exeter Automobile Receivables Trust 2013-1, 2.41%, 5/15/18 (144A) 1,003,230 459,191 Exeter Automobile Receivables Trust 2014-2, 1.06%, 8/15/18 458,439 1,179,361 Exeter Automobile Receivables Trust 2015-1, 1.6%, 6/17/19 (144A) 1,180,373 The accompanying notes are an integral part of these financial statements. 24 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 2,819,581 Exeter Automobile Receivables Trust 2015-2, 1.54%, 11/15/19 (144A) $ 2,820,456 718,809 1.92 Fieldstone Mortgage Investment Trust Series 2004-5, Floating Rate Note, 2/25/35 711,094 275,529 1.27 Fieldstone Mortgage Investment Trust Series 2005-1, Floating Rate Note, 3/25/35 275,478 1,377,527 0.70 First Franklin Mortgage Loan Trust 2005-FFH3, Floating Rate Note, 9/25/35 1,369,567 264,349 0.45 First Franklin Mortgage Loan Trust Series 2005-FF12, Floating Rate Note, 11/25/36 260,578 1,890 0.59 First NLC Trust 2005-2, Floating Rate Note, 9/25/35 1,889 3,400,640 1.98 Flagship Credit Auto Trust 2015-2, 1.98%, 10/15/20 (144A) (e) 3,408,118 1,569,532 0.57 Foothill CLO, Ltd., Floating Rate Note, 2/22/21 (144A) 1,561,580 2,600,000 0.44 Ford Credit Auto Owner Trust 2015-B, Floating Rate Note, 3/15/18 2,597,852 80,342 0.53 Fore CLO, Ltd., Floating Rate Note, 7/20/19 (144A) 80,259 553,000 2.15 Four Corners CLO II, Ltd., Floating Rate Note, 1/26/20 (144A) 541,316 539,687 0.53 Gale Force 3 CLO, Ltd., Floating Rate Note, 4/19/21 (144A) 528,843 2,174,145 GCAT 2015-1 LLC, 3.625%, 5/26/20 (Step) (144A) 2,172,760 540,670 GE Equipment Small Ticket LLC Series 2014-1, 0.59%, 8/24/16 540,639 1,641,277 GLC Trust 2013-1, 3.0%, 7/15/21 (144A) 1,624,864 2,840,085 GMAT 2013-1 Trust, 3.9669%, 8/25/53 (Step) 2,855,104 1,300,000 0.71 GMF Floorplan Owner Revolving Trust, Floating Rate Note, 5/15/20 (144A) 1,293,570 300,000 0.53 Golden Credit Card Trust, Floating Rate Note, 3/15/19 (144A) 298,905 590,000 0.65 Golden Credit Card Trust, Floating Rate Note, 3/15/21 (144A) 587,755 728,966 0.85 GSAA Home Equity Trust 2004-11, Floating Rate Note, 12/25/34 714,385 1,142,805 0.99 GSAA Trust, Floating Rate Note, 6/25/35 1,134,321 2,131,142 0.84 GSAMP Trust 2004-SEA2, Floating Rate Note, 3/25/34 2,130,157 407,900 0.94 GSAMP Trust 2005-HE1, Floating Rate Note, 12/25/34 400,638 96,131 0.55 GSAMP Trust 2005-HE6, Floating Rate Note, 11/25/35 94,814 805,594 0.40 GSAMP Trust 2006-HE1, Floating Rate Note, 12/26/45 792,607 67,950 0.65 GSAMP Trust 2006-SD1, Floating Rate Note, 7/25/45 67,919 1,311,367 0.49 GSAMP Trust 2006-SEA1, Floating Rate Note, 5/25/36 (144A) 1,297,473 972,764 1.54 GSRPM Mortgage Loan Trust 2003-2, Floating Rate Note, 6/25/33 937,588 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 25 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 909,293 0.49 GSRPM Mortgage Loan Trust 2006-1, Floating Rate Note, 3/25/35 (144A) $ 892,291 625,827 0.49 GSRPM Mortgage Loan Trust 2006-2, Floating Rate Note, 9/25/36 (144A) 595,344 1,500,000 2.04 Harch CLO III, Ltd., Floating Rate Note, 4/17/20 (144A) 1,485,387 3,200,000 1.70 Hertz Fleet Lease Funding LP, Floating Rate Note, 7/10/29 (144A) 3,200,000 2,600,000 2.50 Hertz Fleet Lease Funding LP, Floating Rate Note, 7/10/29 (144A) 2,570,490 5,600,000 HLSS Servicer Advance Receivables Trust, 1.4953%, 1/16/46 (144A) 5,594,400 489,929 0.96 Home Equity Asset Trust 2005-2, Floating Rate Note, 7/25/35 488,919 2,485,707 0.66 Home Equity Asset Trust 2005-6, Floating Rate Note, 12/25/35 2,478,376 3,242,079 0.57 Home Equity Asset Trust 2005-7, Floating Rate Note, 1/25/36 3,226,222 229,069 0.36 Home Equity Asset Trust 2006-4, Floating Rate Note, 8/25/36 225,298 1,349,577 0.30 Home Equity Asset Trust 2006-8, Floating Rate Note, 3/25/37 1,332,840 2,621,467 0.94 HomeBanc Mortgage Trust 2004-2, Floating Rate Note, 12/25/34 2,476,385 404,074 0.61 HomeBanc Mortgage Trust 2005-2, Floating Rate Note, 5/25/25 403,318 534,655 0.65 Homestar Mortgage Acceptance Corp., Floating Rate Note, 1/25/35 533,955 4,735,514 0.46 HSBC Home Equity Loan Trust USA 2006-3, Floating Rate Note, 3/20/36 4,708,995 501,412 0.45 HSBC Home Equity Loan Trust USA 2006-4, Floating Rate Note, 3/20/36 498,250 1,943,008 0.42 HSBC Home Equity Loan Trust USA 2007-1, Floating Rate Note, 3/20/36 1,932,805 500,519 0.52 HSBC Home Equity Loan Trust USA 2007-2, Floating Rate Note, 7/20/36 497,221 503,180 0.41 HSBC Home Equity Loan Trust USA 2007-2, Floating Rate Note, 7/20/36 499,377 5,829 1.37 HSBC Home Equity Loan Trust USA 2007-3, Floating Rate Note, 11/20/36 5,830 2,537,728 1.42 HSBC Home Equity Loan Trust USA 2007-3, Floating Rate Note, 11/20/36 2,530,247 3,916,199 1.05 Impac Secured Assets CMN Owner Trust, Floating Rate Note, 2/25/35 3,868,077 1,800,000 2.10 Invitation Homes 2013-SFR1 Trust, Floating Rate Note, 12/19/30 (144A) 1,769,362 The accompanying notes are an integral part of these financial statements. 26 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 2,840,000 2.31 Invitation Homes 2014-SFR1 Trust REMICS, Floating Rate Note, 6/17/31 (144A) $ 2,809,791 2,100,000 1.81 Invitation Homes 2014-SFR2 Trust, Floating Rate Note, 9/18/31 (144A) 2,056,272 2,000,000 1.41 Invitation Homes 2014-SFR3 Trust, Floating Rate Note, 12/18/31 (144A) 1,967,582 2,550,000 2.21 Invitation Homes 2015-SFR2 Trust, Floating Rate Note, 6/17/32 (144A) 2,499,426 3,500,000 1.96 Invitation Homes 2015-SFR3 Trust, Floating Rate Note, 8/19/32 (144A) 3,412,143 817,691 0.51 Inwood Park CDO, Ltd., Floating Rate Note, 1/20/21 (144A) 816,639 3,569,933 0.42 Irwin Home Equity Loan Trust 2005-1, Floating Rate Note, 6/25/25 3,332,025 1,342,583 1.69 Irwin Whole Loan Home Equity Trust 2003-C, Floating Rate Note, 6/25/28 1,326,555 2,591,859 0.66 Irwin Whole Loan Home Equity Trust 2005-B, Floating Rate Note, 12/25/29 2,530,082 579,771 0.98 IXIS Real Estate Capital Trust 2005-HE1, Floating Rate Note, 6/25/35 568,600 464,408 0.88 IXIS Real Estate Capital Trust 2005-HE4, Floating Rate Note, 2/25/36 458,128 2,575,000 0.97 JP Morgan Mortgage Acquisition Corp 2005-FLD1, Floating Rate Note, 7/25/35 2,545,815 791,166 0.41 JP Morgan Mortgage Acquisition Corp 2005-FRE1, Floating Rate Note, 10/25/35 781,387 2,118,020 0.34 JP Morgan Mortgage Acquisition Trust 2006-ACC1, Floating Rate Note, 5/25/36 2,103,274 3,702,000 2.95 Kabbage Funding 2014-1 Resecuritization Trust, Floating Rate Note, 3/8/18 (144A) 3,683,490 1,250,000 1.77 KKR Financial CLO 2007-1, Ltd., Floating Rate Note, 5/15/21 (144A) 1,244,881 683,166 Leaf Receivables Funding 8 LLC, 1.55%, 11/15/17 (144A) 683,343 2,750,000 Leaf Receivables Funding 8 LLC, 5.5%, 9/15/20 (144A) 2,777,522 800,000 LEAF Receivables Funding 9 LLC, 1.98%, 9/15/21 (144A) 801,471 138,211 0.66 Lehman ABS Manufactured Housing Contract Trust 2002-A, Floating Rate Note, 6/15/33 134,934 1,666,667 1.25 Lockwood Grove CLO, Ltd., Floating Rate Note, 1/25/24 (144A) 1,665,713 70,918 2.44 Madison Avenue Manufactured Housing Contract Trust 2002-A, Floating Rate Note, 3/25/32 70,912 1,700,000 Master Credit Card Trust II, 1.64%, 1/22/18 (144A) 1,704,848 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 27 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 1,095,892 0.83 MASTR Adjustable Rate Mortgages Trust 2004-11, Floating Rate Note, 11/25/34 $ 1,091,345 1,150,000 MMCA Auto Owner Trust 2012-A, 3.27%, 7/16/18 (144A) 1,151,082 985,296 1.12 Morgan Stanley ABS Capital I Inc Trust 2004-SD3, Floating Rate Note, 6/25/34 (144A) 986,190 17,606 0.97 Morgan Stanley ABS Capital I Inc Trust 2005-HE3, Floating Rate Note, 7/25/35 17,585 2,500,000 0.99 Morgan Stanley ABS Capital I Inc Trust 2005-HE3, Floating Rate Note, 7/25/35 2,414,182 51,627 0.90 Morgan Stanley ABS Capital I Inc Trust 2005-WMC3, Floating Rate Note, 3/25/35 51,446 1,355,632 0.83 Morgan Stanley ABS Capital I, Inc. Trust 2005-NC2, Floating Rate Note, 3/25/35 1,345,718 174,443 0.27 Morgan Stanley Structured Trust, Floating Rate Note, 6/25/37 172,829 2,600,000 0.79 MOTOR 2015-1 Plc, Floating Rate Note, 6/27/22 (144A) 2,601,012 924,746 Nations Equipment Finance Funding II LLC, 1.558%, 7/20/18 (144A) 925,065 409,436 0.34 Nationstar Home Equity Loan Trust 2007-A, Floating Rate Note, 3/25/37 400,811 803,247 0.90 New Century Home Equity Loan Trust 2005-1, Floating Rate Note, 3/25/35 796,728 2,600,000 1.95 NextGear Floorplan Master Owner Trust, Floating Rate Note, 7/15/19 (144A) 2,601,045 38,209 0.40 Nomura Home Equity Loan Inc Home Equity Loan Trust Series 2006-HE1, Floating Rate Note, 2/25/36 38,171 368,901 0.97 NovaStar Mortgage Funding Trust Series 2003-1, Floating Rate Note, 5/25/33 360,376 2,443,000 1.84 NovaStar Mortgage Funding Trust Series 2004-4, Floating Rate Note, 3/25/35 2,405,427 624,641 1.27 NovaStar Mortgage Funding Trust Series 2004-4, Floating Rate Note, 3/25/35 624,810 5,200,000 NRZ Advance Receivables Trust Advance Receivables Backed 2015-T1, 2.3147%, 8/15/46 (144A) 5,199,997 2,531,520 OAK Hill Advisors Residential Loan Trust 2014-NPL2, 3.475%, 4/25/54 (Step) (144A) 2,526,791 1,700,000 Ocwen Master Advance Receivables Trus, 2.5365%, 9/17/46 (144A) 1,700,000 2,397,580 0.99 Option One Mortgage Loan Trust 2005-1, Floating Rate Note, 2/25/35 2,349,329 1,208,194 0.45 Option One Mortgage Loan Trust 2005-4 Asset-Backed Certificates Series 2005-4, Floating Rate Note, 11/25/35 1,195,602 The accompanying notes are an integral part of these financial statements. 28 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 39,142 Option One Mortgage Loan Trust 2007-FXD2, 5.9%, 3/25/37 (Step) $ 35,936 708,589 1.32 Option One Woodbridge Loan Trust 2002-1, Floating Rate Note, 3/25/32 (144A) 702,117 874,365 5.46 Origen Manufactured Housing Contract Trust 2004-B, Floating Rate Note, 11/15/35 887,706 2,600,000 Oscar US Funding Trust III, 0.6%, 10/17/16 (144A) 2,600,000 415,551 0.77 Ownit Mortgage Loan Trust Series 2005-5, Floating Rate Note, 10/25/36 412,605 847,456 1.21 Park Place Securities Inc Asset-Backed Pass-Through Certificates Series 2004-WCW, Floating Rate Note, 9/25/34 840,869 1,297,522 1.14 Park Place Securities Inc Asset-Backed Pass-Through Ctfs Ser 2004-WHQ2, Floating Rate Note, 1/25/35 1,293,324 228,248 0.45 Park Place Securities Inc Asset-Backed Pass-Through Ctfs Ser 2005-WHQ4, Floating Rate Note, 9/25/35 219,155 240,457 1.13 Park Place Securities, Inc. Asset-Backed Pass-Through Certificates Series 2004-MCW, Floating Rate Note, 10/25/34 239,693 1,770,249 0.56 Park Place Securities, Inc. Asset-Backed Pass-Through Certificates Series 2005-WHQ4, Floating Rate Note, 9/25/35 1,758,730 1,400,000 0.81 PFS Financing Corp., Floating Rate Note, 10/15/19 (144A) 1,393,671 1,700,000 1.06 PFS Financing Corp., Floating Rate Note, 10/15/19 (144A) 1,695,978 3,240,000 0.76 PFS Financing Corp., Floating Rate Note, 2/15/18 (144A) 3,238,053 4,145,000 0.81 PFS Financing Corp., Floating Rate Note, 2/15/19 (144A) 4,133,249 950,000 0.83 PFS Financing Corp., Floating Rate Note, 4/15/20 (144A) 944,649 1,424,260 Prestige Auto Receivables Trust 2013-1, 1.33%, 5/15/19 (144A) 1,427,370 4,141,806 Pretium Mortgage Credit Partners I 2015-NPL2 LLC, 3.75%, 5/27/30 (Step) (144A) 4,141,202 4,750,000 Progreso Receivables Funding II LLC, 3.5%, 7/8/19 (144A) 4,771,021 3,050,000 Progreso Receivables Funding III LLC, 3.625%, 1/30/25 (144A) 3,064,171 1,700,000 Progreso Receivables Funding LLC, 3.0%, 7/8/20 1,703,108 3,000,000 2.61 Progress Residential 2015-SFR1 Trust, Floating Rate Note, 2/20/32 (144A) 2,975,325 2,972,413 0.85 Quest Trust REMICS, Floating Rate Note, 3/25/34 (144A) 2,895,894 768,566 1.14 RAAC Series 2005-RP1 Trust, Floating Rate Note, 7/25/37 (144A) 759,769 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 29 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 1,206,248 0.99 RAAC Series 2005-RP3 Trust, Floating Rate Note, 5/25/39 (144A) $ 1,182,516 138,085 0.49 RAAC Series 2006-RP1 Trust, Floating Rate Note, 10/25/45 (144A) 137,780 1,962,819 0.44 RAAC Series 2006-RP2 Trust, Floating Rate Note, 2/25/37 (144A) 1,937,597 761,633 1.13 RAMP Series 2004-RS11 Trust, Floating Rate Note, 11/25/34 751,227 1,094,019 0.68 RAMP Series 2004-RZ1 Trust, Floating Rate Note, 3/25/34 1,090,570 858,266 0.60 RAMP Series 2005-EFC4 Trust, Floating Rate Note, 9/25/35 857,146 357,392 0.69 RAMP Series 2005-RS6 Trust, Floating Rate Note, 6/25/35 355,289 424,371 0.59 RAMP Series 2005-RZ3 Trust, Floating Rate Note, 9/25/35 422,055 162,167 0.38 RAMP Series 2006-NC1 Trust, Floating Rate Note, 12/25/35 161,545 1,464,420 0.35 RAMP Series 2006-RZ3 Trust, Floating Rate Note, 10/25/35 1,447,065 582,675 0.97 RASC Series 2004-KS10 Trust, Floating Rate Note, 11/25/34 582,661 85,139 0.84 RASC Series 2005-KS3 Trust, Floating Rate Note, 4/25/35 85,149 107,511 0.92 RASC Series 2005-KS5 Trust, Floating Rate Note, 6/25/35 107,504 2,048,512 RBSHD 2013-1 Trust, 4.6853%, 10/25/47 (Step) (144A) 2,050,731 109,925 1.09 Salomon Mortgage Loan Trust Series 2001-CB4, Floating Rate Note, 11/25/33 108,791 920,171 0.74 SASCO Mortgage Loan Trust 2005-GEL1, Floating Rate Note, 12/25/34 898,552 263,766 0.76 SASCO Mortgage Loan Trust 2005-GEL2, Floating Rate Note, 4/25/35 262,025 15,080 2.67 SASCO Mortgage Pass-Through Certificates Series 2004-S4, Floating Rate Note, 12/25/34 15,079 3,269,435 0.66 Saxon Asset Securities Trust 2005-3, Floating Rate Note, 11/25/35 3,224,020 985,497 0.43 Saxon Asset Securities Trust 2005-4, Floating Rate Note, 11/25/37 980,582 3,778,000 2.26 Silver Bay Realty 2014-1 Trust, Floating Rate Note, 9/18/31 (144A) 3,686,043 190,158 Small Business Administration Participation Certificates, 0.58%, 10/17/16 (144A) 190,103 128,633 SMART ABS Series 2012-2US Trust, 1.59%, 10/14/16 (144A) 128,787 The accompanying notes are an integral part of these financial statements. 30 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 58,854 0.66 SMART ABS Series 2013-1US Trust, Floating Rate Note, 9/14/16 $ 58,857 755,392 0.64 SMART ABS Series 2013-2US Trust, Floating Rate Note, 1/17/17 755,354 2,250,000 0.63 SMART ABS Series 2015-1US Trust, Floating Rate Note, 8/14/17 2,250,292 2,400,000 SNAAC Auto Receivables Trust 2013-1, 4.56%, 4/15/20 (144A) 2,443,831 169,853 SNAAC Auto Receivables Trust 2014-1, 1.03%, 9/17/18 (144A) 169,823 1,463,997 0.92 Soundview Home Loan Trust 2005-DO1, Floating Rate Note, 5/25/35 1,453,070 656,886 0.46 Soundview Home Loan Trust 2005-OPT4, Floating Rate Note, 12/25/35 645,279 329,015 0.58 Specialty Underwriting & Residential Finance Trust Series 2005-AB2, Floating Rate Note, 6/25/36 327,284 542,247 0.52 Specialty Underwriting & Residential Finance Trust Series 2005-AB2, Floating Rate Note, 6/25/36 539,290 250,485 0.39 Specialty Underwriting & Residential Finance Trust Series 2006-BC1, Floating Rate Note, 12/25/36 248,878 3,640,376 0.49 Specialty Underwriting & Residential Finance Trust Series 2006-BC1, Floating Rate Note, 12/25/36 3,530,739 756,157 Springleaf Funding Trust 2013-A, 2.58%, 9/15/21 (144A) 757,909 2,854,104 0.92 Structured Asset Investment Loan Trust 2005-6, Floating Rate Note, 7/25/35 2,846,737 843,702 0.39 Structured Asset Investment Loan Trust 2006-1, Floating Rate Note, 1/25/36 826,429 973,084 0.79 Structured Asset Securities Corp Mortgage Loan Trust 2005-S7, Floating Rate Note, 12/25/35 (144A) 954,040 2,331,871 0.34 Structured Asset Securities Corp Mortgage Loan Trust 2006-EQ1, Floating Rate Note, 7/25/36 2,271,447 1,323,064 0.41 Structured Asset Securities Corp Mortgage Loan Trust 2006-GEL4, Floating Rate Note, 10/25/36 (144A) 1,311,362 4,034,172 0.50 Structured Asset Securities Corp Mortgage Loan Trust 2007-TC1, Floating Rate Note, 4/25/31 (144A) 3,809,747 834,485 0.41 Structured Asset Securities Corp Trust 2005-AR1, Floating Rate Note, 9/25/35 826,423 1,938,267 Sunset Mortgage Loan Co 2014-NPL2 LLC, 3.721%, 11/16/44 (Step) (144A) 1,936,619 4,559,977 1.51 SWAY Residential 2014-1 Trust, Floating Rate Note, 1/20/32 (144A) 4,507,246 739,447 1.13 Terwin Mortgage Trust Series TMTS 2003-8HE, Floating Rate Note, 12/25/34 719,473 2,610,295 0.64 Terwin Mortgage Trust Series TMTS 2005-10HE, Floating Rate Note, 6/25/36 2,601,321 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 31 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 1,073,236 Toyota Auto Receivables 2014-C Owner Trust, 0.51%, 2/15/17 1,072,553 3,079,000 1.45 Trade MAPS 1, Ltd., Floating Rate Note, 12/10/18 (144A) 3,070,256 2,795,000 0.90 Trade MAPS 1, Ltd., Floating Rate Note, 12/10/18 (144A) 2,795,903 1,400,000 1.16 Trafigura Securitisation Finance Plc. 2014-1, Floating Rate Note, 4/16/18 (144A) 1,400,444 750,501 1.90 Truman Capital Mortgage Loan Trust, Floating Rate Note, 1/25/34 734,179 4,229,138 U.S. Residential Opportunity Fund IV Trust 2015-1, 3.7213%, 2/27/35 (144A) 4,222,752 342,567 United Auto Credit Securitization Trust 2013-1, 2.9%, 12/15/17 (144A) 343,395 2,500,000 United Auto Credit Securitization Trust 2013-1, 4.4%, 4/15/19 (144A) 2,507,310 2,500,000 United Auto Credit Securitization Trust 2015-1, 1.68%, 9/15/17 (144A) 2,507,495 3,629,559 US Residential Opportunity Fund III Trust 2015-1, 3.7213%, 1/29/35 (144A) 3,624,013 686,014 VOLT XIX LLC, 3.875%, 4/26/55 (Step) 687,486 2,307,837 VOLT XXV LLC, 3.5%, 6/26/45 (Step) (144A) 2,294,553 2,694,703 VOLT XXXI LLC, 3.375%, 2/25/55 (Step) (144A) 2,685,495 2,274,654 VOLT XXXIII LLC, 3.5%, 3/25/55 (Step) (144A) 2,265,921 2,352,288 VOLT XXXVI LLC, 3.625%, 7/25/45 (Step) (144A) 2,341,000 3,700,000 VOLT XXXVIII LLC, 3.875%, 9/25/45 (Step) (144A) 3,696,892 749,397 0.57 Wells Fargo Home Equity Asset-Backed Securities 2005-3 Trust, Floating Rate Note, 12/25/35 742,844 1,300,000 0.44 Wells Fargo Home Equity Asset-Backed Securities 2006-1 Trust REMICS, Floating Rate Note, 7/25/36 1,217,286 2,600,000 0.96 Westlake Automobile Receivables Trust 2015-2, Floating Rate Note, 7/16/18 (144A) 2,600,387 703,991 Wheels SPV 2 LLC, 0.84%, 3/20/23 (144A) 702,435 28,929 0.48 Wilshire Mortgage Loan Trust, Floating Rate Note, 5/25/28 28,074 10,375,000 0.58 World Financial Network Credit Card Master Trust, Floating Rate Note, 12/16/19 10,375,000 1,550,000 0.68 World Financial Network Credit Card Master Trust, Floating Rate Note, 2/15/22 1,546,678 --------------- $ 444,000,598 --------------- Total Banks $ 444,068,357 --------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 32 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 7.7% Other Diversified Financial Services -- 2.2% 2,401,979 0.41 321 Henderson Receivables I LLC, Floating Rate Note, 6/15/41 (144A) $ 2,331,188 314,528 Ascentium Equipment Receivables 2014-1 LLC, 1.04%, 1/10/17 (144A) 314,458 1,700,000 Ascentium Equipment Receivables 2014-1 LLC, 1.58%, 10/10/18 (144A) 1,704,956 220,996 AXIS Equipment Finance Receivables II LLC, 1.75%, 6/20/16 220,796 2,886,477 BCC Funding VIII LLC, 1.794%, 6/22/20 (144A) 2,887,804 3,200,000 Capital Auto Receivables Asset Trust 2013-1, 1.74%, 10/22/18 3,212,643 1,001,000 Chase Issuance Trust, 0.54%, 10/16/17 1,000,999 2,700,000 0.35 Chase Issuance Trust, Floating Rate Note, 10/16/17 2,700,000 2,500,000 0.45 Chase Issuance Trust, Floating Rate Note, 11/15/18 2,498,502 6,480,000 0.25 Chase Issuance Trust, Floating Rate Note, 4/15/19 6,459,355 150,000 0.45 Chase Issuance Trust, Floating Rate Note, 4/15/19 149,261 3,000,000 0.42 Chase Issuance Trust, Floating Rate Note, 4/16/18 2,997,975 2,310,000 CNH Equipment Trust 2012-A, 2.09%, 8/15/18 2,317,866 855,623 CNH Equipment Trust 2013-A, 0.69%, 6/15/18 855,655 1,550,000 0.81 CNH Wholesale Master Note Trust, Floating Rate Note, 8/15/19 (144A) 1,547,024 2,100,000 2.11 Colony American Homes 2014-2, Floating Rate Note, 7/19/31 (144A) 2,054,501 3,125,000 Discover Card Execution Note Trust, 0.69%, 8/15/18 3,124,981 3,915,000 0.39 Discover Card Execution Note Trust, Floating Rate Note, 10/15/18 3,915,525 1,263,808 Enterprise Fleet Financing LLC, 0.87%, 9/20/19 1,262,449 1,337,705 Enterprise Fleet Financing LLC, 0.93%, 4/20/18 (144A) 1,337,409 962,703 0.43 Fifth Third Auto Trust 2014-3, Floating Rate Note, 5/15/17 962,756 1,726,813 FNA 2014-1 Trust, 1.296%, 12/10/22 (144A) 1,722,225 1,300,000 1.05 Gracechurch Card Funding Plc, Floating Rate Note, 5/15/19 (144A) 1,306,280 311,241 Kubota Credit Owner Trust 2014-1, 0.58%, 2/15/17 311,097 1,606,926 0.42 Mastr Asset Backed Securities Trust 2006-AB1 REMICS, Floating Rate Note, 2/25/36 1,593,571 1,320,791 0.38 Mastr Asset Backed Securities Trust 2006-NC1, Floating Rate Note, 1/25/36 1,309,202 3,625,869 0.49 Mastr Specialized Loan Trust, Floating Rate Note, 1/25/36 (144A) 3,526,545 234,393 0.37 Nelnet Student Loan Trust 2005-1, Floating Rate Note, 10/26/20 234,003 697,760 PFS Tax Lien Trust 2014-1, 1.44%, 5/15/29 697,922 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 33 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Other Diversified Financial Services -- (continued) 830,709 Prestige Auto Receivables Trust 2014-1, 0.97%, 3/15/18 (144A) $ 830,121 1,900,288 Sierra Timeshare 2013-1 Receivables Funding LLC, 2.39%, 11/20/29 (144A) 1,901,402 72,917 0.41 TAL Advantage I LLC, Floating Rate Note, 4/20/21 (144A) 72,670 923,548 TAL Advantage V LLC, 1.7%, 5/20/39 (144A) 919,247 1,685,433 0.43 World Omni Auto Receivables Trust 2014-B, Floating Rate Note, 1/16/18 1,685,278 1,919,035 0.42 World Omni Automobile Lease Securitization Trust 2014-A, Floating Rate Note, 3/15/17 1,914,775 --------------- $ 61,880,441 --------------------------------------------------------------------------------------------------------- Specialized Finance -- 0.5% 300,000 0.58 Ally Master Owner Trust, Floating Rate Note, 1/16/18 $ 299,972 2,600,000 0.61 Ally Master Owner Trust, Floating Rate Note, 6/17/19 2,596,355 830,158 Alterna Funding I LLC, 1.639%, 2/15/21 (144A) 827,302 237,897 1.56 Conseco Finance Corp., Floating Rate Note, 11/17/31 231,322 3,255,000 0.65 GE Dealer Floorplan Master Note Trust, Floating Rate Note, 10/20/19 3,238,188 1,190,000 0.60 GE Dealer Floorplan Master Note Trust, Floating Rate Note, 4/20/18 1,188,816 2,670,000 0.58 GE Dealer Floorplan Master Note Trust, Floating Rate Note, 7/22/19 2,651,112 1,422,964 NYCTL 2014-A Trust, 1.03%, 11/10/27 (144A) 1,421,851 --------------- $ 12,454,918 --------------------------------------------------------------------------------------------------------- Consumer Finance -- 3.9% 288,097 0.42 Ally Auto Receivables Trust 2014-SN1, Floating Rate Note, 10/20/16 $ 288,058 1,889,783 0.60 Ally Auto Receivables Trust 2015-SN1, Floating Rate Note, 6/20/17 1,889,932 103,939 American Credit Acceptance Receivables Trust 2013-1, 1.45%, 4/16/18 (144A) 103,940 3,600,000 American Credit Acceptance Receivables Trust 2013-1, 4.94%, 6/15/20 (144A) 3,648,362 157,114 American Credit Acceptance Receivables Trust 2014-1, 1.14%, 3/12/18 (144A) 157,098 356,251 American Credit Acceptance Receivables Trust 2014-2, 0.99%, 10/10/17 (144A) 356,111 385,552 American Credit Acceptance Receivables Trust 2014-3, 0.99%, 8/10/18 (144A) 385,219 990,775 American Credit Acceptance Receivables Trust 2014-4, 1.33%, 7/10/18 (144A) 990,408 350,000 0.47 American Express Credit Account Master Trust, Floating Rate Note, 1/15/20 350,148 The accompanying notes are an integral part of these financial statements. 34 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Consumer Finance -- (continued) 3,300,000 0.49 American Express Credit Account Master Trust, Floating Rate Note, 5/15/20 $ 3,293,304 991,695 AmeriCredit Automobile Receivables Trust 2012-1, 2.67%, 1/8/18 995,343 152,706 AmeriCredit Automobile Receivables Trust 2013-2, 0.65%, 12/8/17 152,720 438,623 0.48 AmeriCredit Automobile Receivables Trust 2014-2, Floating Rate Note, 10/10/17 438,472 2,000,000 0.49 BA Credit Card Trust, Floating Rate Note, 1/15/20 1,998,846 6,400,000 0.47 BA Credit Card Trust, Floating Rate Note, 9/16/19 6,396,288 2,350,000 0.73 Cabela's Credit Card Master Note Trust, Floating Rate Note, 2/18/20 (144A) 2,351,276 1,600,000 0.55 Cabela's Credit Card Master Note Trust, Floating Rate Note, 3/16/20 1,597,304 3,630,000 0.80 Cabela's Credit Card Master Note Trust, Floating Rate Note, 6/17/19 (144A) 3,635,158 75,574 California Republic Auto Receivables Trust 2012-1, 1.18%, 8/15/17 (144A) 75,585 154,312 California Republic Auto Receivables Trust 2013-1, 1.41%, 9/17/18 (144A) 154,743 3,400,000 0.28 Capital One Multi-Asset Execution Trust, Floating Rate Note, 12/16/19 3,389,613 1,950,000 0.38 Capital One Multi-Asset Execution Trust, Floating Rate Note, 2/15/19 1,949,846 5,470,000 0.29 Capital One Multi-Asset Execution Trust, Floating Rate Note, 6/17/19 5,455,937 6,945,000 0.29 Capital One Multi-Asset Execution Trust, Floating Rate Note, 8/15/18 6,944,306 4,600,000 0.66 CarMax Auto Owner Trust 2015-3, Floating Rate Note, 11/15/18 4,596,587 18,313 0.93 Chase Funding Trust Series 2002-4, Floating Rate Note, 10/25/32 16,991 6,300,000 0.25 Chase Issuance Trust, Floating Rate Note, 3/15/19 6,276,306 1,650,000 Citibank Credit Card Issuance Trust, 5.1%, 11/20/17 1,659,877 3,490,000 0.51 Citibank Credit Card Issuance Trust, Floating Rate Note, 11/7/18 3,488,621 9,931,000 0.43 Citibank Credit Card Issuance Trust, Floating Rate Note, 2/7/18 9,931,000 5,495,000 0.40 Citibank Credit Card Issuance Trust, Floating Rate Note, 5/9/18 5,493,906 259,100 CPS Auto Receivables Trust 2013-B, 1.82%, 9/15/20 (144A) 258,171 282,775 CPS Auto Receivables Trust 2014-A, 1.21%, 8/15/18 282,189 1,565,720 CPS Auto Receivables Trust 2014-C, 1.31%, 2/15/19 (144A) 1,556,254 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 35 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Consumer Finance -- (continued) 267,158 CPS Auto Trust, 1.48%, 3/16/20 (144A) $ 266,720 330,274 CPS Auto Trust, 1.82%, 12/16/19 (144A) 329,781 330,000 Credit Acceptance Auto Loan Trust 2013-2, 1.5%, 4/15/21 (144A) 330,244 1,200,160 Dell Equipment Finance Trust 2014-1, 0.64%, 7/22/16 (144A) 1,199,410 5,059 First Investors Auto Owner Trust 2012-2, 1.47%, 5/15/18 (144A) 5,062 1,775,000 First Investors Auto Owner Trust 2013-1, 2.53%, 1/15/20 (144A) 1,772,309 1,022,475 First Investors Auto Owner Trust 2013-2, 1.23%, 3/15/19 (144A) 1,022,647 1,060,656 First Investors Auto Owner Trust 2014-2, 0.86%, 8/15/18 (144A) 1,059,855 1,392,326 First Investors Auto Owner Trust 2014-3, 1.06%, 11/15/18 (144A) 1,392,069 4,400,000 1.04 First National Master Note Trust, Floating Rate Note, 9/15/20 4,400,080 1,093,932 0.37 Ford Credit Auto Lease Trust 2014-B, Floating Rate Note, 3/15/17 1,093,675 2,305,110 0.46 Ford Credit Auto Owner Trust 2015-A, Floating Rate Note, 1/15/18 2,303,883 350,000 0.59 Ford Credit Floorplan Master Owner Trust A, Floating Rate Note, 1/15/18 349,927 900,000 0.61 Ford Credit Floorplan Master Owner Trust A, Floating Rate Note, 2/15/19 898,024 4,300,000 0.45 Golden Credit Card Trust, Floating Rate Note, 2/15/18 (144A) 4,299,170 990,000 0.63 Golden Credit Card Trust, Floating Rate Note, 9/15/18 (144A) 990,514 286,172 Honda Auto Receivables 2012-4 Owner Trust, 0.52%, 8/18/16 286,120 66,736 Honda Auto Receivables 2013-1 Owner Trust, 0.48%, 11/21/16 66,720 359,040 Honda Auto Receivables 2013-2 Owner Trust, 0.53%, 2/16/17 358,885 417,938 Honda Auto Receivables 2014-1 Owner Trust, 0.41%, 9/21/16 417,820 225,794 Hyundai Auto Receivables Trust 2012-A, 0.95%, 12/15/16 225,809 18,067 Hyundai Auto Receivables Trust 2014-B, 0.44%, 2/15/17 18,062 1,825,000 0.63 Master Credit Card Trust II, Floating Rate Note, 1/22/18 (144A) 1,825,827 39,603 0.38 Mercedes Benz Auto Lease Trust 2014-A, Floating Rate Note, 6/15/16 39,602 The accompanying notes are an integral part of these financial statements. 36 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Consumer Finance -- (continued) 655,039 Nissan Auto Receivables 2013-A Owner Trust, 0.5%, 5/15/17 $ 654,776 782,987 Volkswagen Auto Lease Trust 2014-A, 0.52%, 10/20/16 782,732 202,846 0.43 Volkswagen Auto Lease Trust 2014-A, Floating Rate Note, 10/20/16 202,382 538,652 Volvo Financial Equipment LLC Series 2013-1, 0.74%, 3/15/17 (144A) 538,664 350,659 Volvo Financial Equipment LLC Series 2014-1, 0.54%, 11/15/16 (144A) 350,597 --------------- $ 108,039,285 --------------------------------------------------------------------------------------------------------- Asset Management & Custody Banks -- 0.6% 566,565 0.75 Accredited Mortgage Loan Trust 2005-1, Floating Rate Note, 4/25/35 $ 562,738 4,702,608 Engs Commercial Finance Trust 2015-1, 0.7%, 8/22/16 (144A) 4,702,622 595,563 Horizon Funding Trust 2013-1, 3.0%, 5/15/18 (144A) 597,424 349,465 Navitas Equipment Receivables LLC 2013-1, 1.95%, 11/15/16 349,483 5,024,700 Newstar Commercial Lease Funding 2015-1 LLC, 3.27%, 4/15/19 (144A) 5,013,741 1,957,866 RMAT 2015-1 LLC, 4.09%, 7/27/20 (Step) (144A) 1,959,108 3,700,828 VOLT XXXVII LLC, 3.625%, 7/25/45 (Step) (144A) 3,693,552 --------------- $ 16,878,668 --------------------------------------------------------------------------------------------------------- Investment Banking & Brokerage -- 0.5% 235,996 0.95 Chesapeake Funding LLC, Floating Rate Note, 11/7/23 (144A) $ 235,996 250,000 2.20 Chesapeake Funding LLC, Floating Rate Note, 11/7/23 (144A) 250,200 2,700,000 0.70 Chesapeake Funding LLC, Floating Rate Note, 2/7/27 (144A) 2,680,668 1,000,000 1.95 Chesapeake Funding LLC, Floating Rate Note, 2/7/27 (144A) 1,001,569 2,047,901 0.62 Chesapeake Funding LLC, Floating Rate Note, 3/7/26 2,041,647 600,081 1.45 Chesapeake Funding LLC, Floating Rate Note, 4/7/24 (144A) 601,376 675,595 0.65 Chesapeake Funding LLC, Floating Rate Note, 5/7/24 (144A) 675,181 3,534,000 2.05 Chesapeake Funding LLC, Floating Rate Note, 5/7/24 (144A) 3,536,029 1,709,252 Westlake Automobile Receivables Trust 2014-1, 0.7%, 5/15/17 (144A) 1,708,654 --------------- $ 12,731,320 --------------- Total Diversified Financials $ 211,984,632 --------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 37 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- REAL ESTATE -- 0.0%+ Real Estate Services -- 0.0%+ 412,446 0.38 HSI Asset Securitization Corp. Trust 2006-OPT1, Floating Rate Note, 12/25/35 $ 405,250 --------------- Total Real Estate $ 405,250 --------------------------------------------------------------------------------------------------------- GOVERNMENT -- 0.2% Government -- 0.2% 2,685,214 2.19 Fannie Mae Connecticut Avenue Securities, Floating Rate Note, 10/25/23 $ 2,709,977 610,435 Federal Home Loan Banks, 2.9%, 4/20/17 625,865 1,355,642 1.64 Freddie Mac Structured Agency Credit Risk Debt Notes, Floating Rate Note, 11/25/23 1,357,098 421,094 0.84 Fremont Home Loan Trust 2005-B, Floating Rate Note, 4/25/35 420,357 --------------- $ 5,113,297 --------------- Total Government $ 5,113,297 --------------------------------------------------------------------------------------------------------- TOTAL ASSET BACKED SECURITIES (Cost $680,704,525) $ 680,766,836 --------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- 28.1% ENERGY -- 0.1% Oil & Gas Exploration & Production -- 0.1% 3,535,061 0.55 Four Corners CLO III, Ltd., Floating Rate Note, 7/22/20 (144A) $ 3,504,350 --------------- Total Energy $ 3,504,350 --------------------------------------------------------------------------------------------------------- TRANSPORTATION -- 0.0%+ Trucking -- 0.0%+ 613,025 0.75 Hertz Fleet Lease Funding LP, Floating Rate Note, 12/10/27 (144A) $ 613,025 500,000 1.25 Hertz Fleet Lease Funding LP, Floating Rate Note, 12/10/27 (144A) 499,802 --------------- $ 1,112,827 --------------- Total Transportation $ 1,112,827 --------------------------------------------------------------------------------------------------------- BANKS -- 21.4% Thrifts & Mortgage Finance -- 21.4% 276,997 A10 Securitization 2013-1 LLC, 2.4%, 11/17/25 (144A) $ 277,876 3,209,653 0.95 Aberdeen Loan Funding, Ltd., Floating Rate Note, 11/1/18 (144A) 3,181,741 1,750,000 1.95 Aberdeen Loan Funding, Ltd., Floating Rate Note, 11/1/18 (144A) 1,745,119 2,256,444 0.50 ACAS CLO 2007-1, Ltd., Floating Rate Note, 4/20/21 (144A) 2,249,873 The accompanying notes are an integral part of these financial statements. 38 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 2,500,000 1.65 ACRE Commercial Mortgage Trust 2014-FL2, Floating Rate Note, 8/15/31 (144A) $ 2,500,602 3,282,334 1.20 ACRE Commercial Mortgage Trust 2014-FL2, Floating Rate Note, 8/15/31 (144A) 3,262,263 1,030,751 0.47 Adjustable Rate Mortgage Trust 2005-5, Floating Rate Note, 9/25/35 967,334 480,321 0.82 Alternative Loan Trust 2003-3T1, Floating Rate Note, 5/25/33 473,847 86,189 Alternative Loan Trust 2004-4CB, 4.25%, 4/25/34 86,282 2,068,274 0.77 Alternative Loan Trust 2004-6CB, Floating Rate Note, 4/25/34 2,003,018 1,000,000 1.09 Alternative Loan Trust 2004-J13, Floating Rate Note, 2/25/35 972,907 3,000,000 1.59 Apidos CLO IX, Floating Rate Note, 7/17/23 (144A) 2,993,221 5,000,000 1.96 Arbor Realty Collateralized Loan Obligation 2015-FL1, Ltd., Floating Rate Note, 3/15/25 (144A) 5,000,000 1,223,070 1.72 Arran Residential Mortgages Funding 2010-1 Plc, Floating Rate Note, 5/16/47 (144A) 1,224,793 1,925,976 0.48 ASG Resecuritization Trust 2010-3, Floating Rate Note, 12/29/45 (144A) 1,852,808 3,613,000 2.41 BAMLL Commercial Mortgage Securities Trust 2014-FL1, Floating Rate Note, 12/17/31 (144A) 3,610,785 1,920,000 1.31 BAMLL Commercial Mortgage Securities Trust 2014-ICTS, Floating Rate Note, 6/15/28 (144A) (e) 1,914,104 3,490,000 2.81 BAMLL Commercial Mortgage Securities Trust 2014-INLD REMICS, Floating Rate Note, 12/17/29 (144A) 3,486,287 7,000,000 2.44 BAMLL Re-REMIC Trust 2014-FRR7, Floating Rate Note, 10/26/44 (144A) 6,894,594 882,607 5.37 Banc of America Commercial Mortgage Trust 2006-1, Floating Rate Note, 9/10/45 883,376 3,590,000 5.46 Banc of America Commercial Mortgage Trust 2006-1, Floating Rate Note, 9/10/45 3,616,451 1,941,555 0.53 Banc of America Funding 2005-A Trust, Floating Rate Note, 2/20/35 1,877,270 1,201,520 5.32 Banc of America Merrill Lynch Commercial Mortgage, Inc., Floating Rate Note, 9/10/47 1,200,266 100,807 3.14 Banc of America Mortgage 2003-A Trust, Floating Rate Note, 2/25/33 99,810 325,506 2.75 Banc of America Mortgage 2003-F Trust, Floating Rate Note, 7/25/33 327,910 1,468,788 2.73 Banc of America Mortgage 2004-D Trust, Floating Rate Note, 5/25/34 1,474,659 379,746 2.55 Banc of America Mortgage 2004-I Trust, Floating Rate Note, 10/25/34 371,260 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 39 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 331,897 1.19 Bayview Commercial Asset Trust 2008-1, Floating Rate Note, 1/25/38 (144A) $ 331,503 3,971,802 1.81 BBCMS Trust 2014-BXO REMICS, Floating Rate Note, 8/16/27 (144A) 3,933,879 3,150,000 2.21 BBCMS Trust 2015-SLP, Floating Rate Note, 2/15/28 (144A) 3,111,472 1,596,852 2.97 BCAP LLC 2009-RR13-I Trust, Floating Rate Note, 9/26/35 (144A) 1,628,297 681,728 2.55 BCAP LLC 2013-RR3 Trust, Floating Rate Note, 5/28/36 (144A) 687,434 937,306 2.98 BCAP LLC 2013-RR7 Trust, Floating Rate Note, 12/27/34 964,490 987,538 1.03 Bear Stearns ALT-A Trust 2004-11, Floating Rate Note, 11/25/34 966,660 1,762,504 0.89 Bear Stearns ALT-A Trust 2004-12, Floating Rate Note, 1/25/35 1,719,460 1,116,898 1.03 Bear Stearns ALT-A Trust 2004-12, Floating Rate Note, 1/25/35 1,056,718 2,833,387 1.03 Bear Stearns ALT-A Trust 2004-12, Floating Rate Note, 1/25/35 2,692,293 2,815,604 0.89 Bear Stearns ALT-A Trust 2004-12, Floating Rate Note, 1/25/35 2,747,281 519,710 0.93 Bear Stearns ALT-A Trust 2004-13, Floating Rate Note, 11/25/34 512,230 2,406,636 0.79 Bear Stearns ALT-A Trust 2004-4, Floating Rate Note, 6/25/34 2,304,111 1,107,147 2.59 Bear Stearns ARM Trust 2003-3, Floating Rate Note, 5/25/33 1,111,614 324,016 2.92 Bear Stearns ARM Trust 2004-3, Floating Rate Note, 7/25/34 314,677 478,037 2.38 Bear Stearns ARM Trust 2005-5, Floating Rate Note, 8/25/35 482,760 241,123 1.29 Bear Stearns Asset Backed Securities Trust 2003-AC5, Floating Rate Note, 10/25/33 223,767 1,262,624 5.40 Bear Stearns Commercial Mortgage Securities Trust 2005-PWR10, Floating Rate Note, 12/11/40 1,262,659 755,160 4.99 Bear Stearns Commercial Mortgage Securities Trust 2005-PWR9, Floating Rate Note, 9/11/42 756,072 2,949,769 5.60 Bear Stearns Commercial Mortgage Securities Trust 2006-PWR11, Floating Rate Note, 3/11/39 2,972,857 2,774,753 5.89 Bear Stearns Commercial Mortgage Securities Trust 2006-PWR12, Floating Rate Note, 9/11/38 2,824,551 381,746 2.74 Bear Stearns Mortgage Securities, Inc., Floating Rate Note, 6/25/30 390,139 2,957,456 2.69 Bellemeade Re, Ltd., Floating Rate Note, 7/25/25 (144A) 2,955,608 The accompanying notes are an integral part of these financial statements. 40 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 150,000 1.56 BLCP Hotel Trust, Floating Rate Note, 8/15/29 (144A) $ 147,979 1,375,000 1.96 Boca Hotel Portfolio Trust 2013-BOCA, Floating Rate Note, 8/17/26 (144A) 1,372,027 3,823,000 3.06 BXHTL 2015-JWRZ Mortgage Trust, Floating Rate Note, 5/15/29 (144A) 3,780,760 2,794,054 0.55 Callidus Debt Partners Clo Fund VI, Ltd., Floating Rate Note, 10/23/21 (144A) 2,736,086 3,300,000 2.06 Carefree Portfolio Trust 2014-CARE, Floating Rate Note, 11/15/29 (144A) 3,316,903 4,900,000 2.71 CDGJ Commercial Mortgage Trust 2014-BXCH, Floating Rate Note, 12/15/27 (144A) 4,869,860 4,500,000 2.35 CFCRE 2015-RUM Mortgage Trust, Floating Rate Note, 7/15/30 (144A) 4,426,866 1,050,000 1.41 CGBAM Commercial Mortgage Trust 2014-HD, Floating Rate Note, 2/18/31 (144A) 1,042,797 5,670,000 1.16 CG-CCRE Commercial Mortgage Trust 2014-FL1, Floating Rate Note, 6/16/31 (144A) 5,645,829 6,770,000 2.11 CGWF Commercial Mortgage Trust 2013-RKWH REMICS, Floating Rate Note, 11/15/30 (144A) 6,768,010 118,138 Chase Mortgage Finance Trust Series 2005-S1, 5.5%, 5/25/35 118,755 110,299 0.52 Chevy Chase Funding LLC Mortgage-Backed Certificates Series 2004-1, Floating Rate Note, 1/25/35 (144A) 100,072 50,355 0.49 Chevy Chase Funding LLC Mortgage-Backed Certificates Series 2004-3, Floating Rate Note, 8/25/35 (144A) 46,371 657,856 0.69 CHL Mortgage Pass-Through Trust 2003-15 REMICS, Floating Rate Note, 6/25/18 642,130 169,799 0.57 CIFC Funding 2007-I, Ltd., Floating Rate Note, 5/10/21 (144A) 167,587 6,492 Citicorp Mortgage Securities REMIC Pass-Through Certificates Trust Series 2005-4, 5.0%, 7/25/20 6,710 1,124,754 Citicorp Mortgage Securities REMIC Pass-Through Certificates Trust Series 2005-7, 5.0%, 10/25/35 1,149,454 4,900,000 5.97 Citigroup Commercial Mortgage Trust 2006-C4, Floating Rate Note, 3/17/49 4,978,679 3,000,000 2.31 Citigroup Commercial Mortgage Trust 2015-SSHP REMICS, Floating Rate Note, 9/15/27 (144A) 3,001,437 1,759,359 Citigroup Mortgage Loan Trust 2010-4 REMICS, 5.0%, 10/25/35 (144A) 1,826,078 110,813 1.20 Citigroup Mortgage Loan Trust 2010-7 REMICS, Floating Rate Note, 9/25/37 (144A) 110,735 2,022 Citigroup Mortgage Loan Trust, Inc., 6.5%, 6/25/16 2,019 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 41 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 950,000 4.65 City Center Trust 2011-CCHP, Floating Rate Note, 7/17/28 (144A) $ 957,484 1,311,961 0.79 CNL Commercial Mortgage Loan Trust 2002-1, Floating Rate Note, 10/25/28 (144A) 1,259,483 4,500,000 2.10 Colony Mortgage Capital Series 2015-FL3, Ltd., Floating Rate Note, 9/5/32 (144A) 4,500,000 2,956,529 5.95 COMM 2006-C7 Mortgage Trust, Floating Rate Note, 6/10/46 3,000,135 4,970,000 2.36 COMM 2014-FL5 Mortgage Trust, Floating Rate Note, 10/17/31 (144A) 4,943,475 5,740,000 1.84 COMM 2014-KYO Mortgage Trust, Floating Rate Note, 6/11/27 (144A) 5,670,121 2,300,000 1.01 COMM 2014-PAT Mortgage Trust REMICS, Floating Rate Note, 8/13/27 (144A) 2,277,046 2,722,000 1.80 COMM 2014-PAT Mortgage Trust, Floating Rate Note, 8/13/27 (144A) 2,671,866 5,454,000 1.96 COMM 2014-SAVA Mortgage Trust, Floating Rate Note, 6/15/34 (144A) 5,425,852 7,340,000 1.81 COMM 2014-TWC Mortgage Trust, Floating Rate Note, 2/13/32 (144A) 7,319,499 697,463 2.14 Commercial Mortgage Pass Through Certificates, Floating Rate Note, 11/19/26 (144A) 696,206 3,500,000 1.80 Commercial Mortgage Pass Through Certificates, Floating Rate Note, 11/19/26 (144A) 3,497,392 2,533,631 5.28 Commercial Mortgage Trust 2005-GG5, Floating Rate Note, 4/10/37 2,532,866 4,500,000 2.73 Cratos CLO, Ltd., Floating Rate Note, 5/19/21 (144A) 4,488,813 3,450,988 5.61 Credit Suisse Commercial Mortgage Trust Series 2006-C1, Floating Rate Note, 2/15/39 3,454,881 1,907,194 5.86 Credit Suisse Commercial Mortgage Trust Series 2006-C2, Floating Rate Note, 3/15/39 1,930,468 4,434,000 6.01 Credit Suisse Commercial Mortgage Trust Series 2006-C3 REMICS, Floating Rate Note, 6/15/38 4,548,951 352,836 0.93 Credit Suisse First Boston Mortgage Securities Corp., Floating Rate Note, 6/25/34 342,174 1,539,893 0.46 Credit Suisse First Boston Mortgage Securities, 05-6, Floating Rate Note, 7/25/35 1,504,394 841,173 2.80 Credit Suisse Mortgage Capital Certificates REMICS, Floating Rate Note, 7/27/36 (144A) 850,618 3,624,899 1.78 Crown Point CLO, Ltd., Floating Rate Note, 11/21/22 (144A) 3,610,743 2,300,000 2.46 CSMC 2015-TWNI Trust, Floating Rate Note, 3/15/28 (144A) 2,280,673 6,470,000 1.45 CSMC Series 2014-ICE, Floating Rate Note, 4/15/27 (144A) 6,439,313 The accompanying notes are an integral part of these financial statements. 42 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 3,500,000 2.06 CSMC Trust 2015-DEAL, Floating Rate Note, 4/16/29 (144A) $ 3,467,226 3,750,000 3.06 CSMC Trust 2015-SAND, Floating Rate Note, 8/15/30 (144A) 3,750,360 1,460,000 1.51 Del Coronado Trust 2013-DEL, Floating Rate Note, 3/16/26 (144A) 1,455,912 1,850,000 1.80 EQTY 2014-INNS Mortgage Trust REMICS, Floating Rate Note, 5/8/31 (144A) 1,822,862 3,530,000 1.40 EQTY 2014-INNS Mortgage Trust, Floating Rate Note, 5/8/31 (144A) 3,492,554 139,391 1.30 Extended Stay America Trust 2013-ESH, Floating Rate Note, 12/5/31 (144A) 138,783 785,627 2.71 First Horizon Mortgage Pass-Through Trust 2003-AR3, Floating Rate Note, 9/25/33 786,682 1,750,000 0.74 Fore CLO, Ltd., Floating Rate Note, 7/20/19 (144A) 1,732,434 2,555,760 Freddie Mac, 4.0%, 12/15/23 2,601,828 7,251,735 4.20 FREMF Mortgage Trust 2014-KF05 REMICS, Floating Rate Note, 9/25/21 (144A) 7,255,715 3,750,000 1.69 Gale Force 3 Clo, Ltd., Floating Rate Note, 4/19/21 (144A) 3,554,716 690,115 Global Mortgage Securitization, Ltd., 5.25%, 4/25/32 666,944 371,436 0.51 Global Mortgage Securitization, Ltd., Floating Rate Note, 11/25/32 (144A) 361,488 3,570,630 0.46 Global Mortgage Securitization, Ltd., Floating Rate Note, 4/25/32 3,419,250 3,764,123 5.23 GMAC Commercial Mortgage Securities Inc Series 2006-C1 Trust, Floating Rate Note, 11/10/45 3,770,537 3,500,000 3.05 Goldman Sachs Asset Management CLO Plc, Floating Rate Note, 8/1/22 (144A) 3,484,348 3,350,000 1.51 GP Portfolio Trust 2014-GGP, Floating Rate Note, 2/16/27 (144A) 3,314,406 2,072,134 5.55 GS Mortgage Securities Trust 2006-GG6 REMICS, Floating Rate Note, 4/10/38 2,072,215 2,000,000 1.96 GS Mortgage Securities Trust 2014-GSFL, Floating Rate Note, 7/15/31 (144A) 1,989,728 1,179,189 0.97 GSAA Home Equity Trust 2004-6, Floating Rate Note, 6/25/34 1,144,807 246,040 0.93 GSAA Home Equity Trust 2004-8, Floating Rate Note, 9/25/34 242,462 678,794 2.72 HarborView Mortgage Loan Trust 2004-1, Floating Rate Note, 4/19/34 677,397 248,553 1.32 HarborView Mortgage Loan Trust 2004-4, Floating Rate Note, 6/19/34 240,176 1,421,425 1.29 Homestar Mortgage Acceptance Corp. REMICS, Floating Rate Note, 9/25/34 1,407,924 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 43 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 4,009,668 0.83 Homestar Mortgage Acceptance Corp., Floating Rate Note, 3/25/34 $ 3,845,172 739,019 0.89 Homestar Mortgage Acceptance Corp., Floating Rate Note, 6/25/34 727,886 1,498,713 0.64 Homestar Mortgage Acceptance Corp., Floating Rate Note, 7/25/34 1,486,373 1,545,624 0.77 Homestar Mortgage Acceptance Corp., Floating Rate Note, 7/25/34 1,539,602 2,480,000 1.91 Hyatt Hotel Portfolio Trust 2015-HYT, Floating Rate Note, 11/15/29 (144A) 2,487,641 479,904 1.10 Impac CMB Trust Series 2003-8, Floating Rate Note, 10/25/33 462,277 1,932,608 0.84 Impac CMB Trust Series 2004-4, Floating Rate Note, 9/25/34 1,846,537 1,684,431 0.82 Impac CMB Trust Series 2004-4, Floating Rate Note, 9/25/34 1,609,893 474,259 1.04 Impac CMB Trust Series 2004-5, Floating Rate Note, 8/25/34 465,549 481,353 0.99 Impac CMB Trust Series 2004-6, Floating Rate Note, 10/25/34 458,740 1,599,513 1.02 Impac CMB Trust Series 2004-8, Floating Rate Note, 8/25/34 1,542,223 233,276 2.82 Impac CMB Trust Series 2004-8, Floating Rate Note, 8/25/34 223,933 816,001 0.55 Impac Secured Assets Trust 2006-2, Floating Rate Note, 8/25/36 796,456 763,799 0.40 Impac Secured Assets Trust 2006-5, Floating Rate Note, 12/25/36 722,426 111,750 6.45 JP Morgan Chase Commercial Mortgage Securities Corp. Pass-Through Certificates Series 2002 CIBC4, Floating Rate Note, 5/12/34 115,000 222,600 4.84 JP Morgan Chase Commercial Mortgage Securities Trust 2004-LN2, Floating Rate Note, 7/15/41 221,778 2,808,513 5.04 JP Morgan Chase Commercial Mortgage Securities Trust 2005-LDP4, Floating Rate Note, 10/15/42 2,807,797 1,525,646 0.49 JP Morgan Chase Commercial Mortgage Securities Trust 2006-FL2, Floating Rate Note, 11/15/18 (144A) 1,495,545 167,333 0.57 JP Morgan Chase Commercial Mortgage Securities Trust 2006-FL2, Floating Rate Note, 11/15/18 (144A) 160,146 3,512,000 5.56 JP Morgan Chase Commercial Mortgage Securities Trust 2006-LDP6, Floating Rate Note, 4/15/43 3,542,438 71,491 0.36 JP Morgan Chase Commercial Mortgage Securities Trust 2006-LDP9, Floating Rate Note, 5/15/47 70,848 5,876,568 JP Morgan Chase Commercial Mortgage Securities Trust 2007-CIBC18, 5.44%, 6/12/47 6,087,455 The accompanying notes are an integral part of these financial statements. 44 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 5,600,000 1.46 JP Morgan Chase Commercial Mortgage Securities Trust 2014-BXH, Floating Rate Note, 4/15/27 (144A) $ 5,591,454 4,280,000 1.61 JP Morgan Chase Commercial Mortgage Securities Trust 2014-CBM, Floating Rate Note, 10/15/29 (144A) 4,241,493 3,470,000 2.16 JP Morgan Chase Commercial Mortgage Securities Trust 2014-CBM, Floating Rate Note, 10/15/29 (144A) 3,436,469 3,510,000 1.70 JP Morgan Chase Commercial Mortgage Securities Trust 2014-FBLU REMICS, Floating Rate Note, 12/15/28 (144A) 3,508,800 2,910,000 2.20 JP Morgan Chase Commercial Mortgage Securities Trust 2014-FBLU, Floating Rate Note, 12/15/28 (144A) 2,911,406 1,700,000 1.96 JP Morgan Chase Commercial Mortgage Securities Trust 2014-FL4, Floating Rate Note, 12/16/30 (144A) 1,697,618 2,500,000 2.31 JP Morgan Chase Commercial Mortgage Securities Trust 2014-FL5 REMICS, Floating Rate Note, 7/15/31 (144A) 2,487,478 4,240,000 1.61 JP Morgan Chase Commercial Mortgage Securities Trust 2014-FL6, Floating Rate Note, 11/17/31 (144A) 4,221,654 3,750,000 1.13 JP Morgan Chase Commercial Mortgage Securities Trust 2014-INN, Floating Rate Note, 6/15/29 (144A) 3,723,045 3,500,000 1.91 JP Morgan Chase Commercial Mortgage Securities Trust 2014-INN, Floating Rate Note, 6/15/29 (144A) 3,484,159 3,770,000 1.81 JP Morgan Chase Commercial Mortgage Securities Trust 2014-PHH, Floating Rate Note, 8/16/27 (144A) 3,765,084 4,000,000 2.46 JP Morgan Chase Commercial Mortgage Securities Trust 2015-COSMO, Floating Rate Note, 1/15/32 (144A) 3,971,296 3,600,000 2.01 JP Morgan Chase Commercial Mortgage Securities Trust 2015-FL7, Floating Rate Note, 5/15/28 3,552,793 4,500,000 2.94 JP Morgan Chase Commercial Mortgage Securities Trust 2015-SGP, Floating Rate Note, 7/15/36 (144A) 4,500,000 5,900,278 0.69 JP Morgan Seasoned Mortgage Trust 2014-1, Floating Rate Note, 5/25/33 (144A) 5,631,530 3,687,713 1.73 Lanark Master Issuer Plc, Floating Rate Note, 12/22/54 (144A) 3,700,799 1,059,967 0.83 Lanark Master Issuer Plc, Floating Rate Note, 12/22/54 (144A) 1,060,438 80,144 LB-UBS Commercial Mortgage Trust 2004-C1, 4.568%, 1/15/31 80,895 2,048,302 LB-UBS Commercial Mortgage Trust 2006-C1 REMICS, 5.156%, 2/15/31 2,051,429 3,800,000 6.05 LB-UBS Commercial Mortgage Trust 2006-C4, Floating Rate Note, 6/15/38 3,882,908 463,320 1.55 LCM X LP, Floating Rate Note, 4/15/22 (144A) 462,881 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 45 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 804,370 1.15 Lehman Brothers Small Balance Commercial Mortgage Trust 2007-3 Class 1A4, Floating Rate Note, 10/25/37 (144A) $ 800,356 1,213,249 1.25 Lehman Brothers Small Balance Commercial Mortgage Trust 2007-3, Floating Rate Note, 10/25/37 (144A) 1,207,861 770,347 0.42 Lehman Brothers Small Balance Commercial, Floating Rate Note, 4/25/31 (144A) 732,522 2,021,839 0.43 Lehman Brothers Small Balance Commercial, Floating Rate Note, 4/25/31 (144A) 1,929,263 2,190,928 0.90 Lehman XS Trust Series 2005-2, Floating Rate Note, 8/25/35 2,075,438 7,319,332 2.20 LSTAR Securities Investment Trust 2014-2, Floating Rate Note, 11/1/19 (144A) 7,282,707 3,461,166 2.20 LSTAR Securities Investment Trust 2015-5, Floating Rate Note, 4/1/20 (144A) 3,450,751 4,130,442 2.19 LSTAR Securities Investment Trust 2015-7, Floating Rate Note, 7/1/20 (144A) 4,073,087 2,884,471 2.20 LSTAR Securities Investment Trust 2015-8, Floating Rate Note, 8/1/20 (144A) 2,849,924 701,901 2.24 MASTR Adjustable Rate Mortgages Trust 2003-3, Floating Rate Note, 9/25/33 703,924 1,330,601 0.54 MASTR Alternative Loan Trust 2005-1, Floating Rate Note, 2/25/35 1,304,842 141,042 0.60 MASTR Asset Securitization Trust 2003-6, Floating Rate Note, 7/25/18 136,923 1,101,332 0.65 Mellon Residential Funding Corp. Mortgage Pass-Through Trust Series 2000-TBC3, Floating Rate Note, 12/15/30 1,050,195 1,070,281 2.55 Merrill Lynch Mortgage Investors Trust Series 2005-A9, Floating Rate Note, 12/25/35 1,063,283 1,422,103 1.35 Merrill Lynch Mortgage Investors Trust Series MLCC 2003-A, Floating Rate Note, 3/25/28 1,326,754 1,393,156 0.87 Merrill Lynch Mortgage Investors Trust Series MLCC 2003-B, Floating Rate Note, 4/25/28 1,348,221 1,813,931 0.85 Merrill Lynch Mortgage Investors Trust Series MLCC 2003-C REMICS, Floating Rate Note, 6/25/28 1,724,854 1,309,592 1.14 Merrill Lynch Mortgage Investors Trust Series MLCC 2003-C, Floating Rate Note, 6/25/28 1,290,925 1,592,488 0.81 Merrill Lynch Mortgage Investors Trust Series MLCC 2003-E, Floating Rate Note, 10/25/28 1,520,532 731,878 0.83 Merrill Lynch Mortgage Investors Trust Series MLCC 2003-G, Floating Rate Note, 1/25/29 700,674 190,092 1.86 Merrill Lynch Mortgage Investors Trust Series MLCC 2003-G, Floating Rate Note, 1/25/29 189,222 1,271,228 0.83 Merrill Lynch Mortgage Investors Trust Series MLCC 2003-H, Floating Rate Note, 1/25/29 1,251,939 The accompanying notes are an integral part of these financial statements. 46 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 1,773,393 0.65 Merrill Lynch Mortgage Investors Trust Series MLCC 2004-A REMICS, Floating Rate Note, 4/25/29 $ 1,702,195 371,246 0.96 Merrill Lynch Mortgage Investors Trust Series MLCC 2004-B, Floating Rate Note, 5/25/29 360,659 2,061,464 0.75 Merrill Lynch Mortgage Investors Trust Series MLCC 2004-C, Floating Rate Note, 7/25/29 1,922,233 111,766 1.44 Merrill Lynch Mortgage Investors Trust Series MLCC 2004-C, Floating Rate Note, 7/25/29 106,996 689,850 2.10 Merrill Lynch Mortgage Investors Trust Series MLCC 2004-D, Floating Rate Note, 9/25/29 689,816 2,442,852 1.25 Merrill Lynch Mortgage Investors Trust Series MLCC 2004-E, Floating Rate Note, 11/25/29 2,359,054 2,336,177 0.75 Merrill Lynch Mortgage Investors Trust Series MLCC 2004-G, Floating Rate Note, 1/25/30 2,199,179 1,111,846 1.04 Merrill Lynch Mortgage Investors Trust Series MLCC 2004-G, Floating Rate Note, 1/25/30 1,080,953 2,142,108 0.65 Merrill Lynch Mortgage Investors Trust Series MLCC 2005-A, Floating Rate Note, 3/25/30 2,080,704 2,118,318 5.29 Merrill Lynch Mortgage Trust 2005-LC1, Floating Rate Note, 1/12/44 2,117,770 6,475,000 5.78 Merrill Lynch Mortgage Trust 2006-C2, Floating Rate Note, 8/12/43 6,667,573 5,410,000 6.03 Merrill Lynch Mortgage Trust 2007-C1, Floating Rate Note, 6/12/50 5,641,326 3,700,000 6.07 ML-CFC Commercial Mortgage Trust 2006-2, Floating Rate Note, 6/12/46 3,776,527 3,200,000 5.79 Morgan Stanley Capital I Trust 2006-HQ9, Floating Rate Note, 7/12/44 3,281,059 137,820 5.16 Morgan Stanley Capital I Trust 2006-TOP21, Floating Rate Note, 10/12/52 137,672 2,145,094 6.01 Morgan Stanley Capital I Trust 2006-TOP23, Floating Rate Note, 8/12/41 2,187,367 1,591,178 5.51 Morgan Stanley Capital I Trust 2007-TOP25, Floating Rate Note, 11/12/49 1,651,268 3,860,000 1.96 Morgan Stanley Capital I Trust 2015-XLF1, Floating Rate Note, 8/14/31 (144A) 3,840,673 2,870,000 2.41 Morgan Stanley Capital I Trust 2015-XLF1, Floating Rate Note, 8/14/31 (144A) 2,853,833 2,369,398 0.46 Morgan Stanley Mortgage Loan Trust 2005-5AR, Floating Rate Note, 9/25/35 2,347,266 1,699,094 0.47 Morgan Stanley Mortgage Loan Trust 2005-6AR, Floating Rate Note, 11/25/35 1,641,306 451,812 0.46 Morgan Stanley Mortgage Loan Trust 2005-6AR, Floating Rate Note, 11/25/35 449,266 2,502,204 0.97 MortgageIT Trust 2004-1, Floating Rate Note, 11/25/34 2,394,739 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 47 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 5,326,846 0.93 MortgageIT Trust 2004-2, Floating Rate Note, 12/25/34 $ 5,148,908 1,435,069 0.71 MortgageIT Trust 2005-2, Floating Rate Note, 5/25/35 1,370,168 370,555 0.56 NewStar Commercial Loan Trust 2007-1, Floating Rate Note, 9/30/22 (144A) 366,148 2,750,000 2.19 Newstar Trust, Floating Rate Note, 1/20/23 (144A) 2,741,255 3,561,150 3.11 Nomura Resecuritization Trust 2011-4R, Floating Rate Note, 6/26/47 (144A) 3,572,064 1,686,794 2.04 NorthStar 2013-1, Floating Rate Note, 8/27/29 (144A) 1,688,377 4,989,520 0.58 Opteum Mortgage Acceptance Corp Trust 2005-4, Floating Rate Note, 11/25/35 4,603,461 4,337,620 0.50 Opteum Mortgage Acceptance Corp Trust 2005-4, Floating Rate Note, 11/25/35 4,074,452 905,905 3.00 ORES 2014-LV3 LLC, 3.0%, 3/27/24 (144A) (e) 905,905 295,284 ORES NPL 2013-LV2 LLC, 3.081%, 9/25/25 (144A) 294,989 3,500,000 0.54 Pepper Residential Securities Trust No 14, Floating Rate Note, 6/12/16 3,499,758 3,750,000 1.66 PFP 2015-2, Ltd., Floating Rate Note, 7/14/34 (144A) 3,750,251 5,200,000 2.35 RAIT 2014-FL2 Trust, Floating Rate Note, 5/15/31 (144A) 5,152,430 3,695,314 1.45 RAIT 2014-FL3 Trust, Floating Rate Note, 12/15/31 (144A) (e) 3,686,046 57,604 0.75 RALI Series 2002-QS16 Trust, Floating Rate Note, 10/25/17 55,847 585,448 0.60 RALI Series 2003-QS10 Trust, Floating Rate Note, 5/25/33 570,463 1,852,345 0.70 RALI Series 2003-QS11 Trust, Floating Rate Note, 6/25/33 1,724,427 788,078 0.65 RALI Series 2003-QS22 Trust, Floating Rate Note, 12/26/33 713,868 629,770 0.65 RALI Series 2003-QS5 Trust, Floating Rate Note, 3/25/18 615,196 846,196 0.65 RALI Series 2003-QS9 Trust, Floating Rate Note, 5/25/18 827,663 422,502 RALI Series 2004-QS5 Trust, 4.75%, 4/25/34 432,270 431,185 0.80 RALI Series 2004-QS5 Trust, Floating Rate Note, 4/25/34 425,785 3,012,435 0.49 RALI Series 2005-QA1 Trust, Floating Rate Note, 1/25/35 2,876,429 198,887 0.59 Regatta Funding, Ltd., Floating Rate Note, 6/15/20 (144A) 197,859 5,197,397 1.65 RESI Finance LP 2003-CB1, Floating Rate Note, 7/9/35 4,811,905 The accompanying notes are an integral part of these financial statements. 48 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 2,205,764 1.04 RESI MAC, 2014-1A, Floating Rate Note, 6/12/19 $ 2,203,116 531,202 0.65 Residential Asset Securitization Trust 2003-A15, Floating Rate Note, 2/25/34 490,526 340,149 0.60 Residential Asset Securitization Trust 2003-A2, Floating Rate Note, 5/25/33 312,537 4,920,000 1.26 Resource Capital Corp 2014-CRE2, Ltd., Floating Rate Note, 4/15/32 (144A) 4,886,677 2,000,000 1.59 Resource Capital Corp 2015-CRE4, Ltd., Floating Rate Note, 8/17/32 (144A) (e) 2,000,000 3,000,000 2.36 Resource Capital Corp. CRE Notes 2013, Ltd., Floating Rate Note, 6/15/16 (144A) 3,000,777 2,719,775 RREF 2015-LT7 LLC, 3.0%, 12/25/32 (144A) 2,719,384 2,532,725 Selene Non-Performing Loans LLC, 2.9814%, 5/25/54 (Step) (144A) 2,510,974 151,326 0.98 Sequoia Mortgage Trust 10, Floating Rate Note, 10/20/27 142,211 459,488 1.08 Sequoia Mortgage Trust 2003-2, Floating Rate Note, 6/20/33 447,382 2,137,798 0.84 Sequoia Mortgage Trust 2003-5, Floating Rate Note, 9/20/33 2,084,242 239,632 0.86 Sequoia Mortgage Trust 2003-8, Floating Rate Note, 1/20/34 228,790 477,253 0.86 Sequoia Mortgage Trust 2004-10, Floating Rate Note, 11/20/34 450,116 319,388 1.78 Sequoia Mortgage Trust 2004-7, Floating Rate Note, 8/20/34 321,556 2,849,114 0.68 Sequoia Mortgage Trust 2005-1, Floating Rate Note, 2/20/35 2,680,392 1,057,080 0.96 Sequoia Mortgage Trust 2005-1, Floating Rate Note, 2/20/35 1,000,703 1,035,218 0.92 Sequoia Mortgage Trust 4, Floating Rate Note, 11/22/24 1,030,619 298,230 1.57 Springleaf Mortgage Loan Trust 2012-3, Floating Rate Note, 12/26/59 (144A) 298,149 920,230 1.78 Springleaf Mortgage Loan Trust 2013-2, Floating Rate Note, 12/28/65 (144A) 920,853 372,282 2.92 Structured Adjustable Rate Mortgage Loan Trust Class 1A1, Floating Rate Note, 3/25/34 369,764 449,712 2.50 Structured Adjustable Rate Mortgage Loan Trust, Floating Rate Note, 11/25/34 444,463 3,192,140 1.04 Structured Adjustable Rate Mortgage Loan Trust, Floating Rate Note, 11/25/34 2,936,768 491,985 2.44 Structured Adjustable Rate Mortgage Loan Trust, Floating Rate Note, 3/25/34 496,226 17,621 0.59 Structured Adjustable Rate Mortgage Loan Trust, Floating Rate Note, 6/25/35 17,618 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 49 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 2,153,686 0.56 Structured Adjustable Rate Mortgage Loan Trust, Floating Rate Note, 7/25/34 $ 2,073,388 738,754 0.92 Structured Asset Mortgage Investments II Trust 2004-AR1, Floating Rate Note, 3/19/34 705,284 3,993,081 0.90 Structured Asset Mortgage Investments II Trust 2004-AR8, Floating Rate Note, 5/19/35 3,879,838 1,679,960 1.12 Structured Asset Mortgage Investments Trust 2002-AR5, Floating Rate Note, 5/19/33 1,641,057 159,950 2.56 Structured Asset Securities Corp. Mortgage Certificates Series 2003-31A, Floating Rate Note, 10/25/33 158,668 1,149,549 1.13 Structured Asset Securities Corp. Mortgage Pass-Through Certificates Series 1998-8, Floating Rate Note, 8/25/28 1,136,781 903,631 2.42 Structured Asset Securities Corp. Mortgage Pass-Through Certificates Series 2003-24A, Floating Rate Note, 7/25/33 889,528 145,904 0.69 Structured Asset Securities Corp. Mortgage Pass-Through Certificates Series 2003-35, Floating Rate Note, 12/25/33 144,718 352,112 0.50 Structured Asset Securities Corp. Trust 2005-14, Floating Rate Note, 7/25/35 300,122 3,050,000 1.56 Symphony CLO, Ltd., Floating Rate Note, 7/23/23 (144A) 3,043,997 592,166 1.74 Thornburg Mortgage Securities Trust 2004-4, Floating Rate Note, 12/25/44 583,187 2,096,598 2.19 Velocity Commercial Capital Loan Trust 2014-1, Floating Rate Note, 9/25/44 (144A) 2,091,356 750,000 1.63 Venture XII CLO, Ltd., Floating Rate Note, 2/28/24 (144A) 748,478 1,218,873 VFC 2014-2 LLC, 2.75%, 7/20/30 (144A) 1,218,302 1,189,488 VFC 2015-3 LLC, 2.75%, 12/20/31 (144A) 1,187,742 1,959,598 VOLT NPL X LLC, 3.375%, 10/26/54 (Step) (144A) 1,957,294 2,068,668 3.63 VOLT XXX LLC, 3.625%, 10/25/57 (Step) (e) 2,065,706 3,000,000 1.61 Voya CLO, Ltd., Floating Rate Note, 10/15/22 (144A) 2,994,255 4,350,000 5.52 Wachovia Bank Commercial Mortgage Trust Series 2006-C23 REMICS, Floating Rate Note, 1/15/45 4,382,647 1,685,434 5.42 Wachovia Bank Commercial Mortgage Trust Series 2006-C23 REMICS, Floating Rate Note, 1/15/45 1,686,337 2,782,696 5.90 Wachovia Bank Commercial Mortgage Trust Series 2006-C25, Floating Rate Note, 5/15/43 2,804,755 4,500,000 5.60 Wachovia Bank Commercial Mortgage Trust Series 2006-C28 REMICS, Floating Rate Note, 10/15/48 4,665,938 2,500,000 2.06 Wells Fargo Commercial Mortgage Trust 2014-TISH REMICS, Floating Rate Note, 2/16/27 (144A) 2,455,995 The accompanying notes are an integral part of these financial statements. 50 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 3,000,000 2.97 Wells Fargo Credit Risk Transfer Securities Trust 2015, Floating Rate Note, 11/25/25 (144A) $ 3,000,000 5,752,834 2.74 Wells Fargo Mortgage Backed Securities 2005-AR13 Trust, Floating Rate Note, 5/25/35 5,781,414 1,062,228 0.52 Westwood CDO II, Ltd., Floating Rate Note, 4/25/22 (144A) 1,045,606 --------------- $ 592,734,474 --------------- Total Banks $ 592,734,474 --------------------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 1.2% Other Diversified Financial Services -- 0.9% 5,502,440 5.89 Credit Suisse Commercial Mortgage Trust Series 2007-C3, Floating Rate Note, 6/15/39 $ 5,750,952 7,219,623 6.15 Credit Suisse Commercial Mortgage Trust Series 2007-C4 REMICS, Floating Rate Note, 9/15/39 7,633,033 2,200,850 0.35 Crusade Global Trust No 1 of 2007, Floating Rate Note, 4/19/38 2,171,848 2,087,280 0.38 Crusade Global Trust No.2 of 2006, Floating Rate Note, 11/15/37 2,079,963 4,040,407 1.70 Hilton USA Trust 2013-HLF, Floating Rate Note, 11/5/30 (144A) 4,034,096 1,300,814 2.10 Hilton USA Trust 2013-HLF, Floating Rate Note, 11/5/30 (144A) 1,297,968 2,000,000 0.53 Pepper Residential Securities Trust, Floating Rate Note, 4/10/16 (144A) 1,998,638 287,775 2.85 Rialto Capital Management LLC, 2.85%, 5/15/24 (144A) (e) 287,303 --------------- $ 25,253,801 --------------------------------------------------------------------------------------------------------- Specialized Finance -- 0.1% 579,477 1.69 Fosse Master Issuer Plc, Floating Rate Note, 10/19/54 (144A) $ 579,712 73,471 2.31 Nomura Asset Acceptance Corp. Alternative Loan Trust Series 2004-AR4, Floating Rate Note, 12/25/34 73,679 7,016 Nomura Asset Acceptance Corp. Alternative Loan Trust Series 2005-WF1, 4.786%, 3/25/35 7,024 887,000 1.89 Permanent Master Issuer Plc, Floating Rate Note, 7/15/42 (144A) 887,325 --------------- $ 1,547,740 --------------------------------------------------------------------------------------------------------- Investment Banking & Brokerage -- 0.2% 4,591,427 Banc of America Commercial Mortgage Trust 2007-1, 5.451%, 1/15/49 $ 4,793,427 --------------- Total Diversified Financials $ 31,594,968 --------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 51 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- GOVERNMENT -- 5.4% Government -- 5.4% 2,610,023 1.15 Fannie Mae Connecticut Avenue Securities, Floating Rate Note, 5/25/24 $ 2,585,645 3,810,799 1.39 Fannie Mae Connecticut Avenue Securities, Floating Rate Note, 7/25/24 3,802,472 1,892,313 0.54 Fannie Mae Trust 2003-W6, Floating Rate Note, 9/25/42 1,882,486 200,002 2.29 Fannie Mae Trust 2005-W4, Floating Rate Note, 6/25/45 210,876 1,797,382 0.45 Fannie Mae Whole Loan, Floating Rate Note, 11/25/46 1,800,948 2,593,752 Fannie Mae, 3.0%, 6/25/22 2,671,593 1,326,313 Fannie Mae, 4.5%, 9/25/35 1,366,019 650,921 Fannie Mae, 5.0%, 6/25/34 661,518 216,541 Federal Home Loan Mortgage Corp. REMICS, 3.5%, 6/15/28 217,659 19,363 Federal Home Loan Mortgage Corp. REMICS, 4.0%, 11/15/23 19,442 976,768 0.60 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 1/15/33 985,409 289,621 0.50 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 1/15/36 289,842 3,085,446 0.50 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 1/15/37 3,095,168 90,522 0.35 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 10/15/20 90,460 84,147 1.15 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 10/15/31 86,217 1,041,927 0.78 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 10/15/37 1,055,261 503,931 0.82 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 10/15/37 510,957 98,147 0.80 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 11/15/31 99,785 263,895 1.20 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 11/15/33 270,525 159,092 0.55 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 11/15/35 159,659 798,584 0.55 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 11/15/36 802,732 399,896 0.55 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 11/15/36 401,747 457,882 0.60 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 11/15/40 458,976 124,804 0.60 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 12/15/20 125,563 The accompanying notes are an integral part of these financial statements. 52 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Government -- (continued) 411,785 0.65 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 12/15/28 $ 416,525 157,268 0.55 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 12/15/32 158,655 26,075 0.70 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 12/15/32 26,299 502,432 0.60 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 12/15/32 504,619 663,476 0.60 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 12/15/32 666,992 800,440 0.90 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 12/15/39 811,501 562,367 0.55 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 12/15/41 563,812 199,670 0.43 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 2/15/19 199,717 315,122 0.50 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 2/15/25 315,840 227,600 0.55 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 2/15/29 229,462 747,484 0.50 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 2/15/30 747,584 596,976 0.60 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 2/15/33 602,750 344,522 0.75 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 2/15/33 348,607 761,099 0.50 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 2/15/36 762,655 312,553 0.55 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 2/15/36 313,643 866,923 0.50 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 2/15/37 867,877 525,893 0.50 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 2/15/39 527,330 1,237,409 1.25 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 3/15/24 1,268,793 591,080 1.20 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 3/15/32 606,669 181,315 0.90 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 3/15/32 184,640 843,260 1.20 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 3/15/32 870,024 898,984 0.50 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 3/15/36 904,928 183,162 0.65 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 3/15/39 184,166 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 53 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Government -- (continued) 2,218,424 0.60 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 3/15/41 $ 2,226,792 546,550 0.50 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 4/15/36 548,487 106,442 0.55 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 5/15/29 107,078 358,918 1.70 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 5/15/33 372,907 791,666 0.54 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 5/15/35 793,048 421,082 0.50 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 5/15/35 422,166 434,836 0.60 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 5/15/36 438,250 245,633 0.54 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 5/15/37 246,764 191,134 1.45 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 5/15/37 195,515 88,302 0.55 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 5/15/41 88,539 72,382 0.65 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 6/15/23 72,683 447,126 0.60 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 6/15/33 450,152 464,078 0.62 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 6/15/36 467,466 1,849,561 0.51 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 6/15/36 1,857,334 462,095 0.60 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 6/15/38 463,649 150,587 0.44 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 7/15/21 150,914 503,668 0.60 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 7/15/23 505,844 526,794 0.44 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 7/15/34 525,675 954,688 0.70 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 7/15/36 961,134 36,633 0.60 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 7/15/36 36,843 658,307 0.40 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 7/15/36 659,051 447,820 0.55 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 7/15/40 448,887 398,931 0.40 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 8/15/26 398,852 The accompanying notes are an integral part of these financial statements. 54 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Government -- (continued) 701,807 0.45 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 8/15/35 $ 700,339 362,269 0.45 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 8/15/35 361,924 703,169 0.45 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 8/15/36 704,283 719,362 0.50 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 9/15/26 720,871 150,111 0.80 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 9/15/32 152,460 320,465 0.62 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 9/15/36 322,621 257,163 0.60 Federal Home Loan Mortgage Corp. REMICS, Floating Rate Note, 9/15/36 258,728 1,578,255 Federal Home Loan Mortgage Corp., 3.0%, 12/15/24 1,615,575 637,302 0.45 Federal Home Loan Mortgage Corp., Floating Rate Note, 1/15/35 640,675 412,724 0.55 Federal Home Loan Mortgage Corp., Floating Rate Note, 2/15/18 413,948 499,394 1.20 Federal Home Loan Mortgage Corp., Floating Rate Note, 3/15/32 512,565 498,029 0.80 Federal Home Loan Mortgage Corp., Floating Rate Note, 4/15/28 506,235 292,243 0.80 Federal Home Loan Mortgage Corp., Floating Rate Note, 6/15/31 297,032 3,988,659 0.90 Federal Home Loan Mortgage Corp., Floating Rate Note, 8/15/35 4,041,249 9,738 Federal National Mortgage Association REMICS, 4.5%, 1/25/39 9,805 209,016 0.86 Federal National Mortgage Association REMICS, Floating Rate Note, 1/18/32 212,727 330,659 0.89 Federal National Mortgage Association REMICS, Floating Rate Note, 1/25/32 337,171 139,020 0.84 Federal National Mortgage Association REMICS, Floating Rate Note, 1/25/33 141,676 369,644 0.70 Federal National Mortgage Association REMICS, Floating Rate Note, 1/25/33 373,978 356,206 0.74 Federal National Mortgage Association REMICS, Floating Rate Note, 1/25/40 361,985 537,233 0.50 Federal National Mortgage Association REMICS, Floating Rate Note, 10/25/35 538,584 17,358 0.49 Federal National Mortgage Association REMICS, Floating Rate Note, 10/25/35 17,381 2,228,363 0.59 Federal National Mortgage Association REMICS, Floating Rate Note, 10/25/36 2,237,925 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 55 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Government -- (continued) 108,395 0.75 Federal National Mortgage Association REMICS, Floating Rate Note, 10/25/37 $ 109,641 581,699 0.79 Federal National Mortgage Association REMICS, Floating Rate Note, 10/25/37 588,012 540,993 1.41 Federal National Mortgage Association REMICS, Floating Rate Note, 10/25/38 554,837 1,827,489 0.39 Federal National Mortgage Association REMICS, Floating Rate Note, 10/27/37 1,817,456 1,646,736 1.21 Federal National Mortgage Association REMICS, Floating Rate Note, 11/18/32 1,690,331 385,150 0.79 Federal National Mortgage Association REMICS, Floating Rate Note, 11/25/31 391,619 338,932 0.79 Federal National Mortgage Association REMICS, Floating Rate Note, 11/25/31 344,625 646,598 0.69 Federal National Mortgage Association REMICS, Floating Rate Note, 11/25/33 650,994 542,976 0.49 Federal National Mortgage Association REMICS, Floating Rate Note, 11/25/34 546,075 294,530 0.51 Federal National Mortgage Association REMICS, Floating Rate Note, 11/25/36 295,084 91,973 0.79 Federal National Mortgage Association REMICS, Floating Rate Note, 12/25/23 93,287 287,153 1.19 Federal National Mortgage Association REMICS, Floating Rate Note, 12/25/23 292,869 83,701 0.74 Federal National Mortgage Association REMICS, Floating Rate Note, 12/25/30 85,076 788,854 1.09 Federal National Mortgage Association REMICS, Floating Rate Note, 12/25/31 807,069 334,263 0.80 Federal National Mortgage Association REMICS, Floating Rate Note, 12/25/32 339,157 221,618 0.43 Federal National Mortgage Association REMICS, Floating Rate Note, 12/25/36 222,472 543,296 0.81 Federal National Mortgage Association REMICS, Floating Rate Note, 12/25/37 550,573 193,066 0.59 Federal National Mortgage Association REMICS, Floating Rate Note, 12/25/38 193,264 1,023 0.64 Federal National Mortgage Association REMICS, Floating Rate Note, 2/25/17 1,024 301,731 0.94 Federal National Mortgage Association REMICS, Floating Rate Note, 2/25/33 308,024 676,988 0.54 Federal National Mortgage Association REMICS, Floating Rate Note, 2/25/33 682,348 711,840 0.50 Federal National Mortgage Association REMICS, Floating Rate Note, 2/25/35 712,845 620,042 0.44 Federal National Mortgage Association REMICS, Floating Rate Note, 2/25/37 620,746 The accompanying notes are an integral part of these financial statements. 56 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Government -- (continued) 411,792 0.39 Federal National Mortgage Association REMICS, Floating Rate Note, 2/25/37 $ 411,710 200,702 0.89 Federal National Mortgage Association REMICS, Floating Rate Note, 2/25/38 202,817 357,106 0.64 Federal National Mortgage Association REMICS, Floating Rate Note, 2/25/38 358,662 107,147 0.69 Federal National Mortgage Association REMICS, Floating Rate Note, 3/25/23 107,669 470,912 0.69 Federal National Mortgage Association REMICS, Floating Rate Note, 3/25/24 476,370 262,895 0.64 Federal National Mortgage Association REMICS, Floating Rate Note, 3/25/28 264,240 1,190,283 0.59 Federal National Mortgage Association REMICS, Floating Rate Note, 3/25/34 1,198,686 102,247 0.49 Federal National Mortgage Association REMICS, Floating Rate Note, 3/25/36 102,767 193,207 1.19 Federal National Mortgage Association REMICS, Floating Rate Note, 3/25/37 198,326 700,471 0.44 Federal National Mortgage Association REMICS, Floating Rate Note, 3/25/37 703,017 403,975 0.45 Federal National Mortgage Association REMICS, Floating Rate Note, 3/25/37 404,211 1,694,458 0.41 Federal National Mortgage Association REMICS, Floating Rate Note, 3/25/45 1,698,130 66,335 0.49 Federal National Mortgage Association REMICS, Floating Rate Note, 4/25/25 66,417 1,792,517 1.10 Federal National Mortgage Association REMICS, Floating Rate Note, 4/25/32 1,833,888 886,451 0.69 Federal National Mortgage Association REMICS, Floating Rate Note, 4/25/33 896,429 404,400 0.69 Federal National Mortgage Association REMICS, Floating Rate Note, 4/25/42 408,728 336,907 0.70 Federal National Mortgage Association REMICS, Floating Rate Note, 5/25/33 341,065 584,956 0.54 Federal National Mortgage Association REMICS, Floating Rate Note, 5/25/36 587,502 1,139,338 0.50 Federal National Mortgage Association REMICS, Floating Rate Note, 5/25/36 1,141,883 917,630 0.59 Federal National Mortgage Association REMICS, Floating Rate Note, 5/25/37 921,345 207,979 0.79 Federal National Mortgage Association REMICS, Floating Rate Note, 5/25/40 210,591 996,236 0.69 Federal National Mortgage Association REMICS, Floating Rate Note, 5/25/40 1,001,418 886,807 0.74 Federal National Mortgage Association REMICS, Floating Rate Note, 5/25/40 893,429 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 57 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Government -- (continued) 217,160 0.59 Federal National Mortgage Association REMICS, Floating Rate Note, 6/25/23 $ 218,014 689,759 0.64 Federal National Mortgage Association REMICS, Floating Rate Note, 6/25/36 694,783 774,366 0.43 Federal National Mortgage Association REMICS, Floating Rate Note, 6/25/37 773,438 66,254 0.42 Federal National Mortgage Association REMICS, Floating Rate Note, 6/25/37 66,180 297,588 0.44 Federal National Mortgage Association REMICS, Floating Rate Note, 6/25/37 297,621 81,147 0.64 Federal National Mortgage Association REMICS, Floating Rate Note, 6/25/37 81,821 50,818 0.71 Federal National Mortgage Association REMICS, Floating Rate Note, 7/18/27 51,455 372,754 0.79 Federal National Mortgage Association REMICS, Floating Rate Note, 7/25/31 379,016 262,971 0.79 Federal National Mortgage Association REMICS, Floating Rate Note, 7/25/31 267,501 170,088 1.19 Federal National Mortgage Association REMICS, Floating Rate Note, 7/25/32 173,514 415,633 0.59 Federal National Mortgage Association REMICS, Floating Rate Note, 7/25/34 420,067 136,073 0.64 Federal National Mortgage Association REMICS, Floating Rate Note, 7/25/34 137,334 1,755,515 0.50 Federal National Mortgage Association REMICS, Floating Rate Note, 7/25/35 1,756,416 2,121,269 0.44 Federal National Mortgage Association REMICS, Floating Rate Note, 7/25/35 2,120,913 239,010 0.48 Federal National Mortgage Association REMICS, Floating Rate Note, 7/25/36 240,194 243,394 0.59 Federal National Mortgage Association REMICS, Floating Rate Note, 7/25/37 244,460 194,495 0.69 Federal National Mortgage Association REMICS, Floating Rate Note, 8/25/31 196,965 75,624 0.79 Federal National Mortgage Association REMICS, Floating Rate Note, 8/25/32 76,868 252,112 0.69 Federal National Mortgage Association REMICS, Floating Rate Note, 8/25/32 255,159 12,327 0.59 Federal National Mortgage Association REMICS, Floating Rate Note, 8/25/33 12,379 236,099 0.74 Federal National Mortgage Association REMICS, Floating Rate Note, 8/25/36 238,082 15,023 0.99 Federal National Mortgage Association REMICS, Floating Rate Note, 9/25/20 15,109 65,764 1.09 Federal National Mortgage Association REMICS, Floating Rate Note, 9/25/21 66,958 The accompanying notes are an integral part of these financial statements. 58 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Government -- (continued) 318,319 0.69 Federal National Mortgage Association REMICS, Floating Rate Note, 9/25/32 $ 322,383 1,765,473 0.70 Federal National Mortgage Association REMICS, Floating Rate Note, 9/25/33 1,786,311 602,844 0.76 Federal National Mortgage Association REMICS, Floating Rate Note, 9/25/36 609,139 643,953 0.69 Federal National Mortgage Association REMICS, Floating Rate Note, 9/25/37 651,082 335,863 0.64 Federal National Mortgage Association REMICS, Floating Rate Note, 9/25/37 338,227 333,867 0.76 Federal National Mortgage Association REMICS, Floating Rate Note, 9/25/37 337,637 190,275 0.74 Federal National Mortgage Association REMICS, Floating Rate Note, 9/25/37 192,474 287,153 2.04 Federal National Mortgage Association, Floating Rate Note, 12/25/23 295,729 6,210,285 0.49 Federal National Mortgage Association, Floating Rate Note, 12/25/33 6,230,381 12,915,738 0.64 Federal National Mortgage Association, Floating Rate Note, 2/25/38 13,041,511 1,377,773 0.49 Federal National Mortgage Association, Floating Rate Note, 3/25/18 1,380,153 117,808 2.71 Federal National Mortgage Association, Floating Rate Note, 4/25/35 125,819 513,440 0.55 Freddie Mac Strips, Floating Rate Note, 12/15/36 515,505 388,924 0.45 Freddie Mac Strips, Floating Rate Note, 8/15/36 389,422 1,681,333 0.50 Freddie Mac Strips, Floating Rate Note, 8/15/36 1,686,411 540,941 1.59 Freddie Mac Structured Agency Credit Risk Debt Notes, Floating Rate Note, 10/25/24 540,992 1,342,483 1.19 Freddie Mac Structured Agency Credit Risk Debt Notes, Floating Rate Note, 2/25/24 1,342,483 826,685 1.54 Freddie Mac Structured Agency Credit Risk Debt Notes, Floating Rate Note, 8/25/24 826,560 1,764,494 Freddie Mac, 2.0%, 2/15/25 1,789,892 620,274 Freddie Mac, 3.0%, 7/15/36 629,188 3,500,000 3.54 FREMF Mortgage Trust Class C, Floating Rate Note, 11/25/46 (144A) 3,526,698 483,207 Government National Mortgage Association, 4.0%, 7/20/34 487,094 762,045 0.40 Government National Mortgage Association, Floating Rate Note, 1/16/33 763,756 1,059,457 0.45 Government National Mortgage Association, Floating Rate Note, 1/16/35 1,060,300 300,804 0.88 Government National Mortgage Association, Floating Rate Note, 10/16/39 306,262 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 59 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Government -- (continued) 694,791 0.60 Government National Mortgage Association, Floating Rate Note, 10/20/38 $ 696,505 1,011,210 0.45 Government National Mortgage Association, Floating Rate Note, 2/20/35 1,013,056 215,373 0.75 Government National Mortgage Association, Floating Rate Note, 4/16/32 218,002 434,818 0.60 Government National Mortgage Association, Floating Rate Note, 5/16/38 435,227 210,777 0.70 Government National Mortgage Association, Floating Rate Note, 6/16/31 211,708 419,916 1.20 Government National Mortgage Association, Floating Rate Note, 8/16/39 430,620 372,883 0.70 Government National Mortgage Association, Floating Rate Note, 8/20/38 375,124 574,216 0.45 Government National Mortgage Association, Floating Rate Note, 9/16/31 575,765 821,642 0.76 NCUA Guaranteed Notes Trust REMICS, Floating Rate Note, 12/8/20 827,388 1,014,285 0.73 NCUA Guaranteed Notes Trust REMICS, Floating Rate Note, 3/2/21 (e) 1,015,038 870,803 0.64 NCUA Guaranteed Notes Trust, Floating Rate Note, 10/7/20 875,086 2,458,255 0.57 NCUA Guaranteed Notes Trust, Floating Rate Note, 11/6/17 2,462,522 259,853 0.76 NCUA Guaranteed Notes Trust, Floating Rate Note, 12/8/20 261,592 894,674 0.59 NCUA Guaranteed Notes Trust, Floating Rate Note, 3/11/20 897,315 852,504 0.57 NCUA Guaranteed Notes Trust, Floating Rate Note, 4/6/20 852,721 --------------- $ 149,085,867 --------------- Total Government $ 149,085,867 --------------------------------------------------------------------------------------------------------- TOTAL COLLATERALIZED MORTGAGE OBLIGATIONS (Cost $780,613,631) $ 778,032,486 --------------------------------------------------------------------------------------------------------- CORPORATE BONDS -- 29.7% ENERGY -- 1.9% Integrated Oil & Gas -- 0.7% 2,640,000 0.38 Chevron Corp., Floating Rate Note, 11/9/16 $ 2,638,836 2,550,000 0.45 Chevron Corp., Floating Rate Note, 3/2/18 2,534,532 1,980,000 0.33 Exxon Mobil Corp., Floating Rate Note, 3/15/17 1,977,329 3,020,000 0.48 Shell International Finance BV, Floating Rate Note, 11/15/16 3,020,048 2,140,000 0.48 Statoil ASA, Floating Rate Note, 11/9/17 2,126,927 The accompanying notes are an integral part of these financial statements. 60 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Integrated Oil & Gas -- (continued) 3,355,000 0.66 Total Capital Canada, Ltd., Floating Rate Note, 1/15/16 $ 3,357,204 2,500,000 Total Capital International SA, 0.75%, 1/25/16 2,502,318 --------------- $ 18,157,194 --------------------------------------------------------------------------------------------------------- Oil & Gas Exploration & Production -- 0.8% 7,849,000 0.66 Canadian Natural Resources, Ltd., Floating Rate Note, 3/30/16 $ 7,831,709 4,815,000 0.74 Devon Energy Corp., Floating Rate Note, 12/15/15 4,810,464 6,604,000 Marathon Oil Corp., 0.9%, 11/1/15 6,602,560 640,000 Total Capital SA, 2.3%, 3/15/16 645,361 1,730,000 Total Capital SA, 3.125%, 10/2/15 1,730,000 --------------- $ 21,620,094 --------------------------------------------------------------------------------------------------------- Oil & Gas Storage & Transportation -- 0.4% 3,320,000 Boardwalk Pipelines LP, 5.5%, 2/1/17 $ 3,417,226 1,650,000 0.93 Enbridge, Inc., Floating Rate Note, 10/1/16 1,641,915 3,355,000 Enterprise Products Operating LLC, 3.2%, 2/1/16 3,377,844 3,544,000 0.96 TransCanada PipeLines, Ltd., Floating Rate Note, 6/30/16 3,542,182 --------------- $ 11,979,167 --------------- Total Energy $ 51,756,455 --------------------------------------------------------------------------------------------------------- MATERIALS -- 0.3% Fertilizers & Agricultural Chemicals -- 0.1% 2,145,000 Monsanto Co., 2.75%, 4/15/16 $ 2,167,181 --------------------------------------------------------------------------------------------------------- Diversified Metals & Mining -- 0.1% 1,795,000 0.53 BHP Billiton Finance USA, Ltd., Floating Rate Note, 9/30/16 $ 1,791,864 1,130,000 1.12 Rio Tinto Finance USA Plc, Floating Rate Note, 6/17/16 1,130,738 --------------- $ 2,922,602 --------------------------------------------------------------------------------------------------------- Steel -- 0.1% 2,500,000 1.35 Glencore Funding LLC, Floating Rate Note, 4/16/18 (144A) $ 2,159,770 1,800,000 1.49 Glencore Funding LLC, Floating Rate Note, 5/27/16 (144A) 1,698,739 --------------- $ 3,858,509 --------------- Total Materials $ 8,948,292 --------------------------------------------------------------------------------------------------------- CAPITAL GOODS -- 0.6% Industrial Conglomerates -- 0.2% 6,330,000 0.49 Tyco Electronics Group SA, Floating Rate Note, 1/29/16 $ 6,327,398 --------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 61 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Construction & Farm Machinery & Heavy Trucks -- 0.3% 2,500,000 0.42 Caterpillar Financial Services Corp., Floating Rate Note, 3/3/17 $ 2,493,062 1,500,000 0.57 John Deere Capital Corp., Floating Rate Note, 10/11/16 1,501,958 1,800,000 0.40 John Deere Capital Corp., Floating Rate Note, 12/10/15 1,799,984 2,883,000 0.38 John Deere Capital Corp., Floating Rate Note, 2/25/16 2,883,222 --------------- $ 8,678,226 --------------------------------------------------------------------------------------------------------- Industrial Machinery -- 0.1% 2,650,000 Xylem, Inc. New York, 3.55%, 9/20/16 $ 2,705,311 --------------- Total Capital Goods $ 17,710,935 --------------------------------------------------------------------------------------------------------- TRANSPORTATION -- 0.1% Railroads -- 0.1% 1,670,000 0.44 Canadian National Railway Co., Floating Rate Note, 11/14/17 $ 1,654,708 --------------- Total Transportation $ 1,654,708 --------------------------------------------------------------------------------------------------------- AUTOMOBILES & COMPONENTS -- 1.9% Automobile Manufacturers -- 1.9% 1,500,000 0.63 Daimler Finance North America LLC, Floating Rate Note, 3/10/17 (144A) $ 1,488,062 1,275,000 0.75 Daimler Finance North America LLC, Floating Rate Note, 3/2/18 (144A) 1,259,467 2,370,000 0.77 Daimler Finance North America LLC, Floating Rate Note, 5/18/18 (144A) 2,340,574 2,845,000 0.98 Daimler Finance North America LLC, Floating Rate Note, 8/1/16 (144A) 2,843,785 2,061,000 0.62 Daimler Finance North America LLC, Floating Rate Note, 8/1/17 (144A) 2,038,618 2,665,000 1.01 Daimler Finance North America LLC, Floating Rate Note, 8/3/17 (144A) 2,652,930 1,375,000 Ford Motor Credit Co. LLC, 1.7%, 5/9/16 1,378,900 2,600,000 1.22 Ford Motor Credit Co. LLC, Floating Rate Note, 1/9/18 2,576,376 1,715,000 0.73 Ford Motor Credit Co. LLC, Floating Rate Note, 11/8/16 1,704,633 3,500,000 0.91 Ford Motor Credit Co. LLC, Floating Rate Note, 3/27/17 3,450,720 2,600,000 0.80 Ford Motor Credit Co. LLC, Floating Rate Note, 9/8/17 2,547,342 1,300,000 Nissan Motor Acceptance Corp., 1.0%, 3/15/16 (144A) 1,299,912 The accompanying notes are an integral part of these financial statements. 62 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Automobile Manufacturers -- (continued) 2,000,000 0.83 Nissan Motor Acceptance Corp., Floating Rate Note, 3/3/17 (144A) $ 1,993,872 1,500,000 0.98 Nissan Motor Acceptance Corp., Floating Rate Note, 9/26/16 (144A) 1,500,116 2,600,000 Toyota Motor Credit Corp., 2.0%, 9/15/16 2,630,433 2,589,000 0.52 Toyota Motor Credit Corp., Floating Rate Note, 5/16/17 2,583,291 3,800,000 0.61 Toyota Motor Credit Corp., Floating Rate Note, 5/17/16 3,803,466 2,250,000 0.75 Toyota Motor Credit Corp., Floating Rate Note, 7/13/18 2,246,897 650,000 0.37 Toyota Motor Credit Corp., Floating Rate Note, 9/23/16 649,687 2,500,000 0.77 Volkswagen Group of America Finance LLC, Floating Rate Note, 11/20/17 (144A) 2,321,702 1,900,000 0.55 Volkswagen Group of America Finance LLC, Floating Rate Note, 5/23/16 (144A) 1,870,793 6,790,000 Volkswagen International Finance NV, 1.15%, 11/20/15 (144A) 6,782,864 1,750,000 0.76 Volkswagen International Finance NV, Floating Rate Note, 11/18/16 (144A) 1,700,400 --------------- $ 53,664,840 --------------- Total Automobiles & Components $ 53,664,840 --------------------------------------------------------------------------------------------------------- MEDIA -- 0.2% Broadcasting -- 0.2% 3,744,000 0.83 NBCUniversal Enterprise, Inc., Floating Rate Note, 4/15/16 (144A) $ 3,748,122 1,300,000 0.97 NBCUniversal Enterprise, Inc., Floating Rate Note, 4/15/18 (144A) 1,298,760 --------------- $ 5,046,882 --------------- Total Media $ 5,046,882 --------------------------------------------------------------------------------------------------------- RETAILING -- 0.3% Internet Retail -- 0.2% 5,450,000 Amazon.com, Inc., 0.65%, 11/27/15 $ 5,451,771 --------------------------------------------------------------------------------------------------------- Home Improvement Retail -- 0.1% 2,600,000 0.71 The Home Depot, Inc., Floating Rate Note, 9/15/17 $ 2,604,043 --------------------------------------------------------------------------------------------------------- Automotive Retail -- 0.0%+ 1,230,000 0.61 Volkswagen Group of America Finance LLC, Floating Rate Note, 11/22/16 (144A) $ 1,192,233 --------------- Total Retailing $ 9,248,047 --------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 63 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- FOOD & STAPLES RETAILING -- 0.0%+ Hypermarkets & Super Centers -- 0.0%+ 955,000 Wal-Mart Stores, Inc., 0.6%, 4/11/16 $ 956,014 --------------- Total Food & Staples Retailing $ 956,014 --------------------------------------------------------------------------------------------------------- FOOD, BEVERAGE & TOBACCO -- 0.5% Brewers -- 0.2% 3,700,000 Anheuser-Busch InBev Finance, Inc., 0.8%, 1/15/16 $ 3,703,367 1,900,000 0.49 Anheuser-Busch InBev Finance, Inc., Floating Rate Note, 1/27/17 1,894,946 --------------- $ 5,598,313 --------------------------------------------------------------------------------------------------------- Soft Drinks -- 0.1% 3,460,000 0.49 PepsiCo, Inc., Floating Rate Note, 2/26/16 $ 3,461,287 --------------------------------------------------------------------------------------------------------- Packaged Foods & Meats -- 0.2% 1,895,000 0.49 General Mills, Inc., Floating Rate Note, 1/28/16 $ 1,895,313 1,765,000 0.59 General Mills, Inc., Floating Rate Note, 1/29/16 1,764,020 --------------- $ 3,659,333 --------------- Total Food, Beverage & Tobacco $ 12,718,933 --------------------------------------------------------------------------------------------------------- HOUSEHOLD & PERSONAL PRODUCTS -- 0.1% Household Products -- 0.1% 2,950,000 The Procter & Gamble Co., 1.8%, 11/15/15 $ 2,954,956 --------------- Total Household & Personal Products $ 2,954,956 --------------------------------------------------------------------------------------------------------- HEALTH CARE EQUIPMENT & SERVICES -- 0.6% Health Care Equipment -- 0.2% 4,020,000 0.79 Becton Dickinson and Co., Floating Rate Note, 6/15/16 $ 4,019,256 1,695,000 St. Jude Medical, Inc., 2.5%, 1/15/16 1,703,306 --------------- $ 5,722,562 --------------------------------------------------------------------------------------------------------- Health Care Distributors -- 0.1% 2,993,000 McKesson Corp., 3.25%, 3/1/16 $ 3,019,234 --------------------------------------------------------------------------------------------------------- Health Care Services -- 0.2% 4,494,000 Express Scripts Holding Co., 3.125%, 5/15/16 $ 4,545,142 --------------------------------------------------------------------------------------------------------- Managed Health Care -- 0.1% 2,600,000 0.74 UnitedHealth Group, Inc., Floating Rate Note, 1/17/17 $ 2,599,953 --------------- Total Health Care Equipment & Services $ 15,886,891 --------------------------------------------------------------------------------------------------------- PHARMACEUTICALS, BIOTECHNOLOGY & LIFE SCIENCES -- 0.8% Biotechnology -- 0.1% 2,500,000 1.06 Baxalta, Inc., Floating Rate Note, 6/22/18 (144A) $ 2,504,432 --------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 64 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Pharmaceuticals -- 0.6% 5,300,000 0.53 Bayer US Finance LLC, Floating Rate Note, 10/7/16 (144A) $ 5,289,352 3,000,000 0.68 EMD Finance LLC, Floating Rate Note, 3/17/17 (144A) 2,987,148 3,650,000 Merck & Co, Inc., 0.7%, 5/18/16 3,655,599 2,500,000 0.40 Merck & Co., Inc., Floating Rate Note, 2/10/17 2,497,960 500,000 0.47 Merck & Co., Inc., Floating Rate Note, 5/18/16 500,274 2,100,000 0.42 Pfizer, Inc., Floating Rate Note, 5/15/17 2,098,408 --------------- $ 17,028,741 --------------------------------------------------------------------------------------------------------- Life Sciences Tools & Services -- 0.1% 1,300,000 Thermo Fisher Scientific, Inc., 3.2%, 3/1/16 $ 1,312,035 --------------- Total Pharmaceuticals, Biotechnology & Life Sciences $ 20,845,208 --------------------------------------------------------------------------------------------------------- BANKS -- 8.5% Diversified Banks -- 5.4% 1,725,000 1.08 ABN AMRO Bank NV, Floating Rate Note, 10/28/16 (144A) $ 1,731,538 1,000,000 Bank of America Corp., 1.25%, 1/11/16 1,001,494 1,325,000 Bank of America Corp., 3.75%, 7/12/16 1,351,399 6,000,000 1.10 Bank of America Corp., Floating Rate Note, 3/22/16 6,010,806 1,423,000 0.89 Bank of America Corp., Floating Rate Note, 8/25/17 1,420,416 2,455,000 0.73 Bank of America NA, Floating Rate Note, 6/5/17 2,448,732 2,965,000 Bank of Montreal, 0.8%, 11/6/15 2,965,898 2,300,000 0.53 Bank of Montreal, Floating Rate Note, 7/14/17 2,291,439 2,665,000 0.91 Bank of Montreal, Floating Rate Note, 7/31/18 2,661,991 1,640,000 0.54 Bank of Nova Scotia Houston, Floating Rate Note, 10/23/15 1,640,085 821,000 0.90 Barclays Bank Plc, Floating Rate Note, 2/17/17 820,467 2,590,000 0.94 Caisse Centrale Desjardins, Floating Rate Note, 1/29/18 (144A) 2,599,674 3,200,000 0.95 Citigroup, Inc., Floating Rate Note, 11/15/16 3,203,933 2,630,000 0.98 Citigroup, Inc., Floating Rate Note, 11/24/17 2,632,427 1,325,000 1.07 Citigroup, Inc., Floating Rate Note, 4/1/16 1,326,544 2,500,000 0.55 Citigroup, Inc., Floating Rate Note, 6/9/16 2,487,510 3,700,000 1.24 Citigroup, Inc., Floating Rate Note, 7/25/16 3,710,841 1,800,000 0.49 Commonwealth Bank of Australia, Floating Rate Note, 12/4/15 (144A) 1,800,162 2,000,000 0.65 Commonwealth Bank of Australia, Floating Rate Note, 3/13/17 (144A) 1,997,640 2,500,000 0.41 Cooperatieve Centrale Raiffeisen-Boerenleenbank BA New York, Floating Rate Note, 10/23/15 2,499,980 3,975,000 0.77 Cooperatieve Centrale Raiffeisen-Boerenleenbank BA New York, Floating Rate Note, 3/18/16 3,980,334 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 65 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Diversified Banks -- (continued) 1,000,000 HSBC Bank Middle East, Ltd., 3.0%, 10/21/15 $ 999,867 2,690,000 1.10 ING Bank NV, Floating Rate Note, 8/17/18 (144A) 2,693,744 1,528,000 JPMorgan Chase & Co., 1.1%, 10/15/15 1,528,351 2,000,000 0.94 JPMorgan Chase & Co., Floating Rate Note, 10/15/15 2,000,218 2,000,000 0.79 JPMorgan Chase & Co., Floating Rate Note, 2/15/17 1,998,444 1,800,000 0.90 JPMorgan Chase & Co., Floating Rate Note, 2/26/16 1,801,669 3,800,000 0.79 JPMorgan Chase & Co., Floating Rate Note, 3/1/18 3,779,594 2,500,000 0.82 Lloyds Bank Plc, Floating Rate Note, 5/14/18 2,485,830 2,600,000 1.10 Lloyds Bank Plc, Floating Rate Note, 8/17/18 2,598,487 2,500,000 0.93 Macquarie Bank, Ltd., Floating Rate Note, 10/27/17 (144A) 2,488,670 1,670,000 0.92 Mizuho Bank, Ltd., Floating Rate Note, 3/26/18 (144A) 1,665,312 2,000,000 0.72 Mizuho Bank, Ltd., Floating Rate Note, 4/16/17 (144A) 1,992,660 2,425,000 0.85 MUFG Americas Holdings Corp., Floating Rate Note, 2/9/18 2,427,634 1,950,000 0.65 National Australia Bank, Ltd., Floating Rate Note, 3/17/17 (144A) 1,948,226 2,650,000 Nordea Bank AB, 0.875%, 5/13/16 (144A) 2,649,936 2,175,000 0.63 Nordea Bank AB, Floating Rate Note, 4/4/17 2,172,090 2,700,000 0.74 Nordea Bank AB, Floating Rate Note, 5/13/16 (144A) 2,704,433 2,600,000 1.17 Nordea Bank AB, Floating Rate Note, 9/17/18 (144A) 2,606,932 1,300,000 Royal Bank of Canada, 0.8%, 10/30/15 1,300,403 1,000,000 Royal Bank of Canada, 1.45%, 9/9/16 1,007,024 1,875,000 0.61 Royal Bank of Canada, Floating Rate Note, 1/23/17 1,876,132 2,500,000 0.54 Royal Bank of Canada, Floating Rate Note, 10/13/17 2,490,412 1,800,000 0.51 Royal Bank of Canada, Floating Rate Note, 12/16/15 1,800,194 500,000 0.57 Royal Bank of Canada, Floating Rate Note, 2/3/17 499,568 2,200,000 0.53 Royal Bank of Canada, Floating Rate Note, 6/16/17 2,192,175 1,325,000 0.84 Royal Bank of Canada, Floating Rate Note, 7/30/18 1,323,497 2,000,000 0.74 Royal Bank of Canada, Floating Rate Note, 9/9/16 2,004,572 2,600,000 0.71 Sumitomo Mitsui Banking Corp., Floating Rate Note, 1/10/17 2,597,683 1,500,000 0.96 Sumitomo Mitsui Banking Corp., Floating Rate Note, 7/19/16 1,503,150 1,500,000 1.11 Sumitomo Mitsui Trust Bank, Ltd., Floating Rate Note, 9/16/16 (144A) 1,504,300 4,735,000 0.73 Svenska Handelsbanken AB, Floating Rate Note, 3/21/16 4,740,871 3,650,000 0.75 Svenska Handelsbanken AB, Floating Rate Note, 9/23/16 3,657,800 1,800,000 0.71 The Bank of Nova Scotia, Floating Rate Note, 12/13/16 1,801,202 The accompanying notes are an integral part of these financial statements. 66 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Diversified Banks -- (continued) 3,255,000 0.69 The Bank of Nova Scotia, Floating Rate Note, 3/15/16 $ 3,257,171 1,500,000 0.80 The Bank of Nova Scotia, Floating Rate Note, 7/15/16 1,503,928 1,000,000 0.69 The Bank of Tokyo-Mitsubishi UFJ, Ltd., Floating Rate Note, 3/10/17 (144A) 997,457 2,525,000 0.59 The Bank of Tokyo-Mitsubishi UFJ, Ltd., Floating Rate Note, 9/8/17 (144A) 2,511,075 2,000,000 0.70 The Huntington National Bank, Floating Rate Note, 4/24/17 1,986,844 4,025,000 0.48 The Toronto-Dominion Bank, Floating Rate Note, 11/6/15 4,025,423 2,000,000 0.52 The Toronto-Dominion Bank, Floating Rate Note, 5/2/17 1,994,850 2,600,000 0.83 The Toronto-Dominion Bank, Floating Rate Note, 7/23/18 2,597,080 1,320,000 0.45 The Toronto-Dominion Bank, Floating Rate Note, 7/8/16 1,320,784 2,800,000 0.74 The Toronto-Dominion Bank, Floating Rate Note, 9/9/16 2,806,664 2,500,000 0.91 Wells Fargo & Co., Floating Rate Note, 4/23/18 2,509,398 2,000,000 0.61 Westpac Banking Corp., Floating Rate Note, 5/19/17 1,997,502 --------------- $ 148,932,566 --------------------------------------------------------------------------------------------------------- Regional Banks -- 3.1% 6,390,000 0.73 American Express Centurion Bank, Floating Rate Note, 11/13/15 $ 6,391,917 2,500,000 BB&T Corp., 3.2%, 3/15/16 2,521,728 500,000 0.58 Branch Banking & Trust Co., Floating Rate Note, 5/23/17 497,132 6,144,000 0.61 Branch Banking & Trust Co., Floating Rate Note, 9/13/16 6,133,481 4,150,000 0.73 Capital One NA, Floating Rate Note, 3/22/16 4,146,149 1,000,000 1.47 Capital One NA, Floating Rate Note, 8/17/18 1,002,799 3,790,000 Fifth Third Bancorp, 3.625%, 1/25/16 3,823,382 1,727,000 0.70 Fifth Third Bancorp, Floating Rate Note, 12/20/16 1,716,315 1,735,000 Fifth Third Bank Cincinnati Ohio, 1.15%, 11/18/16 1,735,743 1,800,000 0.79 Fifth Third Bank Cincinnati Ohio, Floating Rate Note, 11/18/16 1,798,276 3,330,000 0.69 Fifth Third Bank Cincinnati Ohio, Floating Rate Note, 2/26/16 3,329,870 4,500,000 0.82 KeyBank NA Cleveland Ohio, Floating Rate Note, 11/25/16 4,500,986 2,500,000 0.80 KeyBank NA Cleveland Ohio, Floating Rate Note, 6/1/18 2,495,892 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 67 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Regional Banks -- (continued) 2,710,000 0.65 Manufacturers & Traders Trust Co., Floating Rate Note, 1/30/17 $ 2,706,474 2,400,000 0.58 Manufacturers & Traders Trust Co., Floating Rate Note, 7/25/17 2,397,722 6,200,000 1.03 MUFG Union Bank NA, Floating Rate Note, 9/26/16 6,207,973 2,850,000 0.64 National City Bank Cleveland Ohio, Floating Rate Note, 12/15/16 2,839,355 2,225,000 0.47 Nordea Bank Finland Plc New York, Floating Rate Note, 6/13/16 2,224,907 650,000 PNC Bank NA, 0.8%, 1/28/16 650,441 2,250,000 0.59 PNC Bank NA, Floating Rate Note, 1/28/16 2,251,375 2,500,000 0.70 PNC Bank NA, Floating Rate Note, 6/1/18 2,485,420 2,500,000 0.60 PNC Bank NA, Floating Rate Note, 8/1/17 2,489,298 3,645,000 0.71 SunTrust Bank, Floating Rate Note, 2/15/17 3,634,499 2,500,000 0.84 UBS AG, Floating Rate Note, 6/1/17 2,498,182 2,600,000 0.60 US Bank NA Cincinnati Ohio, Floating Rate Note, 1/26/18 2,601,071 2,025,000 0.53 US Bank NA Cincinnati Ohio, Floating Rate Note, 1/30/17 2,022,874 2,000,000 0.42 US Bank NA Cincinnati Ohio, Floating Rate Note, 4/22/16 1,999,892 1,983,000 0.64 Wachovia Corp., Floating Rate Note, 10/28/15 1,983,153 1,999,000 0.56 Wachovia Corp., Floating Rate Note, 6/15/17 1,992,437 2,503,000 0.48 Wells Fargo & Co., Floating Rate Note, 10/28/15 2,503,143 3,105,000 0.81 Wells Fargo & Co., Floating Rate Note, 7/20/16 3,112,728 975,000 0.49 Wells Fargo Bank NA, Floating Rate Note, 5/16/16 973,969 --------------- $ 87,668,583 --------------- Total Banks $ 236,601,149 --------------------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 5.0% Other Diversified Financial Services -- 0.5% 2,000,000 0.74 Bank of America NA, Floating Rate Note, 2/14/17 $ 1,996,040 1,865,000 0.51 General Electric Capital Corp., Floating Rate Note, 1/14/16 1,865,267 4,124,000 0.87 General Electric Capital Corp., Floating Rate Note, 1/8/16 4,128,252 1,000,000 0.48 General Electric Capital Corp., Floating Rate Note, 5/11/16 1,000,903 2,000,000 0.55 General Electric Capital Corp., Floating Rate Note, 5/15/17 2,002,010 2,372,000 0.93 General Electric Capital Corp., Floating Rate Note, 7/12/16 2,381,626 500,000 1.38 General Electric Capital Corp., Floating Rate Note, 8/1/17 506,151 The accompanying notes are an integral part of these financial statements. 68 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Other Diversified Financial Services -- (continued) 1,950,000 1.09 Hyundai Capital Services, Inc., Floating Rate Note, 3/18/17 (144A) $ 1,945,421 --------------- $ 15,825,670 --------------------------------------------------------------------------------------------------------- Multi-Sector Holdings -- 0.3% 1,855,000 0.43 Berkshire Hathaway Finance Corp., Floating Rate Note, 1/10/17 $ 1,854,510 2,500,000 0.43 Berkshire Hathaway Finance Corp., Floating Rate Note, 8/14/17 2,494,932 2,775,000 Berkshire Hathaway, Inc., 2.2%, 8/15/16 2,811,899 --------------- $ 7,161,341 --------------------------------------------------------------------------------------------------------- Specialized Finance -- 0.5% 7,060,000 MassMutual Global Funding II, 3.125%, 4/14/16 (144A) $ 7,156,228 3,290,000 0.41 MassMutual Global Funding II, Floating Rate Note, 12/11/15 (144A) 3,290,030 1,800,000 0.58 National Rural Utilities Cooperative Finance Corp., Floating Rate Note, 11/23/16 1,801,181 --------------- $ 12,247,439 --------------------------------------------------------------------------------------------------------- Consumer Finance -- 1.4% 1,300,000 American Express Credit Corp., 1.3%, 7/29/16 $ 1,305,018 5,642,000 0.79 American Express Credit Corp., Floating Rate Note, 7/29/16 5,647,264 2,650,000 0.31 American Honda Finance Corp., Floating Rate Note, 1/11/16 2,649,732 4,885,000 0.78 American Honda Finance Corp., Floating Rate Note, 10/7/16 4,899,631 2,570,000 0.64 American Honda Finance Corp., Floating Rate Note, 12/11/17 2,559,553 3,050,000 0.66 American Honda Finance Corp., Floating Rate Note, 5/26/16 (144A) 3,054,523 1,330,000 0.78 American Honda Finance Corp., Floating Rate Note, 9/20/17 1,330,015 3,600,000 Capital One Financial Corp., 1.0%, 11/6/15 3,600,871 2,500,000 Capital One Financial Corp., 3.15%, 7/15/16 2,540,682 2,930,000 0.94 Capital One Financial Corp., Floating Rate Note, 11/6/15 2,930,615 1,500,000 0.52 Caterpillar Financial Services Corp., Floating Rate Note, 2/26/16 1,500,686 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 69 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Consumer Finance -- (continued) 2,500,000 1.63 General Motors Financial Co, Inc., Floating Rate Note, 4/10/18 $ 2,497,525 910,000 PACCAR Financial Corp., 0.7%, 11/16/15 910,025 1,290,000 0.47 PACCAR Financial Corp., Floating Rate Note, 6/6/17 1,288,293 2,250,000 Toyota Motor Credit Corp., 0.75%, 3/3/17 (Step) 2,249,662 --------------- $ 38,964,095 --------------------------------------------------------------------------------------------------------- Asset Management & Custody Banks -- 0.9% 7,480,000 0.48 State Street Bank & Trust Co., Floating Rate Note, 12/8/15 $ 7,477,330 3,750,000 State Street Corp., 2.875%, 3/7/16 3,786,608 2,850,000 The Bank of New York Mellon Corp., 0.7%, 3/4/16 2,853,112 835,000 The Bank of New York Mellon Corp., 2.5%, 1/15/16 839,942 3,533,000 0.52 The Bank of New York Mellon Corp., Floating Rate Note, 10/23/15 3,533,095 3,275,000 0.51 The Bank of New York Mellon Corp., Floating Rate Note, 3/4/16 3,276,526 2,465,000 0.95 The Goldman Sachs Group, Inc., Floating Rate Note, 5/22/17 2,463,627 --------------- $ 24,230,240 --------------------------------------------------------------------------------------------------------- Investment Banking & Brokerage -- 1.4% 1,210,000 1.30 Macquarie Group, Ltd., Floating Rate Note, 1/31/17 (144A) $ 1,215,470 1,300,000 Morgan Stanley, 1.75%, 2/25/16 1,304,163 2,700,000 1.01 Morgan Stanley, Floating Rate Note, 1/5/18 2,698,974 1,598,000 0.76 Morgan Stanley, Floating Rate Note, 10/15/15 1,598,117 4,350,000 1.53 Morgan Stanley, Floating Rate Note, 2/25/16 4,360,240 7,834,000 Raymond James Financial, Inc., 4.25%, 4/15/16 7,962,470 2,465,000 0.67 The Bear Stearns Companies LLC, Floating Rate Note, 11/21/16 2,460,031 8,285,000 The Charles Schwab Corp., 0.85%, 12/4/15 8,291,247 3,422,000 The Goldman Sachs Group, Inc., 1.6%, 11/23/15 3,426,688 1,305,000 The Goldman Sachs Group, Inc., 5.35%, 1/15/16 1,321,673 4,300,000 0.73 The Goldman Sachs Group, Inc., Floating Rate Note, 3/22/16 4,299,024 --------------- $ 38,938,097 --------------- Total Diversified Financials $ 137,366,882 --------------------------------------------------------------------------------------------------------- INSURANCE -- 6.2% Insurance Brokers -- 0.3% 250,000 0.00 ACE Securities Corp, 7/12/16 (d) $ 232,100 7,325,000 Aon Corp., 3.125%, 5/27/16 7,428,722 --------------- $ 7,660,822 --------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 70 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Life & Health Insurance -- 0.7% 5,100,000 0.54 Jackson National Life Global Funding, Floating Rate Note, 7/29/16 (144A) $ 5,098,501 1,500,000 0.47 Pricoa Global Funding I, Floating Rate Note, 5/16/16 (144A) 1,499,103 3,255,000 0.49 Pricoa Global Funding I, Floating Rate Note, 6/24/16 (144A) 3,251,446 3,770,000 Principal Life Global Funding II, 1.0%, 12/11/15 (144A) 3,772,835 2,530,000 0.65 Principal Life Global Funding II, Floating Rate Note, 5/27/16 (144A) 2,531,404 2,500,000 Prudential Financial, Inc., 3.0%, 5/12/16 2,530,500 --------------- $ 18,683,789 --------------------------------------------------------------------------------------------------------- Multi-line Insurance -- 0.7% 4,126,000 American International Group, Inc., 5.05%, 10/1/15 $ 4,126,000 690,000 Metropolitan Life Global Funding I, 3.125%, 1/11/16 (144A) 694,977 2,500,000 0.82 Metropolitan Life Global Funding I, Floating Rate Note, 7/15/16 (144A) 2,506,745 750,000 0.29 New York Life Global Funding, Floating Rate Note, 10/29/15 (144A) 749,932 6,650,000 0.57 New York Life Global Funding, Floating Rate Note, 12/15/17 (144A) 6,666,565 3,650,000 0.64 New York Life Global Funding, Floating Rate Note, 5/23/16 (144A) 3,656,804 2,675,000 0.35 New York Life Global Funding, Floating Rate Note, 8/5/16 (144A) 2,674,521 --------------- $ 21,075,544 --------------------------------------------------------------------------------------------------------- Reinsurance -- 4.5% 1,250,000 3.66 Acorn Re, Ltd., Floating Rate Note, 7/17/18 (Cat Bond) (144A) $ 1,258,500 1,000,000 5.29 Alamo Re, Ltd., Floating Rate Note, 6/7/17 (Cat Bond) (144A) 1,031,100 1,250,000 5.95 Alamo Re, Ltd., Floating Rate Note, 6/7/18 (Cat Bond) (144A) 1,292,000 1,000,000 Altair Re, Variable Rate Notes, 6/30/17 (f) 1,043,000 500,000 Arlington Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 8/31/16 (f) 513,600 1,500,000 3.47 Atlas IX Capital, Ltd., Floating Rate Note, 1/17/19 (Cat Bond) (144A) 1,526,550 1,000,000 8.15 Atlas Reinsurance VII, Ltd., Floating Rate Note, 1/7/16 (Cat Bond) (144A) 1,012,600 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 71 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Reinsurance -- (continued) 3,325,000 4.37 Blue Danube II, Ltd., Floating Rate Note, 5/23/18 (Cat Bond) (144A) $ 3,353,262 750,000 2.53 Bosphorus Re, Ltd., Floating Rate Note, 5/3/16 (Cat Bond) (144A) 748,050 750,000 3.58 Bosphorus, Ltd., Floating Rate Note, 8/17/18 (Cat Bond) (144A) 744,525 2,250,000 5.30 Caelus Re, Ltd., Floating Rate Note, 3/7/16 (Cat Bond) (144A) 2,273,400 2,550,000 6.86 Caelus Re, Ltd., Floating Rate Note, 4/7/17 (Cat Bond) (144A) 2,634,150 250,000 4.48 Citrus Re, Ltd., Floating Rate Note, 4/18/17 (Cat Bond) (144A) 251,800 1,350,000 4.30 Citrus Re, Ltd., Floating Rate Note, 4/24/17 (Cat Bond) (144A) 1,360,800 500,000 Clarendon Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 6/15/16 (f) 491,850 1,000,000 0.00 Compass Re II, Ltd., Floating Rate Note, 12/8/15 (Cat Bond) 988,200 1,000,000 3.8 Cranberry Re, Ltd., Floating Rate Note, 7/6/18 (Cat Bond) (144A) 1,020,500 250,000 9.06 East Lane Re V, Ltd., Floating Rate Note, 3/16/16 (Cat Bond) (144A) 257,950 2,200,000 3.78 East Lane Re VI, Ltd., Floating Rate Note, 3/13/20 (Cat Bond) (144A) 2,216,500 2,000,000 2.78 East Lane Re VI, Ltd., Floating Rate Note, 3/14/18 (Cat Bond) (144A) 1,983,600 1,300,000 Eden Re II, Ltd., Variable Rate Notes, 4/19/18 (144A) (f) 1,374,750 2,375,100 Exeter Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 1/7/16 (f) 2,539,932 750,000 Fairfield Segregated Account (KANE SAC Ltd.), Variable Rate Notes, 2/2/16 (f) 733,650 1,250,000 7.41 Galileo Re, Ltd., Floating Rate Note, 1/9/19 (Cat Bond) (144A) 1,274,625 2,000,000 6.69 Gator Re, Ltd., Floating Rate Note, 1/9/17 (Cat Bond) (144A) 1,848,000 2,650,000 2.21 Golden State Re II, Ltd., Floating Rate Note, 1/8/19 (Cat Bond) (144A) 2,634,895 2,600,000 Gullane Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 1/22/17 (f) 2,851,420 420,500 Hereford Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 1/7/16 (f) 482,986 1,000,000 4.57 Ibis Re II, Ltd., Floating Rate Note, 6/28/16 (Cat Bond) (144A) 1,023,200 2,500,000 4.07 Ibis Re II, Ltd., Floating Rate Note, 6/28/16 (Cat Bond) (144A) 2,551,500 2,350,000 3.76 Kilimanjaro Re, Ltd., Floating Rate Note, 11/25/19 (Cat Bond) (144A) 2,328,145 The accompanying notes are an integral part of these financial statements. 72 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Reinsurance -- (continued) 2,300,000 4.77 Kilimanjaro Re, Ltd., Floating Rate Note, 4/30/18 (Cat Bond) (144A) $ 2,313,570 1,000,000 4.52 Kilimanjaro Re, Ltd., Floating Rate Note, 4/30/18 (Cat Bond) (144A) 993,100 2,600,000 Kingsbarn 2015 Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 12/18/15 (f) 2,508,740 1,800,000 2.27 Kizuna Re II, Ltd., Floating Rate Note, 4/6/18 (Cat Bond) (144A) 1,803,420 1,000,000 Lahinch Re, Variable Rate Notes, 6/15/16 (f) 996,000 1,910,000 4.27 Longpoint Re, Ltd. III, Floating Rate Note, 5/18/16 (Cat Bond) (144A) 1,937,695 750,000 3.75 Longpoint Re, Ltd. III, Floating Rate Note, 5/24/21 (Cat Bond) (144A) 762,900 750,000 Lorenz Re, Ltd., Variable Rate Notes, 3/31/18 (f) 793,575 2,000,000 2.01 Merna Re V, Ltd., Floating Rate Note, 4/7/17 (Cat Bond) (144A) 1,996,200 1,500,000 4.51 MetroCat Re, Ltd., Floating Rate Note, 8/5/16 (Cat Bond) (144A) 1,535,700 1,111,667 Muirfield Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 1/12/16 (f) 1,220,388 1,750,000 7.57 Multicat Mexico Re, Ltd., Floating Rate Note, 12/4/15 (Cat Bond)(144A) 1,744,750 2,250,000 8.65 Mythen Re, Ltd., Series 2012-2 Class A, Floating Rate Note, 1/5/17 (Cat Bond) (144A) 2,328,525 500,000 11.88 Mythen Re, Ltd., Series 2012-2 Class A, Floating Rate Note, 11/10/16 (Cat Bond) (144A) 518,750 2,250,000 7.27 Northshore Re, Ltd., Floating Rate Note, 7/5/16 (Cat Bond) (144A) 2,303,775 2,500,000 Pangaea Re, Series 2015-1, Principal at Risk Notes, 2/1/19 (f) 2,823,250 2,800,000 Pangaea Re, Series 2015-2, Principal at Risk Notes, 11/30/19 (f) 2,892,120 2,300,000 Pangaea Re., Variable Rate Notes, 7/1/18 (f) 41,400 1,750,000 3.53 Queen City Re, Floating Rate Note, 1/6/19 (Cat Bond) (144A) 1,749,125 1,750,000 8.60 Queen Street VII Re, Ltd., Floating Rate Note, 4/8/16 (Cat Bond) (144A) 1,769,250 1,000,000 5.75 Queen Street X Re, Ltd., Floating Rate Note, 6/8/18 (Cat Bond) (144A) 998,400 1,500,000 8.93 Residential Reinsurance 2011, Ltd., Floating Rate Note, 6/6/17 (Cat Bond) (144A) 1,510,200 1,000,000 12.79 Residential Reinsurance 2012, Ltd., Floating Rate Note, 12/6/16 (Cat Bond) (144A) 1,061,100 2,900,000 4.54 Residential Reinsurance 2012, Ltd., Floating Rate Note, 12/6/16 (Cat Bond) (144A) 2,949,880 1,500,000 5.78 Residential Reinsurance 2012, Ltd., Floating Rate Note, 12/6/16 (Cat Bond) (144A) 1,540,200 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 73 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Reinsurance -- (continued) 900,000 10.03 Residential Reinsurance 2012, Ltd., Floating Rate Note, 6/6/16 (Cat Bond) (144A) $ 950,580 750,000 8.04 Residential Reinsurance 2012, Ltd., Floating Rate Note, 6/6/16 (Cat Bond) (144A) 783,225 850,000 9.28 Residential Reinsurance 2013, Ltd., Floating Rate Note, 6/6/17 (Cat Bond) (144A) 899,555 750,000 3.53 Residential Reinsurance 2014, Ltd., Floating Rate Note, 6/6/18 (Cat Bond) (144A) 759,975 1,000,000 3.02 Sanders Re, Ltd., Floating Rate Note, 5/25/18 (Cat Bond) (144A) 992,700 2,500,000 3.51 Sanders Re, Ltd., Floating Rate Note, 5/5/17 (Cat Bond) (144A) 2,508,750 1,250,000 4.02 Sanders Re, Ltd., Floating Rate Note, 5/5/17 (Cat Bond) (144A) 1,259,500 3,000,000 3.87 Sanders Re, Ltd., Floating Rate Note, 6/7/17 (Cat Bond) (144A) 3,035,400 500,000 Sector Re V, Ltd., Variable Rate Notes, 12/1/19 (144A) (f) 557,400 1,250,000 Sector Re V, Ltd., Variable Rate Notes, 3/1/20 (144A) (f) 1,310,375 1,500,000 8.49 Tar Heel Re, Ltd., Floating Rate Note, 5/9/16 (Cat Bond) (144A) 1,557,000 750,000 5.01 Tradewynd Re, Ltd., Floating Rate Note, 1/8/18 (Cat Bond) (144A) 749,250 1,750,000 3.26 Tramline RE II, Ltd., Floating Rate Note, 7/7/17 (Cat Bond) (144A) 1,729,000 250,000 9.77 Tramline Re II, Ltd., Floating Rate Note, 1/4/19 (Cat Bond) (144A) 256,475 1,147,083 Troon Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 1/12/16 (f) 1,227,953 2,500,000 0.0 Ursa Re, Ltd., Floating Rate Note, 9/21/18 (Cat Bond) (144A) 2,499,000 2,500,000 Versutus Ltd., Series 2015-A, Variable Rate Notes, 12/31/2017 (f) 2,825,000 3,750,000 3.56 Vita Capital V, Ltd., Floating Rate Note, 1/15/17 (Cat Bond) (144A) 3,790,875 1,500,000 2.86 Vita Capital V, Ltd., Floating Rate Note, 1/15/17 (Cat Bond) (144A) 1,514,700 2,750,000 3.80 Vitality Re IV, Ltd., Floating Rate Note, 1/9/18 (Cat Bond) (144A) 2,803,350 1,000,000 2.77 Vitality Re IV, Ltd., Floating Rate Note, 1/9/17 (Cat Bond) (144A) 1,010,000 3,800,000 1.77 Vitality Re V, Ltd., Floating Rate Note, 1/7/19 (Cat Bond) (144A) 3,773,020 --------------- $ 123,530,136 --------------- Total Insurance $ 170,950,291 --------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 74 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- SOFTWARE & SERVICES -- 0.2% Application Software -- 0.0%+ 1,250,000 Igloo Holdings Corp., 8.25%, 12/15/17 (8.25% Cash, 9.00% PIK) (144A) (PIK) $ 1,253,125 --------------------------------------------------------------------------------------------------------- Systems Software -- 0.2% 3,215,000 Oracle Corp., 5.25%, 1/15/16 $ 3,258,013 1,937,000 0.48 Oracle Corp., Floating Rate Note, 7/7/17 1,935,632 --------------- $ 5,193,645 --------------- Total Software & Services $ 6,446,770 --------------------------------------------------------------------------------------------------------- TECHNOLOGY HARDWARE & EQUIPMENT -- 0.2% Communications Equipment -- 0.2% 2,580,000 0.56 Cisco Systems, Inc., Floating Rate Note, 3/3/17 $ 2,579,966 2,550,000 0.65 Cisco Systems, Inc., Floating Rate Note, 6/15/18 2,538,905 --------------- $ 5,118,871 --------------------------------------------------------------------------------------------------------- Computer Storage & Peripherals -- 0.0%+ 1,500,000 0.33 Apple, Inc., Floating Rate Note, 5/3/16 $ 1,500,022 --------------- Total Technology Hardware & Equipment $ 6,618,893 --------------------------------------------------------------------------------------------------------- TELECOMMUNICATION SERVICES -- 1.1% Integrated Telecommunication Services -- 0.9% 3,925,000 AT&T, Inc., 2.4%, 8/15/16 $ 3,968,842 3,875,000 AT&T, Inc., 2.95%, 5/15/16 3,921,194 2,735,000 0.70 AT&T, Inc., Floating Rate Note, 2/12/16 2,732,366 2,881,000 British Telecommunications Plc, 1.625%, 6/28/16 2,892,576 3,300,000 Verizon Communications, Inc., 0.7%, 11/2/15 3,300,568 8,530,000 1.87 Verizon Communications, Inc., Floating Rate Note, 9/15/16 8,610,975 --------------- $ 25,426,521 --------------------------------------------------------------------------------------------------------- Wireless Telecommunication Services -- 0.2% 1,250,000 Altice Financing SA, 7.875%, 12/15/19 (144A) $ 1,293,750 1,500,000 1.29 America Movil SAB de CV, Floating Rate Note, 9/12/16 1,499,606 1,150,000 0.66 Vodafone Group Plc, Floating Rate Note, 2/19/16 1,149,252 --------------- $ 3,942,608 --------------- Total Telecommunication Services $ 29,369,129 --------------------------------------------------------------------------------------------------------- UTILITIES -- 1.2% Electric Utilities -- 0.8% 1,740,000 0.66 Duke Energy Corp., Floating Rate Note, 4/3/17 $ 1,735,098 2,285,000 0.64 Duke Energy Indiana, Inc., Floating Rate Note, 7/11/16 2,284,979 5,100,000 0.48 Duke Energy Progress LLC, Floating Rate Note, 11/20/17 5,042,666 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 75 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Electric Utilities -- (continued) 1,275,000 0.48 Duke Energy Progress LLC, Floating Rate Note, 3/6/17 $ 1,270,680 1,865,000 0.75 Electricite de France SA, Floating Rate Note, 1/20/17 (144A) 1,864,123 1,040,000 Georgia Power Co., 0.625%, 11/15/15 1,039,942 1,090,000 0.61 Georgia Power Co., Floating Rate Note, 3/15/16 1,089,131 1,000,000 0.72 Georgia Power Co., Floating Rate Note, 8/15/16 998,007 2,500,000 LG&E and KU Energy LLC, 2.125%, 11/15/15 2,504,078 1,013,000 0.56 NSTAR Electric Co., Floating Rate Note, 5/17/16 1,011,441 1,665,000 0.88 TECO Finance, Inc., Floating Rate Note, 4/10/18 1,653,460 --------------- $ 20,493,605 --------------------------------------------------------------------------------------------------------- Gas Utilities -- 0.0%+ 1,000,000 DCP Midstream Operating LP, 3.25%, 10/1/15 $ 1,000,000 --------------------------------------------------------------------------------------------------------- Multi-Utilities -- 0.3% 2,376,000 Dominion Resources, Inc. Virginia, 1.95%, 8/15/16 $ 2,392,095 2,500,000 San Diego Gas & Electric Co., 5.3%, 11/15/15 2,513,450 2,500,000 0.48 San Diego Gas & Electric Co., Floating Rate Note, 3/9/17 2,494,420 --------------- $ 7,399,965 --------------------------------------------------------------------------------------------------------- Independent Power Producers & Energy Traders -- 0.1% 1,250,000 NRG Energy, Inc., 8.25%, 9/1/20 $ 1,283,750 2,500,000 PSEG Power LLC, 2.75%, 9/15/16 2,534,950 --------------- $ 3,818,700 --------------- Total Utilities $ 32,712,270 --------------------------------------------------------------------------------------------------------- TOTAL CORPORATE BONDS (Cost $820,426,803) $ 821,457,545 --------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- 6.8% 4,616 Fannie Mae, 7.0%, 10/1/17 $ 4,782 21,820 2.32 Fannie Mae, Floating Rate Note, 1/1/48 23,174 25,691 2.64 Fannie Mae, Floating Rate Note, 10/1/32 26,419 7,254 2.25 Fannie Mae, Floating Rate Note, 11/1/23 7,490 23,050 2.30 Fannie Mae, Floating Rate Note, 2/1/34 23,276 18,687 2.36 Fannie Mae, Floating Rate Note, 9/1/32 19,825 2,133,000 Federal Farm Credit Banks, 0.39%, 4/25/16 2,132,558 2,560,000 0.15 Federal Farm Credit Banks, Floating Rate Note, 10/26/15 2,559,990 2,610,000 0.14 Federal Farm Credit Banks, Floating Rate Note, 2/18/16 2,608,760 The accompanying notes are an integral part of these financial statements. 76 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 10,000,000 0.27 Federal Farm Credit Banks, Floating Rate Note, 6/20/16 $ 10,003,380 10,000,000 0.21 Federal Home Loan Banks, Floating Rate Note, 10/1/15 10,000,000 6,000,000 0.22 Federal Home Loan Banks, Floating Rate Note, 10/7/15 6,000,024 2,640,000 0.22 Federal Home Loan Banks, Floating Rate Note, 10/7/15 2,640,011 6,744 2.45 Federal Home Loan Mortgage Corp., Floating Rate Note, 10/1/23 6,953 14,047 2.61 Federal Home Loan Mortgage Corp., Floating Rate Note, 11/1/33 14,641 6,902 2.59 Federal Home Loan Mortgage Corp., Floating Rate Note, 6/1/35 6,990 8,925,000 0.48 Federal National Mortgage Association, Floating Rate Note, 10/3/16 8,945,287 6,085,000 0.22 Federal National Mortgage Association, Floating Rate Note, 8/26/16 6,086,606 10,515 1.75 Government National Mortgage Association II, Floating Rate Note, 1/20/22 10,887 2,600,000 Private Export Funding Corp., 2.125%, 7/15/16 2,631,611 20,070,000 0.10 U.S. Treasury Note, Floating Rate Note, 1/31/17 20,064,641 20,180,000 0.07 U.S. Treasury Note, Floating Rate Note, 10/31/16 20,174,007 20,175,000 0.08 U.S. Treasury Note, Floating Rate Note, 4/30/16 20,176,957 40,175,000 0.09 U.S. Treasury Note, Floating Rate Note, 4/30/17 40,147,065 13,470,000 0.09 U.S. Treasury Note, Floating Rate Note, 7/31/16 13,471,131 20,095,000 0.09 U.S. Treasury Note, Floating Rate Note, 7/31/17 20,074,302 --------------------------------------------------------------------------------------------------------- TOTAL U.S. GOVERNMENT AND AGENCY OBLIGATIONS (Cost $187,936,832) $ 187,860,767 --------------------------------------------------------------------------------------------------------- MUNICIPAL BONDS -- 0.1% (g) Higher Municipal Education -- 0.0%+ 675,000 President and Fellows of Harvard College, 6.3%, 10/1/37 $ 693,671 --------------------------------------------------------------------------------------------------------- Municipal Student Loan -- 0.1% 834,488 1.18 Louisiana Public Facilities Authority, Floating Rate Note, 4/26/27 $ 840,330 --------------------------------------------------------------------------------------------------------- TOTAL MUNICIPAL BONDS (Cost $1,531,822) $ 1,534,001 --------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 77 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- SENIOR FLOATING RATE LOAN INTERESTS -- 6.5%** ENERGY -- 0.3% Oil & Gas Drilling -- 0.0%+ 705,822 6.00 Drillships Financing Holding, Inc., Tranche B-1 Term Loan, 3/31/21 $ 418,199 62,929 5.75 Offshore Group Investment, Ltd., Term Loan, 3/28/19 20,085 866,250 3.75 Paragon Offshore Finance, Term Loan, 7/16/21 339,282 --------------- $ 777,566 --------------------------------------------------------------------------------------------------------- Oil & Gas Equipment & Services -- 0.1% 1,431,875 3.75 77 Energy, Tranche B Loan (First Lien), 6/17/21 $ 1,218,286 1,986,270 3.88 Fieldwood Energy LLC, Closing Date Loan, 9/25/18 1,705,709 493,750 5.25 McDermott International, Inc., Tranche B Loan (First Lien), 4/11/19 490,047 --------------- $ 3,414,042 --------------------------------------------------------------------------------------------------------- Integrated Oil & Gas -- 0.1% 11,241 4.50 Glenn Pool Oil & Gas Trust, Term Loan, 5/2/16 $ 11,213 2,701,875 4.00 Seadrill Operating LP, Initial Term Loan, 2/14/21 1,658,951 997,500 0.00 Terraform AP Acquisition Holdings, Term Loan (First Lien), 6/26/22 (d) 972,562 --------------- $ 2,642,726 --------------------------------------------------------------------------------------------------------- Oil & Gas Exploration & Production -- 0.1% 997,494 0.00 Penn Products Terminals LLC, Term Loan (First Lien), 4/1/22 (d) $ 992,506 --------------------------------------------------------------------------------------------------------- Oil & Gas Refining & Marketing -- 0.0%+ 444,347 4.25 Western Refining, Inc., Term Loan 2013, 11/12/20 $ 442,056 --------------- Total Energy $ 8,268,896 --------------------------------------------------------------------------------------------------------- MATERIALS -- 0.4% Commodity Chemicals -- 0.1% 1,759,189 4.50 AZ Chem US, Inc., Tranche B Term Loan (First Lien), 6/9/21 $ 1,760,014 381,456 4.25 Tronox Pigments Holland BV, New Term Loan, 3/19/20 334,039 --------------- $ 2,094,053 --------------------------------------------------------------------------------------------------------- Diversified Chemicals -- 0.0%+ 498,750 0.00 Chemours Company LLC, Term Loan (First Lien), 5/12/22 (d) $ 435,575 --------------------------------------------------------------------------------------------------------- Specialty Chemicals -- 0.1% 1,016,046 3.75 Axalta Coating Systems US Holdings, Inc., Refinanced Term B Loan, 2/1/20 $ 1,010,825 71,429 3.50 Chemtura Corp., New Term Loan, 8/29/16 71,414 The accompanying notes are an integral part of these financial statements. 78 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Specialty Chemicals -- (continued) 923,875 4.00 PQ Corp., 2014 Term Loan, 8/7/17 $ 922,432 287,833 2.75 WR Grace & Co-Conn, Delayed Draw Term Loan, 1/23/21 286,394 799,843 2.75 WR Grace & Co-Conn, U.S. Term Loan, 1/23/21 795,843 --------------- $ 3,086,908 --------------------------------------------------------------------------------------------------------- Metal & Glass Containers -- 0.1% 673,740 4.00 Ardagh Holdings USA, Inc., Tranche B-3 Term Loan (First Lien), 12/17/19 672,224 997,500 0.00 Owens-Brockway Glass Container Inc., Term Loan (First Lien), 8/14/22 (d) $ 1,001,964 --------------- $ 1,674,188 --------------------------------------------------------------------------------------------------------- Paper Packaging -- 0.0%+ 172,375 4.25 Multi Packaging Solutions, Inc., Initial Dollar Tranche B Term, 9/30/20 $ 170,867 --------------------------------------------------------------------------------------------------------- Aluminum -- 0.1% 115,800 5.75 Noranda Aluminum Acquisition Corp., Term B Loan, 2/28/19 $ 79,612 1,412,203 0.00 Novelis Inc., Term Loan (First Lien), 5/28/22 (d) 1,396,463 --------------- $ 1,476,075 --------------------------------------------------------------------------------------------------------- Diversified Metals & Mining -- 0.0%+ 1,104,569 3.75 Fortescue Metals Group Ltd., Bank Loan, 6/30/19 $ 908,508 --------------------------------------------------------------------------------------------------------- Steel -- 0.0%+ 354,764 4.75 JMC Steel Group, Inc., Term Loan, 4/1/17 $ 349,442 145,449 4.50 TMS International Corp., Term B Loan, 10/2/20 144,782 --------------- $ 494,224 --------------- Total Materials $ 10,340,398 --------------------------------------------------------------------------------------------------------- CAPITAL GOODS -- 0.5% Aerospace & Defense -- 0.2% 1,865,803 3.75 DigitalGlobe, Inc., Term Loan, 1/25/20 $ 1,859,670 143,055 6.25 DynCorp International, Inc., Term Loan, 7/7/16 140,075 1,280,637 3.75 TransDigm, Inc., Tranche C Term Loan, 2/28/20 1,270,313 2,355,167 3.25 Wesco Aircraft Hardare Corp., Tranche B Term Loan (First Lien), 2/24/21 2,309,045 --------------- $ 5,579,103 --------------------------------------------------------------------------------------------------------- Building Products -- 0.1% 1,072,744 3.50 Armstrong World Industries, Inc., Term Loan B, 3/15/20 $ 1,070,733 852,173 4.00 Quikrete Holdings, Inc., Initial Loan (First Lien), 9/26/20 850,894 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 79 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Building Products -- (continued) 796,449 4.25 Unifrax Corp., New Term B Loan, 12/31/19 $ 791,803 --------------- $ 2,713,430 --------------------------------------------------------------------------------------------------------- Electrical Components & Equipment -- 0.1% 1,059,245 3.00 Southwire Co., Term Loan, 1/31/21 $ 1,040,709 825,437 6.00 WireCo WorldGroup, Inc., Term Loan, 2/15/17 826,984 --------------- $ 1,867,693 --------------------------------------------------------------------------------------------------------- Industrial Conglomerates -- 0.0%+ 67,550 0.00 Kloeckner Pentaplast of America, Term Loan (First Lien), 4/22/20 (d) $ 67,845 158,066 0.00 Kloeckner Pentaplast of America, Term Loan (First Lien), 4/22/20 (d) 158,757 452,994 0.00 Milacron LLC, Term Loan (First Lien), 9/28/20 (d) 456,392 --------------- $ 682,994 --------------------------------------------------------------------------------------------------------- Construction & Farm Machinery & Heavy Trucks -- 0.0%+ 71,613 3.25 Manitowoc Co. Inc. (The), Term B Loan, 12/18/20 $ 71,097 306,461 3.50 Terex Corp., U.S. Term Loan, 8/13/21 306,997 --------------- $ 378,094 --------------------------------------------------------------------------------------------------------- Industrial Machinery -- 0.1% 233,348 4.25 Gardner Denver, Inc., Initial Dollar Term Loan, 7/30/20 $ 221,518 726,517 6.00 NN, Inc., Term Loan, 8/27/21 728,333 1,489,642 4.25 Schaeffler AG, Facility B-USD, 5/15/20 1,493,134 78,201 5.75 Xerium Technologies, Inc., Initial Term Loan, 5/17/19 78,348 --------------- $ 2,521,333 --------------------------------------------------------------------------------------------------------- Trading Companies & Distributors -- 0.0%+ 700,000 0.00 Beacon Roofing Supply Inc, Term Loan (First Lien), 9/25/22 (d) $ 700,000 318,295 3.75 WESCO Distribution, Inc., Tranche B-1 Loan, 12/12/19 318,593 --------------- $ 1,018,593 --------------- Total Capital Goods $ 14,761,240 --------------------------------------------------------------------------------------------------------- COMMERCIAL SERVICES & SUPPLIES -- 0.2% Environmental & Facilities Services -- 0.1% 149,250 0.00 Waste Industries USA Inc., Term Loan (First Lien), 2/20/20 (d) $ 150,182 2,852,011 5.00 Wheelabrator, Term B Loan, 10/15/21 2,799,726 126,437 5.00 Wheelabrator, Term C Loan, 10/15/21 124,119 --------------- $ 3,074,027 --------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 80 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Diversified Support Services -- 0.0%+ 834,186 6.50 Language Line LLC, Term Loan (First Lien), 7/2/21 $ 836,271 --------------------------------------------------------------------------------------------------------- Security & Alarm Services -- 0.1% 509,664 4.25 Allied Security Holdings LLC, Closing Date Term Loan (First Lien), 2/12/21 $ 506,797 316,931 4.00 Garda World Security Corp., Term B Delayed Draw Loan, 11/8/20 312,474 1,238,912 4.00 Garda World Security Corp., Term B Loan, 11/1/20 1,221,491 90,966 4.25 Monitronics International, Inc., Term B Loan, 3/23/18 90,625 --------------- $ 2,131,387 --------------------------------------------------------------------------------------------------------- Human Resource & Employment Services -- 0.0%+ 708,489 0.00 On Assignment Inc., Term Loan (First Lien), 6/5/22 (d) $ 709,703 --------------------------------------------------------------------------------------------------------- Research & Consulting Services -- 0.0%+ 166,109 5.00 Wyle, Tranche B Loan (First Lien), 5/22/21 $ 165,900 --------------- Total Commercial Services & Supplies $ 6,917,288 --------------------------------------------------------------------------------------------------------- TRANSPORTATION -- 0.2% Air Freight & Logistics -- 0.0%+ 196,500 5.25 Syncreon Group BV, Term Loan, 9/26/20 $ 157,855 --------------------------------------------------------------------------------------------------------- Airlines -- 0.2% 500,000 0.00 American Airlines Inc., Term Loan (First Lien), 10/10/21 (d) $ 498,125 2,505,375 0.00 American Airlines Inc., Term Loan (First Lien), 6/27/20 (d) 2,488,935 729,375 3.25 Delta Air Lines, Inc., 2014 Term B-1 Loan, 10/18/18 729,090 300,000 0.00 Delta Air Lines, Inc., Term Loan (First Lien), 8/24/22 (d) 300,225 243,750 3.25 United Airlines, Inc., Class B Term Loan, 4/1/19 243,674 --------------- $ 4,260,049 --------------------------------------------------------------------------------------------------------- Marine -- 0.0%+ 1,405,726 5.25 Navios Maritime Partners LP, Term Loan, 6/27/18 $ 1,405,287 --------------- Total Transportation $ 5,823,191 --------------------------------------------------------------------------------------------------------- AUTOMOBILES & COMPONENTS -- 0.4% Auto Parts & Equipment -- 0.2% 767,374 3.50 Allison Transmission, Inc., Term B-3 Loan, 8/23/19 $ 768,813 995,000 6.00 BBB Industries US, Initial Term Loan, 10/15/21 1,001,829 748,111 0.00 Key Safety Systems, Inc., Term Loan (First Lien), 7/28/21 (d) 731,278 1,242,018 3.75 MPG Holdco I, Inc., Initial Term Loan, 10/20/21 1,240,798 410,279 0.00 TI Group Automotive Systems LLC, Term Loan (First Lien), 6/25/22 (d) 403,441 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 81 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Auto Parts & Equipment -- (continued) 1,187,945 4.00 Tower Automotive Holdings USA LLC, Initial Term Loan (2014), 4/23/20 $ 1,177,551 --------------- $ 5,323,710 --------------------------------------------------------------------------------------------------------- Tires & Rubber -- 0.0%+ 666,667 3.75 The Goodyear Tire & Rubber Co., Term Loan (Second Lien), 3/27/19 $ 669,054 --------------------------------------------------------------------------------------------------------- Automobile Manufacturers -- 0.2% 371,124 3.50 Chrysler Group LLC, Term Loan B, 5/24/17 $ 370,524 2,856,500 3.25 Chrysler Group LLC, Tranche B Term Loan, 12/29/18 2,835,790 495,000 6.00 Crown Group llc, Term Loan (First Lien), 9/30/20 493,453 --------------- $ 3,699,767 --------------------------------------------------------------------------------------------------------- Personal Products -- 0.0%+ 291,667 3.50 Visteon Corp., Tranche B Loan (First Lien), 4/8/21 $ 290,753 --------------- Total Automobiles & Components $ 9,983,284 --------------------------------------------------------------------------------------------------------- CONSUMER DURABLES & APPAREL -- 0.1% Home Furnishings -- 0.0%+ 62,272 3.50 Tempur Sealy International, Inc., New Term B Loan, 3/18/20 $ 62,389 --------------------------------------------------------------------------------------------------------- Apparel, Accessories & Luxury Goods -- 0.1% 497,500 0.00 Hanes Brands, Inc., Term Loan (First Lien), 4/15/22 (d) $ 501,024 958,411 3.25 PVH Corp., Tranche B Term Loan, 12/19/19 964,062 --------------- $ 1,465,086 --------------- Total Consumer Durables & Apparel $ 1,527,475 --------------------------------------------------------------------------------------------------------- CONSUMER SERVICES -- 0.3% Casinos & Gaming -- 0.1% 1,215,625 3.50 MGM Resorts International, Term B Loan, 12/20/19 $ 1,207,838 90,250 3.75 Pinnacle Entertainment, Inc., Tranche B-2 Term Loan, 8/13/20 90,322 1,985,000 6.00 Scientific Games, Initial Term B-2, 10/1/21 1,964,406 --------------- $ 3,262,566 --------------------------------------------------------------------------------------------------------- Hotels, Resorts & Cruise Lines -- 0.1% 489,002 3.50 Four Seasons Holdings Inc., Term Loan, 6/27/20 $ 486,557 1,353,618 3.50 Hilton Worldwide Finance LLC, Initial Term Loan, 9/23/20 1,354,183 --------------- $ 1,840,740 --------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 82 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Leisure Facilities -- 0.0%+ 96,885 3.25 Cedar Fair LP, U.S. Term Facility, 3/6/20 $ 97,293 1,147,125 0.00 Six Flags Theme Parks, Inc., Term Loan (First Lien), 6/30/22 (d) 1,149,993 --------------- $ 1,247,286 --------------------------------------------------------------------------------------------------------- Restaurants -- 0.1% 469,382 3.75 1011778 BC ULC, Term B-2 Loan, 12/12/21 $ 469,170 364,084 4.00 Landry's, Inc., B Term Loan, 4/24/18 364,653 154,400 4.00 NPC International, Inc., Term Loan, 12/28/18 153,306 830,551 4.25 PF Chang's China Bistro, Inc., Term Borrowing, 7/2/19 816,016 --------------- $ 1,803,145 --------------------------------------------------------------------------------------------------------- Education Services -- 0.0%+ 592,260 3.75 Bright Horizons Family Solutions, Inc., Term B Loan, 1/14/20 $ 593,677 595,500 4.25 Bright Horizons Family Solutions, Inc., Term B-1 Loan, 1/30/20 596,493 --------------- $ 1,190,170 --------------------------------------------------------------------------------------------------------- Specialized Consumer Services -- 0.0%+ 383,810 4.00 Weight Watchers International, Inc., Initial Tranche B-2 Term Loan, 4/2/20 $ 208,697 --------------- Total Consumer Services $ 9,552,604 --------------------------------------------------------------------------------------------------------- MEDIA -- 1.0% Broadcasting -- 0.4% 1,629,423 3.00 CBS Outdoor Americas Capital llc, Tranche B Term Loan (First Lien), 1/15/21 $ 1,623,652 997,449 2.70 CSC Holdings LLC, Term B Loan, 4/17/20 993,352 1,000,000 5.00 CSC Holdings LLC, Term Loan (First Lien), 9/25/22 994,464 325,905 4.02 Entercom Radio llc, Term B-2 Loan, 11/23/18 325,956 522,358 3.50 EW Scripps, Term Loan (First Lien), 11/26/20 522,685 1,002,368 3.75 Gray Television, Inc., Term Loan (First Lien), 6/10/21 1,001,220 609,488 4.25 NEP, Amendment No. 4 Incremental Term Loan (First Lien), 1/22/20 598,060 493,703 3.25 Quebecor Media, Inc., Facility B-1 Tranche, 8/17/20 482,594 1,324,782 3.00 Sinclair Television Group, Inc., New Tranche B Term Loan, 4/19/20 1,312,983 997,500 3.50 Sinclair Television Group, Incremental Loan, 7/30/21 992,512 1,443,537 3.81 Tribune Company, Term B Loan, 12/27/20 1,439,478 657,963 4.00 Univision Communications, Inc., Replacement First- Lien Term Loan, 3/1/20 653,119 --------------- $ 10,940,075 --------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 83 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Cable & Satellite -- 0.4% 1,000,000 3.50 CCO Safari III LLC, Term Loan (First Lien), 1/23/23 $ 995,391 1,106,207 3.50 Cequel Communications LLC, Term Loan, 2/14/19 1,099,288 1,295,188 3.00 Charter Communications Operating LLC, Term F Loan, 1/1/21 1,280,732 521,732 3.75 Intelsat Jackson Holdings SA, Tranche B-2 Term Loan, 6/30/19 509,863 727,500 4.00 MCC Georgia LLC, Tranche G Term Loan, 2/8/20 727,651 1,379,000 2.66 Mediacom Illinois LLC, Tranche F Term Loan, 3/31/18 1,373,829 655,383 3.50 Telesat Canada, U.S. Term B Loan, 3/28/19 652,242 218,649 4.50 WideOpenWest Finance LLC, Replacement Term B Loan, 4/1/19 217,487 1,136,553 3.50 Ziggo BV, (USD) Tranche B-3 Term Loan, 1/15/22 1,119,979 1,072,383 3.50 Ziggo BV, Tranche B-1 Term Loan (First Lien), 1/15/22 1,056,744 691,064 3.50 Ziggo BV, Tranche B-2 Term Loan (First Lien), 1/15/22 680,986 --------------- $ 9,714,192 --------------------------------------------------------------------------------------------------------- Movies & Entertainment -- 0.2% 1,446,509 3.50 AMC Entertainment, Inc., Initial Term Loan, 4/30/20 $ 1,446,509 962,264 3.25 Kasima LLC, Term Loan, 5/17/21 961,261 762,440 3.50 Live Nation Entertainment, Inc., Term B-1 Loan, 8/17/20 762,955 1,013,204 3.75 Rovi Solutions Corp., Term B Loan, 7/2/21 996,739 586,500 3.50 Seminole Hard Rock Entertainment, Inc., New Term Loan B, 5/14/20 576,236 1,078,000 3.75 WMG Acquisition Corp., Tranche B Refinancing Term Loan, 7/1/20 1,058,192 --------------- $ 5,801,892 --------------- Total Media $ 26,456,159 --------------------------------------------------------------------------------------------------------- RETAILING -- 0.3% Computer & Electronics Retail -- 0.1% 1,723,750 3.75 Rent-A-Center, Inc., Term Loan (2014), 2/6/21 $ 1,721,595 --------------------------------------------------------------------------------------------------------- Home Improvement Retail -- 0.0%+ 1,218,750 4.50 Apex Tool Group LLC, Term Loan, 2/1/20 $ 1,192,471 --------------------------------------------------------------------------------------------------------- Specialty Stores -- 0.1% 977,500 3.75 Michaels Stores, Inc., Term B Loan, 1/28/20 976,787 1,000,000 0.00 Staples, Inc., Term Loan (First Lien), 4/24/21 (d) $ 997,560 --------------- $ 1,974,347 --------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 84 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Automotive Retail -- 0.1% 1,269,824 3.00 Avis Budget Car Rental LLC, Tranche B Term Loan, 3/15/19 $ 1,269,538 382,166 5.25 CWGS Group LLC, Term Loan, 2/20/20 382,882 729,375 3.75 The Hertz Corp., Tranche B1 Term Loan, 3/11/18 728,099 --------------- $ 2,380,519 --------------- Total Retailing $ 7,268,932 --------------------------------------------------------------------------------------------------------- FOOD & STAPLES RETAILING -- 0.1% Food Distributors -- 0.0%+ 184,036 5.75 AdvancePierre Foods, Inc., Term Loan (First Lien), 7/10/17 $ 184,409 --------------------------------------------------------------------------------------------------------- Food Retail -- 0.1% 1,492,464 5.38 Albertsons LLC, Term B-2 Loan, 3/21/19 $ 1,494,668 495,000 4.75 New Albertson's, Inc., Term Loan (First Lien), 6/24/21 494,938 --------------- $ 1,989,606 --------------- Total Food & Staples Retailing $ 2,174,015 --------------------------------------------------------------------------------------------------------- FOOD, BEVERAGE & TOBACCO -- 0.2% Beverages -- 0.0%+ 750,000 0.00 JBS USA LLC, Term Loan (First Lien), 11/18/22 (d) $ 750,463 --------------------------------------------------------------------------------------------------------- Agricultural Products -- 0.1% 1,566,150 3.25 Darling International, Inc., Term B USD Loan, 12/19/20 $ 1,567,129 --------------------------------------------------------------------------------------------------------- Packaged Foods & Meats -- 0.1% 874,626 3.75 JBS USA LLC, Initial Term Loan, 5/25/18 $ 873,117 2,158,833 3.00 Pinnacle Foods Finance LLC, New Term Loan G, 4/29/20 2,157,820 235,423 3.75 Post Holdings, Inc., Tranche B Loan (First Lien), 5/23/21 235,754 --------------- $ 3,266,691 --------------- Total Food, Beverage & Tobacco $ 5,584,283 --------------------------------------------------------------------------------------------------------- HOUSEHOLD & PERSONAL PRODUCTS -- 0.1% Household Products -- 0.0%+ 165,000 3.82 Spectrum Brands, Inc., Term Loan (First Lien), 6/16/22 $ 165,787 --------------------------------------------------------------------------------------------------------- Personal Products -- 0.1% 400,000 3.50 NBTY, Inc., Term B-2 Loan, 10/1/17 $ 398,300 361,812 4.00 Revlon Consumer Products Corp., Acquisition Term Loan, 8/19/19 362,083 958,583 3.25 Revlon Consumer Products Corp., Replacement Term Loan, 11/19/17 958,942 --------------- $ 1,719,325 --------------- Total Household & Personal Products $ 1,885,112 --------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 85 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- HEALTH CARE EQUIPMENT & SERVICES -- 0.6% Health Care Equipment -- 0.1% 1,480,058 4.50 Kinetic Concepts, Inc., Term DTL-E1 loan, 5/4/18 $ 1,480,522 --------------------------------------------------------------------------------------------------------- Health Care Supplies -- 0.0%+ 1,000,000 0.00 Sterigenics-Nordion Holdings LLC, Term Loan (First Lien), 4/27/22 (d) $ 998,750 --------------------------------------------------------------------------------------------------------- Health Care Services -- 0.2% 548,191 6.25 BioScrip, Inc., Initial Term B Loan, 7/31/20 $ 515,300 328,915 6.50 BioScrip, Inc., Term Loan, 7/31/20 309,180 593,611 4.00 BSN Medical GmbH & Co. KG, Facility B1A, 8/28/19 593,611 470,288 3.50 DaVita HealthCare Partners, Inc., Tranche B Loan (First Lien), 6/19/21 470,958 1,239,384 4.00 Envision Healthcare Corp., Initial Term Loan, 5/25/18 1,241,062 1,470,000 2.33 Fresenius US Finance I, Inc., Tranche B Term Loan, 8/7/19 1,473,675 66,145 7.75 inVentiv Health, Inc., Term B-3 Loan, 5/15/18 66,090 497,475 4.25 National Mentor Holdings, Inc., Tranche B Term Loan, 1/31/21 496,698 910,219 0.00 Pharmaceutical Product Development, Term Loan (First Lien), 8/6/22 (d) 904,435 338,691 4.50 Truven Health Analytics, Inc., New Tranche B Term Loan, 6/6/19 336,675 --------------- $ 6,407,684 --------------------------------------------------------------------------------------------------------- Health Care Facilities -- 0.2% 25,101 3.08 CHS, Incremental 2019 Term G Loan, 12/31/19 $ 25,117 46,186 4.00 CHS, Incremental 2021 Term H Loan, 1/27/21 46,282 1,994,911 2.95 HCA, Inc., Tranche B-5 Term Loan, 3/31/17 1,995,460 483,788 4.50 IASIS Healthcare LLC, Term B-2 Loan, 5/3/18 484,897 1,100,000 4.25 Kindred Healthcare, Inc., Tranche B Loan (First Lien), 4/10/21 1,099,065 487,590 5.25 RegionalCare Hospital Partners, Inc., Term Loan (First Lien), 4/21/19 484,848 227,883 3.75 Select Medical Corp., Series E Tranche B Term Loan, 6/1/18 227,646 977,500 6.75 Steward Health Care System LLC, Term Loan, 4/10/20 976,584 --------------- $ 5,339,899 --------------------------------------------------------------------------------------------------------- Health Care Technology -- 0.1% 837,900 4.25 ConvaTec, Inc., Dollar Term Loan, 12/22/16 $ 837,900 1,591,694 3.75 Emdeon, Inc., Term B-2 Loan, 11/2/18 1,589,041 --------------- $ 2,426,941 --------------- Total Health Care Equipment & Services $ 16,653,796 --------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 86 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- PHARMACEUTICALS, BIOTECHNOLOGY & LIFE SCIENCES -- 0.3% Biotechnology -- 0.0%+ 1,116,966 3.50 Alkermes, Inc., 2019 Term Loan, 9/25/19 $ 1,117,432 --------------------------------------------------------------------------------------------------------- Pharmaceuticals -- 0.3% 421,301 3.75 Endo International, Term Loan (First Lien), 6/24/22 $ 420,742 517,125 3.20 Grifols Worldwide Operations USA, Inc., U.S. Tranche B Term Loam, 4/1/21 517,825 301,188 4.25 JLL, Initial Dollar Term Loan, 1/23/21 297,347 960,375 3.25 Mallinckrodt International Finance SA, Initial Term B Loan, 3/6/21 945,770 1,749,974 4.25 PharMEDium Healthcare Corp., Initial Term Loan (First Lien), 1/23/21 1,733,204 735,633 3.51 Prestige Brands, Inc., Term B-3 Loan, 9/3/21 736,476 617,624 3.25 RPI Finance Trust, Term B-3 Term Loan, 11/9/18 619,169 1,004,483 3.50 RPI Finance Trust, Term B-4 Term Loan, 11/9/20 1,003,855 511,676 3.75 Valeant Pharmaceuticals International, Inc., Series C-2 Tranche B Term Loan, 12/11/19 504,768 213,198 3.50 Valeant Pharmaceuticals International, Inc., Series D-2 Tranche B Term Loan, 2/13/19 210,067 1,313,724 3.75 Valeant Pharmaceuticals International, Inc., Series E1 Tranche B Term Loan, 8/5/20 1,296,482 --------------- $ 8,285,705 --------------- Total Pharmaceuticals, Biotechnology & Life Sciences $ 9,403,137 --------------------------------------------------------------------------------------------------------- BANKS -- 0.0%+ Thrifts & Mortgage Finance -- 0.0%+ 763,188 5.00 Ocwen Financial Corp., Initial Term Loan, 1/15/18 $ 763,427 --------------- Total Banks $ 763,427 --------------------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 0.2% Other Diversified Financial Services -- 0.1% 343,954 3.50 AWAS Finance Luxembourg 2012 SA, Term Loan, 7/16/18 $ 343,094 1,295,000 3.50 Delos Finance SARL, Tranche B Term Loan, 2/27/21 1,295,135 2,080,072 3.50 Fly Funding II Sarl, Term Loan, 8/9/18 2,072,923 488,750 5.00 Livingston International, Inc., Initial Term B-1 Loan (First Lien), 4/18/19 475,309 78,745 5.25 WorldPay, Facility B2A Term Loan, 8/6/17 79,041 --------------- $ 4,265,502 --------------------------------------------------------------------------------------------------------- Specialized Finance -- 0.1% 998,829 4.25 Mirror BidCo Corp., New Incremental Term Loan, 12/18/19 $ 998,829 The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 87 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Specialized Finance -- (continued) 592,500 3.25 SBA Senior Finance II LLC, Incremental Tranche B-1 Term Loan, 3/31/21 $ 587,131 --------------- $ 1,585,960 --------------- Total Diversified Financials $ 5,851,462 --------------------------------------------------------------------------------------------------------- INSURANCE -- 0.1% Insurance Brokers -- 0.1% 1,079,641 4.25 USI Insurance Services LLC, Term B Loan, 12/30/19 $ 1,071,994 --------------------------------------------------------------------------------------------------------- Multi-line Insurance -- 0.0%+ 72,306 0.00 Alliant Holdings LLC, Term Loan (First Lien), 7/28/22 (d) $ 72,125 --------------------------------------------------------------------------------------------------------- Property & Casualty Insurance -- 0.0%+ 489,861 5.75 Confie Seguros Holding II Co., Term B Loan (First Lien), 11/9/18 $ 491,085 --------------- Total Insurance $ 1,635,204 --------------------------------------------------------------------------------------------------------- REAL ESTATE -- 0.2% Mortgage REIT -- 0.1% 1,573,936 3.50 Starwood Property Trust, Inc., Term Loan (First Lien), 4/17/20 $ 1,564,755 --------------------------------------------------------------------------------------------------------- Retail REIT -- 0.1% 1,701,947 0.00 DTZ US Borrower LLC, Term Loan (First Lien), 11/4/21 (d) $ 1,687,853 --------------------------------------------------------------------------------------------------------- Specialized REIT -- 0.0%+ 399,000 0.00 Communications Sales & Leasing, Inc., Term Loan (First Lien), 10/16/22 (d) $ 374,561 979,956 3.25 The GEO Group, Inc., Term Loan, 4/3/20 981,793 --------------- $ 1,356,354 --------------------------------------------------------------------------------------------------------- Real Estate Services -- 0.0%+ 979,933 4.50 Altisource Solutions Sarl, Term B Loan, 12/9/20 $ 872,141 --------------- Total Real Estate $ 5,481,103 --------------------------------------------------------------------------------------------------------- SOFTWARE & SERVICES -- 0.1% Internet Software & Services -- 0.0%+ 954,022 3.50 Dealertrack Technologies, Inc., Term Loan, 2/27/21 $ 952,233 --------------------------------------------------------------------------------------------------------- IT Consulting & Other Services -- 0.0%+ 396,000 5.75 Evergreen Skills Lux Sarl, Initial Term Loan (First Lien), 4/23/21 $ 358,380 226,550 4.50 PSAV Presentation Services, Tranche B Term Loan (First Lien), 1/24/21 225,984 --------------- $ 584,364 --------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 88 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- Application Software -- 0.0%+ 464,702 4.50 Epiq Systems, Inc., Term Loan, 8/27/20 $ 463,540 10,555 8.50 Expert Global Solutions, Inc., Term B Advance (First Lien), 4/3/18 10,568 325,732 3.50 Verint Systems, Inc., Tranche B-2 Term Loan (First Lien), 9/6/19 326,098 --------------- $ 800,206 --------------------------------------------------------------------------------------------------------- Home Entertainment Software -- 0.1% 1,411,209 3.25 Activision Blizzard, Inc., Term Loan, 7/26/20 $ 1,413,071 205,299 5.25 Micro Focus International, Term Loan B, 10/7/21 205,577 --------------- $ 1,618,648 --------------- Total Software & Services $ 3,955,451 --------------------------------------------------------------------------------------------------------- TECHNOLOGY HARDWARE & EQUIPMENT -- 0.2% Communications Equipment -- 0.1% 2,000,000 3.75 Commscope, Inc., Term Loan (First Lien), 5/29/22 $ 1,999,688 165,466 3.25 Commscope, Inc., Tranche 4 Term Loan, 1/14/18 165,362 --------------- $ 2,165,050 --------------------------------------------------------------------------------------------------------- Electronic Equipment Manufacturers -- 0.0%+ 940,909 4.75 Zebra Technologies, Term Loan B, 9/30/21 $ 948,254 --------------------------------------------------------------------------------------------------------- Electronic Components -- 0.1% 637,000 3.25 Belden Finance 2013 LP, Initial Term Loan, 9/9/20 $ 637,390 976,500 6.25 FCI -- Fidji Luxembourg Bc4 Sarl, Term Loan, 12/19/20 976,500 --------------- $ 1,613,890 --------------------------------------------------------------------------------------------------------- Technology Distributors -- 0.0%+ 292,487 0.00 Deltek Systems, Inc., Term Loan (First Lien), 12/31/22 (d) $ 292,792 --------------- Total Technology Hardware & Equipment $ 5,019,986 --------------------------------------------------------------------------------------------------------- SEMICONDUCTORS & SEMICONDUCTOR EQUIPMENT -- 0.1% Semiconductor Equipment -- 0.1% 1,924,641 2.58 Sensata Technologies, Term Loan (First Lien), 10/14/21 $ 1,925,170 --------------------------------------------------------------------------------------------------------- Semiconductors -- 0.0%+ 1,116,072 3.75 Avago Technologies Ltd., Tranche B Term Loan (First Lien), 4/16/21 $ 1,116,666 116,543 3.25 Microsemi Corp., Term Loan (First Lien), 3/14/21 116,223 --------------- $ 1,232,889 --------------- Total Semiconductors & Semiconductor Equipment $ 3,158,059 --------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 89 Schedule of Investments | 9/30/15 (unaudited) (continued) --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- TELECOMMUNICATION SERVICES -- 0.3% Integrated Telecommunication Services -- 0.2% 1,225,000 4.00 Cincinnati Bell, Inc., Tranche B Term Loan, 9/10/20 $ 1,219,488 656,700 4.00 GCI Holdings, Inc., New Term B Loan, 2/2/22 661,215 1,000,000 0.00 Level 3 Financing, Inc., Term Loan (First Lien), 5/31/22 (d) 994,583 1,484,673 0.00 Virgin Media, Term Loan (First Lien), 6/30/23 (d) 1,465,585 1,004,821 3.25 West Corp., B-10 Term Loan (First Lien), 6/30/18 995,165 703,409 3.50 Windstream Services LLC, Tranche B-5 Term Loan, 8/8/19 673,514 --------------- $ 6,009,550 --------------------------------------------------------------------------------------------------------- Wireless Telecommunication Services -- 0.1% 2,168,728 3.00 Crown Castle International Corp., Tranche B-2 Term Loan (First Lien), 1/31/21 $ 2,166,086 266,066 4.50 Numericable U.S. LLC, Tranche B-1 Term Loan, 4/23/20 264,695 230,184 4.50 Numericable-SFR, Tranche B-2 Loan (First Lien), 4/23/20 228,997 727,141 4.00 Syniverse Holdings, Inc., Tranche B Term Loan, 4/23/19 668,970 --------------- $ 3,328,748 --------------- Total Telecommunication Services $ 9,338,298 --------------------------------------------------------------------------------------------------------- UTILITIES -- 0.3% Electric Utilities -- 0.2% 2,546,004 4.75 Atlantic Power LP, Term Loan, 2/20/21 $ 2,541,230 1,173,000 3.00 Calpine Construction Finance Co. LP, Term B-1 Loan, 5/3/20 1,145,630 1,321,238 5.25 Terra-Gen Finance Company, Term Loan, 11/26/21 1,294,813 --------------- $ 4,981,673 --------------------------------------------------------------------------------------------------------- Independent Power Producers & Energy Traders -- 0.1% 289,275 0.00 Calpine Corp, Term Loan (First Lien), 5/28/22 (d) $ 285,478 752,419 4.00 Calpine Corp., Term Loan, 9/27/19 752,157 451,154 4.00 Dynegy, Inc., Tranche B-2 Term Loan, 4/23/20 451,114 1,660,253 2.75 NRG Energy, Inc., Term Loan (2013), 7/1/18 1,630,968 1,497,055 3.75 NSG Holdings LLC, New Term Loan, 12/11/19 1,485,827 --------------- $ 4,605,544 --------------- Total Utilities $ 9,587,217 --------------------------------------------------------------------------------------------------------- TOTAL SENIOR FLOATING RATE LOAN INTERESTS (Cost $184,858,655) $ 181,390,017 --------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 90 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value --------------------------------------------------------------------------------------------------------- TEMPORARY CASH INVESTMENTS -- 1.8% Repurchase Agreements -- 0.7% 20,650,000 $20,650,000 Bank of Nova Scotia, 0.12%, dated 9/30/15 plus accrued interest on 10/1/15 collateralized by the following: $6,710,253 Freddie Mac Giant, 3.5-4.0%, 9/1/28 -- 8/1/45 $10,339 Federal National Mortgage Association (ARM), 2.0%, 12/1/42 $14,133,520 Federal National Mortgage Association, 3.0 -- 6.0%, 3/1/26 -- 9/1/45 $208,958 Government National Mortgage Association II, 5.0%, 5/20/45 $ 20,650,000 20,650,000 $20,650,000 RBC Capital Markets LLC, 0.10%, dated 9/30/15 plus accrued interest on 10/1/15 collateralized by the following: $38,597 Federal Home Loan Mortgage Corp, 2.342 -- 2.476%, 6/1/42 -- 3/1/43 $3,086,387 Federal National Mortgage Association (ARM), 2.858 -3.856%, 12/1/40 -- 12/1/44 $12,625,286 Federal National Mortgage Association, 3.5 -- 4.0%, 2/1/34 -- 9/1/45 $5,312,730 Government National Mortgage Association II, 4.0 -- 4.5%, 4/20/41 -- 9/20/45 20,650,000 20,650,000 $20,650,000 TD Securities USA LLC, 0.07%, dated 9/30/15 plus accrued interest on 10/1/15 collateralized by the following: $21,063,061 U.S. Treasury Notes, 1.625%, 8/15/22 20,650,000 --------------- $ 61,950,000 --------------------------------------------------------------------------------------------------------- Commercial Paper -- 1.1% 2,650,000 0.40 Mizuho Bank, Ltd. New York, Floating Rate Note, 2/5/16 $ 2,650,000 2,575,000 0.60 Skandinaviska Enskilda Banken AB New York NY, Floating Rate Note, 1/4/16 2,575,857 20,650,000 Societe Generale SA, Commercial Paper, 10/1/15 (c) 20,650,004 1,715,000 0.65 Sumitomo Mitsui Banking Corp. New York, Floating Rate Note, 5/2/17 1,714,341 2,500,000 0.50 Svenska Handelsbanken New York NY, Floating Rate Note, 8/17/16 2,500,430 --------------- $ 30,090,632 --------------------------------------------------------------------------------------------------------- TOTAL TEMPORARY CASH INVESTMENTS (Cost $92,039,823) $ 92,040,632 --------------------------------------------------------------------------------------------------------- TOTAL INVESTMENT IN SECURITIES -- 99.1% (Cost $2,748,112,091) (a) $ 2,743,082,284 --------------------------------------------------------------------------------------------------------- OTHER ASSETS & LIABILITIES -- 0.9% $ 25,059,439 --------------------------------------------------------------------------------------------------------- TOTAL NET ASSETS -- 100.0% $ 2,768,141,723 ========================================================================================================= The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 91 Schedule of Investments | 9/30/15 (unaudited) (continued) + Amount rounds to less than 0.1%. (Cat Bond) Catastrophe or Event Linked Bond. At September 30, 2015, the value of these securities amounted to $96,302,747, or 3.5% of total net assets. See Notes to Financial Statements -- Note 1H. (Step) Bond issued with an initial coupon rate which converts to a higher rate at a later date. (144A) Security is exempt from registration under Rule 144A of the Securities Act of 1933. Such securities may be resold normally to qualified institutional buyers in a transaction exempt from registration. At September 30, 2015, the value of these securities amounted to $929,766,458, or 33.6% of total net assets. REIT Real Estate Investment Trust. REMICS Real Estate Mortgage Investment Conduits. (PIK) Represents a pay-in kind security. ARM Adjustable Rate Mortgage. Strips Separate trading of Registered interest and principal of securities. ** Senior floating rate loan interests in which the Fund invests generally pay interest at rates that are periodically redetermined by reference to a base lending rate plus a premium. These base lending rates are generally (i) the lending rate offered by one or more major European banks, such as LIBOR (London InterBank Offered Rate), (ii) the prime rate offered by one or more major United States banks, (iii) the certificate of deposit rate or (iv) other base lending rates used by commercial lenders. The rate shown is the coupon rate at period end. (a) At September 30, 2015, the net unrealized appreciation (depreciation) on investments based on cost for federal income tax purposes of $2,752,822,385 was as follows: Aggregate gross unrealized appreciation for all investments in which there is an excess of value over tax cost $ 2,146,826 Aggregate gross unrealized depreciation for all investments in which there is an excess of tax cost over value (11,886,927) ------------ Net unrealized depreciation $ (9,740,101) ============ (b) Debt obligation with a variable interest rate. Rate shown is rate at end of period. (c) Security issued with a zero coupon. Income is recognized through accretion of discount. (d) Rate to be determined. (e) Security is in default. (f) Structured reinsurance investment. At September 30, 2015, the value of these securities amounted to $27,227,389 or 1.0% of total net assets. See Notes to Financial Statements -- Note 1H. (g) Consists of Revenue Bonds unless otherwise indicated. Purchases and sales of securities (excluding temporary cash investments) for the six months ended September 30, 2015 aggregated $933,346,492 and $675,235,144, respectively. Various inputs are used in determining the value of the Fund's investments. These inputs are summarized in the three broad levels listed below. Level 1 - quoted prices in active markets for identical securities. Level 2 - other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk, etc.) See Notes to Financial Statements -- Note 1A. Level 3 - significant unobservable inputs (including the Fund's own assumptions in determining fair value of investments) See Notes to Financial Statements -- Note 1A. The accompanying notes are an integral part of these financial statements. 92 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 The following is a summary of the inputs used as of September 30, 2015, in valuing the Fund's assets: -------------------------------------------------------------------------------------------------- Level 1 Level 2 Level 3 Total -------------------------------------------------------------------------------------------------- Asset Backed Securities $ -- $ 680,766,836 $ -- $ 680,766,836 Collateralized Mortgage Obligations -- 778,032,486 -- 778,032,486 Corporate Bonds Insurance Reinsurance -- 96,302,747 27,227,389 123,530,136 All Other Corporate Bonds -- 697,927,409 -- 697,927,409 U.S. Government and Agency Obligations -- 187,860,767 -- 187,860,767 Foreign Government Bonds -- -- -- -- Municipal Bonds -- 1,534,001 -- 1,534,001 Senior Floating Rate Loan Interests -- 181,390,017 -- 181,390,017 Repurchase Agreements -- 61,950,000 -- 61,950,000 Commercial Paper -- 30,090,632 -- 30,090,632 -------------------------------------------------------------------------------------------------- Total $ -- $2,715,854,895 $ 27,227,389 $2,743,082,284 ================================================================================================== The following is a reconciliation of assets valued using significant observable inputs (Level 3): -------------------------------------------------------------------------------------------------- Preferred Corporate Stocks Bonds Total -------------------------------------------------------------------------------------------------- Balance as of 3/31/15 $ 2,507,460 $21,186,317 $23,693,777 Realized gain (loss)(1) -- (900) (900) Change in unrealized appreciation (depreciation)(2) -- (575,805) (575,805) Purchases -- 9,746,397 9,746,397 Sales -- (5,636,080) (5,636,080) Transfers in and out of Level 3 categories* (2,507,460) 2,507,460 -- Transfers in and out of Level 3* -- -- -- -------------------------------------------------------------------------------------------------- Balance as of 9/30/15 $ -- $27,227,389 $27,227,389 ================================================================================================== (1) Realized gain (loss) on these securities is included in the net realized gain (loss) from investments in the Statement of Operations. (2) Unrealized appreciation (depreciation) on these securities is included in the change in unrealized appreciation (depreciation) on investments in the Statement of Operations. * Transfers are calculated on the beginning of period values. During the six months ended September 30, 2015, there were no transfers between Levels 1, 2 and 3. Net change in unrealized appreciation (depreciation) of investments still held as of 9/30/15 $(536,481) ---------- The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 93 Statement of Assets and Liabilities | 9/30/15 (unaudited) ASSETS: Investment in securities (cost $2,748,112,091) $2,743,082,284 Cash 41,617,612 Receivables -- Investment securities sold 3,622,358 Fund shares sold 58,581,987 Interest 4,226,952 Other assets 175,768 -------------------------------------------------------------------------------- Total assets $2,851,306,961 ================================================================================ LIABILITIES: Payables -- Investment securities purchased $ 72,324,337 Fund shares repurchased 9,878,562 Distributions 299,925 Due to affiliates 419,063 Accrued expenses 243,351 -------------------------------------------------------------------------------- Total liabilities $ 83,165,238 ================================================================================ NET ASSETS: Paid-in capital $2,792,380,505 Distributions in excess of net investment income (11,097,629) Accumulated net realized loss on investments (8,111,346) Net unrealized depreciation on investments (5,029,807) -------------------------------------------------------------------------------- Total net assets $2,768,141,723 ================================================================================ NET ASSET VALUE PER SHARE: (No par value, unlimited number of shares authorized) Class A (based on $741,412,328/74,358,226 shares) $ 9.97 Class C (based on $584,661,895/58,717,658 shares) $ 9.96 Class C2 (based on $11,230,461/1,128,140 shares) $ 9.95 Class K (based on $5,156,660/516,848 shares) $ 9.98 Class Y (based on $1,425,680,379/142,955,130 shares) $ 9.97 MAXIMUM OFFERING PRICE: Class A ($9.97/97.5%) $ 10.23 ================================================================================ The accompanying notes are an integral part of these financial statements. 94 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 Statement of Operations (unaudited) For the Six Months Ended 9/30/15 INVESTMENT INCOME: Interest $16,835,723 ------------------------------------------------------------------------------------ Total investment income $ 16,835,723 ------------------------------------------------------------------------------------ EXPENSES: Management fees $ 4,115,390 Transfer agent fees and expenses Class A 21,953 Class C 16,560 Class C2 9 Class K 134 Class Y 4,782 Class Z* 167 Distribution fees Class A 725,163 Class C 1,439,399 Class C2 29,196 Administrative expense 376,859 Shareholder communication expense 895,563 Custodian fees 89,160 Registration fees 141,070 Professional fees 70,993 Printing expense 21,465 Fees and expenses of nonaffiliated Trustees 61,945 Miscellaneous 180,367 ------------------------------------------------------------------------------------ Total expenses $ 8,190,175 ------------------------------------------------------------------------------------ Net investment income $ 8,645,548 ------------------------------------------------------------------------------------ REALIZED AND UNREALIZED GAIN (LOSS) ON INVESTMENTS: Net realized loss on investments $ 24,681 Change in net unrealized depreciation on investments (2,010,769) ------------------------------------------------------------------------------------ Net realized and unrealized loss on investments $ (1,986,088) ------------------------------------------------------------------------------------ Net increase in net assets resulting from operations $ 6,659,460 ==================================================================================== * Class Z shares converted to Class Y shares on August 7, 2015. The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 95 Statements of Changes in Net Assets ------------------------------------------------------------------------------------------------ Six Months Ended 9/30/15 Year Ended (unaudited) 3/31/15 ------------------------------------------------------------------------------------------------ FROM OPERATIONS: Net investment income $ 8,645,548 $ 23,237,352 Net realized gain (loss) on investments 24,681 (141,464) Change in net unrealized appreciation (depreciation) on investments (2,010,769) (9,437,084) ------------------------------------------------------------------------------------------------ Net increase in net assets resulting from operations $ 6,659,460 $ 13,658,804 ------------------------------------------------------------------------------------------------ DISTRIBUTIONS TO SHAREOWNERS: Net investment income: Class A ($0.06 and $0.12 per share, respectively) $ (4,284,417) $ (8,726,818) Class C ($0.05 and $0.09 per share, respectively) (2,596,419) (5,456,629) Class C2 ($0.04 and $0.09 per share, respectively) (52,234) (78,135) Class K ($0.07 and $0.14 per share, respectively) (35,913) (29,911) Class Y ($0.07 and $0.14 per share, respectively) (8,357,627) (16,320,776) Class Z ($0.04 and $0.13 per share, respectively)* (7,120) (68,790) ------------------------------------------------------------------------------------------------ Total distributions to shareowners $ (15,333,730) $ (30,681,059) ------------------------------------------------------------------------------------------------ FROM FUND SHARE TRANSACTIONS: Net proceeds from sale of shares $1,214,437,668 $ 2,848,851,687 Reinvestment of distributions 13,492,647 26,801,350 Cost of shares repurchased (945,899,547) (2,430,043,835) ------------------------------------------------------------------------------------------------ Net increase in net assets resulting from Fund share transactions $ 282,030,768 $ 445,609,202 ------------------------------------------------------------------------------------------------ Net increase in net assets $ 273,356,498 $ 428,586,947 NET ASSETS: Beginning of period $2,494,785,225 $ 2,066,198,278 ------------------------------------------------------------------------------------------------ End of period $2,768,141,723 $ 2,494,785,225 ------------------------------------------------------------------------------------------------ Distributions in excess of net investment income $ (11,097,629) $ (4,409,447) ================================================================================================ * Class Z shares converted to Class Y shares on August 7, 2015. The accompanying notes are an integral part of these financial statements. 96 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 ------------------------------------------------------------------------------------------------ Six Months Six Months Ended Ended 9/30/15 9/30/15 Year Ended Year Ended Shares Amount 3/31/15 3/31/15 (unaudited) (unaudited) Shares Amount ------------------------------------------------------------------------------------------------ Class A Shares sold 32,528,171 $ 325,109,108 83,933,411 $ 843,718,437 Reinvestment of distributions 394,678 3,942,020 802,331 8,051,015 Less shares repurchased (27,963,659) (279,442,042) (72,000,258) (723,312,357) ------------------------------------------------------------------------------------------------ Net increase 4,959,190 $ 49,609,086 12,735,484 $ 128,457,095 ================================================================================================ Class C Shares sold 16,492,270 $ 164,534,541 46,730,296 $ 468,963,898 Reinvestment of distributions 257,407 2,567,690 537,145 5,379,841 Less shares repurchased (17,516,591) (174,802,789) (45,018,482) (451,628,403) ------------------------------------------------------------------------------------------------ Net increase (decrease) (766,914) $ (7,700,558) 2,248,959 $ 22,715,336 ================================================================================================ Class C2 Shares sold 284,297 $ 2,834,483 977,969 $ 9,812,274 Reinvestment of distributions 2,931 29,225 4,313 43,166 Less shares repurchased (286,106) (2,851,672) (223,142) (2,236,434) ------------------------------------------------------------------------------------------------ Net increase 1,122 $ 12,036 759,140 $ 7,619,006 ================================================================================================ Class K Shares sold 47,305 $ 473,049 508,487 $ 5,104,776 Reinvestment of distributions 3,593 35,913 2,980 29,827 Less shares repurchased (42,582) (425,934) (3,926) (39,320) ------------------------------------------------------------------------------------------------ Net increase 8,316 $ 83,028 507,541 $ 5,095,283 ================================================================================================ Class Y Shares sold 72,173,297 $ 721,203,562 150,302,046 $ 1,510,576,398 Reinvestment of distributions 691,985 6,912,766 1,318,376 13,231,801 Less shares repurchased (48,653,235) (486,266,253) (123,502,586) (1,240,201,155) ------------------------------------------------------------------------------------------------ Net increase 24,212,047 $ 241,850,075 28,117,836 $ 283,607,044 ================================================================================================ Class Z* Shares sold 28,442 $ 282,925 1,062,915 $ 10,675,904 Reinvestment of distributions 506 5,033 6,556 65,700 Less shares repurchased (212,381) (2,110,857) (1,259,589) (12,626,166) ------------------------------------------------------------------------------------------------ Net decrease (183,433) $ (1,822,899) (190,118) $ (1,884,562) ================================================================================================ * Class Z shares converted to Class Y shares on August 7, 2015. The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 97 Financial Highlights ---------------------------------------------------------------------------------------------------------------------- Six Months Ended Year Year Year 9/30/15 Ended Ended Ended 4/29/11 (unaudited) 3/31/15 3/31/14 3/31/13 to 3/31/12 ---------------------------------------------------------------------------------------------------------------------- Class A Net asset value, beginning of period $ 10.00 $ 10.07 $ 10.08 $ 10.02 $ 10.00 ---------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income (loss) $ 0.04 $ 0.10 $ 0.10 $ 0.13 $ 0.12 Net realized and unrealized gain (loss) on investments (0.01) (0.05) (0.01) 0.08 0.03 ---------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ 0.03 $ 0.05 $ 0.09 $ 0.21 $ 0.15 ---------------------------------------------------------------------------------------------------------------------- Distribution to shareowners: Net investment income $ (0.06) $ (0.12) $ (0.10) $ (0.15) $ (0.13) ---------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ (0.03) $ (0.07) $ (0.01) $ 0.06 $ 0.02 ---------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 9.97 $ 10.00 $ 10.07 $ 10.08 $ 10.02 ====================================================================================================================== Total return* 0.30% 0.54% 0.92% 2.14% 1.48%(a) Ratio of net expenses to average net assets 0.63%** 0.63% 0.66% 0.72% 0.90%** Ratio of net investment income (loss) to average net assets 0.68%** 0.95% 0.93% 0.94% 1.45%** Portfolio turnover rate 54%** 45% 47% 101% 51% Net assets, end of period (in thousands) $741,412 $694,221 $570,468 $381,267 $48,160 Ratios with no waiver of fees and assumption of expenses by the Adviser and no reduction for fees paid indirectly: Total expenses to average net assets 0.63%** 0.63% 0.66% 0.72% 1.03%** Net investment income (loss) to average net assets 0.68%** 0.95% 0.93% 0.94% 1.32%** ====================================================================================================================== * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions, the complete redemption of the investment at net asset value at the end of each period and no sales charges. Total return would be reduced if sales charges were taken into account. ** Annualized. (a) Not Annualized. The accompanying notes are an integral part of these financial statements. 98 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 ---------------------------------------------------------------------------------------------------------------------- Six Months Ended Year Year Year 9/30/15 Ended Ended Ended 4/29/11 (unaudited) 3/31/15 3/31/14 3/31/13 to 3/31/12 ---------------------------------------------------------------------------------------------------------------------- Class C Net asset value, beginning of period $ 9.99 $ 10.05 $ 10.07 $ 10.02 $ 10.00 ---------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income (loss) $ 0.02 $ 0.07 $ 0.08 $ 0.09 $ 0.05 Net realized and unrealized gain (loss) on investments 0.00(b) (0.04) (0.03) 0.07 0.03 ---------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ 0.02 $ 0.03 $ 0.05 $ 0.16 $ 0.08 ---------------------------------------------------------------------------------------------------------------------- Distribution to shareowners: Net investment income $ (0.05) $ (0.09) $ (0.07) $ (0.11) $ (0.06) ---------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ (0.03) $ (0.06) $ (0.02) $ 0.05 $ 0.02 ---------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 9.96 $ 9.99 $ 10.05 $ 10.07 $ 10.02 ====================================================================================================================== Total return* 0.15% 0.34% 0.54% 1.61% 0.82%(a) Ratio of net expenses to average net assets 0.94%** 0.94% 0.97% 1.03% 1.75%** Ratio of net investment income (loss) to average net assets 0.38%** 0.66% 0.62% 0.63% 0.52%** Portfolio turnover rate 54%** 45% 47% 101% 51% Net assets, end of period (in thousands) $584,662 $594,283 $575,457 $330,828 $11,643 Ratios with no waiver of fees and assumption of expenses by the Adviser and no reduction for fees paid indirectly: Total expenses to average net assets 0.94%** 0.94% 0.97% 1.03% 1.87%** Net investment income (loss) to average net assets 0.38%** 0.66% 0.62% 0.63% 0.40%** ====================================================================================================================== * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions, the complete redemption of the investment at net asset value at the end of each period and no sales charges. Total return would be reduced if sales charges were taken into account. ** Annualized. (a) Not Annualized. (b) Amount rounds to less than $0.01 or $(0.01) per share. The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 99 Financial Highlights (continued) ------------------------------------------------------------------------------------ Six Months Ended Year 9/30/15 Ended 8/1/13 (unaudited) 3/31/15 to 3/31/14 ------------------------------------------------------------------------------------ Class C2 Net asset value, beginning of period $ 9.99 $ 10.05 $ 10.04 ------------------------------------------------------------------------------------ Increase (decrease) from investment operations: Net investment income (loss) $ 0.02 $ 0.06 $ 0.07 Net realized and unrealized gain (loss) on investments (0.02) (0.03) (0.01) ------------------------------------------------------------------------------------ Net increase (decrease) from investment operations $ -- $ 0.03 $ 0.06 ------------------------------------------------------------------------------------ Distribution to shareowners: Net investment income $ (0.04) $ (0.09) $ (0.05) ------------------------------------------------------------------------------------ Net increase (decrease) in net asset value $ (0.04) $ (0.06) $ 0.01 ------------------------------------------------------------------------------------ Net asset value, end of period $ 9.95 $ 9.99 $ 10.05 ==================================================================================== Total return* 0.05% 0.33% 0.56%(a) Ratio of net expenses to average net assets 0.94%** 0.95% 0.99%** Ratio of net investment income (loss) to average net assets 0.37%** 0.66% 0.68%** Portfolio turnover rate 54%** 45% 47% Net assets, end of period (in thousands) $ 11,230 $11,258 $ 3,699 ==================================================================================== * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions, the complete redemption of the investment at net asset value at the end of each period. ** Annualized. (a) Not Annualized. The accompanying notes are an integral part of these financial statements. 100 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 ------------------------------------------------------------------------------------------------------------ Six Months Ended Year Year 9/30/15 Ended Ended 12/20/12 (unaudited) 3/31/15 3/31/14 to 3/31/13 ------------------------------------------------------------------------------------------------------------ Class K Net asset value, beginning of period $ 10.01 $ 10.07 $ 10.08 $ 10.09 ------------------------------------------------------------------------------------------------------------ Increase (decrease) from investment operations: Net investment income (loss) $ 0.05 $ 0.14 $ 0.12 $ 0.03 Net realized and unrealized gain (loss) on investments (0.01) (0.06) (0.00)(a) 0.01 ------------------------------------------------------------------------------------------------------------ Net increase (decrease) from investment operations $ 0.04 $ 0.08 $ 0.12 $ 0.04 ------------------------------------------------------------------------------------------------------------ Distribution to shareowners: Net investment income $ (0.07) $ (0.14) $ (0.13) $ (0.05) ------------------------------------------------------------------------------------------------------------ Net increase (decrease) in net asset value $ (0.03) $ (0.06) $ (0.01) $ (0.01) ------------------------------------------------------------------------------------------------------------ Net asset value, end of period $ 9.98 $ 10.01 $ 10.07 $ 10.08 ============================================================================================================ Total return* 0.41% 0.83% 1.16% 0.43%(b) Ratio of net expenses to average net assets 0.41%** 0.41% 0.41% 0.53%** Ratio of net investment income (loss) to average net assets 0.90%** 1.28% 1.19% 1.25%** Portfolio turnover rate 54%** 45% 47% 101% Net assets, end of period (in thousands) $ 5,157 $ 5,091 $ 10 $ 10 ============================================================================================================ * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions, the complete redemption of the investment at net asset value at the end of each period. ** Annualized. (a) Amount rounds to less than $0.01 or $(0.01) per share. (b) Not Annualized. The accompanying notes are an integral part of these financial statements. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 101 Financial Highlights (continued) -------------------------------------------------------------------------------------------------------------------------- Six Months Ended Year Year Year 9/30/15 Ended Ended Ended 4/29/11 (unaudited) 3/31/15 3/31/14 3/31/13 to 3/31/12 -------------------------------------------------------------------------------------------------------------------------- Class Y Net asset value, beginning of period $ 10.01 $ 10.07 $ 10.09 $ 10.03 $ 10.00 -------------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income (loss) $ 0.05 $ 0.11 $ 0.12 $ 0.14 $ 0.14 Net realized and unrealized gain (loss) on investments (0.02) (0.03) (0.02) 0.09 0.04 -------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ 0.03 $ 0.08 $ 0.10 $ 0.23 $ 0.18 -------------------------------------------------------------------------------------------------------------------------- Distribution to shareowners: Net investment income $ (0.07) $ (0.14) $ (0.12) $ (0.17) $ (0.15) -------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ (0.04) $ (0.06) $ (0.02) $ 0.06 $ 0.03 -------------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 9.97 $ 10.01 $ 10.07 $ 10.09 $ 10.03 ========================================================================================================================== Total return* 0.27% 0.79% 0.99% 2.35% 1.79%(a) Ratio of net expenses to average net assets 0.50%** 0.51% 0.54% 0.55% 0.67%** Ratio of net investment income (loss) to average net assets 0.81%** 1.08% 1.05% 1.11% 1.72%** Portfolio turnover rate 54%** 45% 47% 101% 51% Net assets, end of period (in thousands) $1,425,680 $1,188,107 $912,810 $608,818 $99,533 Ratios with no waiver of fees and assumption of expenses by the Adviser and no reduction for fees paid indirectly: Total expenses to average net assets 0.50%** 0.51% 0.54% 0.55% 0.80%** Net investment income (loss) to average net assets 0.81%** 1.08% 1.05% 1.11% 1.59%** ========================================================================================================================== * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions, the complete redemption of the investment at net asset value at the end of each period. ** Annualized. (a) Not Annualized. The accompanying notes are an integral part of these financial statements. 102 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 Notes to Financial Statements | 9/30/15 (unaudited) 1. Organization and Significant Accounting Policies Pioneer Multi-Asset Ultrashort Income Fund (formerly known as Pioneer Multi-Asset Floating Rate Fund) (the Fund) is one of three portfolios comprising Pioneer Series Trust X, a Delaware statutory trust. The Fund is registered under the Investment Company Act of 1940 as a diversified, open-end management investment company. The investment objective of the Fund is to seek a high level of current income to the extent consistent with a relatively high level of stability of principal. Prior to December 1, 2013, the investment objective of the Fund was to seek a high level of current income. Capital appreciation was a secondary objective. The Fund offers five classes of shares designated as Class A, Class C, Class C2, Class K and Class Y shares. Class A, Class C and Class Y shares were commenced operations on April 29, 2011. Class K shares commenced operations on December 20, 2012. Class C2 shares commenced operations on August 1, 2013. The Fund ceased to offer Class Z shares on August 7, 2015. Class Z shares were converted to Class Y shares as of the close of business on August 7, 2015. Each class of shares represents an interest in the same portfolio of investments of the Fund and has identical rights (based on relative net asset values) to assets and liquidation proceeds. Share classes can bear different rates of class-specific fees and expenses, such as transfer agent and distribution fees. Differences in class-specific fees and expenses will result in differences in net investment income and, therefore, the payment of different dividends from net investment income earned by each class. The Amended and Restated Declaration of Trust of the Fund gives the Board the flexibility to specify either per-share voting or dollar-weighted voting when submitting matters for shareholder approval. Under per-share voting, each share of a class of the Fund is entitled to one vote. Under dollar-weighted voting, a shareholder's voting power is determined not by the number of shares owned, but by the dollar value of the shares on the record date. Each share class has exclusive voting rights with respect to matters affecting only that class, including with respect to the distribution plan for that class. There is no distribution plan for Class K or Class Y shares. The Fund's financial statements have been prepared in conformity with U.S. generally accepted accounting principles that require the management of the Fund to, among other things, make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of income, expenses and gains and losses on investments during the reporting period. Actual results could differ from those estimates. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 103 The following is a summary of significant accounting policies followed by the Fund in the preparation of its financial statements: A. Security Valuation Security transactions are recorded as of trade date. The net asset value of the Fund is computed once daily, on each day the New York Stock Exchange (NYSE) is open, as of the close of regular trading on the NYSE. Fixed income securities are valued at prices supplied by independent pricing services, which consider such factors as market prices, market events, quotations from one or more brokers, Treasury spreads, yields, maturities and ratings. Valuations may be supplemented by dealers and other sources, as required. Senior floating rate loan interests (senior loans) are valued in accordance with guidelines established by the Board of Trustees at the mean between the last available bid and asked prices from one or more brokers or dealers as obtained from Loan Pricing Corporation, an independent pricing service. If price information is not available from Loan Pricing Corporation, or if the price information is deemed to be unreliable, price information will be obtained from an alternative loan interest pricing service. If no reliable price quotes are available from either the primary or alternative pricing service, broker quotes will be solicited. Event-linked bonds are valued at the bid price obtained from an independent third party pricing service. Other insurance-linked securities may be valued at the bid price obtained from an independent pricing service, or through a third party using a pricing matrix, insurance industry valuation models, or other fair value methods or techniques to provide an estimated value of the instrument. Shares of money market mutual funds are valued at such funds' net asset value. Cash may include overnight time deposits at approved financial institutions. Securities or senior loans for which independent pricing services are unable to supply prices or for which market prices and/or quotations are not readily available or are considered to be unreliable are valued by a fair valuation team comprised of certain personnel of Pioneer Investment Management, Inc. (PIM), the Fund's investment adviser, pursuant to procedures adopted by the Fund's Board of Trustees. PIMs fair valuation team uses fair value methods approved by the Valuation Committee of the Board of Trustees. PIM's fair valuation team is responsible for monitoring developments that may impact fair valued securities and for discussing and assessing fair values on an ongoing basis, and at least quarterly, with the Valuation Committee of the Board of Trustees. 104 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 The Fund may use fair value methods if it is determined that a significant event has occurred after the close of the exchange or market on which the security trades and prior to the determination of the Fund's net asset value. Examples of a significant event might include political or economic news, corporate restructurings, natural disasters, terrorist activity or trading halts. Thus, the valuation of the Fund's securities may differ significantly from exchange prices and such differences could be material. Inputs used when applying fair value methods to value a security may include credit ratings, the financial condition of the company, current market conditions and comparable securities. At September 30, 2015, no securities were valued using fair value methods (other than securities valued using prices supplied by independent pricing services or broker-dealers or using a third party insurance industry pricing model). B. Investment Income and Transactions Principal amounts of mortgage-backed securities are adjusted for monthly paydowns. Premiums and discounts related to certain mortgage-backed securities are amortized or accreted in proportion to the monthly paydowns. All discounts/premiums on purchase prices of debt securities are accreted/amortized for financial reporting purposes over the life of the respective securities, and such accretion/amortization is included in interest income. Interest income, including interest on income bearing cash accounts, is recorded on the accrual basis, net of unrecoverable foreign taxes withheld at the applicable country rates. Gains and losses on sales of investments are calculated on the identified cost method for both financial reporting and federal income tax purposes. C. Foreign Currency Translation The books and records of the Fund are maintained in U.S. dollars. Amounts denominated in foreign currencies are translated into U.S. dollars using current exchange rates. Net realized gains and losses on foreign currency transactions, if any, represent, among other things, the net realized gains and losses on foreign currency contracts, disposition of foreign currencies and the difference between the amount of income accrued and the U.S. dollars actually received. Further, the effects of changes in foreign currency exchange rates on investments are not segregated in the Statement of Operations from the effects of changes in the market prices of those securities but are included with the net realized and unrealized appreciation or depreciation on investments. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 105 D. Forward Foreign Currency Contracts The Fund may enter into forward foreign currency contracts (contracts) for the purchase or sale of a specific foreign currency at a fixed price on a future date. All contracts are marked to market daily at the applicable exchange rates, and any resulting unrealized appreciation or depreciation are recorded in the Fund's financial statements. The Fund records realized gain and loss at the time a contract is offset by entry into a closing transaction or extinguished by delivery of the currency. Risks may arise upon entering into these contracts from the potential inability of counterparties to meet the terms of the contract and from unanticipated movements in the value of foreign currencies relative to the U.S. dollar. E. Federal Income Taxes It is the Fund's policy to comply with the requirements of the Internal Revenue Code applicable to regulated investment companies and to distribute all of its net taxable income and net realized capital gains, if any, to its shareowners. Therefore, no provision for federal income taxes is required. As of March 31, 2015, the Fund had not accrued any interest or penalties with respect to uncertain tax positions, which, if applicable, would be recorded as an income tax expense in the Statement of Operations. Tax returns filed within the prior three years are subject to examination by Federal and State tax authorities. The amount and character of income and capital gain distributions to shareowners are determined in accordance with federal income tax rules, which may differ from U.S. generally accepted accounting principles. Distributions in excess of net investment income or net realized gains are temporary overdistributions for financial statement purposes resulting from differences in the recognition or classification of income or distributions for financial statement and tax purposes. Capital accounts within the financial statements are adjusted for permanent book/tax differences to reflect tax character, but are not adjusted for temporary differences. The tax character of current year distributions payable will be determined at the end of the current taxable year. The tax character of distributions paid during the year ended March 31, 2015 was as follows: --------------------------------------------------------------------------- 2015 --------------------------------------------------------------------------- Distributions paid from: Ordinary income $30,681,059 --------------------------------------------------------------------------- Total $30,681,059 =========================================================================== The following shows the components of distributable earnings on a federal income tax basis at March 31, 2015: 106 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 --------------------------------------------------------------------------- 2015 --------------------------------------------------------------------------- Distributable earnings: Undistributed ordinary income $ 592,672 Capital loss carryforward (8,135,597) Dividends payable (292,255) Unrealized depreciation (7,729,332) --------------------------------------------------------------------------- Total $ (15,564,512) =========================================================================== The difference between book-basis and tax-basis unrealized depreciation is attributable to the tax deferral of losses on wash sales, adjustments relating to catastrophe bonds and the tax treatment of premium and amortization. F. Fund Shares The Fund records sales and repurchases of its shares as of trade date. Pioneer Funds Distributor, Inc. (PFD), the principal underwriter for the Fund and a wholly owned indirect subsidiary of UniCredit S.p.A. (UniCredit), earned $3,301 in underwriting commissions on the sale of Class A shares during the six months ended September 30, 2015. G. Class Allocations Income, common expenses, and realized and unrealized appreciation and depreciation are calculated at the Fund level and allocated daily to each class of shares based on its respective percentage of adjusted net assets at the beginning of the day. Distribution fees are calculated based on the average daily net asset value attributable to Class A, Class C and Class C2 shares of the Fund, respectively (see Note 4). Class K and Class Y shares do not pay distribution fees. All expenses and fees paid to the transfer agent, Pioneer Investment Management Shareholder Services, Inc. (PIMSS), for its services are allocated among the classes of shares based on the number of accounts in each class and the ratable allocation of related out-of-pocket expenses (see Note 3). The Fund declares as daily dividends substantially all of its net investment income. All dividends are paid on a monthly basis. Short-term capital gain distributions, if any, may be declared with the daily dividends. Distributions to shareowners are recorded as of the ex-dividend date. Distributions paid by the Fund with respect to each class of shares are calculated in the same manner and at the same time except that net investment income dividends to Class A, Class C, Class C2, Class K and Class Y shares can reflect different transfer agent and distribution expense rates. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 107 H. Risks When interest rates rise, the prices of fixed-income securities in the Fund will generally fall. Conversely, when interest rates fall, the prices of fixed-income securities in the Fund will generally rise. Investments in the Fund are subject to possible loss due to the financial failure of issuers of underlying securities and the issuers' inability to meet their debt obligations. The Fund's prospectus contains unaudited information regarding the Fund's principal risks. Please refer to that document when considering the Fund's principal risks. The Fund invests in event-linked bonds. Event-linked bonds are floating rate debt obligations for which the return of principal and the payment of interest are contingent on the non-occurrence of a pre-defined "trigger" event, such as a hurricane or an earthquake of a specific magnitude. The trigger event's magnitude may be based on losses to a company or industry, industry indexes or readings of scientific instruments, or may be based on specified actual losses. If a trigger event, as defined within the terms of an event-linked bond occurs, the Fund may lose a portion or all of its accrued interest and/or principal invested in such event-linked bond. The Fund is entitled to receive principal and interest payments so long as no trigger event occurs of the description and magnitude specified by the instrument. In addition to the specified trigger events, event-linked bonds may expose the Fund to other risks, including but not limited to issuer (credit) default, adverse regulatory or jurisdictional interpretations and adverse tax consequences. In addition to event-linked bonds, the Fund also may invest in other insurance-linked securities ("ILS"). The Fund's investments in ILS may include special purpose vehicles ("SPVs") or similar instruments structured to comprise a portion of a reinsurer's catastrophe-oriented business, known as quota share instruments (sometimes referred to as reinsurance sidecars), or to provide reinsurance relating to specific risks to insurance or reinsurance companies through a collateralized instrument, known as collateralized reinsurance. Structured reinsurance investments also may include industry loss warranties ("ILWs"), are subject to the same risks as event-linked bonds. In addition, because quota share instruments represent an interest in a basket of underlying reinsurance contracts, the Fund has limited transparency into the individual underlying contracts and therefore must rely upon the risk assessment and sound underwriting practices of the issuer. Accordingly, it may be more difficult for PIM to fully evaluate the underlying risk profile of the Fund's investment in quota share instruments and therefore place the Fund's assets at greater risk of loss than if PIM had more complete information. These securities may be difficult to purchase, sell or unwind and may be difficult to value. 108 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 I. Repurchase Agreements Repurchase agreements are arrangements under which the Fund purchases securities from a broker-dealer or a bank, called the counterparty, upon the agreement of the counterparty to repurchase the securities from the Fund at a later date, and at a specific price, which is typically higher than the purchase price paid by the Fund. The securities purchased serve as the Fund's collateral for the obligation of the counterparty to repurchase the securities. The value of the collateral, including accrued interest, is required to be equal to or in excess of the repurchase price. The collateral for all repurchase agreements is held in safekeeping in the customer-only account of the Fund's custodian or a subcustodian of the Fund. The Fund's investment adviser, PIM is responsible for determining that the value of the collateral remains at least equal to the repurchase price. In the event of a default by the counterparty, the Fund is entitled to sell the securities, but the Fund may not be able to sell them for the price at which they were purchased, thus causing a loss to the Fund. Additionally, if the counterparty becomes insolvent, there is some risk that the Fund will not have a right to the securities, or the immediate right to sell the securities. 2. Management Agreement PIM, a wholly owned indirect subsidiary of UniCredit, manages the Fund's portfolio. Management fees are calculated daily at the annual rate equal to 0.35% of the Fund's average daily net assets up to $1 billion and 0.30% on assets over $1 billion. Prior to January 1, 2012, the Fund paid management fees calculated at the annual rate of 0.40% of the Fund's average daily net assets up to $1 billion and 0.35% on assets over $1 billion. For the six months ended September 30, 2015, the effective management fee (excluding waivers and/or assumption of expenses) was equivalent to 0.32% of the Fund's average daily net assets. PIM contractually agreed to limit ordinary operating expenses to the extent required to reduce Fund expenses to 1.15% of the average daily net assets attributable to Class C2 shares. Fees waived and expenses reimbursed during the six months ended September 30, 2015 are reflected on the Statement of Operations. The expense limitation was in effect through August 1, 2015. In addition, under the management and administration agreements, certain other services and costs, including accounting, regulatory reporting, and insurance premiums, are paid by the Fund as administrative reimbursements. Included in "Due to affiliates" reflected on the Statement of Assets and Liabilities is $45,785 in management fees, administrative costs and certain other reimbursements payable to PIM at September 30, 2015. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 109 3. Transfer Agent Prior to November 2, 2015, PIMSS, a wholly owned indirect subsidiary of UniCredit, provided substantially all transfer agent and shareowner services to the Fund at negotiated rates. In addition, the Fund reimbursed PIMSS for out-of-pocket expenses incurred by PIMSS related to shareholder communications activities such as proxy and statement mailings, outgoing phone calls and omnibus relationship contracts. For the six months ended September 30, 2015, such out-of-pocket expenses by class of shares were as follows: -------------------------------------------------------------------------------- Shareholder Communications: -------------------------------------------------------------------------------- Class A $106,752 Class C 105,755 Class C2 2,492 Class K 387 Class Y 678,856 Class Z 1,321 -------------------------------------------------------------------------------- Total $895,563 ================================================================================ Included in "Due to affiliates" reflected on the Statement of Assets and Liabilities is $349,131 in transfer agent fees and out-of-pocket reimbursements payable from PIMSS at September 30, 2015. Effective November 2, 2015, Boston Financial Data Services serves as the transfer agent to the fund at negotiated rates. 4. Distribution Plan The Fund has adopted a Distribution Plan pursuant to Rule 12b-1 of the Investment Company Act of 1940 with respect to its Class A, Class C and Class C2 shares. Pursuant to the Plan, the Fund pays PFD 0.20% of the average daily net assets attributable to Class A shares as compensation for personal services and/or account maintenance services or distribution services with regard to Class A shares. Pursuant to the Plan, the Fund also pays PFD 0.50% of the average daily net assets attributable to Class C and Class C2 shares. The fee for Class C and Class C2 shares consists of a 0.25% service fee and a 0.25% distribution fee paid as compensation for personal services and/or account maintenance services or distribution services with regard to Class C and Class C2 shares. Prior to July 1, 2012, the Fund paid PFD 0.25% of the average daily net assets attributable to Class A shares and 1.00% of the average daily net assets attributable to Class C shares. Included in "Due to affiliates" reflected on the Statement of Assets and Liabilities is $24,147 in distribution fees payable to PFD at September 30, 2015. 110 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 In addition, redemptions of each class of shares (except Class K, Class Y and Class Z shares) may be subject to a contingent deferred sales charge (CDSC). A CDSC of 1.00% may be imposed on redemptions of certain net asset value purchases of Class A shares within 12 months of purchase. For Class C shares purchased prior to July 1, 2012 and Class C2 shares redemptions of shares within 12 months of purchase are subject to a CDSC of 1.00%, based on the lower of cost or market value of shares being redeemed. Shares purchased as part of an exchange remain subject to any CDSC that applied to the original purchase of those shares. For Class C shares purchased on or after July 1, 2012, no contingent deferred sales charge is charged. There is no CDSC for Class K, Class Y and Class Z shares. Proceeds from the CDSCs are paid to PFD. For the six months ended September 30, 2015, CDSCs of $58,331 were paid to PFD. 5. Expense Offset Arrangements The Fund has entered into certain expense offset arrangements with PIMSS, which may result in a reduction in the Fund's total expenses due to interest earned on cash held by PIMSS. For the six months ended September 30, 2015, the Fund's expenses were not reduced under such arrangements. 6. Line of Credit Facility The Fund, along with certain other funds in the Pioneer Family of Funds (the Funds), participates in a committed, unsecured revolving line of credit facility. Borrowings are used solely for temporary or emergency purposes. The Fund may borrow up to the lesser of the amount available under the facility or the limits set for borrowing by the Fund's prospectus and the 1940 Act. The credit facility in effect until June 9, 2015, was in the amount of $215 million. As of June 9, 2015, the facility is in the amount of $240 million. Under such facility, depending on the type of loan, interest on borrowings is payable at the London Interbank Offered Rate (LIBOR) plus 0.90% 0.85% on an annualized basis, or the Alternate Base Rate, which is the greater of (a) the facility's administrative agent's daily announced prime rate on the borrowing date, (b) 2% plus the Federal Funds Rate on the borrowing date and (c) 2% plus the overnight Eurodollar rate on the borrowing date. The Funds pay an annual commitment fee to participate in a credit facility. The commitment fee is allocated among participating Funds based on an allocation schedule set forth in the credit agreement. For the six months ended September 30, 2015, the Fund had no borrowings under the credit facility. 7. Conversion of Class Z shares As of the close of business on August 7, 2015 (the "Conversion Date"), all outstanding Class Z shares of the Fund were converted to Class Y shares. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 111 ADDITIONAL INFORMATION Pioneer Investment Management, Inc. (the "Adviser"), each fund's investment adviser, is currently an indirect, wholly owned subsidiary of UniCredit S.p.A. ("UniCredit"). On November 11, 2015, UniCredit announced that it signed a binding master agreement with Banco Santander and affiliates of Warburg Pincus and General Atlantic (the "Private Equity Firms") with respect to Pioneer Investments ("Pioneer") and Santander Asset Management ("SAM") (the "Transaction"). The Transaction, as described in the UniCredit announcement, will establish a holding company, with the name Pioneer Investments, to be owned by UniCredit (50%) and the Private Equity Firms (50% between them). The holding company will control Pioneer's U.S. operations, including the Adviser. The holding company also will own 66.7% of Pioneer's and SAM's combined operations outside the U.S., while Banco Santander will own directly the remaining 33.3% stake. The closing of the Transaction is expected to happen in 2016, subject to certain regulatory and other approvals, and other conditions. Under the Investment Company Act of 1940, completion of the Transaction will cause each fund's current investment advisory agreement with the Adviser to terminate. Accordingly, each fund's Board of Trustees will be asked to approve a new investment advisory agreement. If approved by the Board, each fund's new investment advisory agreement will be submitted to the shareholders of the fund for their approval. 112 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 Approval of Investment Advisory Agreement Pioneer Investment Management, Inc. (PIM) serves as the investment adviser to Pioneer Multi-Asset Ultrashort Income Fund (the Fund) pursuant to an investment advisory agreement between PIM and the Fund. In order for PIM to remain the investment adviser of the Fund, the Trustees of the Fund must determine annually whether to renew the investment advisory agreement for the Fund. The contract review process began in January 2015 as the Trustees of the Fund agreed on, among other things, an overall approach and timeline for the process. Contract review materials were provided to the Trustees in March 2015 and July 2015. Supplemental contract review materials were provided to the Trustees in September 2015. In addition, the Trustees reviewed and discussed the Fund's performance at regularly scheduled meetings throughout the year and took into account other information related to the Fund provided to the Trustees at regularly scheduled meetings in connection with the review of the Fund's investment advisory agreement. In March 2015, the Trustees, among other things, discussed the memorandum provided by Fund counsel that summarized the legal standards and other considerations that are relevant to the Trustees in their deliberations regarding the renewal of the investment advisory agreement, and reviewed and discussed the qualifications of the investment management teams, as well as the level of investment by the Fund's portfolio managers in the Fund. In July 2015, the Trustees, among other things, reviewed the Fund's management fee and total expense ratios, the financial statements of PIM and its parent companies, the profitability analyses provided by PIM, and possible economies of scale. The Trustees also reviewed the profitability of the institutional business of PIM and PIM's affiliate, Pioneer Institutional Asset Management, Inc. (together with PIM, "Pioneer"), as compared to that of PIM's fund management business, and considered the differences between the fees and expenses of the Fund and the fees and expenses of Pioneer's institutional accounts, as well as the different services provided by PIM to the Fund and by Pioneer to the institutional accounts. The Trustees further considered contract review materials in September 2015. At a meeting held on September 15, 2015, based on their evaluation of the information provided by PIM and third parties, the Trustees of the Fund, including the Independent Trustees voting separately, unanimously approved the renewal of the investment advisory agreement for another year. In approving the renewal of the investment advisory agreement, the Trustees Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 113 considered various factors that they determined were relevant, including the factors described below. The Trustees did not identify any single factor as the controlling factor in determining to approve the renewal of the agreement. Nature, Extent and Quality of Services The Trustees considered the nature, extent and quality of the services that had been provided by PIM to the Fund, taking into account the investment objective and strategy of the Fund. The Trustees also reviewed PIM's investment approach for the Fund and its research process. The Trustees considered the resources of PIM and the personnel of PIM who provide investment management services to the Fund. They also reviewed the amount of non-Fund assets managed by the portfolio managers of the Fund. The Trustees considered the non-investment resources and personnel of PIM involved in PIM's services to the Fund, including PIM's compliance and legal resources and personnel. The Trustees noted the substantial attention and high priority given by PIM's senior management to the Pioneer fund complex. The Trustees considered that PIM supervises and monitors the performance of the Fund's service providers and provides the Fund with personnel (including Fund officers) and other resources that are necessary for the Fund's business management and operations. The Trustees also considered that, as administrator, PIM is responsible for the administration of the Fund's business and other affairs. The Trustees considered the fees paid to PIM for the provision of administration services. Based on these considerations, the Trustees concluded that the nature, extent and quality of services that had been provided by PIM to the Fund were satisfactory and consistent with the terms of the investment advisory agreement. Performance of the Fund In considering the Fund's performance, the Trustees regularly review and discuss throughout the year data prepared by PIM and information comparing the Fund's performance with the performance of its peer group of funds as classified by each of Morningstar, Inc. (Morningstar) and Lipper, and with the performance of the Fund's benchmark index. They also discuss the Fund's performance with PIM on a regular basis. The Trustees' regular reviews and discussions were factored into the Trustees' deliberations concerning the renewal of the advisory agreement. The Trustees indicated that the Fund's performance, when considered in connection with the various other factors, was consistent with the renewal of the investment advisory agreement. 114 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 Management Fee and Expenses The Trustees considered information showing the fees and expenses of the Fund in comparison to the management fees and expense ratios of its peer group of funds as classified by Morningstar and also to the expense ratios of a peer group of funds selected on the basis of criteria determined by the Independent Trustees for this purpose using data provided by Strategic Insight Mutual Fund Research and Consulting, LLC (Strategic Insight), an independent third party. In all quintile rankings referred to below, first quintile is most favorable to the Fund's shareowners. The Trustees considered that the Fund's management fee for the most recent fiscal year was in the third quintile relative to the management fees paid by other funds in its Morningstar peer group for the comparable period. The Trustees also considered the breakpoint in the management fee schedule and the reduced fee rate above a certain asset level. The Trustees considered that the expense ratio of the Fund's Class A shares for the most recent fiscal year was in the second quintile relative to its Morningstar peer group and in the second quintile relative its Strategic Insight peer group, in each case for the comparable period. The Trustees considered that the expense ratio of the Fund's Class Y shares for the most recent fiscal year was in the fourth quintile relative to its Morningstar peer group and in the fifth quintile relative its Strategic Insight peer group, in each case for the comparable period. The Trustees considered the impact of transfer agency, sub-transfer agency, and other non-management fee expenses on the expense ratios of the Fund. The Trustees noted that they separately review the Fund's transfer agency, sub-transfer agency and intermediary arrangements. The Trustees reviewed management fees charged by Pioneer to institutional and other clients, including publicly offered European funds sponsored by affiliates of Pioneer, unaffiliated U.S. registered investment companies (in a sub-advisory capacity), and unaffiliated foreign and domestic separate accounts. The Trustees also considered PIM's costs in providing services to the Fund and Pioneer's costs in providing services to the other clients and considered the differences in management fees and profit margins for Fund and non-Fund services. In evaluating the fees associated with Pioneer's client accounts, the Trustees took into account the respective demands, resources and complexity associated with the Fund and client accounts. The Trustees noted that, in some instances, the fee rates for those clients were lower than the management fee for the Fund and considered that, under the investment advisory agreement with the Fund, PIM performs additional services for the Fund that it does not provide to those other clients or services that are broader in scope, including oversight of the Fund's other service providers and activities related to compliance and the extensive regulatory and tax regimes to Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 115 which the Fund is subject. The Trustees also considered the different entrepreneurial risks associated with PIM's management of the Fund and Pioneer's management of the other client accounts. The Trustees concluded that the management fee payable by the Fund to PIM was reasonable in relation to the nature and quality of the services provided by PIM to the Fund. Profitability The Trustees considered information provided by PIM regarding the profitability of PIM with respect to the advisory services provided by PIM to the Fund, including the methodology used by PIM in allocating certain of its costs to the management of the Fund. The Trustees also considered PIM's profit margin in connection with the overall operation of the Fund. They further reviewed the financial results realized by PIM and its affiliates from non-fund businesses. The Trustees considered PIM's profit margins with respect to the Fund in comparison to the limited industry data available and noted that the profitability of any adviser was affected by numerous factors, including its organizational structure and method for allocating expenses. The Trustees concluded that PIM's profitability with respect to the management of the Fund was not unreasonable. Economies of Scale The Trustees considered PIM's views relating to economies of scale in connection with the Pioneer Funds as fund assets grow and the extent to which any such economies of scale are shared with funds and fund shareholders. The Trustees noted the breakpoint in the management fee schedule. The Trustees recognize that economies of scale are difficult to identify and quantify, and that, among other factors that may be relevant, are the following: fee levels, expense subsidization, investment by PIM in research and analytical capabilities and PIM's commitment and resource allocation to the Fund. The Trustees noted that profitability also may be an indicator of the availability of any economies of scale, although profitability may vary for other reasons including reductions in expenses. The Trustees concluded that economies of scale, if any, were being appropriately shared with the Funds. 116 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 Other Benefits The Trustees considered the other benefits to PIM from its relationship with the Fund. The Trustees considered the character and amount of fees paid by the Fund, other than under the investment advisory agreement, for services provided by PIM and its affiliates. The Trustees further considered the revenues and profitability of PIM's businesses other than the fund business. Pioneer is the principal U.S. asset management business of Pioneer Global Asset Management, the worldwide asset management business of UniCredit Group, which manages over $150 billion in assets (including the Funds). Pioneer and the Funds receive reciprocal intangible benefits from the relationship, including mutual brand recognition and, for the Funds, direct and indirect access to the resources of a large global asset manager. The Trustees concluded that any such benefits received by Pioneer as a result of its relationship with the Funds were reasonable and their consideration of the advisory agreement between the Fund and PIM and the fees thereunder were unaffected by Pioneer's possible receipt of any such intangible benefits. Conclusion After consideration of the factors described above as well as other factors, the Trustees, including all of the Independent Trustees, concluded that the investment advisory agreement between PIM and the Fund, including the fees payable thereunder, was fair and reasonable and voted to approve the proposed renewal of the investment advisory agreement for the Fund. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 117 Trustees, Officers and Service Providers Trustees Advisory Trustee Thomas J. Perna, Chairman Lorraine H. Monchak* David R. Bock Benjamin M. Friedman Officers Margaret B.W. Graham Lisa M. Jones, President and Chief Marguerite A. Piret Executive Officer Fred J. Ricciardi Mark E. Bradley, Treasurer and Kenneth J. Taubes Chief Financial Officer Christopher J. Kelley, Secretary and Chief Legal Officer Investment Adviser and Administrator Pioneer Investment Management, Inc. Custodian and Sub-Administrator Brown Brothers Harriman & Co. Principal Underwriter Pioneer Funds Distributor, Inc. Legal Counsel Morgan, Lewis & Bockius LLP Transfer Agent Boston Financial Data Services, Inc. Proxy Voting Policies and Procedures of the Fund are available without charge, upon request, by calling our toll free number (1-800-225-6292). Information regarding how the Fund voted proxies relating to portfolio securities during the most recent 12-month period ended June 30 is publicly available to shareowners at us.pioneerinvestments.com. This information is also available on the Securities and Exchange Commission's web site at www.sec.gov. * Ms. Monchak is a non-voting Advisory Trustee. 118 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 This page for your notes. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 119 This page for your notes. 120 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 This page for your notes. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 121 This page for your notes. 122 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 This page for your notes. Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 123 This page for your notes. 124 Pioneer Multi-Asset Ultrashort Income Fund | Semiannual Report | 9/30/15 How to Contact Pioneer We are pleased to offer a variety of convenient ways for you to contact us for assistance or information. Call us for: -------------------------------------------------------------------------------- Account Information, including existing accounts, new accounts, prospectuses, applications and service forms 1-800-225-6292 FactFone(SM) for automated fund yields, prices, account information and transactions 1-800-225-4321 Retirement plans information 1-800-622-0176 Write to us: -------------------------------------------------------------------------------- PIMSS, Inc. P.O. Box 55014 Boston, Massachusetts 02205-5014 Our toll-free fax 1-800-225-4240 Our internet e-mail address ask.pioneer@pioneerinvestments.com (for general questions about Pioneer only) Visit our web site: us.pioneerinvestments.com This report must be preceded or accompanied by a prospectus. The Fund files a complete schedule of investments with the Securities and Exchange Commission for the first and third quarters for each fiscal year on Form N-Q. Shareholders may view the filed Form N-Q by visiting the Commission's web site at http://www.sec.gov. The filed form may also be viewed and copied at the Commission's Public Reference Room in Washington, DC. Information regarding the operations of the Public Reference Room may be obtained by calling 1-800-SEC-0330. [LOGO] PIONEER Investments(R) Pioneer Investment Management, Inc. 60 State Street Boston, MA 02109 us.pioneerinvestments.com Securities offered through Pioneer Funds Distributor, Inc. 60 State Street, Boston, MA 02109 Underwriter of Pioneer Mutual Funds, Member SIPC (C) 2015 Pioneer Investments 25249-04-1115 ITEM 2. CODE OF ETHICS. (a) Disclose whether, as of the end of the period covered by the report, the registrant has adopted a code of ethics that applies to the registrant's principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions, regardless of whether these individuals are employed by the registrant or a third party. If the registrant has not adopted such a code of ethics, explain why it has not done so. The registrant has adopted, as of the end of the period covered by this report, a code of ethics that applies to the registrant's principal executive officer, principal financial officer, principal accounting officer and controller. (b) For purposes of this Item, the term "code of ethics" means written standards that are reasonably designed to deter wrongdoing and to promote: (1) Honest and ethical conduct, including the ethical handling of actual or apparent conflicts of interest between personal and professional relationships; (2) Full, fair, accurate, timely, and understandable disclosure in reports and documents that a registrant files with, or submits to, the Commission and in other public communications made by the registrant; (3) Compliance with applicable governmental laws, rules, and regulations; (4) The prompt internal reporting of violations of the code to an appropriate person or persons identified in the code; and (5) Accountability for adherence to the code. (c) The registrant must briefly describe the nature of any amendment, during the period covered by the report, to a provision of its code of ethics that applies to the registrant's principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions, regardless of whether these individuals are employed by the registrant or a third party, and that relates to any element of the code of ethics definition enumerated in paragraph (b) of this Item. The registrant must file a copy of any such amendment as an exhibit pursuant to Item 10(a), unless the registrant has elected to satisfy paragraph (f) of this Item by posting its code of ethics on its website pursuant to paragraph (f)(2) of this Item, or by undertaking to provide its code of ethics to any person without charge, upon request, pursuant to paragraph (f)(3) of this Item. The registrant has made no amendments to the code of ethics during the period covered by this report. (d) If the registrant has, during the period covered by the report, granted a waiver, including an implicit waiver, from a provision of the code of ethics to the registrant's principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions, regardless of whether these individuals are employed by the registrant or a third party, that relates to one or more of the items set forth in paragraph (b) of this Item, the registrant must briefly describe the nature of the waiver, the name of the person to whom the waiver was granted, and the date of the waiver. Not applicable. (e) If the registrant intends to satisfy the disclosure requirement under paragraph (c) or (d) of this Item regarding an amendment to, or a waiver from, a provision of its code of ethics that applies to the registrant's principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions and that relates to any element of the code of ethics definition enumerated in paragraph (b) of this Item by posting such information on its Internet website, disclose the registrant's Internet address and such intention. Not applicable. (f) The registrant must: (1) File with the Commission, pursuant to Item 12(a)(1), a copy of its code of ethics that applies to the registrant's principal executive officer,principal financial officer, principal accounting officer or controller, or persons performing similar functions, as an exhibit to its annual report on this Form N-CSR (see attachment); (2) Post the text of such code of ethics on its Internet website and disclose, in its most recent report on this Form N-CSR, its Internet address and the fact that it has posted such code of ethics on its Internet website; or (3) Undertake in its most recent report on this Form N-CSR to provide to any person without charge, upon request, a copy of such code of ethics and explain the manner in which such request may be made. 	See Item 10(2) ITEM 3. AUDIT COMMITTEE FINANCIAL EXPERT. (a) (1) Disclose that the registrant's board of trustees has determined that the registrant either: (i) Has at least one audit committee financial expert serving on its audit committee; or (ii) Does not have an audit committee financial expert serving on its audit committee. The registrant's Board of Trustees has determined that the registrant has at least one audit committee financial expert. (2) If the registrant provides the disclosure required by paragraph (a)(1)(i) of this Item, it must disclose the name of the audit committee financial expert and whether that person is "independent." In order to be considered "independent" for purposes of this Item, a member of an audit committee may not, other than in his or her capacity as a member of the audit committee, the board of trustees, or any other board committee: (i) Accept directly or indirectly any consulting, advisory, or other compensatory fee from the issuer; or (ii) Be an "interested person" of the investment company as defined in Section 2(a)(19) of the Act (15 U.S.C. 80a-2(a)(19)). Ms. Marguerite A. Piret, an independent trustee, is such an audit committee financial expert. (3) If the registrant provides the disclosure required by paragraph (a)(1) (ii) of this Item, it must explain why it does not have an audit committee financial expert. Not applicable. ITEM 4. PRINCIPAL ACCOUNTANT FEES AND SERVICES. (a) Disclose, under the caption AUDIT FEES, the aggregate fees billed for each of the last two fiscal years for professional services rendered by the principal accountant for the audit of the registrant's annual financial statements or services that are normally provided by the accountant in connection with statutory and regulatory filings or engagements for those fiscal years. n/a (b) Disclose, under the caption AUDIT-RELATED FEES, the aggregate fees billed in each of the last two fiscal years for assurance and related services by the principal accountant that are reasonably related to the performance of the audit of the registrant's financial statements and are not reported under paragraph (a) of this Item. Registrants shall describe the nature of the services comprising the fees disclosed under this category. n/a (c) Disclose, under the caption TAX FEES, the aggregate fees billed in each of the last two fiscal years for professional services rendered by the principal accountant for tax compliance, tax advice, and tax planning. Registrants shall describe the nature of the services comprising the fees disclosed under this category. n/a (d) Disclose, under the caption ALL OTHER FEES, the aggregate fees billed in each of the last two fiscal years for products and services provided by the principal accountant, other than the services reported in paragraphs (a) through (c) of this Item. Registrants shall describe the nature of the services comprising the fees disclosed under this category. n/a (e) (1) Disclose the audit committee's pre-approval policies and procedures described in paragraph (c)(7) of Rule 2-01 of Regulation S-X. PIONEER FUNDS APPROVAL OF AUDIT, AUDIT-RELATED, TAX AND OTHER SERVICES PROVIDED BY THE INDEPENDENT AUDITOR SECTION I - POLICY PURPOSE AND APPLICABILITY The Pioneer Funds recognize the importance of maintaining the independence of their outside auditors. Maintaining independence is a shared responsibility involving Pioneer Investment Management, Inc ("PIM"), the audit committee and the independent auditors. The Funds recognize that a Fund's independent auditors: 1) possess knowledge of the Funds, 2) are able to incorporate certain services into the scope of the audit, thereby avoiding redundant work, cost and disruption of Fund personnel and processes, and 3) have expertise that has value to the Funds. As a result, there are situations where it is desirable to use the Fund's independent auditors for services in addition to the annual audit and where the potential for conflicts of interests are minimal. Consequently, this policy, which is intended to comply with Rule 210.2-01(C)(7), sets forth guidelines and procedures to be followed by the Funds when retaining the independent audit firm to perform audit, audit-related tax and other services under those circumstances, while also maintaining independence. Approval of a service in accordance with this policy for a Fund shall also constitute approval for any other Fund whose pre-approval is required pursuant to Rule 210.2-01(c)(7)(ii). In addition to the procedures set forth in this policy, any non-audit services that may be provided consistently with Rule 210.2-01 may be approved by the Audit Committee itself and any pre-approval that may be waived in accordance with Rule 210.2-01(c)(7)(i)(C) is hereby waived. Selection of a Fund's independent auditors and their compensation shall be determined by the Audit Committee and shall not be subject to this policy. SECTION II - POLICY ---------------- -------------------------------- ------------------------------------------------- SERVICE SERVICE CATEGORY DESCRIPTION SPECIFIC PRE-APPROVED SERVICE SUBCATEGORIES CATEGORY ---------------- -------------------------------- ------------------------------------------------- I. AUDIT Services that are directly o Accounting research assistance SERVICES related to performing the o SEC consultation, registration independent audit of the Funds statements, and reporting o Tax accrual related matters o Implementation of new accounting standards o Compliance letters (e.g. rating agency letters) o Regulatory reviews and assistance regarding financial matters o Semi-annual reviews (if requested) o Comfort letters for closed end offerings ---------------- -------------------------------- ------------------------------------------------- II. Services which are not o AICPA attest and agreed-upon procedures AUDIT-RELATED prohibited under Rule o Technology control assessments SERVICES 210.2-01(C)(4) (the "Rule") o Financial reporting control assessments and are related extensions of o Enterprise security architecture the audit services support the assessment audit, or use the knowledge/expertise gained from the audit procedures as a foundation to complete the project. In most cases, if the Audit-Related Services are not performed by the Audit firm, the scope of the Audit Services would likely increase. The Services are typically well-defined and governed by accounting professional standards (AICPA, SEC, etc.) ---------------- -------------------------------- ------------------------------------------------- ------------------------------------- ------------------------------------ AUDIT COMMITTEE APPROVAL POLICY AUDIT COMMITTEE REPORTING POLICY ------------------------------------- ------------------------------------ o "One-time" pre-approval o A summary of all such for the audit period for all services and related fees pre-approved specific service reported at each regularly subcategories. Approval of the scheduled Audit Committee independent auditors as meeting. auditors for a Fund shall constitute pre approval for these services. ------------------------------------- ------------------------------------ o "One-time" pre-approval o A summary of all such for the fund fiscal year within services and related fees a specified dollar limit (including comparison to for all pre-approved specified dollar limits) specific service subcategories reported quarterly. o Specific approval is needed to exceed the pre-approved dollar limit for these services (see general Audit Committee approval policy below for details on obtaining specific approvals) o Specific approval is needed to use the Fund's auditors for Audit-Related Services not denoted as "pre-approved", or to add a specific service subcategory as "pre-approved" ------------------------------------- ------------------------------------ SECTION III - POLICY DETAIL, CONTINUED ----------------------- --------------------------- ----------------------------------------------- SERVICE CATEGORY SERVICE CATEGORY SPECIFIC PRE-APPROVED SERVICE SUBCATEGORIES DESCRIPTION ----------------------- --------------------------- ----------------------------------------------- III. TAX SERVICES Services which are not o Tax planning and support prohibited by the Rule, o Tax controversy assistance if an officer of the Fund o Tax compliance, tax returns, excise determines that using the tax returns and support Fund's auditor to provide o Tax opinions these services creates significant synergy in the form of efficiency, minimized disruption, or the ability to maintain a desired level of confidentiality. ----------------------- --------------------------- ----------------------------------------------- ------------------------------------- ------------------------- AUDIT COMMITTEE APPROVAL POLICY AUDIT COMMITTEE REPORTING POLICY ------------------------------------- ------------------------- ------------------------------------- ------------------------- o "One-time" pre-approval o A summary of for the fund fiscal year all such services and within a specified dollar limit related fees 				 (including comparison 			 to specified dollar 			 limits) reported 			 quarterly. o Specific approval is needed to exceed the pre-approved dollar limits for these services (see general Audit Committee approval policy below for details on obtaining specific approvals) o Specific approval is needed to use the Fund's auditors for tax services not denoted as pre-approved, or to add a specific service subcategory as "pre-approved" ------------------------------------- ------------------------- SECTION III - POLICY DETAIL, CONTINUED ----------------------- --------------------------- ----------------------------------------------- SERVICE CATEGORY SERVICE CATEGORY SPECIFIC PRE-APPROVED SERVICE SUBCATEGORIES DESCRIPTION ----------------------- --------------------------- ----------------------------------------------- IV. OTHER SERVICES Services which are not o Business Risk Management support prohibited by the Rule, o Other control and regulatory A. SYNERGISTIC, if an officer of the Fund compliance projects UNIQUE QUALIFICATIONS determines that using the Fund's auditor to provide these services creates significant synergy in the form of efficiency, minimized disruption, the ability to maintain a desired level of confidentiality, or where the Fund's auditors posses unique or superior qualifications to provide these services, resulting in superior value and results for the Fund. ----------------------- --------------------------- ----------------------------------------------- --------------------------------------- ------------------------ AUDIT COMMITTEE APPROVAL POLICY AUDIT COMMITTEE REPORTING POLICY ------------------------------------- -------------------------- o "One-time" pre-approval o A summary of for the fund fiscal year within all such services and a specified dollar limit related fees 			 (including comparison 			 to specified dollar 				 limits) reported quarterly. o Specific approval is needed to exceed the pre-approved dollar limits for these services (see general Audit Committee approval policy below for details on obtaining specific approvals) o Specific approval is needed to use the Fund's auditors for "Synergistic" or "Unique Qualifications" Other Services not denoted as pre-approved to the left, or to add a specific service subcategory as "pre-approved" ------------------------------------- -------------------------- SECTION III - POLICY DETAIL, CONTINUED ----------------------- ------------------------- ----------------------------------------------- SERVICE CATEGORY SERVICE CATEGORY SPECIFIC PROHIBITED SERVICE SUBCATEGORIES DESCRIPTION ----------------------- ------------------------- ----------------------------------------------- PROHIBITED SERVICES Services which result 1. Bookkeeping or other services in the auditors losing related to the accounting records or independence status financial statements of the audit under the Rule. client* 2. Financial information systems design and implementation* 3. Appraisal or valuation services, fairness* opinions, or contribution-in-kind reports 4. Actuarial services (i.e., setting actuarial reserves versus actuarial audit work)* 5. Internal audit outsourcing services* 6. Management functions or human resources 7. Broker or dealer, investment advisor, or investment banking services 8. Legal services and expert services unrelated to the audit 9. Any other service that the Public Company Accounting Oversight Board determines, by regulation, is impermissible ----------------------- ------------------------- ----------------------------------------------- ------------------------------------------- ------------------------------ AUDIT COMMITTEE APPROVAL POLICY AUDIT COMMITTEE REPORTING POLICY ------------------------------------------- ------------------------------ o These services are not to be o A summary of all performed with the exception of the(*) services and related services that may be permitted fees reported at each if they would not be subject to audit regularly scheduled procedures at the audit client (as Audit Committee meeting defined in rule 2-01(f)(4)) level will serve as continual the firm providing the service. confirmation that has 				 not provided any restricted services. ------------------------------------------- ------------------------------ -------------------------------------------------------------------------------- GENERAL AUDIT COMMITTEE APPROVAL POLICY: o For all projects, the officers of the Funds and the Fund's auditors will each make an assessment to determine that any proposed projects will not impair independence. o Potential services will be classified into the four non-restricted service categories and the "Approval of Audit, Audit-Related, Tax and Other Services" Policy above will be applied. Any services outside the specific pre-approved service subcategories set forth above must be specifically approved by the Audit Committee. o At least quarterly, the Audit Committee shall review a report summarizing the services by service category, including fees, provided by the Audit firm as set forth in the above policy. -------------------------------------------------------------------------------- (2) Disclose the percentage of services described in each of paragraphs (b) through (d) of this Item that were approved by the audit committee pursuant to paragraph (c)(7)(i)(C) of Rule 2-01 of Regulation S-X. n/a (f) If greater than 50 percent, disclose the percentage of hours expended on the principal accountants engagement to audit the registrant's financial statements for the most recent fiscal year that were attributed to work performed by persons other than the principal accountant's full-time, permanent employees. N/A (g) Disclose the aggregate non-audit fees billed by the registrants accountant for services rendered to the registrant, and rendered to the registrants investment adviser (not including any sub-adviser whose role is primarily portfolio management and is subcontracted with or overseen by another investment adviser), and any entity controlling, controlled by, or under common control with the adviser that provides ongoing services to the registrant for each of the last two fiscal years of the registrant. n/a (h) Disclose whether the registrants audit committee of the board of trustees has considered whether the provision of non-audit services that were rendered to the registrants investment adviser (not including any subadviser whose role is primarily portfolio management and is subcontracted with or overseen by another investment adviser), and any entity controlling, controlled by, or under common control with the investment adviser that provides ongoing services to the registrant that were not pre-approved pursuant to paragraph (c)(7)(ii) of Rule 2-01 of Regulation S-X is compatible with maintaining the principal accountant's independence. The Fund's audit committee of the Board of Trustees has considered whether the provision of non-audit services that were rendered to the Affiliates (as defined) that were not pre- approved pursuant to paragraph (c)(7)(ii) of Rule 2-01 of Regulation S-X is compatible with maintaining the principal accountant's independence. ITEM 5. AUDIT COMMITTEE OF LISTED REGISTRANTS (a) If the registrant is a listed issuer as defined in Rule 10A-3 under the Exchange Act (17 CFR 240.10A-3), state whether or not the registrant has a separately-designated standing audit committee established in accordance with Section 3(a)(58)(A) of the Exchange Act (15 U.S.C. 78c(a)(58)(A)). If the registrant has such a committee, however designated, identify each committee member. If the entire board of directors is acting as the registrant's audit committee as specified in Section 3(a)(58)(B) of the Exchange Act (15 U.S.C. 78c(a)(58)(B)), so state. N/A (b) If applicable, provide the disclosure required by Rule 10A-3(d) under the Exchange Act (17 CFR 240.10A-3(d)) regarding an exemption from the listing standards for audit committees. N/A ITEM 6. SCHEDULE OF INVESTMENTS. File Schedule of Investments in securities of unaffiliated issuers as of the close of the reporting period as set forth in 210.1212 of Regulation S-X [17 CFR 210.12-12], unless the schedule is included as part of the report to shareholders filed under Item 1 of this Form. Included in Item 1 ITEM 7. DISCLOSURE OF PROXY VOTING POLICIES AND PROCEDURES FOR CLOSED-END MANAGEMENT INVESTMENT COMPANIES. A closed-end management investment company that is filing an annual report on this Form N-CSR must, unless it invests exclusively in non-voting securities, describe the policies and procedures that it uses to determine how to vote proxies relating to portfolio securities, including the procedures that the company uses when a vote presents a conflict between the interests of its shareholders, on the one hand, and those of the company's investment adviser; principal underwriter; or any affiliated person (as defined in Section 2(a)(3) of the Investment Company Act of 1940 (15 U.S.C. 80a-2(a)(3)) and the rules thereunder) of the company, its investment adviser, or its principal underwriter, on the other. Include any policies and procedures of the company's investment adviser, or any other third party, that the company uses, or that are used on the company's behalf, to determine how to vote proxies relating to portfolio securities. Not applicable to open-end management investment companies. ITEM 8. PORTFOLIO MANAGERS OF CLOSED-END MANAGEMENT INVESTMENT COMPANIES. (a) If the registrant is a closed-end management investment company that is filing an annual report on this Form N-CSR,provide the following information: (1) State the name, title, and length of service of the person or persons employed by or associated with the registrant or an investment adviser of the registrant who are primarily responsible for the day-to-day management of the registrant's portfolio ("Portfolio Manager"). Also state each Portfolio Manager's business experience during the past 5 years. Not applicable to open-end management investment companies. ITEM 9. PURCHASES OF EQUITY SECURITIES BY CLOSED-END MANAGEMENT INVESTMENT COMPANY AND AFFILIATED PURCHASERS. (a) If the registrant is a closed-end management investment company, in the following tabular format, provide the information specified in paragraph (b) of this Item with respect to any purchase made by or on behalf of the registrant or any affiliated purchaser, as defined in Rule 10b-18(a)(3) under the Exchange Act (17 CFR 240.10b-18(a)(3)), of shares or other units of any class of the registrant's equity securities that is registered by the registrant pursuant to Section 12 of the Exchange Act (15 U.S.C. 781). Not applicable to open-end management investment companies. ITEM 10. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS. Describe any material changes to the procedures by which shareholders may recommend nominees to the registrant's board of directors, where those changes were implemented after the registrant last provided disclosure in response to the requirements of Item 407(c)(2)(iv) of Regulation S-R(17 CFR 229.407)(as required by Item 22(b)(15)) of Schedule 14A (17 CFR 240.14a-101), or this Item. There have been no material changes to the procedures by which the shareholders may recommend nominees to the registrant's board of directors since the registrant last provided disclosure in response to the requirements of Item 407(c)(2)(iv) of Regulation S-R of Schedule 14(A) in its definitive proxy statement, or this item. ITEM 11. CONTROLS AND PROCEDURES. (a) Disclose the conclusions of the registrant's principal executive and principal financials officers, or persons performing similar functions, regarding the effectiveness of the registrant's disclosure controls and procedures (as defined in Rule 30a-3(c) under the Act (17 CFR 270.30a-3(c))) as of a date within 90 days of the filing date of the report that includes the disclosure required by this paragraph, based on the evaluation of these controls and procedures required by Rule 30a-3(b) under the Act (17 CFR 270.30(a)-3(b) and Rules 13a-15(b) or 15d-15(b) under the Exchange Act (17 CFR 240.13a-15(b) or 240.15d-15(b)). The registrant's principal executive officer and principal financial officer have concluded that the registrant's disclosure controls and procedures are effective based on the evaluation of these controls and procedures as of a date within 90 days of the filing date of this report. (b) Disclose any change in the registrant's internal control over financial reporting (as defined in Rule 30a-3(d) under the Act (17CFR 270.30a-3(d)) that occured during the second fiscal quarter of the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting. There were no significant changes in the registrant's internal control over financial reporting that occurred during the second fiscal quarter of the period covered by this report that have materially affected, or are reasonably likely to materially affect, the registrant's internal control over financial reporting. The registrant's principal executive officer and principal financial officer, however, voluntarily are reporting the following information: In August of 2006 the registrant's investment adviser enhanced its internal procedures for reporting performance information required to be included in prospectuses. Those enhancements involved additional internal controls over the appropriateness of performance data generated for this purpose. Such enhancements were made following an internal review which identified prospectuses relating to certain classes of shares of a limited number of registrants where, inadvertently, performance information not reflecting the deduction of applicable sales charges was included. Those prospectuses were revised, and the revised prospectuses were distributed to shareholders. ITEM 12. EXHIBITS. (a) File the exhibits listed below as part of this Form. Letter or number the exhibits in the sequence indicated. (1) Any code of ethics, or amendment thereto, that is the subject of the disclosure required by Item 2, to the extent that the registrant intends to satisfy the Item 2 requirements through filing of an exhibit. (2) A separate certification for each principal executive officer and principal financial officer of the registrant as required by Rule 30a-2(a) under the Act (17 CFR 270.30a-2(a)) , exactly as set forth below: Filed herewith. SIGNATURES [See General Instruction F] Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized. (Registrant) Pioneer Series Trust X By (Signature and Title)* /s/ Lisa M. Jones Lisa M. Jones, President & Chief Executive Officer Date November 30, 2015 Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated. By (Signature and Title)* /s/ Lisa M. Jones Lisa M. Jones, President & Chief Executive Officer Date November 30, 2015 By (Signature and Title)* /s/ Mark Bradley Mark Bradley, Treasurer & Chief Accounting & Financial Officer Date November 30, 2015 * Print the name and title of each signing officer under his or her signature.