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 811-21978 Pioneer Series Trust VI (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: October 31 Date of reporting period: November 1, 2015 through April 30, 2016 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 Floating Rate Fund -------------------------------------------------------------------------------- Semiannual Report | April 30, 2016 -------------------------------------------------------------------------------- Ticker Symbols: Class A FLARX Class C FLRCX Class K FLRKX Class Y FLYRX [LOGO] PIONEER Investments(R) visit us: us.pioneerinvestments.com Table of Contents President's Letter 2 Portfolio Management Discussion 4 Portfolio Summary 8 Prices and Distributions 9 Performance Update 10 Comparing Ongoing Fund Expenses 14 Schedule of Investments 16 Financial Statements 47 Notes to Financial Statements 55 Trustees, Officers and Service Providers 69 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 1 President's Letter Dear Shareowner, Global financial markets began 2016 on shaky footing, delivering the kind of volatility that challenged investors in 2015. US equities fell by 10% through the first six weeks of the year, only to recover the losses by the end of the first quarter. Fixed-income markets were also acutely affected, with concerns about falling oil prices and a weak global economy leading to a sell-off in credit-sensitive sectors, especially high-yield bonds, as investors fled to the perceived safety of government bonds. Like equities, credit markets recovered much of their lost ground by the end of the first quarter. Midway through the first quarter, market sentiment shifted, as expectations grew that major central banks would extend their accommodative monetary policies in the hopes of driving economic growth. The US Federal Reserve (the Fed) backed off plans to raise interest rates four times in 2016, and the European Central Bank announced a more comprehensive asset-purchasing program in the hopes of encouraging lending, and boosting both inflation and economic growth. The Bank of Japan also followed a monetary easing path, announcing negative interest rates in January. As 2016 moves along, we continue to see central bank policies as generally supportive of the US economy - for which we maintain an expectation of modest growth this year - against an overall global economic backdrop that remains unsettled and points towards generally lower growth. Economies around the world in both developed and emerging markets are experiencing deep structural changes. Current challenges include incomplete debt deleveraging in both emerging and developed markets, where debt levels continue to grow, the transition of many emerging markets economies from export/investment-driven models to more domestic demand-driven models, and aging populations, which are reducing productivity and limiting economic growth potential (primarily in the developed markets but also in emerging markets such as China). Geopolitical instability on many fronts, the rising risk of policy mistakes, and market liquidity issues combine to increase the possibility of sharp swings in asset values. Meanwhile, in the US, as always in a presidential election year, the political rhetoric of 2016 has the potential to impact domestic sectors such as health care. Throughout Pioneer's history, we have believed in the importance of active management. During periods of market volatility, we view the value of active management as even more compelling. Our experienced and tenured investment teams focus on identifying value across global markets using proprietary research, careful risk management, and a long-term perspective. 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 Floating Rate Fund | Semiannual Report | 4/30/16 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 the trust you have placed in us 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. April 30, 2016 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. Past performance is no guarantee of future results. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 3 Portfolio Management Discussion | 4/30/16 Floating-rate bank loans generated positive, albeit modest, returns during the six-month period ended April 30, 2016. In the following interview, Jonathan Sharkey discusses the factors that influenced the performance of Pioneer Floating Rate Fund during the six-month period. Mr. Sharkey, a senior vice president and a portfolio manager at Pioneer, is responsible for the day-to-day management of the Fund. Q How did the Fund perform during the six-month period ended April 30, 2016? A Pioneer Floating Rate Fund's Class A shares returned 1.30% at net asset value during the six-month period ended April 30, 2016, while the Fund's benchmark, the Barclays High Yield Loans Performing Index (the Barclays Index), returned 1.68%. During the same period, the average return of the 217 mutual funds in Lipper's Loan Participating Funds category was 1.00%, and the average return of the 260 mutual funds in Morningstar's Bank Loan Funds category was 1.00%. Q How would you describe the investment environment for bank loans during the six-month period ended April 30, 2016? A The period started out with a continuation of the difficult environment for credit-sensitive investments, including bank loans, which had prevailed for most of 2015. Then, growing worries about the health of the world economy became pervasive in the market, principally due to the confluence of several factors, including weakening prices for oil and other basic commodities, evidence of slowing economic growth in China, and a renewed debt crisis in Greece that potentially threatened the wider European economy. Market trends finally shifted in mid-February 2016 when the US dollar peaked in value, oil and commodity prices began to strengthen, and the more credit-sensitive sectors of the fixed-income market started to rally. The new strength in the credit sectors continued over the final 10 weeks of the six-month period. While bank loans participated in the rally, lower-rated securities led the market's snapback. Outflows from bank loans during most of the six-month period were one of the factors limiting returns for the asset class. Although the loan market did enjoy a brief net-inflow of investment money during the month of March 2016, outflows from the asset class dominated the other five months of the period. One of the principal reasons for the shortage of investment dollars in bank loans was the decline in the issuance of collateralized loan obligations (CLOs) over most of the period. CLOs are investment pools of 4 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 institutional assets formed to invest in bank loans, and issuance of CLOs increased in only two of the period's six months (March and April). Moreover, even during the two good months, the level of issuance was below the average monthly pace established throughout 2015. In addition, net outflows of cash translated into less demand for bank loans. Q What were the main factors that affected the Fund's performance relative to the benchmark Barclays Index during the six-month period ended April 30, 2016? A The Fund's slight underperformance of its benchmark during the period is attributable mainly to the up-in-quality tilt of the portfolio, as we maintained relatively large weightings in the higher-quality tiers of the bank-loan market. The higher-quality bias in the portfolio tended to detract from the Fund's relative performance, most notably during the late-period rally in the credit sectors, when lower-rated debt turned in the strongest returns. While the Fund's quality bias has served to protect investment capital during previous periods of market stress - during much of 2015, for example - it can be a performance detractor when lower-quality loans spearhead rallies in more volatile market environments. In addition, the Fund's underweighted positions in loans to the energy and retailing industries - two groups that helped lead the market rally in the latter weeks of the six-month period - had a negative effect on benchmark-relative results, as did the Fund's small position in short-term US Treasuries. In contrast, the Fund's investments in loans of consumer cyclical, industrial, capital goods, and basic industries companies all contributed positively to benchmark-relative performance during the period. With regard to individual holdings, positive contributors to the Fund's benchmark-relative performance during the period included loans to Fortescue, a metals company; Laureate, a for-profit higher-education corporation; Securus Technology, a prison telephone system provider; and Nexeo, a chemical distribution company. Individual positions that detracted from the Fund's benchmark-relative returns during the period included loans to EP Energy, a gas company; Dixie Electric, which provides electrical services to offshore drilling operations; Targus, a manufacturer of components for laptops and other technology devices; and Navios Maritime, a shipping company. Navios struggled during the period due to a decrease in demand as well as organizational problems associated with its parent company. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 5 Q Did the Fund have any exposure to derivative securities during the six-month period ended April 30, 2016? If so, did the investments have any material impact on benchmark-relative performance? A We did hold a small position in credit default swaps in the portfolio, which we used as a way to increase liquidity. The exposure had no material impact on the Fund's benchmark-relative return during the period. Q What factors affected the Fund's yield, or distributions to shareholders, during the six-month period ended April 30, 2016? A The Fund was able to increase its dividend* in April 2016, as the rates on a number of positions reset higher, which, in turn, generated more current portfolio income. Q What is your investment outlook? A We believe the US economy should be able to grow at a moderate pace of 2.0% to 2.25% in 2016, despite getting off to a slow start in the first quarter, when gross domestic product (GDP) struggled to reach 1%. While poor sales figures and a slowdown in capital spending - both of which are tied to weakness in the energy markets - played a role in the first quarter's disappointing GDP figures, we still see persuasive evidence that the domestic economy is strengthening, as employment growth has been relentless and household formation and new-home construction data have been encouraging. We also are beginning to see early signs of wage inflation. Given this view, we think there is enough domestic economic strength to justify one or two more interest-rate increases by the US Federal Reserve in the coming months -- more than the current market consensus. Two or more resets of the influential Federal funds rate would trigger increases in the interest rates of floating-rate loans, and potentially increase the Fund's income. Such a development would be good for the entire floating-rate loan asset class, as loans were selling at discounts to their par (face) values as of the end of the six-month period. While prices for bank loans are relatively low in relation to long-term averages, the default rates on loans also remain below long-term historical averages. We believe floating-rate loans offer potential opportunities for appropriate, income-oriented investors, while also providing the possibility of near-term capital appreciation as short-term interest rates move higher. * Dividends are not guaranteed. 6 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 Please refer to the Schedule of Investments on pages 16-46 for a full listing of Fund securities. All investments are subject to risk, including the possible loss of principal. In the past several years, financial markets have experienced increased volatility, depressed valuations, decreased liquidity and heightened uncertainty. These conditions may continue, recur, worsen or spread. Debt securities rated below investment grade are commonly referred to as "junk bonds" and are considered speculative. Below-investment-grade debt securities involve greater risk of loss, are subject to greater price volatility and are less liquid, especially during periods of economic uncertainty or change, than higher-rated debt securities. The Fund may invest in high-yield securities of any rating, including securities that are in default at the time of purchase. Securities with floating interest rates generally are less sensitive to interest rate changes but may decline in value if their interest rates do not rise as much, or as quickly, as prevailing interest rates. Unlike fixed-rate securities, floating-rate securities generally will not increase in value if interest rates decline. Changes in interest rates also will affect the amount of interest income the Fund earns on its floating-rate investments. Investing in foreign and/or emerging markets securities involves risks relating to interest rates, currency exchange rates, economic, and political conditions. 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. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 7 Portfolio Summary | 4/30/16 Portfolio Diversification* -------------------------------------------------------------------------------- (As a percentage of total investment portfolio) [THE FOLLOWING DATA WAS REPRESENTED AS A PIE CHART IN THE PRINTED MATERIAL] Senior Secured Loans 84.7% U.S. Government Securities 4.9% U.S. Corporate Bonds 4.7% International Corporate Bonds 2.4% Temporary Cash Investment 0.9% Collateralized Mortgage Obligations 0.8% Asset Backed Securities 0.7% Exchange Traded Fund 0.6% U.S. Preferred Stocks 0.2% U.S. Common Stocks 0.1% * Includes investments in insurance-linked securities totaling 2.0% of total investment portfolio. 10 Largest Holdings -------------------------------------------------------------------------------- (As a percentage of long-term holdings)** 1. U.S. Treasury Note, Floating Rate Note, 10/31/17 1.42% -------------------------------------------------------------------------------- 2. Avago Technologies Finance, Term Loan (First Lien), 11/13/22 0.96 -------------------------------------------------------------------------------- 3. Federal Farm Credit Banks, Floating Rate Note, 9/19/16 0.92 -------------------------------------------------------------------------------- 4. Charter Communications Operating LLC, Term F Loan, 1/1/21 0.73 -------------------------------------------------------------------------------- 5. U.S. Treasury Bills, 5/19/16 0.72 -------------------------------------------------------------------------------- 6. U.S. Treasury Note, Floating Rate Note, 4/30/17 0.69 -------------------------------------------------------------------------------- 7. U.S. Treasury Note, Floating Rate Note, 1/31/17 0.68 -------------------------------------------------------------------------------- 8. Scientific Games, Initial Term B-2, 10/1/21 0.68 -------------------------------------------------------------------------------- 9. Albertsons LLC, Term B-2 Loan, 3/21/19 0.67 -------------------------------------------------------------------------------- 10. American Airlines, Inc., 2015 Term Loan (New), 6/27/20 0.61 -------------------------------------------------------------------------------- ** This list excludes temporary cash investments and derivative instruments. The Fund is actively managed, and current holdings may be different. The holdings listed should not be considered recommendations to buy or sell any securities listed. 8 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 Prices and Distributions | 4/30/16 Net Asset Value per Share -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- Class 4/30/16 10/31/15 -------------------------------------------------------------------------------- A $6.70 $6.73 -------------------------------------------------------------------------------- C $6.71 $6.74 -------------------------------------------------------------------------------- K $6.70 $6.73 -------------------------------------------------------------------------------- Y $6.72 $6.75 -------------------------------------------------------------------------------- Distributions per Share: 11/1/15-4/30/16 -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- Net Investment Short-Term Long-Term Class Income Capital Gains Capital Gains -------------------------------------------------------------------------------- A $0.1152 $-- $-- -------------------------------------------------------------------------------- C $0.0920 $-- $-- -------------------------------------------------------------------------------- K $0.1279 $-- $-- -------------------------------------------------------------------------------- Y $0.1282 $-- $-- -------------------------------------------------------------------------------- The Barclays High Yield Loans Performing Index is an unmanaged index that provides broad and comprehensive total return metrics of the universe of syndicated term loans. To be included in the index, a bank loan must be dollar denominated, have at least $150 million in funded loans, a minimum term of one year, and a minimum initial spread of LIBOR+1.25%. Index returns are calculated monthly, 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 10-13. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 9 Performance Update | 4/30/16 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 Floating Rate Fund at public offering price during the periods shown, compared to that of the Barclays High Yield Loans Performing Index. Cumulative Total Returns (As of April 30, 2016) -------------------------------------------------------------------------------- Net Public Barclays High Asset Offering Yield Loans Value Price Performing Period (NAV) (POP) Index -------------------------------------------------------------------------------- Life of Class (2/14/2007) 3.45% 2.94% 4.19% 5 years 3.22 2.27 3.64 1 year 1.00 -3.50 0.38 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated March 1, 2016) -------------------------------------------------------------------------------- Gross -------------------------------------------------------------------------------- 1.10% -------------------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment Pioneer Floating Barclays High Yield Loans Rate Fund Performing Index 2/07 $ 9,550 $10,000 4/07 $ 9,664 $10,181 4/08 $ 9,422 $ 9,955 4/09 $ 8,466 $ 8,704 4/10 $10,477 $11,492 4/11 $11,142 $12,279 4/12 $11,559 $12,610 4/13 $12,294 $13,613 4/14 $12,614 $14,108 4/15 $12,927 $14,631 4/16 $13,057 $14,686 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. POP returns reflect deduction of maximum 4.50% sales charge. NAV 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. 10 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 Performance Update | 4/30/16 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 Floating Rate Fund during the periods shown, compared to that of the Barclays High Yield Loans Performing Index. Cumulative Total Returns (As of April 30, 2016) -------------------------------------------------------------------------------- Barclays High Yield Loans If If Performing Period Held Redeemed Index -------------------------------------------------------------------------------- Life of Class (2/14/2007) 2.65% 2.65% 4.19% 5 years 2.46 2.46 3.64 1 year 0.30 0.30 0.38 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated March 1, 2016) -------------------------------------------------------------------------------- Gross -------------------------------------------------------------------------------- 1.84% -------------------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment Pioneer Floating Barclays High Yield Loans Rate Fund Performing Index 2/07 $10,000 $10,000 4/07 $10,095 $10,181 4/08 $ 9,753 $ 9,955 4/09 $ 8,696 $ 8,704 4/10 $10,683 $11,492 4/11 $11,266 $12,279 4/12 $11,582 $12,610 4/13 $12,244 $13,613 4/14 $12,469 $14,108 4/15 $12,686 $14,631 4/16 $12,724 $14,686 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. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 11 Performance Update | 4/30/16 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 Floating Rate Fund during the periods shown, compared to that of the Barclays High Yield Loans Performing Index. Cumulative Total Returns (As of April 30, 2016) -------------------------------------------------------------------------------- Net Barclays High Asset Yield Loans Value Performing Period (NAV) Index -------------------------------------------------------------------------------- Life of Class (2/14/2007) 3.56% 4.19% 5 years 3.42 3.64 1 year 1.25 0.38 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated March 1, 2016) -------------------------------------------------------------------------------- Gross -------------------------------------------------------------------------------- 0.73% -------------------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment Pioneer Floating Barclays High Yield Loans Rate Fund Performing Index 2/07 $10,000 $10,000 4/07 $10,115 $10,181 4/08 $ 9,862 $ 9,955 4/09 $ 8,861 $ 8,704 4/10 $10,966 $11,492 4/11 $11,662 $12,279 4/12 $12,098 $12,610 4/13 $12,868 $13,613 4/14 $13,231 $14,108 4/15 $13,628 $14,631 4/16 $13,798 $14,686 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 10, 2013, 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 10, 2013, 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. 12 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 Performance Update | 4/30/16 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 Floating Rate Fund during the periods shown, compared to that of the Barclays High Yield Loans Performing Index. Cumulative Total Returns (As of April 30, 2016) -------------------------------------------------------------------------------- Net Barclays High Asset Yield Loans Value Performing Period (NAV) Index -------------------------------------------------------------------------------- Life of Class (2/14/2007) 3.71% 4.19% 5 years 3.58 3.64 1 year 1.41 0.38 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated March 1, 2016) -------------------------------------------------------------------------------- Gross Net -------------------------------------------------------------------------------- 0.82% 0.70% -------------------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $5 Million Investment Pioneer Floating Barclays High Yield Loans Rate Fund Performing Index 2/07 $5,000,000 $5,000,000 4/07 $5,057,400 $5,090,732 4/08 $4,933,654 $4,977,316 4/09 $4,433,295 $4,351,911 4/10 $5,504,693 $5,746,192 4/11 $5,866,555 $6,139,730 4/12 $6,093,369 $6,304,798 4/13 $6,514,421 $6,806,517 4/14 $6,706,511 $7,054,110 4/15 $6,896,275 $7,315,388 4/16 $6,993,735 $7,343,236 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 March 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 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 Floating Rate Fund | Semiannual Report | 4/30/16 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 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 Floating Rate Fund Based on actual returns from November 1, 2015, through April 30, 2016. -------------------------------------------------------------------------------- Share Class A C K Y -------------------------------------------------------------------------------- Beginning Account $ 1,000.00 $ 1,000.00 $ 1,000.00 $ 1,000.00 Value on 11/1/15 -------------------------------------------------------------------------------- Ending Account $ 1,013.00 $ 1,009.50 $ 1,014.90 $ 1,015.00 Value (after expenses) on 4/30/16 -------------------------------------------------------------------------------- Expenses Paid $ 5.06 $ 8.69 $ 3.56 $ 3.51 During Period* -------------------------------------------------------------------------------- * Expenses are equal to the Fund's annualized net expense ratio of 1.01%, 1.74%, 0.71% and 0.70% for Class A, Class C, Class K and Class Y shares respectively, multiplied by the average account value over the period, multiplied by 182/366 (to reflect the one-half year period). 14 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 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 Floating Rate Fund Based on a hypothetical 5% return per year before expenses, reflecting the period from November 1, 2015, through April 30, 2016. -------------------------------------------------------------------------------- Share Class A C K Y -------------------------------------------------------------------------------- Beginning Account $ 1,000.00 $ 1,000.00 $ 1,000.00 $ 1,000.00 Value on 11/1/15 -------------------------------------------------------------------------------- Ending Account $ 1,019.84 $ 1,016.21 $ 1,021.33 $ 1,021.38 Value (after expenses) on 4/30/16 -------------------------------------------------------------------------------- Expenses Paid $ 5.07 $ 8.72 $ 3.57 $ 3.52 During Period* -------------------------------------------------------------------------------- * Expenses are equal to the Fund's annualized net expense ratio of 1.01%, 1.74%, 0.71% and 0.70% for Class A, Class C, Class K and Class Y shares respectively, multiplied by the average account value over the period, multiplied by 182/366 (to reflect the one-half year period). Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 15 Schedule of Investments | 4/30/16 (unaudited) -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- PREFERRED STOCKS -- 0.2% BANKS -- 0.1% Diversified Banks -- 0.1% 18,434 6.99 Citigroup Capital XIII, Floating Rate Note, 10/30/40 $ 482,049 --------------- Total Banks $ 482,049 -------------------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 0.1% Consumer Finance -- 0.1% 40,000 6.40 GMAC Capital Trust I, Floating Rate Note, 2/15/40 $ 1,002,800 --------------- Total Diversified Financials $ 1,002,800 -------------------------------------------------------------------------------------------------------- TOTAL PREFERRED STOCKS (Cost $1,565,230) $ 1,484,849 -------------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------------------- Shares -------------------------------------------------------------------------------------------------------- COMMON STOCKS -- 0.1% COMMERCIAL SERVICES & SUPPLIES -- 0.0%+ Diversified Support Services -- 0.0%+ 32 IAP Worldwide Services, Inc. $ 42,996 --------------- Total Commercial Services & Supplies $ 42,996 -------------------------------------------------------------------------------------------------------- AUTOMOBILES & COMPONENTS -- 0.0%+ Auto Parts & Equipment -- 0.0%+ 50 Lear Corp. $ 5,756 --------------- Total Automobiles & Components $ 5,756 -------------------------------------------------------------------------------------------------------- CONSUMER SERVICES -- 0.1% Education Services -- 0.1% 26,266 Cengage Learning Holdings II, Inc. $ 505,620 --------------- Total Consumer Services $ 505,620 -------------------------------------------------------------------------------------------------------- RETAILING -- 0.0%+ Computer & Electronics Retail -- 0.0%+ 54,675 Targus Cayman SubCo., Ltd. (g) $ 191,362 --------------- Total Retailing $ 191,362 -------------------------------------------------------------------------------------------------------- TOTAL COMMON STOCKS (Cost $1,222,504) $ 745,734 -------------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------------------- Principal Amount ($) -------------------------------------------------------------------------------------------------------- ASSET BACKED SECURITIES -- 0.2% BANKS -- 0.1% Thrifts & Mortgage Finance -- 0.1% 500,000 2.07 KKR Financial CLO 2007-1, Ltd., Floating Rate Note, 5/15/21 (144A) $ 493,935 --------------- Total Banks $ 493,935 -------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 16 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 0.0%+ Specialized Finance -- 0.0%+ 249,665 0.86 Lease Investment Flight Trust, Floating Rate Note, 7/15/31 $ 54,926 249,665 0.82 Lease Investment Flight Trust, Floating Rate Note, 7/15/31 56,799 --------------- $ 111,725 --------------- Total Diversified Financials $ 111,725 -------------------------------------------------------------------------------------------------------- REAL ESTATE -- 0.1% Real Estate Services -- 0.1% 1,000,000 3.74 Home Partners of America 2016-1 Trust, Floating Rate Note, 3/18/33 (144A) $ 988,490 --------------- Total Real Estate $ 988,490 -------------------------------------------------------------------------------------------------------- TOTAL ASSET BACKED SECURITIES (Cost $1,800,271) $ 1,594,150 -------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- 0.8% BANKS -- 0.8% Thrifts & Mortgage Finance -- 0.8% 1,000,000 2.38 BHMS 2014-ATLS Mortgage Trust REMICS, Floating Rate Note, 7/8/33 (144A) $ 980,886 1,000,000 2.93 CDGJ Commercial Mortgage Trust 2014-BXCH, Floating Rate Note, 12/15/27 (144A) 984,952 1,000,000 3.73 Citigroup Commercial Mortgage Trust 2015-SHP2, Floating Rate Note, 7/15/27 (144A) 988,143 1,000,000 4.33 GS Mortgage Securities Trust 2014-GSFL, Floating Rate Note, 7/15/31 (144A) 961,434 1,000,000 2.68 JP Morgan Chase Commercial Mortgage Securities Trust 2015-COSMO, Floating Rate Note, 1/15/32 (144A) 988,817 --------------- $ 4,904,232 --------------- Total Banks $ 4,904,232 -------------------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 0.0%+ Other Diversified Financial Services -- 0.0%+ 350,760 4.43 Velocity Commercial Capital Loan Trust 2011-1, Floating Rate Note, 8/25/40 (144A) $ 336,730 --------------- Total Diversified Financials $ 336,730 -------------------------------------------------------------------------------------------------------- TOTAL COLLATERALIZED MORTGAGE OBLIGATIONS (Cost $5,220,142) $ 5,240,962 -------------------------------------------------------------------------------------------------------- CORPORATE BONDS -- 7.4% ENERGY -- 1.1% Oil & Gas Equipment & Services -- 0.1% 615,000 Weatherford International, Ltd., 9.625%, 3/1/19 $ 645,750 -------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 17 Schedule of Investments | 4/30/16 (unaudited) (continued) -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- Oil & Gas Exploration & Production -- 0.4% 1,000,000 Gulfport Energy Corp., 6.625%, 5/1/23 $ 970,000 1,000,000 Oasis Petroleum, Inc., 6.875%, 3/15/22 892,500 800,000 WPX Energy, Inc., 7.5%, 8/1/20 762,000 --------------- $ 2,624,500 -------------------------------------------------------------------------------------------------------- Oil & Gas Storage & Transportation -- 0.2% 1,405,000 NuStar Logistics LP, 6.75%, 2/1/21 $ 1,390,950 --------------- Total Energy $ 4,661,200 -------------------------------------------------------------------------------------------------------- MATERIALS -- 0.4% Commodity Chemicals -- 0.1% 610,000 Rain CII Carbon LLC, 8.0%, 12/1/18 (144A) $ 524,600 -------------------------------------------------------------------------------------------------------- Specialty Chemicals -- 0.1% 900,000 INEOS Group Holdings SA, 5.875%, 2/15/19 (144A) $ 913,500 -------------------------------------------------------------------------------------------------------- Construction Materials -- 0.0%+ 350,000 Cemex SAB de CV, 5.875%, 3/25/19 (144A) $ 357,840 -------------------------------------------------------------------------------------------------------- Metal & Glass Containers -- 0.2% 1,000,000 Ardagh Group, 3.876%, 5/15/21 (144A) $ 1,000,000 -------------------------------------------------------------------------------------------------------- Aluminum -- 0.1% 350,000 Constellium NV, 7.875%, 4/1/21 (144A) $ 360,500 -------------------------------------------------------------------------------------------------------- Paper Products -- 0.1% 795,000 Resolute Forest Products, Inc., 5.875%, 5/15/23 $ 598,238 --------------- Total Materials $ 3,754,678 -------------------------------------------------------------------------------------------------------- CAPITAL GOODS -- 0.1% Construction & Engineering -- 0.1% 750,000 MasTec, Inc., 4.875%, 3/15/23 $ 690,000 --------------- Total Capital Goods $ 690,000 -------------------------------------------------------------------------------------------------------- TRANSPORTATION -- 0.1% Airlines -- 0.1% 500,000 Air Canada 2013-1 Class C Pass Through Trust, 6.625%, 5/15/18 (144A) $ 503,750 --------------- Total Transportation $ 503,750 -------------------------------------------------------------------------------------------------------- MEDIA -- 0.1% Advertising -- 0.0%+ 370,000 MDC Partners, Inc., 6.5%, 5/1/24 (144A) $ 383,172 -------------------------------------------------------------------------------------------------------- Cable & Satellite -- 0.1% 540,000 Virgin Media Secured Finance Plc, 5.375%, 4/15/21 (144A) $ 564,300 --------------- Total Media $ 947,472 -------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 18 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- RETAILING -- 0.1% Specialty Stores -- 0.1% 660,000 Outerwall, Inc., 6.0%, 3/15/19 $ 589,050 --------------- Total Retailing $ 589,050 -------------------------------------------------------------------------------------------------------- HEALTH CARE EQUIPMENT & SERVICES -- 1.0% Health Care Services -- 0.1% 510,000 RegionalCare Hospital Partners Holdings, Inc., 8.25%, 5/1/23 (144A) $ 530,400 -------------------------------------------------------------------------------------------------------- Health Care Facilities -- 0.7% 1,000,000 Centene Escrow Corp., 5.625%, 2/15/21 (144A) $ 1,052,500 1,500,000 CHS, 5.125%, 8/15/18 1,518,750 1,500,000 CHS, 6.875%, 2/1/22 1,357,500 1,000,000 Universal Hospital Services, Inc., 7.625%, 8/15/20 933,800 --------------- $ 4,862,550 -------------------------------------------------------------------------------------------------------- Managed Health Care -- 0.2% 1,000,000 Molina Healthcare, Inc., 5.375%, 11/15/22 (144A) $ 1,032,500 --------------- Total Health Care Equipment & Services $ 6,425,450 -------------------------------------------------------------------------------------------------------- BANKS -- 0.6% Diversified Banks -- 0.6% 1,000,000 6.30 Bank of America Corp., Floating Rate Note (Perpetual) $ 1,047,500 1,550,000 7.62 BNP Paribas SA, Floating Rate Note (Perpetual) (144A) 1,584,875 1,000,000 5.90 Citigroup, Inc., Floating Rate Note (Perpetual) 997,500 180,000 5.95 Citigroup, Inc., Floating Rate Note (Perpetual) 177,750 --------------- $ 3,807,625 --------------- Total Banks $ 3,807,625 -------------------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 0.5% Specialized Finance -- 0.1% 615,000 Nationstar Mortgage LLC, 6.5%, 8/1/18 $ 599,625 -------------------------------------------------------------------------------------------------------- Consumer Finance -- 0.2% 1,000,000 5.55 Capital One Financial Corp., Floating Rate Note (Perpetual) $ 998,000 -------------------------------------------------------------------------------------------------------- Investment Banking & Brokerage -- 0.2% 1,500,000 2.40 The Goldman Sachs Group, Inc., Floating Rate Note, 2/25/21 $ 1,505,912 --------------- Total Diversified Financials $ 3,103,537 -------------------------------------------------------------------------------------------------------- INSURANCE -- 2.0% Reinsurance -- 2.0% 500,000 6.20 Alamo Re, Ltd., Floating Rate Note, 6/7/18 (Cat Bond) (144A) $ 513,650 500,000 3.82 Atlas IX Capital DAC, Floating Rate Note, 1/17/19 (Cat Bond) (144A) $ 509,200 The accompanying notes are an integral part of these financial statements. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 19 Schedule of Investments | 4/30/16 (unaudited) (continued) -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- Reinsurance (continued) 600,000 Berwick 2016-1 Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 2/1/18 (e) (f) $ 610,380 500,000 4.56 Blue Danube II, Ltd., Floating Rate Note, 5/23/16 (Cat Bond) (144A) 500,250 250,000 7.06 Caelus Re, Ltd., Floating Rate Note, 4/7/17 (Cat Bond) (144A) 253,300 600,000 Carnosutie 2016-N,Segregated Account (Kane SAC Ltd.), Variance Rate Notes, 11/30/20 (e) (f) 612,060 350,000 Gleneagles Segregated Account (KANE SAC Ltd), Variable Rate Notes, 11/30/20 (e) (f) 360,080 600,000 Gullane Segregated Account (KANE SAC Ltd.), Variable Rate Note 11/30/20 (e) (f) 635,640 500,000 6.96 Kilimanjaro Re, Ltd., Floating Rate Note, 12/6/19 (144A) 502,200 250,000 9.46 Kilimanjaro Re, Ltd., Floating Rate Note, 12/6/19 (144A) 252,725 650,000 4.98 Kilimanjaro Re, Ltd., Floating Rate Note, 4/30/18 (Cat Bond) (144A) 650,000 1,350,000 4.49 Longpoint Re, Ltd. III, Floating Rate Note, 5/18/16 (Cat Bond) (144A) 1,347,570 250,000 Madison Re. Variable Rate Notes, 3/31/19 (e) (f) 250,000 500,000 7.48 Northshore Re, Ltd., Floating Rate Note, 7/5/16 (Cat Bond) (144A) 501,700 600,000 Pangaea Re., Variable Rate Notes, 2/1/20 (e) (f) 607,860 500,000 4.80 PennUnion Re, Ltd., Floating Rate Note, 12/7/18 (Cat Bond) (144A) 499,650 250,000 5.80 Queen Street IX Re, Ltd., Floating Rate Note, 6/8/17 (Cat Bond) (144A) 249,625 350,000 10.30 Residential Reinsurance 2012, Ltd., Floating Rate Note, 6/6/16 (Cat Bond) (144A) 351,750 250,000 9.52 Residential Reinsurance 2013, Ltd., Floating Rate Note, 6/6/17 (Cat Bond) (144A) 258,400 250,000 7.55 Residential Reinsurance 2015, Ltd., Floating Rate Note, 12/6/19 (Cat Bond) (144A) 251,175 350,000 Resilience Re, Ltd., 4/7/17 (Cat Bond) (e) (f) 316,540 500,000 3.73 Sanders Re, Ltd., Floating Rate Note, 5/5/17 (Cat Bond) (144A) 496,350 500,000 4.11 Sanders Re, Ltd., Floating Rate Note, 6/7/17 (Cat Bond) (144A) 500,750 600,000 St. Andrews Segregated Account (Kane SAC Ltd.), Variance Rate Notes, 2/1/18 (e) (f) 616,020 1,250,000 8.80 Tar Heel Re, Ltd., Floating Rate Note, 5/9/16 (Cat Bond) (144A) 1,249,875 --------------- $ 12,896,750 --------------- Total Insurance $ 12,896,750 -------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 20 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- SOFTWARE & SERVICES -- 0.2% Internet Software & Services -- 0.2% 1,295,000 j2 Cloud Services, Inc., 8.0%, 8/1/20 $ 1,351,656 --------------- Total Software & Services $ 1,351,656 -------------------------------------------------------------------------------------------------------- SEMICONDUCTORS & SEMICONDUCTOR EQUIPMENT -- 0.1% Semiconductors -- 0.1% 750,000 Micron Technology, Inc., 5.25%, 8/1/23 (144A) $ 606,008 --------------- Total Semiconductors & Semiconductor Equipment $ 606,008 -------------------------------------------------------------------------------------------------------- TELECOMMUNICATION SERVICES -- 1.1% Integrated Telecommunication Services -- 1.0% 2,500,000 CenturyLink, Inc., 6.45%, 6/15/21 $ 2,550,000 1,500,000 Cincinnati Bell, Inc., 8.375%, 10/15/20 1,537,500 2,100,000 Frontier Communications Corp., 8.5%, 4/15/20 2,220,750 --------------- $ 6,308,250 -------------------------------------------------------------------------------------------------------- Wireless Telecommunication Services -- 0.1% 500,000 Intelsat Jackson Holdings SA, 8.0%, 2/15/24 (144A) $ 517,500 --------------- Total Telecommunication Services $ 6,825,750 -------------------------------------------------------------------------------------------------------- UTILITIES -- 0.2% Gas Utilities -- 0.0%+ 250,000 Ferrellgas LP, 6.5%, 5/1/21 $ 238,125 -------------------------------------------------------------------------------------------------------- Independent Power Producers & Energy Traders -- 0.2% 521,000 NRG Energy, Inc., 6.25%, 7/15/22 $ 510,747 375,000 Star Energy Geothermal Wayang Windu, Ltd., 6.125%, 3/27/20 (144A) 378,792 --------------- $ 889,539 --------------- Total Utilities $ 1,127,664 -------------------------------------------------------------------------------------------------------- TOTAL CORPORATE BONDS (Cost $47,378,232) $ 47,290,590 -------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- 5.0% 6,000,000 0.53 Federal Farm Credit Banks, Floating Rate Note, 9/19/16 $ 6,001,746 4,700,000 U.S. Treasury Bills, 5/19/16 (c) 4,699,657 3,200,000 U.S. Treasury Bills, 5/26/16 (c) 3,199,648 4,445,000 0.33 U.S. Treasury Note, Floating Rate Note, 1/31/17 4,445,596 9,215,000 0.42 U.S. Treasury Note, Floating Rate Note, 10/31/17 9,223,502 4,450,000 0.32 U.S. Treasury Note, Floating Rate Note, 4/30/17 4,449,818 -------------------------------------------------------------------------------------------------------- TOTAL U.S. GOVERNMENT AND AGENCY OBLIGATIONS (Cost $32,003,558) $ 32,019,967 -------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 21 Schedule of Investments | 4/30/16 (unaudited) (continued) -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- SENIOR FLOATING RATE LOAN INTERESTS -- 85.5%** ENERGY -- 1.8% Oil & Gas Drilling -- 0.5% 2,976,786 6.00 Drillships Financing Holding, Inc., Tranche B-1 Term Loan, 3/31/21 $ 1,458,625 1,750,000 7.50 Jonah Energy LLC, Term Loan (Second Lien), 5/8/21 1,211,875 1,201,861 4.50 Pacific Drilling SA, Term Loan, 6/3/18 347,788 1,975,000 5.25 Paragon Offshore Finance, Term Loan, 7/16/21 508,562 --------------- $ 3,526,850 -------------------------------------------------------------------------------------------------------- Oil & Gas Equipment & Services -- 0.1% 1,661,750 5.75 FR Dixie Acquisition Corp., Term Loan, 1/23/21 $ 789,331 -------------------------------------------------------------------------------------------------------- Integrated Oil & Gas -- 0.4% 1,570,401 5.25 ExGen Renewables I LLC, Term Loan, 2/5/21 $ 1,582,179 30,316 4.50 Glenn Pool Oil & Gas Trust, Term Loan, 5/2/16 30,240 1,344,063 4.00 Seadrill Operating LP, Initial Term Loan, 2/14/21 661,111 --------------- $ 2,273,530 -------------------------------------------------------------------------------------------------------- Oil & Gas Exploration & Production -- 0.1% 439,453 3.50 EP Energy LLC, Tranche B-3 Loan, 5/24/18 $ 351,563 -------------------------------------------------------------------------------------------------------- Oil & Gas Refining & Marketing -- 0.5% 1,487,468 5.25 Chelsea Petroleum Products I LLC, Tranche B Term Loan, 7/22/22 $ 1,450,282 933,719 3.75 Pilot Travel Centers LLC, Refinancing Tranche B Term Loan, 10/3/21 939,555 876,758 4.25 Western Refining, Inc., Term Loan 2013, 11/12/20 867,808 --------------- $ 3,257,645 -------------------------------------------------------------------------------------------------------- Oil & Gas Storage & Transportation -- 0.2% 350,000 3.59 Energy Transfer Equity LP, Loan (2013), 12/2/19 $ 330,604 464,706 4.00 Energy Transfer Equity LP, Loan (2015), 12/2/19 446,118 859,569 4.75 Penn Products Terminals LLC, Tranche B Term Loan, 4/1/22 840,229 --------------- $ 1,616,951 -------------------------------------------------------------------------------------------------------- Coal & Consumable Fuels -- 0.0%+ 195,833 18.15 Bumi Resources Tbk PT, Term Loan, 8/15/13 $ 39,167 --------------- Total Energy $ 11,855,037 -------------------------------------------------------------------------------------------------------- MATERIALS -- 9.5% Commodity Chemicals -- 0.4% 283,906 4.75 Eco Services Operations, Initial Term Loan, 10/8/21 $ 277,163 2,393,813 4.50 Tronox Pigments Holland BV, New Term Loan, 3/19/20 2,323,868 --------------- $ 2,601,031 -------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 22 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- Diversified Chemicals -- 1.1% 1,296,750 6.50 Azelis Finance SA, Dollar Term Loan (First Lien), 12/1/22 $ 1,304,044 496,250 3.75 Chemours Company LLC, Term Loan (First Lien), 5/12/22 485,084 2,027,977 5.00 Nexeo Solutions LLC, Initial Term Loan, 2/26/17 2,025,442 382,947 5.00 Orion Engineered Carbons GmbH, Initial Dollar Term Loan, 7/25/21 384,384 798,000 5.75 Plaskolite, Inc., Term Loan (First Lien), 11/2/22 799,995 1,995,595 3.75 Tata Chemicals North America, Inc., Term Loan, 8/7/20 1,975,639 --------------- $ 6,974,588 -------------------------------------------------------------------------------------------------------- Fertilizers & Agricultural Chemicals -- 0.2% 992,500 4.25 Methanol Holdings Trinidad, Ltd., Initial Term Loan, 6/2/22 $ 923,025 -------------------------------------------------------------------------------------------------------- Specialty Chemicals -- 3.4% 1,730,953 4.50 Allnex Luxembourg & CY SCA, Tranche B-1 Term Loan, 10/4/19 $ 1,728,789 898,108 4.50 Allnex Luxembourg & CY SCA, Tranche B-2 Term Loan, 10/4/19 896,985 2,186,124 3.75 Axalta Coating Systems US Holdings, Inc., Refinanced Term B Loan, 2/1/20 2,186,295 321,135 3.50 Chemtura Corp., New Term Loan, 8/29/16 322,339 3,311,008 5.00 CSM Bakery Solutions LLC, Term Loan (First Lien), 7/3/20 3,283,073 775,000 5.25 GCP Applied Technologies Inc., Term Loan (First Lien), 1/22/22 779,521 842,513 3.50 Huntsman International LLC, 2015 Extended Term B Dollar Loan, 4/19/19 842,162 2,674,375 5.50 MacDermid, Inc., Tranche B Term Loan (First Lien), 6/7/20 2,630,291 2,629,621 4.25 OMNOVA Solutions, Inc., Term B-1 Loan, 5/31/18 2,614,829 498,750 3.75 PolyOne Corp., Initial Loan, 11/6/22 499,841 3,484,455 4.00 PQ Corp., 2014 Term Loan, 8/7/17 3,486,995 1,558,694 5.75 PQ Corp., Term Loan (First Lien), 10/28/22 1,570,072 124,063 4.50 Royal Holdings, Inc., Initial Term Loan (First Lien), 6/12/22 123,539 175,000 8.50 Royal Holdings, Inc., Initial Term Loan (Second Lien), 6/12/23 167,635 870,937 2.75 WR Grace & Co-Conn, U.S. Term Loan, 1/23/21 867,889 --------------- $ 22,000,255 -------------------------------------------------------------------------------------------------------- Construction Materials -- 0.5% 1,352,850 3.50 American Builders & Contractors Supply Co, Inc., Term B Loan, 4/16/20 $ 1,357,078 The accompanying notes are an integral part of these financial statements. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 23 Schedule of Investments | 4/30/16 (unaudited) (continued) -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- Construction Materials (continued) 1,799,526 4.25 CeramTec Service GmbH, Initial Dollar Term B-1 Loan, 8/30/20 $ 1,800,651 --------------- $ 3,157,729 -------------------------------------------------------------------------------------------------------- Metal & Glass Containers -- 0.7% 293,880 4.00 Ardagh Holdings USA, Inc., Tranche B-3 Term Loan (First Lien), 12/17/19 $ 294,064 1,991,663 5.50 BWay Intermediate, Initial Term Loan, 8/14/20 1,988,177 995,002 5.75 Prolampac Intermediate, Inc., Initial Term Loan (First Lien), 7/23/22 983,186 942,875 4.50 Tekni-Plex, Inc., Tranche B-1 Term Loan (First Lien), 4/15/22 935,018 --------------- $ 4,200,445 -------------------------------------------------------------------------------------------------------- Paper Packaging -- 1.1% 2,255,655 4.00 Berry Plastics Group, Inc., Term F Loan, 9/17/22 $ 2,265,241 438,628 8.00 Caraustar Industries, Inc., Incremental Term Loan, 6.75%, 5/1/19 437,715 1,382,548 8.00 Caraustar Industries, Inc., Term Loan, 5/1/19 1,379,668 1,046,674 8.02 Clondalkin Acquisition BV, Term Loan, 5/31/20 1,041,441 402,568 4.50 Coveris Holdings SA, USD Term Loan, 4/14/19 399,549 1,786,063 4.25 Multi Packaging Solutions, Inc., Initial Dollar Tranche B Term, 9/30/20 1,786,063 --------------- $ 7,309,677 -------------------------------------------------------------------------------------------------------- Aluminum -- 0.2% 1,488,750 4.00 Novelis, Inc., Initial Term Loan, 5/28/22 $ 1,483,353 -------------------------------------------------------------------------------------------------------- Diversified Metals & Mining -- 0.7% 2,301,119 4.25 Fortescue Metals Group Ltd., Bank Loan, 6/30/19 $ 2,177,722 2,954,261 4.00 US Silica Co., Term Loan, 7/23/20 2,577,592 --------------- $ 4,755,314 -------------------------------------------------------------------------------------------------------- Steel -- 0.8% 987,413 4.50 Atkore International, Inc., Term Loan (First Lien), 3/27/21 $ 972,807 1,537,814 4.75 JMC Steel Group, Inc., Term Loan, 4/1/17 1,536,853 939,815 3.75 Signode Industrial Group US, Inc., Tranche B Term Loan (First Lien), 3/21/21 933,941 1,683,840 4.50 TMS International Corp., Term B Loan, 10/2/20 1,532,294 --------------- $ 4,975,895 -------------------------------------------------------------------------------------------------------- Paper Products -- 0.4% 1,653,881 6.25 Appvion, Inc., Term Commitment, 6/28/19 $ 1,581,523 1,188,708 4.25 Rack Holdings, Inc., Tranche B-1 USD Term Loan, 10/1/21 1,164,934 --------------- $ 2,746,457 --------------- Total Materials $ 61,127,769 -------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 24 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- CAPITAL GOODS -- 9.6% Aerospace & Defense -- 2.7% 2,462,055 4.00 Accudyne Industries Borrower SCA, Refinancing Term Loan, 12/13/19 $ 2,228,160 1,240,625 5.50 Alion Science & Technology Corp., Term Loan (First Lien), 8/13/21 1,229,770 2,709,436 4.75 DigitalGlobe, Inc., Term Loan, 1/25/20 2,721,268 1,839,808 6.25 DynCorp International, Inc., Term Loan, 7/7/16 1,798,412 436,534 5.25 Standard Aero, Ltd., Term Loan (First Lien), 6/23/22 436,534 1,211,629 7.00 TASC, Inc., First Lien Term Loan, 2/28/17 1,208,085 2,387,047 5.75 The SI Organization, Inc., Term Loan (First Lien), 11/19/19 2,390,031 2,052,750 5.50 TurboCombustor Technology, Inc., Initial Term Loan, 10/18/20 1,842,343 623,685 3.25 Wesco Aircraft Hardare Corp., Tranche B Term Loan (First Lien), 2/24/21 614,329 2,856,467 4.50 WP CPP Holdings LLC, Term B-3 Loan (First Lien), 12/28/19 2,749,350 --------------- $ 17,218,282 -------------------------------------------------------------------------------------------------------- Building Products -- 2.5% 2,200,000 4.00 Armstrong World Industries, Inc., Term Loan B, 2/23/23 $ 2,211,000 2,239,688 6.00 Builders FirstSource, Inc., Initial Term Loan, 7/24/22 2,240,738 1,461,118 4.25 NCI Building Systems, Inc., Tranche B Term Loan, 6/24/19 1,454,612 1,856,877 3.50 Nortek, Inc., Incremental-1 Loan, 10/30/20 1,831,345 2,294,250 6.25 Quanex Building Products Corp., Initial Term Loan, 10/7/22 2,302,853 2,750,955 4.00 Quikrete Holdings, Inc., Initial Loan (First Lien), 9/26/20 2,750,669 1,215,813 4.00 Summit Materials LLC, Restatement Effective Date Term Loan, 6/26/22 1,217,205 2,060,793 4.25 Unifrax Corp., New Term B Loan, 12/31/19 1,957,754 --------------- $ 15,966,176 -------------------------------------------------------------------------------------------------------- Construction & Engineering -- 0.0%+ 310,178 3.75 Aecom Technology, Term Loan B, 10/15/21 $ 312,117 -------------------------------------------------------------------------------------------------------- Electrical Components & Equipment -- 0.9% 851,767 5.25 Pelican Products, Inc., Term Loan (First Lien), 4/8/20 $ 800,661 2,904,793 3.00 Southwire Co., Term Loan, 1/31/21 2,855,775 1,916,091 6.00 WireCo WorldGroup, Inc., Term Loan, 2/15/17 1,895,733 --------------- $ 5,552,169 -------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 25 Schedule of Investments | 4/30/16 (unaudited) (continued) -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- Industrial Conglomerates -- 1.1% 191,287 4.25 CeramTec Acquisition Corp., Initial Dollar Term B-2 Loan, 8/30/20 $ 191,407 548,373 4.25 CeramTec GmbH, Dollar Term B-3 Loan, 8/30/20 548,716 1,245,168 4.50 Doosan Infracore, Tranche B Term, 5/28/21 1,230,382 1,692,278 4.25 Filtration Group, Inc., Term Loan (First Lien), 11/21/20 1,690,163 1,228,109 4.25 Gates Global LLC, Tranche B Term Loan (First Lien), 6/12/21 1,180,519 401,342 5.00 Kloeckner Pentaplast of America, Inc., Initial U.S. Borrower Dollar Term Loan, 4/22/20 402,345 171,514 5.00 KP Germany Erste GmbH, Initial German Borrower Dollar Term Loan, 4/22/20 171,942 1,500,000 4.50 Milacron LLC, Term Loan, 9/28/20 1,503,750 --------------- $ 6,919,224 -------------------------------------------------------------------------------------------------------- Construction & Farm Machinery & Heavy Trucks -- 0.4% 1,182,038 6.50 Navistar, Inc., Tranche B Term Loan, 8/17/17 $ 1,123,920 1,500,000 4.50 Terex Corporation, Term Loan (First Lien), 12/15/22 1,481,250 --------------- $ 2,605,170 -------------------------------------------------------------------------------------------------------- Industrial Machinery -- 1.7% 2,050,000 7.25 Blount International, Inc., Initial Term Loan, 4/5/23 $ 2,050,000 2,322,299 4.25 Gardner Denver, Inc., Initial Dollar Term Loan, 7/30/20 2,176,431 1,476,923 5.75 Manitowoc Foodservice, Inc., Term B Loan, 2/5/23 1,491,385 1,990,000 0.00 NN, Inc., Initial Term Loan, 10/2/22 1,980,050 1,211,603 5.25 Tank Holding Corp., Initial Term Loan, 7/9/19 1,157,081 1,869,980 6.25 Xerium Technologies, Inc., Initial Term Loan, 5/17/19 1,827,905 --------------- $ 10,682,852 -------------------------------------------------------------------------------------------------------- Trading Companies & Distributors -- 0.3% 1,442,750 4.25 Univar USA, Inc., Initial Dollar Term Loan, 6/25/22 $ 1,427,121 817,831 3.75 WESCO Distribution, Inc., Tranche B-1 Loan, 12/12/19 820,387 --------------- $ 2,247,508 --------------- Total Capital Goods $ 61,503,498 -------------------------------------------------------------------------------------------------------- COMMERCIAL SERVICES & SUPPLIES -- 3.1% Environmental & Facilities Services -- 1.2% 471,732 3.75 ADS Waste Holdings, Inc., Initial Tranche B-2, 10/9/19 $ 470,848 1,240,625 5.25 Infiltrator Systems Integrated LLC, Term B Loan, 5/21/22 1,243,209 1,163,250 4.25 Waste Industries USA, Inc., Initial Term Loan, 2/20/20 1,170,520 1,864,781 5.50 Wastequip LLC, Term Loan, 8/9/19 1,864,781 The accompanying notes are an integral part of these financial statements. 26 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- Environmental & Facilities Services (continued) 1,946,363 4.00 WCA Waste Corp., Term Loan, 3/23/18 $ 1,945,146 945,881 5.00 Wheelabrator, Term B Loan, 10/15/21 916,914 42,146 5.00 Wheelabrator, Term C Loan, 10/15/21 40,855 --------------- $ 7,652,273 -------------------------------------------------------------------------------------------------------- Office Services & Supplies -- 0.2% 1,246,875 4.25 West Corp., Term B-11 Loan, 11/20/21 $ 1,250,771 -------------------------------------------------------------------------------------------------------- Diversified Support Services -- 0.9% 250,335 8.02 IAP Worldwide Services, Inc., Term Loan, 7/18/19 $ 248,770 499,922 7.00 infoGroup, Inc., Term B Loan, 5/26/18 479,300 1,000,000 4.25 KAR Auction Services, Inc., Tranche B-3 Term Loan, 2/28/23 1,003,750 1,354,559 6.50 Language Line LLC, Initial Term Loan (First Lien), 7/2/21 1,350,326 2,048,401 4.00 MTL Publishing LLC, Term B-3 Loan, 8/14/22 2,049,681 770,000 8.02 Ryan LLC, Tranche B Term Loan, 8/5/20 753,638 --------------- $ 5,885,465 -------------------------------------------------------------------------------------------------------- Security & Alarm Services -- 0.6% 908,399 4.25 Allied Security Holdings LLC, Closing Date Term Loan (First Lien), 2/12/21 $ 904,613 1,966,912 4.00 Garda World Security Corp., Term B Loan, 11/1/20 1,936,588 503,163 4.00 Garda World Security Corp., Term B Loan, 11/8/20 495,406 831,069 4.25 Monitronics International, Inc., Term B Loan, 3/23/18 797,826 --------------- $ 4,134,433 -------------------------------------------------------------------------------------------------------- Human Resource & Employment Services -- 0.2% 1,231,712 3.75 On Assignment, Inc., Initial Term B Loan, 6/5/22 $ 1,237,101 --------------- Total Commercial Services & Supplies $ 20,160,043 -------------------------------------------------------------------------------------------------------- TRANSPORTATION -- 2.8% Air Freight & Logistics -- 0.5% 541,872 6.50 CEVA Group Plc, Pre-Funded L/C Loan, 3/19/21 $ 475,944 560,000 6.50 Ceva Intercompany BV, Dutch BV Term, 3/19/21 491,866 96,552 6.50 Ceva Logistics Canada, ULC, Canadian Term Loan, 3/19/21 84,805 772,414 6.50 Ceva Logistics U.S. Holdings, Inc., US Term Loan, 3/19/21 678,437 1,661,750 5.25 Syncreon Group BV, Term Loan, 9/26/20 1,395,870 --------------- $ 3,126,922 -------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 27 Schedule of Investments | 4/30/16 (unaudited) (continued) -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- Airlines -- 1.7% 1,572,000 4.00 Air Canada, Replacement Term Loan, 9/26/19 $ 1,581,335 3,969,300 3.25 American Airlines, Inc., 2015 Term Loan (New), 6/27/20 3,953,177 889,875 3.50 American Airlines, Inc., Tranche B-1 Term Loan (Consenting), 5/23/19 890,616 2,303,707 3.25 Atlantic Aviation FBO, Inc., Term Loan (2013), 6/1/20 2,299,867 597,000 3.25 Delta Air Lines Inc., Term Loan (First Lien), 8/24/22 599,015 1,697,500 3.25 United Airlines, Inc., Class B Term Loan, 4/1/19 1,699,198 --------------- $ 11,023,208 -------------------------------------------------------------------------------------------------------- Marine -- 0.4% 926,449 9.75 Commercial Barge Line Co., Initial Term Loan, 11/6/20 $ 810,643 1,939,706 5.25 Navios Maritime Partners LP, Term Loan, 6/27/18 1,716,640 --------------- $ 2,527,283 -------------------------------------------------------------------------------------------------------- Trucking -- 0.1% 111,025 4.00 The Kenan Advantage Group, Inc., Initial Canadian Term Loan, 7/24/22 $ 110,933 341,076 4.00 The Kenan Advantage Group, Inc., Initial U.S. Term Loan, 7/24/22 340,792 --------------- $ 451,725 -------------------------------------------------------------------------------------------------------- Marine Ports & Services -- 0.1% 763,393 5.25 SeaStar Solutions, Term Loan, 1/22/21 $ 762,120 --------------- Total Transportation $ 17,891,258 -------------------------------------------------------------------------------------------------------- AUTOMOBILES & COMPONENTS -- 3.5% Auto Parts & Equipment -- 2.7% 1,601,155 6.00 Affinia Group, Inc., Tranche B-2 Term Loan, 4/25/20 $ 1,598,113 2,268,490 3.50 Allison Transmission, Inc., Term B-3 Loan, 8/23/19 2,275,580 2,023,767 4.00 Cooper Standard Intermediate Holdco 2 LLC, Term Loan, 3/28/21 2,023,767 1,993,677 5.75 Electrical Components International, Inc., Loan, 4/17/21 1,997,415 1,589,866 4.75 Federal-Mogul Corporation, Tranche C Term, 4/15/21 1,522,297 645,979 4.75 Key Safety Systems, Inc., Initial Term Loan, 7/28/21 647,190 1,449,891 3.75 MPG Holdco I, Inc., Tranche B-1 Term Loan (2015), 10/20/21 1,443,677 812,927 4.25 Schaeffler AG, Facility B-USD, 5/15/20 819,532 1,564,781 4.50 TI Group Automotive Systems LLC, Initial US Term Loan, 6/25/22 1,564,781 2,917,263 4.00 Tower Automotive Holdings USA LLC, Initial Term Loan (2014), 4/23/20 2,917,263 807,917 3.50 Visteon Corp., Tranche B Loan (First Lien), 4/8/21 806,655 --------------- $ 17,616,270 -------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 28 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- Tires & Rubber -- 0.2% 1,087,500 3.75 The Goodyear Tire & Rubber Co., Term Loan (Second Lien), 3/27/19 $ 1,091,239 -------------------------------------------------------------------------------------------------------- Automobile Manufacturers -- 0.6% 1,426,698 3.50 Chrysler Group LLC, Term Loan B, 5/24/17 $ 1,428,604 1,151,286 3.25 Chrysler Group LLC, Tranche B Term Loan, 12/29/18 1,152,293 1,206,625 6.00 Crown Group llc, Term Loan (First Lien), 9/30/20 1,164,393 --------------- $ 3,745,290 --------------- Total Automobiles & Components $ 22,452,799 -------------------------------------------------------------------------------------------------------- CONSUMER DURABLES & APPAREL -- 1.8% Home Furnishings -- 0.4% 2,581,653 4.25 Serta Simmons Bedding LLC, Term Loan, 10/1/19 $ 2,590,932 -------------------------------------------------------------------------------------------------------- Homebuilding -- 0.2% 1,300,000 5.75 GCA Merger Sub, Inc., Term Loan (First Lien), 2/22/23 $ 1,306,500 -------------------------------------------------------------------------------------------------------- Housewares & Specialties -- 0.7% 2,490,717 4.50 Reynolds Group Holdings, Inc., Incremental U.S. Term Loan, 12/31/18 $ 2,501,614 2,420,598 5.50 World Kitchen LLC, U.S. Term Loan, 3/4/19 2,422,110 --------------- $ 4,923,724 -------------------------------------------------------------------------------------------------------- Leisure Products -- 0.2% 1,112,584 3.75 Bombardier Recreational Products, Inc., Term B-2 Loan, 1/30/19 $ 1,113,379 -------------------------------------------------------------------------------------------------------- Apparel, Accessories & Luxury Goods -- 0.2% 1,100,534 3.25 PVH Corp., Tranche B Term Loan, 12/19/19 $ 1,108,003 -------------------------------------------------------------------------------------------------------- Footwear -- 0.1% 498,744 0.00 Regal Cinemas Corp., Term Loan, 3/17/22 $ 501,432 --------------- Total Consumer Durables & Apparel $ 11,543,970 -------------------------------------------------------------------------------------------------------- CONSUMER SERVICES -- 6.3% Casinos & Gaming -- 1.4% 3,286,985 4.25 CityCenter Holdings LLC, Term B Loan, 10/16/20 $ 3,300,340 868,438 4.25 Eldorado Resorts, Inc., Initial Term Loan, 7/17/22 871,332 200,000 3.11 Pinnacle Entertainments Inc., Term Loan (First Lien), 11/24/22 201,125 4,487,188 6.00 Scientific Games, Initial Term B-2, 10/1/21 4,432,502 --------------- $ 8,805,299 -------------------------------------------------------------------------------------------------------- Hotels, Resorts & Cruise Lines -- 1.0% 2,698,209 3.50 Four Seasons Holdings Inc., Term Loan, 6/27/20 $ 2,701,582 1,134,079 3.50 Hilton Worldwide Finance LLC, Initial Term Loan, 9/23/20 1,138,615 1,657,500 4.00 Sabre GLBL, Inc., Incremental Term Loan, 2/19/19 1,664,060 1,047,061 4.00 Sabre GLBL, Inc., Term B Loan, 2/19/19 1,051,097 --------------- $ 6,555,354 -------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 29 Schedule of Investments | 4/30/16 (unaudited) (continued) -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- Leisure Facilities -- 0.9% 1,520,311 3.25 Cedar Fair LP, U.S. Term Facility, 3/6/20 $ 1,528,851 1,899,731 5.53 L.A. Fitness International, LLC, Tranche B Term Loan (First Lien), 4/25/20 1,866,485 769,188 4.25 Life Time Fitness, Inc., Closing Date Term Loan, 6/4/22 766,303 1,687,250 3.50 Six Flags Theme Parks, Inc., Tranche B Term Loan, 6/30/22 1,695,686 --------------- $ 5,857,325 -------------------------------------------------------------------------------------------------------- Restaurants -- 0.7% 677,921 3.75 1011778 BC ULC, Term B-2 Loan, 12/12/21 $ 679,828 1,623,571 4.00 Landry's, Inc., B Term Loan, 4/24/18 1,627,124 2,369,004 4.25 PF Chang's China Bistro, Inc., Term Borrowing, 7/2/19 2,265,360 --------------- $ 4,572,312 -------------------------------------------------------------------------------------------------------- Education Services -- 1.2% 2,599,233 3.75 Bright Horizons Family Solutions, Inc., Term B Loan, 1/14/20 $ 2,607,356 1,339,127 4.00 Houghton Mifflin Harcourt Publishers, Inc., Term Loan, 5/11/21 1,314,018 3,407,796 5.00 Laureate Education, Inc., New Series 2018 Extended Term Loan, 6/16/18 3,169,250 925,923 6.25 McGraw-Hill Global Education Holdings LLC, Term B Loan, 3/22/19 927,370 --------------- $ 8,017,994 -------------------------------------------------------------------------------------------------------- Specialized Consumer Services -- 1.1% 346,740 5.50 Creative Artists Agency LLC, Amendment No. 3 Incremental Term Loan, 12/10/21 $ 347,119 1,742,239 5.25 GENEX Holdings, Inc., Term B Loan (First Lien), 5/22/21 1,726,994 2,190,000 6.00 Kindercare Education LLC, Initial Term Loan (First Lien), 8/13/22 2,179,050 1,445,364 5.00 Prime Security Services Borrower LLC, Term B Loan (First Lien), 6/19/21 1,449,580 650,000 5.50 Prime Security Services Borrower LLC., Term Loan (First Lien), 4/21/22 653,149 916,421 4.00 Weight Watchers International, Inc., Initial Tranche B-2 Term Loan, 4/2/20 677,769 --------------- $ 7,033,661 --------------- Total Consumer Services $ 40,841,945 -------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 30 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- MEDIA -- 7.4% Advertising -- 0.4% 2,584,478 6.75 Affinion Group, Inc., Tranche B Term Loan, 4/30/18 $ 2,283,226 -------------------------------------------------------------------------------------------------------- Broadcasting -- 2.1% 1,149,525 4.50 Catalina Holding Corp., Tranche B Term Loan (First Lien), 4/3/21 $ 981,407 681,004 3.00 CBS Outdoor Americas Capital llc, Tranche B Term Loan (First Lien), 1/15/21 679,373 1,738,282 4.00 Entercom Radio llc, Term B-2 Loan, 11/23/18 1,739,007 1,500,000 3.94 Gray Television, Inc., Term Loan (First Lien), 6/10/21 1,503,562 798,000 4.25 Gray Television, Inc., Term Loan C, 6/13/21 802,489 1,768,500 4.25 Hubbard Radio LLC, Term Loan, 5/12/22 1,725,761 1,462,500 3.25 Quebecor Media, Inc., Facility B-1 Tranche, 8/17/20 1,453,969 709,706 3.00 Sinclair Television Group, Inc., New Tranche B Term Loan, 4/19/20 707,754 584,287 4.25 Townsquare Media, Inc., Initial Term Loan, 3/17/22 579,661 2,816,277 4.10 Tribune Media Co., Term B Loan, 12/27/20 2,809,675 727,079 4.00 Univision Communications, Inc., 2013 Incremental Term Loan (C-3), 3/1/20 727,468 --------------- $ 13,710,126 -------------------------------------------------------------------------------------------------------- Cable & Satellite -- 2.1% 1,800,000 3.50 CCO Safari III LLC, Term I Loan, 1/23/23 $ 1,809,803 4,765,250 3.00 Charter Communications Operating LLC, Term F Loan, 1/1/21 4,761,157 1,913,109 3.75 Intelsat Jackson Holdings SA, Tranche B-2 Term Loan, 6/30/19 1,798,801 440,315 4.25 Learfield Communications, Inc., 2014 Replacement Term Loan (First Lien), 10/9/20 440,591 466,800 3.25 MCC Iowa LLC, Tranche H Term Loan, 1/29/21 467,384 1,492,424 6.75 MediArena Acquisition BV, Dollar Term B Loan (First Lien), 8/6/21 1,280,997 1,207,098 3.60 Ziggo BV, (USD) Tranche B-3 Term Loan, 1/15/22 1,204,552 1,138,945 3.65 Ziggo BV, Tranche B-1 Term Loan (First Lien), 1/15/22 1,136,543 733,957 3.65 Ziggo BV, Tranche B-2 Term Loan (First Lien), 1/15/22 732,410 --------------- $ 13,632,238 -------------------------------------------------------------------------------------------------------- Movies & Entertainment -- 2.0% 2,120,042 4.00 AMC Entertainment, Inc., Initial Term Loan, 4/30/20 $ 2,132,631 2,089,500 5.00 CDS US Intermediate Holdings, Inc., Initial Term Loan (First Lien), 6/25/22 2,026,815 157,767 3.75 Cinedigm Digital Funding 1 LLC, Term Loan, 2/28/18 156,584 1,506,107 3.25 Kasima LLC, Term Loan, 5/17/21 1,500,930 1,520,653 3.50 Live Nation Entertainment, Inc., Term B-1 Loan, 8/17/20 1,528,890 The accompanying notes are an integral part of these financial statements. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 31 Schedule of Investments | 4/30/16 (unaudited) (continued) -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- Movies & Entertainment (continued) 248,322 4.75 NVA Holdings, Inc., Term Loan (First Lien), 8/8/21 $ 248,012 1,945,000 3.50 Seminole Hard Rock Entertainment, Inc., Term Loan, 5/14/20 1,945,000 3,095,625 3.75 WMG Acquisition Corp., Tranche B Refinancing Term Loan, 7/1/20 3,070,198 --------------- $ 12,609,060 -------------------------------------------------------------------------------------------------------- Publishing -- 0.8% 1,739,325 7.00 Cengage Learning Acquisitions, Inc., Term Loan, 3/6/20 $ 1,732,367 2,639,250 6.25 McGraw-Hill School Education Holdings llc, Term B Loan, 12/18/19 2,643,375 1,006,645 0.00 Quincy Newspapers, Inc., Term Loan B, 10/19/22 1,005,387 --------------- $ 5,381,129 --------------- Total Media $ 47,615,779 -------------------------------------------------------------------------------------------------------- RETAILING -- 2.3% Department Stores -- 0.2% 1,657,596 4.25 Neiman Marcus Group, Ltd. LLC, Other Term Loan, 10/25/20 $ 1,582,412 -------------------------------------------------------------------------------------------------------- Apparel Retail -- 0.1% 656,682 4.75 Hudson's Bay Co., Initial Term Loan, 8/14/22 $ 660,273 -------------------------------------------------------------------------------------------------------- Computer & Electronics Retail -- 0.0%+ 54,675 9.32 Targus Group International, Inc., Tranche A-2 Term Loan, 15.0% (15.0% PIK 0% cash), 12/31/19 (g) $ 54,675 164,026 9.32 Targus Group International, Inc., Tranche A-2/B Term Loan, 14.0% (14.0% PIK 0% cash), 12/31/19 (g) 164,026 --------------- $ 218,701 -------------------------------------------------------------------------------------------------------- Home Improvement Retail -- 0.5% 3,350,633 4.50 Apex Tool Group LLC, Term Loan, 2/1/20 $ 3,289,903 -------------------------------------------------------------------------------------------------------- Specialty Stores -- 0.6% 1,995,000 5.75 Pet Acquisition Merger LLC, Term Loan (First Lien), 1/15/23 $ 2,009,605 519,750 4.25 PetSmart, Inc., Tranche B-1 Loan, 3/10/22 518,716 1,000,000 4.75 Staples Escrow LLC, Initial Loan, 1/29/22 1,002,708 --------------- $ 3,531,029 -------------------------------------------------------------------------------------------------------- Automotive Retail -- 0.6% 556,777 3.00 Avis Budget Car Rental LLC, Tranche B Term Loan, 3/15/19 $ 556,515 1,122,019 5.75 CWGS Group LLC, Term Loan, 2/20/20 1,120,616 1,693,125 3.75 The Hertz Corp., Tranche B1 Term Loan, 3/11/18 1,695,091 The accompanying notes are an integral part of these financial statements. 32 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- Automotive Retail (continued) 485,000 3.00 The Hertz Corp., Tranche B-2 Term Loan, 3/11/18 $ 484,333 --------------- $ 3,856,555 -------------------------------------------------------------------------------------------------------- Homefurnishing Retail -- 0.3% 1,596,000 0.00 Mattress Holding Corp., 2016 Incremental Loan, 10/20/21 $ 1,589,683 --------------- Total Retailing $ 14,728,556 -------------------------------------------------------------------------------------------------------- FOOD & STAPLES RETAILING -- 1.5% Drug Retail -- 0.1% 687,750 4.50 Hearthside Group Holdings LLC, Term Loan (First Lien), 4/24/21 $ 687,079 -------------------------------------------------------------------------------------------------------- Food Distributors -- 0.7% 1,515,940 5.75 AdvancePierre Foods, Inc., Term Loan (First Lien), 7/10/17 $ 1,519,324 1,348,866 4.75 Clearwater Seafoods LP, Term Loan B 2013, 6/26/19 1,355,610 1,719,000 4.25 Del Monte Foods Consumer Products, Inc., Term Loan (First Lien), 11/26/20 1,671,727 --------------- $ 4,546,661 -------------------------------------------------------------------------------------------------------- Food Retail -- 0.7% 4,309,733 5.50 Albertsons LLC, Term B-2 Loan, 3/21/19 $ 4,321,663 --------------- Total Food & Staples Retailing $ 9,555,403 -------------------------------------------------------------------------------------------------------- FOOD, BEVERAGE & TOBACCO -- 2.4% Agricultural Products -- 0.3% 1,960,000 3.25 Darling International, Inc., Term B USD Loan, 12/19/20 $ 1,964,263 -------------------------------------------------------------------------------------------------------- Packaged Foods & Meats -- 2.1% 1,402,726 4.50 CTI Foods Holding Co LLC, Term Loan (First Lien), 6/29/20 $ 1,367,658 1,246,638 4.50 Dole Food Co, Inc., Tranche B Term Loan, 10/25/18 1,246,638 1,755,000 3.75 JBS USA LLC, Incremental Term Loan, 9/18/20 1,755,737 1,749,252 3.75 JBS USA LLC, Initial Term Loan, 5/25/18 1,750,345 1,893,333 5.25 Keurig Green Mountain, Inc., Term B USD Loan, 2/10/23 1,904,756 2,712,880 3.00 Pinnacle Foods Finance LLC, Tranche G Term Loan, 4/29/20 2,714,334 828,750 3.00 Pinnacle Foods Finance LLC, Tranche H Term Loan, 4/29/20 829,009 306,050 3.75 Post Holdings, Inc., Tranche B Loan (First Lien), 5/23/21 307,931 1,549,669 4.94 Shearer's Foods, LLC, Term Loan (First Lien), 6/19/21 1,545,795 --------------- $ 13,422,203 --------------- Total Food, Beverage & Tobacco $ 15,386,466 -------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 33 Schedule of Investments | 4/30/16 (unaudited) (continued) -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- HOUSEHOLD & PERSONAL PRODUCTS -- 1.5% Household Products -- 0.5% 496,250 3.25 Energizer Spinco Inc., Term Loan (First Lien), 5/20/22 $ 495,316 1,376,529 3.50 Spectrum Brands, Inc., USD Term Loan, 6/16/22 1,384,272 1,162,029 4.01 SRAM LLC, Term Loan (First Lien), 4/10/20 1,022,585 --------------- $ 2,902,173 -------------------------------------------------------------------------------------------------------- Personal Products -- 1.0% 980,000 4.25 Atrium Innovations, Inc., Term Loan, 1/29/21 $ 905,275 250,000 7.75 Atrium Innovations, Inc., Tranche B Term Loan (Second Lien), 7/29/21 207,500 1,233,078 4.00 NBTY Inc., Term Loan (First Lien), 4/27/23 1,238,473 1,996,233 3.75 NBTY, Inc., Term B-2 Loan, 10/1/17 1,998,978 497,472 4.25 Party City Holdings, Inc., Term Loan, 8/6/22 496,726 1,603,541 4.00 Revlon Consumer Products Corp., Acquisition Term Loan, 8/19/19 1,607,050 --------------- $ 6,454,002 --------------- Total Household & Personal Products $ 9,356,175 -------------------------------------------------------------------------------------------------------- HEALTH CARE EQUIPMENT & SERVICES -- 7.1% Health Care Equipment -- 0.4% 699,375 3.50 Hill-Rom Holdings, Inc., Initial Term B Loan, 7/30/22 $ 703,091 2,007,748 4.50 Kinetic Concepts, Inc., Term DTL-E1 loan, 5/4/18 2,009,504 --------------- $ 2,712,595 -------------------------------------------------------------------------------------------------------- Health Care Supplies -- 0.6% 997,500 5.25 Greatbatch, Ltd., Term B Loan, 10/14/22 $ 1,002,332 1,389,793 4.00 Halyard Health, Inc., Term Loan, 11/1/21 1,391,092 680,333 5.00 Immucor, Inc., Term B-2 Loan, 8/19/18 651,986 1,145,250 4.25 Sterigenics-Nordion Holdings LLC, Initial Term Loan, 4/27/22 1,145,250 --------------- $ 4,190,660 -------------------------------------------------------------------------------------------------------- Health Care Services -- 3.3% 880,085 5.50 Aegis Toxicology Corp., Tranche B Term Loan (First Lien), 2/20/21 $ 800,877 1,013,828 4.25 Alliance HealthCare Services, Inc., Initial Term Loan, 6/3/19 970,741 392,602 6.50 Ardent Legacy Acquisitions, Inc., Term Loan, 7/31/21 394,565 1,201,045 6.50 BioScrip, Inc., Initial Term B Loan, 7/31/20 1,104,962 720,627 6.50 BioScrip, Inc., Term Loan, 7/31/20 662,977 1,508,762 4.00 BSN Medical GmbH & Co. KG, Facility B1A, 8/28/19 1,493,674 2,789,702 4.25 Envision Healthcare Corp., Initial Term Loan, 5/25/18 2,796,676 997,500 4.50 Envision Healthcare Corp., Tranche B-2 Term Loan, 10/28/22 1,001,657 The accompanying notes are an integral part of these financial statements. 34 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- Health Care Services (continued) 322,563 4.50 Genoa a QoL Healthcare Co LLC, Initial Term Loan (First Lien), 4/21/22 $ 322,562 945,250 5.50 Global Healthcare Exchange LLC, Term Loan (First Lien), 8/13/22 945,546 1,062,830 4.25 National Mentor Holdings, Inc., Tranche B Term Loan, 1/31/21 1,061,834 683,722 4.50 National Surgical Hospitals, Inc., Term Loan (First Lien), 5/15/22 673,877 500,000 4.25 Pharmaceutical Product Development LLC, Incremental Term Loan, 8/18/22 500,000 950,939 4.25 Pharmaceutical Product Development LLC, Initial Term Loan, 8/6/22 950,939 600,000 6.50 Precyse Acquisition Corp., Initial Term Loan (First Lien), 10/19/22 599,250 855,998 5.25 Surgery Center Holdings, Inc., Initial Term Loan (First Lien), 7/24/20 853,858 3,042,375 4.50 Team Health, Inc., Tranche B Term Loan, 11/17/22 3,057,587 2,743,125 5.25 US Renal Care, Inc., Initial Term Loan (First Lien), 11/16/22 2,754,270 --------------- $ 20,945,852 -------------------------------------------------------------------------------------------------------- Health Care Facilities -- 2.2% 573,563 4.50 Acadia Healthcare Co, Inc., Tranche B-2 Term Loan, 1/27/23 $ 578,761 238,017 3.78 CHS, Incremental 2018 Term F Loan, 12/31/18 237,181 539,062 3.38 CHS, Incremental 2019 Term G Loan, 12/31/19 531,762 991,860 4.00 CHS, Incremental 2021 Term H Loan, 1/27/21 978,594 496,250 4.00 Concentra, Inc., Tranche B Term Loan (First Lien), 5/8/22 495,009 325,313 3.38 HCA, Inc., Tranche B-4 Term Loan, 5/1/18 326,348 2,522,260 4.25 Kindred Healthcare, Inc., Tranche B Loan (First Lien), 4/10/21 2,515,954 249,069 9.75 MMM Holdings, Inc., Term Loan, 10/9/17 (d) 162,518 2,000,000 6.75 Quorum Health Corp., Term Loan (First Lien), 4/12/22 1,999,688 437,054 6.00 Select Medical Corp., Series E Tranche B Term Loan, 6/1/18 437,185 1,300,000 6.00 Select Medical Corp., Series F Tranche B Term Loan, 3/4/21 1,312,188 2,432,469 6.75 Steward Health Care System LLC, Term Loan, 4/10/20 2,395,982 2,000,000 6.25 Vizient, Inc., Initial Term Loan, 2/9/23 2,019,166 --------------- $ 13,990,336 -------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 35 Schedule of Investments | 4/30/16 (unaudited) (continued) -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- Managed Health Care -- 0.0%+ 181,072 9.75 MSO of Puerto Rico, Inc., MSO Term Loan, 12/12/17 (d) $ 118,150 -------------------------------------------------------------------------------------------------------- Health Care Technology -- 0.6% 2,414,446 3.75 Change Healthcare Holdings, Inc., Term B-2 Loan, 11/2/18 $ 2,412,937 603,829 4.25 ConvaTec, Inc., Dollar Term Loan, 12/22/16 606,470 967,530 3.50 IMS Health, Inc., Term B Dollar Loan, 3/17/21 969,747 --------------- $ 3,989,154 --------------- Total Health Care Equipment & Services $ 45,946,747 -------------------------------------------------------------------------------------------------------- PHARMACEUTICALS, BIOTECHNOLOGY & LIFE SCIENCES -- 3.4% Biotechnology -- 0.7% 3,172,954 3.50 Alkermes, Inc., 2019 Term Loan, 9/25/19 $ 3,168,988 1,233,869 7.00 Lantheus Medical Imaging, Inc., Initial Term Loan, 6/25/22 1,104,313 --------------- $ 4,273,301 -------------------------------------------------------------------------------------------------------- Pharmaceuticals -- 2.3% 1,353,391 6.00 Akorn, Inc., Term Loan B, 11/13/20 $ 1,358,466 1,596,000 5.25 Concordia Healthcare Corp., Initial Dollar Term Loan, 10/20/21 1,587,022 2,082,900 4.25 DPx Holdings BV, 2015 Incremental Dollar Term Loan, 1/23/21 2,068,580 1,662,321 3.75 Endo Luxembourg Finance I Co Sarl, 2015 Incremental Term B Loan, 6/24/22 1,659,550 1,176,000 3.44 Grifols Worldwide Operations USA, Inc., U.S. Tranche B Term Loam, 4/1/21 1,178,940 1,372,000 3.25 Mallinckrodt International Finance SA, Initial Term B Loan, 3/6/21 1,343,417 826,425 3.52 Prestige Brands, Inc., Term B-3 Loan, 9/3/21 829,696 353,935 3.25 RPI Finance Trust, Term B-3 Term Loan, 11/9/18 354,415 1,081,400 3.50 RPI Finance Trust, Term B-4 Term Loan, 11/9/20 1,086,356 1,265,132 4.75 Valeant Pharmaceuticals International, Inc., Series C-2 Tranche B Term Loan, 12/11/19 1,235,086 1,968,617 4.75 Valeant Pharmaceuticals International, Inc., Series E-1 Tranche B Term Loan, 8/5/20 1,917,762 593,406 5.00 Valeant Pharmaceuticals, Series F-1, 3/11/22 582,280 --------------- $ 15,201,570 -------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 36 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- Life Sciences Tools & Services -- 0.4% 2,238,750 5.75 Albany Molecular Research, Inc., Term Loan, 7/14/21 $ 2,247,145 410,933 4.25 Catalent Pharma Solutions, Dollar Term Loan, 5/20/21 413,405 --------------- $ 2,660,550 --------------- Total Pharmaceuticals, Biotechnology & Life Sciences $ 22,135,421 -------------------------------------------------------------------------------------------------------- BANKS -- 0.2% Thrifts & Mortgage Finance -- 0.2% 1,434,413 5.50 Ocwen Financial Corp., Initial Term Loan, 1/15/18 $ 1,412,897 --------------- Total Banks $ 1,412,897 -------------------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 2.9% Other Diversified Financial Services -- 1.4% 738,750 5.50 4L Technologies Inc., Term Loan, 5/8/20 $ 664,875 1,088,273 3.50 AWAS Finance Luxembourg 2012 SA, Term Loan, 7/16/18 1,091,674 475,000 3.50 Delos Finance SARL, Tranche B Term Loan, 2/27/21 477,449 2,520,248 3.50 Fly Funding II Sarl, Loan, 8/9/19 2,515,129 2,479,875 5.00 Livingston International, Inc., Initial Term B-1 Loan (First Lien), 4/18/19 2,312,483 1,952,168 5.00 Nord Anglia Education, Initial Term Loan, 3/31/21 1,918,005 --------------- $ 8,979,615 -------------------------------------------------------------------------------------------------------- Specialized Finance -- 0.5% 1,614,018 4.25 Mirror BidCo Corp., New Incremental Term Loan, 12/18/19 $ 1,605,948 1,278,900 3.50 Trans Union LLC, 2016 Incremental Term B-2 Commitment, 4/9/21 1,275,304 --------------- $ 2,881,252 -------------------------------------------------------------------------------------------------------- Asset Management & Custody Banks -- 0.4% 750,000 5.25 CNT Holdings III Corp., Term Loan (First Lien), 1/15/23 $ 751,719 1,877,923 4.75 Vistra Group Ltd., Term Loan (First Lien), 7/21/22 1,849,754 --------------- $ 2,601,473 -------------------------------------------------------------------------------------------------------- Investment Banking & Brokerage -- 0.6% 1,970,427 4.75 Duff & Phelps Corp., Initial Term Loan, 4/23/20 $ 1,966,323 1,937,658 4.25 Guggenheim Partners Investment Management Holdings LLC, Initial Term Loan, 7/22/20 1,942,099 --------------- $ 3,908,422 --------------- Total Diversified Financials $ 18,370,762 -------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 37 Schedule of Investments | 4/30/16 (unaudited) (continued) -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- INSURANCE -- 1.0% Insurance Brokers -- 0.4% 297,735 4.50 National Financial Partners Corp., Tranche B Term Loan (First Lien), 7/1/20 $ 294,851 2,057,799 4.25 USI Insurance Services LLC, Term B Loan, 12/30/19 2,035,293 --------------- $ 2,330,144 -------------------------------------------------------------------------------------------------------- Life & Health Insurance -- 0.2% 78,704 6.75 Integro, Ltd., Delayed Draw Term Loan (First Lien), 10/9/22 $ 75,949 1,168,368 6.75 Integro, Ltd., Initial Term Loan (First Lien), 10/9/22 1,127,475 --------------- $ 1,203,424 -------------------------------------------------------------------------------------------------------- Multi-line Insurance -- 0.1% 679,467 4.50 Alliant Holdings I LLC, Initial Term Loan, 7/28/22 $ 674,796 -------------------------------------------------------------------------------------------------------- Property & Casualty Insurance -- 0.3% 2,112,936 5.75 Confie Seguros Holding II Co., Term B Loan (First Lien), 11/9/18 $ 2,082,562 --------------- Total Insurance $ 6,290,926 -------------------------------------------------------------------------------------------------------- REAL ESTATE -- 2.0% Mortgage REIT -- 0.3% 2,087,083 3.50 Starwood Property Trust, Inc., Term Loan, 4/17/20 $ 2,074,038 -------------------------------------------------------------------------------------------------------- Hotel & Resort REIT -- 0.4% 2,735,000 4.00 MGM Growth Properties Operating Partnership LP, Term B Loan, 4/7/23 $ 2,755,512 -------------------------------------------------------------------------------------------------------- Retail REIT -- 0.3% 1,738,741 4.25 DTZ US Borrower LLC, 2015-1 Additional Term Loan (First Lien), 11/4/21 $ 1,740,189 -------------------------------------------------------------------------------------------------------- Specialized REIT -- 0.7% 2,114,673 5.00 Communications Sales & Leasing, Inc., Term Loan, 10/16/22 $ 2,079,428 2,289,200 3.25 The GEO Group, Inc., Term Loan, 4/3/20 2,286,338 --------------- $ 4,365,766 -------------------------------------------------------------------------------------------------------- Real Estate Services -- 0.3% 2,129,015 4.50 Altisource Solutions Sarl, Term B Loan, 12/9/20 $ 1,857,566 --------------- Total Real Estate $ 12,793,071 -------------------------------------------------------------------------------------------------------- SOFTWARE & SERVICES -- 5.2% Internet Software & Services -- 0.4% 1,333,125 5.50 Match Group, Inc., Term B-1 Loan, 10/27/22 $ 1,344,790 980,589 6.00 Vocus, Inc., Tranche B Loan (First Lien), 5/23/21 977,525 --------------- $ 2,322,315 -------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 38 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- IT Consulting & Other Services -- 1.3% 1,402,167 3.75 Booz Allen Hamilton, Inc., Refinance Tranche B, 7/31/19 $ 1,411,631 1,965,000 5.75 Evergreen Skills Lux Sarl, Initial Term Loan (First Lien), 4/23/21 1,729,200 782,870 4.50 Kronos, Inc., Incremental Term Loan (First Lien), 10/30/19 783,751 1,246,875 3.75 NXP BV, Tranche B Loan, 10/30/20 1,252,720 681,100 4.50 PSAV Presentation Services, Tranche B Term Loan (First Lien), 1/24/21 668,329 817,012 3.75 Science Applications International Corp., Tranche B Incremental Loan, 4/21/22 821,097 997,494 6.50 Sitel Worldwide Corp., Term Loan (First Lien), 8/21/21 993,753 855,000 7.00 TaxAct, Inc., Initial Term Loan, 12/31/22 862,481 --------------- $ 8,522,962 -------------------------------------------------------------------------------------------------------- Data Processing & Outsourced Services -- 0.4% 248,125 3.75 Black Knight InfoServ LLC, Term B Loan, 5/7/22 $ 248,742 1,454,838 4.44 First Data Corp., 2021 Extended Dollar Term Loan, 3/24/21 1,460,112 750,000 4.19 First Data Corp., New 2022B Dollar Term Loan, 7/10/22 750,670 --------------- $ 2,459,524 -------------------------------------------------------------------------------------------------------- Application Software -- 2.0% 1,527,416 4.07 Applied Systems, Inc., Initial Term Loan (First Lien), 1/15/21 $ 1,525,189 2,433,673 4.50 Epiq Systems, Inc., Term Loan, 8/27/20 2,427,589 981,847 8.50 Expert Global Solutions, Inc., Term B Advance (First Lien), 4/3/18 964,664 1,106,449 3.75 Infor., Tranche B-5 Term Loan (First Lien), 6/3/20 1,083,332 1,628,366 7.50 Serena Software, Inc., Term Loan, 4/10/20 1,628,705 1,243,115 6.25 STG-Fairway Acquisitions, Inc., Term Loan (First Lien), 3/4/19 1,219,030 1,728,237 3.50 Verint Systems, Inc., Tranche B-2 Term Loan (First Lien), 9/6/19 1,732,558 2,188,681 4.25 Vertafore, Inc., Term Loan 2013, 10/3/19 2,195,748 --------------- $ 12,776,815 -------------------------------------------------------------------------------------------------------- Systems Software -- 0.8% 1,234,375 5.75 AVG Technologies N.V., Term Loan, 10/15/20 $ 1,231,289 2,800,088 4.00 EZE Software Group LLC, Term B-1 Loan, 4/6/20 2,792,214 491,250 5.00 MSC Software Corp., Initial Term Loan (First Lien), 5/28/20 471,600 533,729 4.25 Sybil Finance BV, Refinancing Term Loan, 3/20/20 535,620 --------------- $ 5,030,723 -------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 39 Schedule of Investments | 4/30/16 (unaudited) (continued) -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- Home Entertainment Software -- 0.3% 984,500 3.25 Activision Blizzard, Inc., Term Loan, 7/26/20 $ 990,858 1,155,868 5.25 Micro Focus International, Term Loan B, 10/7/21 1,156,157 --------------- $ 2,147,015 --------------- Total Software & Services $ 33,259,354 -------------------------------------------------------------------------------------------------------- TECHNOLOGY HARDWARE & EQUIPMENT -- 2.3% Communications Equipment -- 0.5% 1,258,861 3.41 Belden Finance 2013 LP, Initial Term Loan, 9/9/20 $ 1,256,500 393,000 3.75 Ciena Corp., Term Loan, 7/15/19 392,263 400,000 4.25 Ciena Corporation, Term Loan (First Lien), 4/25/21 402,500 522,431 3.31 Commscope, Inc., Tranche 4 Term Loan, 1/14/18 522,261 348,250 3.83 CommScope, Inc., Tranche 5 Term Loan (2015), 12/29/22 349,266 --------------- $ 2,922,790 -------------------------------------------------------------------------------------------------------- Technology Hardware, Storage & Peripherals -- 0.5% 2,500,000 5.25 Diebold Inc., Term Loan (First Lien), 3/18/23 $ 2,510,395 1,000,000 6.25 Western Digital Corp., U.S. Term B Loan, 3/30/23 985,625 --------------- $ 3,496,020 -------------------------------------------------------------------------------------------------------- Electronic Equipment Manufacturers -- 0.2% 1,421,818 4.75 Zebra Technologies, Term Loan B, 9/30/21 $ 1,434,017 -------------------------------------------------------------------------------------------------------- Electronic Components -- 0.4% 337,154 3.50 Generac Power Systems, Inc., Term Loan B, 5/31/20 $ 336,100 1,900,000 5.75 Mirion Technologies Finance LLC, Initial Term Loan (First Lien), 1/26/22 1,887,333 --------------- $ 2,223,433 -------------------------------------------------------------------------------------------------------- Technology Distributors -- 0.7% 1,770,880 3.25 CDW LLC, Term Loan, 4/25/20 $ 1,772,263 1,361,941 5.00 Deltek, Inc., Term Loan (First Lien), 12/31/22 1,361,941 203,033 4.02 SS&C European Holdings SARL, Term B-2 Loan, 6/29/22 203,957 1,425,074 4.01 SS&C Technologies, Inc., Term B-1 Loan, 6/29/22 1,431,564 --------------- $ 4,769,725 --------------- Total Technology Hardware & Equipment $ 14,845,985 -------------------------------------------------------------------------------------------------------- SEMICONDUCTORS & SEMICONDUCTOR EQUIPMENT -- 1.9% Semiconductor Equipment -- 0.6% 1,101,117 3.50 Emtegris, Inc., Term Loan B, 3/25/21 $ 1,100,658 1,000,000 4.75 MKS Instruments Inc., Term Loan (First Lien), 4/19/23 1,005,625 475,549 2.88 Sensata Technologies BV, Sixth Amendment Term Loan, 10/14/21 475,797 The accompanying notes are an integral part of these financial statements. 40 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- Semiconductor Equipment (continued) 1,054,061 4.25 VAT Holding AG, Term Loan, 2/11/21 $ 1,034,297 --------------- $ 3,616,377 -------------------------------------------------------------------------------------------------------- Semiconductors -- 1.3% 6,225,000 4.25 Avago Technologies Finance, Term Loan (First Lien), 11/13/22 $ 6,240,133 491,250 4.50 M/A-COM Technology, Initial Term Loan, 5/7/21 491,250 678,625 5.25 Microsemi Corp., Closing Date Term B Loan, 12/17/22 684,393 1,175,000 5.25 ON Semiconductor Corp., Term Loan (First Lien), 3/31/23 1,182,784 --------------- $ 8,598,560 --------------- Total Semiconductors & Semiconductor Equipment $ 12,214,937 -------------------------------------------------------------------------------------------------------- TELECOMMUNICATION SERVICES -- 3.1% Cable & Satellite -- 0.4% 2,439,843 3.50 Telesat Canada, U.S. Term B Loan, 3/28/19 $ 2,441,855 -------------------------------------------------------------------------------------------------------- Integrated Telecommunication Services -- 1.8% 2,730,000 4.00 Cincinnati Bell, Inc., Tranche B Term Loan, 9/10/20 $ 2,721,810 602,350 4.00 GCI Holdings, Inc., New Term B Loan, 2/2/22 604,232 1,500,000 0.00 Level 3 Financing, Inc., Tranche B-II 2022 Term Loan, 5/31/22 1,504,532 1,210,000 5.50 Sable International Finance Ltd., Term Loan (First Lien) B-1, 12/2/22 1,216,806 990,000 5.50 Sable International Finance Ltd., Term Loan (First Lien) B-2, 12/2/22 992,166 786,212 4.75 Securus Technologies Holdings, Inc., Initial Term Loan (First Lien), 4/30/20 750,996 504,991 3.65 Virgin Media Investment Holdings, Ltd., F Facility, 6/30/23 504,754 1,613,307 3.25 West Corp., B-10 Term Loan (First Lien), 6/30/18 1,608,392 975,240 3.50 Windstream Services LLC, Tranche B-5 Term Loan, 8/8/19 964,675 790,000 5.75 Windstream Services LLC, Tranche B-6 Term Loan, 3/16/21 791,317 --------------- $ 11,659,680 -------------------------------------------------------------------------------------------------------- Wireless Telecommunication Services -- 0.9% 2,385,656 4.25 Altice US Finance I Corp., Initial Term Loan, 12/14/22 $ 2,387,643 1,100,000 0.00 Numericable US LLC, USD TLB-7 Loan, 1/31/24 1,108,709 996,150 4.00 Syniverse Holdings, Inc., Initial Term Loan, 4/23/19 806,882 1,668,273 4.00 Syniverse Holdings, Inc., Tranche B Term Loan, 4/23/19 1,351,301 448,875 3.50 T-Mobile USA, Inc., Senior Lien Term Loan, 11/3/22 452,073 --------------- $ 6,106,608 --------------- Total Telecommunication Services $ 20,208,143 -------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 41 Schedule of Investments | 4/30/16 (unaudited) (continued) -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- UTILITIES -- 2.9% Electric Utilities -- 1.2% 2,492,860 0.00 APLP Holdings LP, Term Loan, 4/12/23 $ 2,486,628 2,577,125 3.00 Calpine Construction Finance Co. LP, Term B-1 Loan, 5/3/20 2,534,172 886,029 5.75 Rhode Island State Energy Partners, Term B Advance, 11/23/22 877,169 679,080 3.75 Texas Competitive Electric Holdings Co LLC, DIP Term Loan, 5/5/16 678,939 1,349,105 5.50 TPF II Power, LLC, Term Loan, 10/2/21 1,348,686 --------------- $ 7,925,594 -------------------------------------------------------------------------------------------------------- Water Utilities -- 0.3% 1,710,625 4.75 WTG Holdings III Corp., Term Loan (First Lien), 12/12/20 $ 1,691,380 -------------------------------------------------------------------------------------------------------- Independent Power Producers & Energy Traders -- 1.4% 1,384,538 3.50 Calpine Corp., Term Loan, 5/28/22 $ 1,375,992 531,415 4.00 Calpine Corp., Term Loan, 9/27/19 531,803 1,196,923 4.00 Dynegy, Inc., Tranche B-2 Term Loan, 4/23/20 1,189,143 2,027,942 2.75 NRG Energy, Inc., Term Loan (2013), 7/1/18 2,022,662 3,199,390 3.75 NSG Holdings LLC, New Term Loan, 12/11/19 3,151,399 958,642 5.00 TerraForm AP Acquisition Holdings LLC, Term Loan, 6/26/22 843,605 --------------- $ 9,114,604 --------------- Total Utilities $ 18,731,578 -------------------------------------------------------------------------------------------------------- TOTAL SENIOR FLOATING RATE LOAN INTERESTS (Cost $560,935,943) $ 550,228,519 -------------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------------------- Shares -------------------------------------------------------------------------------------------------------- MUTUAL FUNDS -- 0.6% DIVERSIFIED FINANCIALS -- 0.6% Other Diversified Financial Services -- 0.6% 36,000 iShares iBoxx $ High Yield Corporate Bond ETF $ 3,018,600 50,000 PowerShares Senior Loan Portfolio 1,154,500 --------------- $ 4,173,100 --------------- Total Diversified Financials $ 4,173,100 -------------------------------------------------------------------------------------------------------- TOTAL MUTUAL FUNDS (Cost $4,085,668) $ 4,173,100 -------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 42 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 -------------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value -------------------------------------------------------------------------------------------------------- TEMPORARY CASH INVESTMENTS -- 1.0% Commercial Paper -- 1.0% 1,605,000 Barclays, Floating Rate Note, 5/2/16 (c) $ 1,604,960 1,605,000 BNP Paribas, Commercial Papar, 5/2/16 (c) 1,604,950 1,605,000 Prudential Funding LLC, Floating Rate Note, 5/2/16 (c) 1,604,955 1,605,000 Total CP, Floating Rate Note, 5/2/16 (c) 1,604,955 --------------- $ 6,419,820 -------------------------------------------------------------------------------------------------------- TOTAL TEMPORARY CASH INVESTMENTS (Cost $6,419,943) $ 6,419,820 -------------------------------------------------------------------------------------------------------- TOTAL INVESTMENT IN SECURITIES -- 100.8% (Cost $660,631,491) (a) $ 649,197,691 -------------------------------------------------------------------------------------------------------- OTHER ASSETS & LIABILITIES -- (0.8)% $ (5,666,124) -------------------------------------------------------------------------------------------------------- TOTAL NET ASSETS -- 100.0% $ 643,531,567 ======================================================================================================== + Amount rounds to less than 0.1%. (Cat Bond) Catastrophe or event-linked bond. At April 30, 2016, the value of these securities amounted to $8,449,785 or 1.3% of total net assets. See Notes to Financial Statements -- Note 1H. (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 April 30, 2016, the value of these securities amounted to $25,921,794 or 4.0% of total net assets. REIT Real Estate Investment Trust. (Perpetual) Security with no stated maturity date. ** 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 U.S. banks, (iii) the 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 April 30, 2016, the net unrealized depreciation on investments based on cost for federal income tax purposes of $660,812,695 was as follows: Aggregate gross unrealized appreciation for all investments in which there is an excess of value over tax cost $ 3,659,771 Aggregate gross unrealized depreciation for all investments in which there is an excess of tax cost over value (15,274,775) ------------ Net unrealized depreciation $(11,615,004) ============ (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 in default. The accompanying notes are an integral part of these financial statements. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 43 Schedule of Investments | 4/30/16 (unaudited) (continued) (e) Structured reinsurance investment. At April 30, 2016, the value of these securities amounted to $4,008,580 or 0.6% of total net assets. See Notes to Financial Statements -- Note 1H. (f) Rate to be determined. (g) Security is valued using fair value methods (other than prices supplied by independent pricing services). See Notes to Financial Statements -- Note 1A. Purchases and sales of securities (excluding temporary cash investments) for the six months ended April 30, 2016 were as follows: ------------------------------------------------------------------------------------------------- Purchases Sales ------------------------------------------------------------------------------------------------- Long-Term U.S. Government $ 9,205,537 $ -- Other Long-Term Securities $156,928,403 $ 95,132,426 CENTRALLY CLEARED CREDIT DEFAULT SWAP AGREEMENTS -- SELL PROTECTION --------------------------------------------------------------------------------------------------------- Premiums Notional Obligation Credit Expiration Paid Unrealized Principal ($)(1) Exchange Entity/Index Coupon Rating(2) Date (Received) Appreciation --------------------------------------------------------------------------------------------------------- 1,361,250 Chicago Markit CDX North 5.00% B+ 6/20/20 $ 81,943 $ (9,132) Mercantile America High Exchange Yield Index 3,000,000 Chicago Markit CDX North 1.00% B+ 12/20/20 (6,531) 33,603 Mercantile America Investment Exchange Grade Index 1,530,000 Chicago Markit CDX North 5.00% B+ 12/20/20 (14,550) 57,932 Mercantile America High Exchange Yield Index --------------------------------------------------------------------------------------------------------- $ 60,862 $ 82,403 (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 the weighted average of all the underlying securities in the index. 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. 44 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 The following is a summary of the inputs used as of April 30, 2016, in valuing the Fund's investments: ---------------------------------------------------------------------------------------------------- Level 1 Level 2 Level 3 Total ---------------------------------------------------------------------------------------------------- Preferred Stocks $1,484,849 $ -- $ -- $ 1,484,849 Common Stocks Automobiles & Components Auto Parts & Equipment 5,756 -- -- 5,756 Retailing Computer & Electronics Retail -- -- 191,362 191,362 All Other Common Stocks -- 548,616 -- 548,616 Asset Backed Securities -- 1,594,150 -- 1,594,150 Collateralized Mortgage Obligations -- 5,240,962 -- 5,240,962 Corporate Bonds Insurance Reinsurance -- 8,888,170 4,008,580 12,896,750 All Other Corporate Bonds -- 34,393,840 -- 34,393,840 U.S. Government and Agency Obligations -- 32,019,967 -- 32,019,967 Senior Floating Rate Loan Interests Retailing Computer & Electronics Retail -- -- 218,701 218,701 All Other Senior Floating Rate Loan Interests -- 550,009,818 -- 550,009,818 Mutual Funds 4,173,100 -- -- 4,173,100 Commercial Paper -- 6,419,820 -- 6,419,820 ---------------------------------------------------------------------------------------------------- Total $5,663,705 $ 639,115,343 $ 4,418,643 $649,197,691 ==================================================================================================== ---------------------------------------------------------------------------------------------------- Level 1 Level 2 Level 3 Total ---------------------------------------------------------------------------------------------------- Other Financial Instruments Net unrealized appreciation on index credit default swap contracts $ -- $ 82,403 $ -- $ 82,403 ---------------------------------------------------------------------------------------------------- Total Other Financial Instruments $ -- $ 82,403 $ -- $ 82,403 ==================================================================================================== The following is a summary of the fair valuation of certain Fund's assets and liabilities as of April 30, 2016: ---------------------------------------------------------------------------------------------------- Level 1 Level 2 Level 3 Total ---------------------------------------------------------------------------------------------------- Assets: Restricted cash $ -- $ 173,249 $ -- $ 173,249 Liabilities: Variation margin for centrally cleared swap contracts -- 5,543 -- 5,543 ---------------------------------------------------------------------------------------------------- Total $ -- $ 178,792 $ -- $ 178,792 ==================================================================================================== The accompanying notes are an integral part of these financial statements. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 45 Schedule of Investments | 4/30/16 (unaudited) (continued) The following is a reconciliation of assets valued using significant unobservable inputs (Level 3): ----------------------------------------------------------------------------------------------------- Senior Common Corporate Floating Stocks Bonds Rate Notes Total ----------------------------------------------------------------------------------------------------- Balance as of 10/31/15 $ -- $ 596,223 $ -- $ 596,223 Realized gain (loss)(1) -- -- -- -- Change in unrealized appreciation (depreciation)(2) -- 45,121 -- 45,121 Purchases 191,362 3,915,336 218,701 4,325,399 Sales -- (548,100) -- (548,100) Transfers in to Level 3* -- -- -- -- Transfers out of Level 3* -- -- -- -- Transfers in and out of Level 3 activity -- -- -- -- ----------------------------------------------------------------------------------------------------- Balance as of 4/30/16 $191,362 $4,008,580 $ 218,701 $4,418,643 ===================================================================================================== (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 April 30, 2016, there were no transfers between Levels 1, 2 and 3. Net change in unrealized appreciation (depreciation) of investments still held as of 4/30/16 $45,121 ------- The accompanying notes are an integral part of these financial statements. 46 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 Statement of Assets and Liabilities | 4/30/16 (unaudited) ASSETS: Investment in securities (cost $660,631,491) $ 649,197,691 Cash 2,825,602 Restricted cash* 173,249 Receivables -- Investment securities sold 28,985,017 Fund shares sold 4,259,099 Interest 2,401,958 Dividends 8,141 Centrally cleared swap contracts, premium paid 60,862 Due from Pioneer Investment Management, Inc. 65,627 Prepaid expenses 71,140 ---------------------------------------------------------------------------------------- Total assets $ 688,048,386 ======================================================================================== LIABILITIES: Payables -- Investment securities purchased $ 40,824,531 Fund shares repurchased 3,100,019 Distributions 217,843 Trustee fees 1,512 Variation margin for centrally cleared swap contracts 5,543 Due to affiliates 174,812 Accrued expenses 192,559 ---------------------------------------------------------------------------------------- Total liabilities $ 44,516,819 ======================================================================================== NET ASSETS: Paid-in capital $667,979,712 Distributions in excess of net investment income (72,755) Accumulated net realized loss on investments and swap contracts (13,024,072) Net unrealized depreciation on investments (11,433,800) Net unrealized appreciation on swap contracts 82,403 Net unrealized appreciation on delayed draw loan commitments 79 ---------------------------------------------------------------------------------------- Total net assets $ 643,531,567 ======================================================================================== NET ASSET VALUE PER SHARE: (No par value, unlimited number of shares authorized) Class A (based on $182,482,734/27,230,959 shares) $ 6.70 Class C (based on $88,762,315/13,231,938 shares) $ 6.71 Class K (based on $689,083/102,850 shares) $ 6.70 Class Y (based on $371,597,435/55,307,611 shares) $ 6.72 MAXIMUM OFFERING PRICE: Class A ($6.70 (divided by) 95.5%) $ 7.02 ======================================================================================== * Represents restricted cash deposited at the custodian and/or counterparty for derivative contracts. The accompanying notes are an integral part of these financial statements. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 47 Statement of Operations (unaudited) For the Six Months Ended 4/30/16 INVESTMENT INCOME: Interest $13,347,780 Dividends 95,760 ------------------------------------------------------------------------------------------------- Total investment income $13,443,540 ------------------------------------------------------------------------------------------------- EXPENSES: Management fees $ 1,794,709 Transfer agent fees Class A 8,666 Class C 3,819 Class K 23 Class Y 10,698 Distribution fees Class A 219,280 Class C 448,250 Shareholder communications expense 160,516 Administrative expense 105,884 Custodian fees 39,196 Registration fees 43,943 Professional fees 55,637 Printing expense 9,691 Fees and expenses of nonaffiliated Trustees 12,010 Miscellaneous 137,388 ------------------------------------------------------------------------------------------------- Total expenses $ 3,049,710 Less fees waived and expenses reimbursed by Pioneer Investment Management, Inc. (184,222) ------------------------------------------------------------------------------------------------- Net expenses $ 2,865,488 ------------------------------------------------------------------------------------------------- Net investment income $10,578,052 ------------------------------------------------------------------------------------------------- REALIZED AND UNREALIZED GAIN (LOSS) ON INVESTMENTS, SWAP CONTRACTS AND DELAYED DRAW LOAN COMMITMENTS Net realized gain (loss) on: Investments $(3,727,771) Swap contracts 52,247 Delayed draw loan commitments (12) $(3,675,536) ------------------------------------------------------------------------------------------------- Change in net unrealized appreciation (depreciation) on: Investments $ 1,865,711 Swap contracts 78,449 Delayed draw loan commitments (3,333) $ 1,940,827 ------------------------------------------------------------------------------------------------- Net realized and unrealized loss on investments, swap contracts and delayed draw loan commitments $(1,734,709) ------------------------------------------------------------------------------------------------- Net increase in net assets resulting from operations $ 8,843,343 ================================================================================================= The accompanying notes are an integral part of these financial statements. 48 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 Statements of Changes in Net Assets ------------------------------------------------------------------------------------------------ Six Months Ended 4/30/16 Year Ended (unaudited) 10/31/15 ------------------------------------------------------------------------------------------------ FROM OPERATIONS: Net investment income (loss) $ 10,578,052 $ 22,034,023 Net realized gain (loss) on investments and swap contracts (3,675,536) (4,788,749) Change in net unrealized appreciation (depreciation) on investments, swap contracts and delayed draw loan commitments 1,940,827 (7,422,136) ------------------------------------------------------------------------------------------------ Net increase in net assets resulting from operations $ 8,843,343 $ 9,823,138 ------------------------------------------------------------------------------------------------ DISTRIBUTIONS TO SHAREOWNERS: Net investment income: Class A ($0.12 and $0.23 per share, respectively) $ (3,068,664) $ (6,819,255) Class C ($0.09 and $0.19 per share, respectively) (1,252,652) (2,752,797) Class K* ($0.13 and $0.26 per share, respectively) (13,150) (19,162) Class Y ($0.13 and $0.26 per share, respectively) (6,608,818) (12,261,475) Class Z** ($0.00 and $0.19 per share, respectively) -- (102,418) ------------------------------------------------------------------------------------------------ Total distributions to shareowners $ (10,943,284) $ (21,955,107) ------------------------------------------------------------------------------------------------ FROM FUND SHARE TRANSACTIONS: Net proceeds from sale of shares $ 167,440,829 $ 196,814,951 Reinvestment of distributions 9,917,765 19,923,924 Cost of shares repurchased (124,134,671) (331,831,538) ------------------------------------------------------------------------------------------------ Net Increase (decrease) in net assets resulting from Fund share transactions $ 53,223,923 $ (115,092,663) ------------------------------------------------------------------------------------------------ Net Increase (decrease) in net assets $ 51,123,982 $ (127,224,632) NET ASSETS: Beginning of period 592,407,585 719,632,217 ------------------------------------------------------------------------------------------------ End of period $ 643,531,567 $ 592,407,585 ------------------------------------------------------------------------------------------------ Undistributed (distributions in excess of) net investment income $ (72,755) $ 292,477 ================================================================================================ * Class K shares commenced operations on December 10, 2013. ** Class Z shares converted to Class Y shares on August 7, 2015. The accompanying notes are an integral part of these financial statements. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 49 Statements of Changes in Net Assets (continued) -------------------------------------------------------------------------------------------------- Six Months Six Months Ended Ended 4/30/16 4/30/16 Year Ended Year Ended Shares Amount 10/31/15 10/31/15 (unaudited) (unaudited) Shares Amount -------------------------------------------------------------------------------------------------- Class A Shares sold 6,015,203 $ 39,716,351 8,071,604 $ 55,022,985 Reinvestment of distributions 445,764 2,946,976 957,018 6,514,616 Less shares repurchased (5,222,172) (34,522,799) (17,843,127) (121,562,711) -------------------------------------------------------------------------------------------------- Net increase (decrease) 1,238,795 $ 8,140,528 (8,814,505) $ (60,025,110) ================================================================================================== Class C Shares sold 1,757,381 $ 11,637,174 2,422,862 $ 16,560,977 Reinvestment of distributions 171,579 1,135,738 364,313 2,483,342 Less shares repurchased (2,483,769) (16,429,764) (5,321,906) (36,300,891) -------------------------------------------------------------------------------------------------- Net decrease (554,809) $ (3,656,852) (2,534,731) $ (17,256,572) ================================================================================================== Class K* Shares sold -- $ -- 107,395 $ 730,438 Reinvestment of distributions -- -- -- -- Less shares repurchased -- -- (5,984) (40,870) -------------------------------------------------------------------------------------------------- Net increase -- $ -- 101,411 $ 689,568 ================================================================================================== Class Y Shares sold 17,519,834 $116,087,304 18,061,494 $ 123,616,077 Reinvestment of distributions 879,905 5,835,051 1,585,617 10,825,526 Less shares repurchased (11,048,290) (73,182,108) (22,868,910) (156,327,282) -------------------------------------------------------------------------------------------------- Net increase (decrease) 7,351,449 $ 48,740,247 (3,221,799) $ (21,885,679) ================================================================================================== Class Z** Shares sold -- $ -- 129,737 $ 884,474 Reinvestment of distributions -- -- 14,657 100,440 Less shares repurchased -- -- (2,561,729) (17,599,784) -------------------------------------------------------------------------------------------------- Net decrease -- $ -- (2,417,335) $ (16,614,870) ================================================================================================== * Class K shares commenced operations on December 10, 2013. ** Class Z shares converted to Class Y shares on August 7, 2015. The accompanying notes are an integral part of these financial statements. 50 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 Financial Highlights ------------------------------------------------------------------------------------------------------------------------------------ Six Months Ended Year Year Year Year Year 4/30/16 Ended Ended Ended Ended Ended (unaudited) 10/31/15 10/31/14 10/31/13 10/31/12 10/31/11 ------------------------------------------------------------------------------------------------------------------------------------ Class A Net asset value, beginning of period $ 6.73 $ 6.86 $ 6.95 $ 6.95 $ 6.77 $ 6.87 ------------------------------------------------------------------------------------------------------------------------------------ Increase (decrease) from investment operations: Net investment income (loss) $ 0.11(a) $ 0.24(a) $ 0.24 $ 0.28 $ 0.33 $ 0.31 Net realized and unrealized gain (loss) on investments (0.02) (0.14) (0.09) 0.01 0.16 (0.11) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) from investment operations $ 0.09 $ 0.10 $ 0.15 $ 0.29 $ 0.49 $ 0.20 ------------------------------------------------------------------------------------------------------------------------------------ Distribution to shareowners: Net investment income $ (0.12) $ (0.23) $ (0.24) $ (0.29) $ (0.31) $ (0.30) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) in net asset value $ (0.03) $ (0.13) $ (0.09) $ -- $ 0.18 $ (0.10) ------------------------------------------------------------------------------------------------------------------------------------ Net asset value, end of period $ 6.70 $ 6.73 $ 6.86 $ 6.95 $ 6.95 $ 6.77 ==================================================================================================================================== Total return* 1.30% 1.53% 2.17% 4.24% 7.43% 2.98% Ratio of net expenses to average net assets 1.01%** 1.08% 1.07% 1.06% 1.11% 1.10% Ratio of net investment income (loss) to average net assets 3.42%** 3.48% 3.49% 3.88% 4.77% 4.47% Portfolio turnover rate 32%** 24% 43% 40% 42% 57% Net assets, end of period (in thousands) $182,483 $174,979 $238,764 $ 266,832 $179,260 $176,701 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 1.04%** 1.10% 1.07% 1.10% 1.11% 1.12% Net investment income (loss) to average net assets 3.39%** 3.46% 3.49% 3.85% 4.77% 4.45% ==================================================================================================================================== * 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) The per-share data presented above is based on the average shares outstanding for the period presented. The accompanying notes are an integral part of these financial statements. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 51 Financial Highlights (continued) ------------------------------------------------------------------------------------------------------------------------------- Six Months Ended Year Year Year Year Year 4/30/16 Ended Ended Ended Ended Ended (unaudited) 10/31/15 10/31/14 10/31/13 10/31/12 10/31/11 ------------------------------------------------------------------------------------------------------------------------------- Class C Net asset value, beginning of period $ 6.74 $ 6.87 $ 6.96 $ 6.95 $ 6.78 $ 6.87 ------------------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income (loss) $ 0.09(a) $ 0.19(a) $ 0.19 $ 0.23 $ 0.27 $ 0.26 Net realized and unrealized gain (loss) on investments (0.03) (0.13) (0.09) 0.02 0.16 (0.10) ------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ 0.06 $ 0.06 $ 0.10 $ 0.25 $ 0.43 $ 0.16 ------------------------------------------------------------------------------------------------------------------------------- Distribution to shareowners: Net investment income $ (0.09) $ (0.19) $ (0.19) $ (0.24) $ (0.26) $ (0.25) ------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ (0.03) $ (0.13) $ (0.09) $ 0.01 $ 0.17 $ (0.09) ------------------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 6.71 $ 6.74 $ 6.87 $ 6.96 $ 6.95 $ 6.78 =============================================================================================================================== Total return* 0.95% 0.81% 1.43% 3.61% 6.46% 2.33% Ratio of net expenses to average net assets 1.74%** 1.81% 1.78% 1.80% 1.86% 1.89% Ratio of net investment income (loss) to average net assets 2.69%** 2.74% 2.79% 3.13% 4.02% 3.68% Portfolio turnover rate 32%** 24% 43% 40% 42% 57% Net assets, end of period (in thousands) $88,762 $92,924 $112,117 $129,093 $70,655 $65,238 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 1.76%** 1.84% 1.78% 1.83% 1.86% 1.89% Net investment income (loss) to average net assets 2.67%** 2.71% 2.79% 3.09% 4.02% 3.68% =============================================================================================================================== * 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) The per-share data presented above is based on the average shares outstanding for the period presented. The accompanying notes are an integral part of these financial statements. 52 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 ----------------------------------------------------------------------------------------------------------------- Six Months Ended Year 4/30/16 Ended 12/10/13 to (unaudited) 10/31/15 10/31/14 ----------------------------------------------------------------------------------------------------------------- Class K Net asset value, beginning of period $ 6.73 $ 6.86 $ 6.95 ----------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income (loss) $ 0.12(a) $ 0.26(a) $ 0.24 Net realized and unrealized gain (loss) on investments (0.02) (0.13) (0.09) ----------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ 0.10 $ 0.13 $ 0.15 ----------------------------------------------------------------------------------------------------------------- Distribution to shareowners: Net investment income $ (0.13) $ (0.26) $ (0.24) ----------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ (0.03) $ (0.13) $ (0.09) ----------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 6.70 $ 6.73 $ 6.86 ================================================================================================================= Total return* 1.49% 1.92% 2.21%(b) Ratio of net expenses to average net assets 0.71%** 0.71% 0.69%** Ratio of net investment income (loss) to average net assets 3.73%** 3.81% 3.45%** Portfolio turnover rate 32%** 24% 43% Net assets, end of period (in thousands) $ 689 $ 693 $ 10 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 0.73%** 0.73% 0.69%** Net investment income (loss) to average net assets 3.70%** 3.79% 3.45%** ================================================================================================================= * 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) The per-share data presented above is based on the average shares outstanding for the period presented. (b) Not Annualized. The accompanying notes are an integral part of these financial statements. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 53 Financial Highlights (continued) --------------------------------------------------------------------------------------------------------------------------------- Six Months Ended Year Year Year Year Year 4/30/16 Ended Ended Ended Ended Ended (unaudited) 10/31/15 10/31/14 10/31/13 10/31/12 10/31/11 --------------------------------------------------------------------------------------------------------------------------------- Class Y Net asset value, beginning of period $ 6.75 $ 6.88 $ 6.97 $ 6.96 $ 6.78 $ 6.89 --------------------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income (loss) $ 0.12(a) $ 0.26(a) $ 0.27 $ 0.31 $ 0.35 $ 0.33 Net realized and unrealized gain (loss) on investments (0.02) (0.13) (0.10) 0.02 0.16 (0.12) --------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ 0.10 $ 0.13 $ 0.17 $ 0.33 $ 0.51 $ 0.21 --------------------------------------------------------------------------------------------------------------------------------- Distribution to shareowners: Net investment income $ (0.13) $ (0.26) $ (0.26) $ (0.32) $ (0.33) $ (0.32) --------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ (0.03) $ (0.13) $ (0.09) $ 0.01 $ 0.18 $ (0.11) --------------------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 6.72 $ 6.75 $ 6.88 $ 6.97 $ 6.96 $ 6.78 ================================================================================================================================= Total return* 1.50% 1.92% 2.50% 4.77% 7.78% 3.11% Ratio of net expenses to average net assets 0.70%** 0.70% 0.70% 0.70% 0.70% 0.88% Ratio of net investment income (loss) to average net assets 3.72%** 3.84% 3.86% 4.16% 5.17% 4.70% Portfolio turnover rate 32%** 24% 43% 40% 42% 57% Net assets, end of period (in thousands) $371,597 $323,812 $352,115 $425,245 $18,805 $60,596 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 0.79%** 0.82% 0.82% 0.83% 0.85% 0.88% Net investment income (loss) to average net assets 3.64%** 3.72% 3.74% 4.04% 5.02% 4.70% ================================================================================================================================= * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions and the complete redemption of the investment at net asset value at the end of each period. ** Annualized. (a) The per-share data presented above is based on the average shares outstanding for the period presented. The accompanying notes are an integral part of these financial statements. 54 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 Notes to Financial Statements | 4/30/16 (unaudited) 1. Organization and Significant Accounting Policies Pioneer Floating Rate Fund (the Fund) is a series of Pioneer Series Trust VI, 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 produce a high level of current income. The Fund offers four classes of shares designated as Class A, Class C, Class K and Class Y shares. Class K shares commenced operations on December 10, 2013. Class Z shares 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 of Trustees 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: A. Security Valuation 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. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 55 Fixed-income securities are valued by using 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, or may use a pricing matrix or other fair value methods or techniques to provide an estimated value of the security or instrument. A pricing matrix is a means of valuing a debt security on the basis of current market prices for other debt securities, historical trading patterns in the market for fixed income securities and/or other factors. Valuations may be supplemented by dealers and other sources, as required. Non-U.S. debt securities that are listed on an exchange will be valued at the bid price obtained from an independent third party pricing service. Loan interests 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 third party 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 or catastrophe bonds are valued at the bid price obtained from an independent third party pricing service. Other insurance linked securities (including sidecars, collateralized reinsurance and industry loss warranties) 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. Equity securities that have traded on an exchange are valued by using the last sale price on the principal exchange where they are traded. Equity securities that have not traded on the date of valuation, or securities for which sale prices are not available, generally are valued using the mean between the last bid and asked prices or, if both last bid and asked prices are not available, at the last quoted bid price. Last sale and bid and asked prices are provided by independent third party pricing services. In the case of equity securities not traded on an exchange, prices are typically determined by independent third party pricing services using a variety of techniques and methods. Foreign securities are valued in U.S. dollars based on foreign currency exchange rate quotations supplied by a third party pricing service. Trading in non-U.S. equity securities is substantially completed each day at various times prior to the close of the NYSE. The values of such securities used in 56 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 computing the net asset value of the Fund's shares are determined as of such times. The fund may use a fair value model developed by an independent pricing service to value non-U.S. equity securities. Swap contracts, including interest rate swaps, caps and floors (other than centrally cleared swap contracts) are valued at the dealer quotations obtained from reputable International Swap Dealer association members. Centrally cleared swaps are valued at the daily settlement price provided by the central clearing counterparty. Securities or loan 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. PIM's 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. 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. At April 30, 2016, three securities 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 0.1% of net assets. 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 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 57 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. Dividend and interest income are reported net of unrecoverable foreign taxes withheld at the applicable country rates. Security transactions are recorded as of trade date. 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 federal income tax provision is required. As of October 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 during the year ended October 31, 2015 was as follows: --------------------------------------------------------------------------- 2015 --------------------------------------------------------------------------- Distributions paid from: Ordinary income $21,955,107 --------------------------------------------------------------------------- Total $21,955,107 =========================================================================== 58 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 The following shows the components of distributable earnings on a federal income tax basis at October 31, 2015: ---------------------------------------------------------------------------- 2015 ---------------------------------------------------------------------------- Distributable earnings: Undistributed ordinary income $ 661,055 Capital loss carryforward (9,342,426) Dividend payable (195,447) Net unrealized depreciation (13,471,386) ---------------------------------------------------------------------------- Total $(22,348,204) ============================================================================ 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, the tax treatment of premium and amortization, the mark-to-market of swap contracts, tax basis adjustments on interest accruals on preferred stock, interest on defaulted bonds and other holdings. 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 is 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 5). E. 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 $6,065 in underwriting commissions on the sale of Class A shares during the six months ended April 30, 2016. F. 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 K and Class Y shares do not pay distribution fees. All Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 59 expenses and fees paid to the Fund's transfer agent 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 K and Class Y shares can reflect different transfer agent and distribution expense rates. G. Risks The value of securities held by the fund may go up or down, sometimes rapidly or unpredictably, due to general market conditions, such as real or perceived adverse economic, political or regulatory conditions, inflation, changes in interest rates, lack of liquidity in the bond markets or adverse investor sentiment. In the past several years, financial markets have experienced increased volatility, depressed valuations, decreased liquidity and heightened uncertainty. These conditions may continue, recur, worsen or spread. 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 invests in below investment grade (high yield) debt securities. Debt securities rated below investment grade are commonly referred to as "junk bonds" and are considered speculative. These securities involve greater risk of loss, are subject to greater price volatility, and are less liquid, especially during periods of economic uncertainty or change, than higher rated debt securities. The Fund's investments in foreign markets or countries with limited developing markets may also subject the Fund to a greater degree of risk than investments in a developed market. Risks associated with these markets include disruptive political or economic conditions and the possible imposition of adverse governmental laws or currency exchange restrictions. Interest rates in the U.S. recently have been historically low, so the Fund faces a heightened risk that interest rates may rise. A general rise in interest rates may cause investors to move out of fixed income securities on a large scale, which could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions from the Fund. 60 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 Certain securities in which the Fund invests, including floating rate loans, once sold, may not settle for an extended period (for example, several weeks or even longer). The Fund will not receive its sale proceeds until that time, which may constrain the Fund's ability to meet its obligations (including obligations to redeeming shareholders). 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. H. Insurance-Linked Securities (ILS) 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 occurs, as defined within the terms of an event-linked bond, 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. 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"). A traditional ILW takes the form of a bilateral reinsurance contract, but there are also products that take the form of derivatives, collateralized structures, or exchange traded instruments. Structured reinsurance investments, including quota share instruments, collateralized reinsurance investments and ILWs, generally are subject to the same risks as event-linked bonds. In addition, where the instruments are based on the performance 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 structured reinsurance investments and Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 61 therefore the Fund's assets are placed at greater risk of loss than if PIM had more complete information. Structured reinsurance instruments generally will be considered illiquid securities by the Fund. These securities may be difficult to purchase, sell or unwind. Illiquid securities also may be difficult to value. If the Fund is forced to sell an illiquid asset, the Fund may be forced to sell at a loss. 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. As of and for the six months ended April 30, 2016, the Fund had no open repurchase agreements. J. 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 62 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 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. 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. The amount of cash deposited with the broker as collateral at April 30, 2016 was $245,000 and is recorded within "Restricted cash" in the Statement of Assets and Liabilities. Open centrally cleared swap contracts at April 30, 2016, are listed in the Schedule of Investments. The average value of swap contracts open during the six months ended April 30, 2016, was $68,847. 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 0.60% of the Fund's average daily net assets up to $500 million and 0.55% on assets over $500 million. For the six months ended April 30, 2016, the annualized management fee (excluding waivers and/or assumption of expenses) was equivalent to 0.59% of the Fund's average daily net assets. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 63 PIM has contractually agreed to limit ordinary operating expenses to the extent required to reduce Fund expenses to 0.70% of the Fund's average daily net assets attributable to Class Y shares. Fees waived and expenses reimbursed during the six months ended April 30, 2016, are reflected on the Statement of Operations. These expense limitations are in effect through March 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 $103,534 in management fees, administrative costs and certain other reimbursements payable to PIM at April 30, 2016. 3. Transfer Agent Prior to November 2, 2015, Pioneer Investment Management Shareholder Services, Inc. (PIMSS), a wholly owned indirect subsidiary of UniCredit, provided substantially all transfer agent and shareowner services to the Fund at negotiated rates. Effective November 2, 2015, Boston Financial Data Services, Inc. serves as the transfer agent to the Fund at negotiated rates. For the six months ended April 30, 2016, such out-of-pocket expenses by class of shares were as follows: -------------------------------------------------------------------------------- Shareholder Communications: -------------------------------------------------------------------------------- Class A $ 45,701 Class C 13,344 Class K 3 Class Z 101,468 -------------------------------------------------------------------------------- Total $160,516 ================================================================================ Included in "Due to affiliates" reflected on the Statement of Assets and Liabilities is $60,271 in transfer agent fees and out-of-pocket reimbursements payable to the transfer agent at April 30, 2016. 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 (the Plan). 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 64 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 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 $11,007 in distribution fees payable to PFD at April 30, 2016. 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 purchases 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 April 30, 2016, CDSCs in the amount of $21,383 were paid to PFD. 5. Forward Foreign Currency Contracts At April 30, 2016, 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. There were no forward foreign currency contracts outstanding during the six months ended April 30, 2016. 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. For the period from June 9, 2015, to February 9, 2016, the facility was in the amount of $240 million. Effective February 10, 2016, the facility is in the amount of $220 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 April 30, 2016, the Fund had no borrowings under the credit facility. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 65 7. 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 April 30, 2016, was as follows: ----------------------------------------------------------------------------------- Statement of Assets and Liabilities Foreign Interest Credit Exchange Equity Commodity Rate Risk Risk Rate Risk Risk Risk ----------------------------------------------------------------------------------- Liabilities Unrealized depreciation on swap contracts $-- $5,543 $-- $-- $-- ----------------------------------------------------------------------------------- Total Value $-- $5,543 $-- $-- $-- =================================================================================== 66 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 The effect of derivative instruments (not considered to be hedging instruments for accounting disclosure purposes) on the Statement of Operations by risk exposure at April 30, 2016, was as follows: -------------------------------------------------------------------------------------- Statement of Operations Foreign Interest Credit Exchange Equity Commodity Rate Risk Risk Rate Risk Risk Risk -------------------------------------------------------------------------------------- Net realized gain (loss) on Swap contracts $-- $52,247 $-- $-- $-- -------------------------------------------------------------------------------------- Total Value $-- $52,247 $-- $-- $-- ====================================================================================== Change in net unrealized appreciation (depreciation) on Swap contracts $-- $78,449 $-- $-- $-- -------------------------------------------------------------------------------------- Total Value $-- $78,449 $-- $-- $-- ====================================================================================== 8. Bridge and Delayed Draw Loan Commitments Bridge loans are designed to provide temporary or "bridge" financing to a borrower pending the sale of identified assets, the arrangement of longer-term loans or the issuance and sale of debt obligations. As of April 30, 2016, the Fund had the following bridge loan and delayed draw loan commitments outstanding: ----------------------------------------------------------------------------------------- Unrealized Appreciation/ Loan Shares Cost Value Depreciation ----------------------------------------------------------------------------------------- Charter Communications Operating LLC, Bridge Loan 50,725 $ 50,725 $ 50,725 $-- CCO Holdings Bridge Loan 311,594 311,594 311,594 -- Kenan Advantage Group Delayed Draw 45,638 45,521 45,600 79 ----------------------------------------------------------------------------------------- Total 407,957 $407,840 $407,919 $79 ========================================================================================= Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 67 ADDITIONAL INFORMATION (unaudited) PIM, the Fund's investment adviser, is currently an indirect, wholly owned subsidiary of 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 previously announced by UniCredit, 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 PIM. 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. Under the Investment Company Act of 1940, completion of the Transaction will cause the Fund's current investment advisory agreement with PIM to terminate. Accordingly, the Fund's Board of Trustees will be asked to approve a new investment advisory agreement. If approved by the Board, the Fund's new investment advisory agreement will be submitted to the shareholders of the Fund for their approval. 68 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 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 Shareowner Services and 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. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 69 This page for your notes. 70 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 This page for your notes. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 71 This page for your notes. 72 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 This page for your notes. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 73 This page for your notes. 74 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 This page for your notes. Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 75 This page for your notes. 76 Pioneer Floating Rate Fund | Semiannual Report | 4/30/16 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: -------------------------------------------------------------------------------- Pioneer Funds 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) 2016 Pioneer Investments 20856-09-0616 Pioneer Flexible Opportunities Fund -------------------------------------------------------------------------------- Semiannual Report | April 30, 2016 -------------------------------------------------------------------------------- Ticker Symbols: Class A PMARX Class C PRRCX Class R MUARX Class Y PMYRX [LOGO] PIONEER Investments(R) visit us: us.pioneerinvestments.com Table of Contents President's Letter 2 Portfolio Management Discussion 4 Portfolio Summary 11 Prices and Distributions 12 Performance Update 13 Comparing Ongoing Fund Expenses 17 Schedule of Investments 19 Consolidated Financial Statements 36 Consolidated Notes to Financial Statements 44 Trustees, Officers and Service Providers 63 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 1 President's Letter Dear Shareowner, Global financial markets began 2016 on shaky footing, delivering the kind of volatility that challenged investors in 2015. US equities fell by 10% through the first six weeks of the year, only to recover the losses by the end of the first quarter. Fixed-income markets were also acutely affected, with concerns about falling oil prices and a weak global economy leading to a sell-off in credit-sensitive sectors, especially high-yield bonds, as investors fled to the perceived safety of government bonds. Like equities, credit markets recovered much of their lost ground by the end of the first quarter. Midway through the first quarter, market sentiment shifted, as expectations grew that major central banks would extend their accommodative monetary policies in the hopes of driving economic growth. The US Federal Reserve (the Fed) backed off plans to raise interest rates four times in 2016, and the European Central Bank announced a more comprehensive asset-purchasing program in the hopes of encouraging lending, and boosting both inflation and economic growth. The Bank of Japan also followed a monetary easing path, announcing negative interest rates in January. As 2016 moves along, we continue to see central bank policies as generally supportive of the US economy - for which we maintain an expectation of modest growth this year - against an overall global economic backdrop that remains unsettled and points towards generally lower growth. Economies around the world in both developed and emerging markets are experiencing deep structural changes. Current challenges include incomplete debt deleveraging in both emerging and developed markets, where debt levels continue to grow, the transition of many emerging markets economies from export/investment-driven models to more domestic demand-driven models, and aging populations, which are reducing productivity and limiting economic growth potential (primarily in the developed markets but also in emerging markets such as China). Geopolitical instability on many fronts, the rising risk of policy mistakes, and market liquidity issues combine to increase the possibility of sharp swings in asset values. Meanwhile, in the US, as always in a presidential election year, the political rhetoric of 2016 has the potential to impact domestic sectors such as health care. Throughout Pioneer's history, we have believed in the importance of active management. During periods of market volatility, we view the value of active management as even more compelling. Our experienced and tenured investment teams focus on identifying value across global markets using proprietary research, careful risk management, and a long-term perspective. 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 Flexible Opportunities Fund | Semiannual Report | 4/30/16 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 the trust you have placed in us 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. April 30, 2016 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. Past performance is no guarantee of future results. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 3 Portfolio Management Discussion | 4/30/16 In the following discussion, Michele Garau and Howard Weiss review recent market events and describe the factors that affected the performance of Pioneer Flexible Opportunities Fund during the six-month period ended April 30, 2016. Mr. Garau, Head of Balanced Portfolios, a senior vice president and portfolio manager at Pioneer, is responsible for the day-to-day management of the Fund, along with Mr. Weiss, CFA, a vice president and portfolio manager at Pioneer. Q How did the Fund perform during the six-month period ended April 30, 2016? A Pioneer Flexible Opportunities Fund's Class A shares returned 0.52% at net asset value during the six-month period ended April 30, 2016, while the Fund's benchmark, the Barclays US Treasury TIPS 1-10 Year Index (the Barclays Index), returned 3.12%. During the same period, the average return of the 340 mutual funds in Lipper's Alternative Global Macro Funds category was -0.47%, and the average return of the 388 mutual funds in Morningstar's Tactical Allocation Funds category was -0.49%. Q Could you discuss some of the investment decisions that factored into the Fund's benchmark-relative performance during the six-month period ended April 30, 2016? A We retained a tilt toward equities and away from bonds in the Fund's portfolio during the period, based on our belief that stocks offered the more compelling long-term return prospects. While we believe such positioning is appropriate from a longer-term standpoint, it was a headwind to the Fund's benchmark-relative results during the past six months. The vast majority of equity indices, both domestic and global, finished the six-month period with negative returns, the result of a prolonged stretch of weakness from the beginning of the reporting period (November 2015) through the middle of February 2016. During that timeframe, higher-risk assets struggled mightily due to mounting evidence of slowing global economic growth as well as concerns that the US Federal Reserve (the Fed) would hike interest rates several times in 2016. The fears receded in the second half of the reporting period once economic data stabilized, the world's major central banks adopted increasingly aggressive monetary policies, and the Fed reiterated its intention to raise rates at only a gradual pace after its initial, small rate hike in December. Although stocks rebounded significantly in response to the improved backdrop, the rally was not enough to overcome the earlier shortfall, and so the Fund's relative returns suffered a negative impact from the portfolio's strong tilt towards equities. 4 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 On the plus side, the fixed-income markets delivered healthy, positive returns during the period. The combination of weaker economic growth, favorable central-bank actions and elevated demand for perceived safer investments led to strong across-the-board returns for bonds over the six-month period. In that environment, the Fund's fixed-income allocation aided benchmark-relative performance and provided a measure of stability through the downturn in higher-risk asset classes. The Fund's allocation to real estate also made a positive contribution to benchmark-relative results. That portion of the portfolio is largely allocated to real estate investment trusts (REITs), with a concentration in Singapore, Hong Kong, and lodging REITs headquartered in the United States. REITs performed very well over the six-month period due to the favorable combination of healthy global property markets and declining bond yields. The Fund's position in a gold futures contract also added to relative performance, given the substantial rally in gold prices from the beginning of January onward. Q Could you discuss specific aspects of the Fund's positioning as of April 30, 2016? A We continued to employ top-down investment strategy during the six-month period. The Fund's asset allocation is a function of our long-term investment orientation, and we believe global market conditions have not shifted to the point that would warrant a broad-based repositioning. Overall, approximately 59% of the Fund's portfolio was allocated to equities as of April 30, 2016, and approximately 27% was in fixed income. In addition, roughly 8% of the portfolio was allocated to REITs, and the remainder was in cash. The Fund's equity allocation includes weightings of approximately 30% in the United States and 20% in the developed markets. The portfolio also had a 9% allocation to equities in the emerging markets. The portfolio's positions in non-US stocks were a drag on the Fund's benchmark-relative results over the period, as both Japanese and Chinese equities produced negative returns. Nevertheless, we believe Japan is one of the most attractive developed markets due to the potentially transformational impact of Prime Minister Abe's economic reforms.We also believe Chinese stocks have become even more compelling following their recent underperformance, as we think the worst is likely over for that nation's economy. Therefore, we remained on the lookout for the chance to add to the Fund's position in China during the period. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 5 Q What are some notable elements of the Fund's stock portfolio as of April 30, 2016? A We continue to employ a theme-based approach to equity investing, which is designed to capitalize on trends that we think can drive longer-term outperformance for the related positions. For instance, the Fund holds a sizable weighting in stocks that seem poised to benefit from the worldwide health care revolution. We anticipate that demand for health care is likely to increase due to rising global wealth, the health needs of aging and growing populations, and the growing prevalence of chronic diseases. We believe health care stocks, in general, are safer and have greater upside potential than most fixed-income securities, yet they offer exposure to important demographic trends as well as below-average sensitivity to broader economic cycles. We also see an opportunity in the defense/aerospace industry. Airlines face an increasing need to upgrade their aging fleets of airplanes, and defense spending in the West appears set to turn slowly higher. In that portion of the equity market, we emphasize companies with weaker ties to economic cycles that also have strong share buyback programs in place. Our focus on buybacks in the aerospace industry underscores our broader preference for owning shares of companies that display a shareholder-focused approach to capital allocation. That is reflected in the Fund's investments in several exchange-traded funds (ETFs) linked to stocks that regularly increase their dividends*, as well as the PowerShares International BuyBack Achievers ETF. Other notable themes within the portfolio's equity allocation include global infrastructure and hotel operators in the United States and Japan. Q How is the Fund's fixed-income portfolio positioned as of April 30, 2016? A We find most developed-market bonds unattractive, since their yields do not offer a compelling alternative to the opportunities available in the stock market. However, we have retained Fund positions in Australian and New Zealand government debt, based in part on the improving outlook for commodities. The Fund also has exposure to the bonds of gold mining companies, as spot gold prices have remained well above the cash costs of production for the issuers represented in the portfolio. We believe the securities now offer extremely appealing valuations following the broad-based selloff in the commodity-sensitive areas of the bond market. * Dividends are not guaranteed. 6 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 Gold-related bonds, in fact, staged a powerful rebound in the second half of the six-month period, resulting in a meaningful contribution to the Fund's overall performance. In addition, we have retained a modest Fund weighting in emerging markets debt, with a focus on select opportunities in US dollar-denominated bonds in Russia, Mexico, and Indonesia, plus smaller investments in local-currency bonds and corporate issues in those same three countries. In terms of portfolio activity, we established a small position in high-yield bonds during the six-month period. Severe dislocations within the fixed-income markets caused valuations in the high-yield sectors to fall to attractive levels for the first time since 2015. Accordingly, we elected to increase the Fund's weighting in the asset class through positions in the bonds of companies where we believed yields had risen too far, given the underlying risks. Q Can you discuss how you use derivatives as part of your investment strategy for the Fund during the six-month period ended April 30, 2016, and how the use of derivatives affected the Fund's performance, if at all? A We use derivatives across a broad spectrum of asset classes for the purposes of establishing specific market or issuer exposure in the Fund's portfolio, and to attempt to hedge downside risk. The derivative vehicles we use include, but are not limited to equity, fixed-income, and commodity futures; credit-linked securities; ETFs (long or short positions); currency forwards or futures (also long or short positions); and options -- both index and individual issuers. (Long/Short trading strategies involve the buying, or going long, and selling, or going short, of certain securities, usually in an attempt to mitigate market risk. In general, long positions are expected to rise in value, while short positions are expected to decrease in value.) The use of derivatives had a positive impact on the Fund's performance during the six-month period. Q Do you have any closing thoughts for investors? A We continue to employ a flexible, go-anywhere investment approach that we believe enables the Fund to adapt to changing market conditions by investing in any asset class or region. Rather than being constrained by a "style box" or an index-tracking strategy, we have the ability to be active in Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 7 seeking out investment opportunities, while at the same time attempting to manage the Fund's risk in response to the constantly evolving market environment. We think this approach is well suited to an investment environment characterized by elevated volatility and wide divergences among the underlying trends currently affecting the global financial markets. Please refer to the Schedule of Investments on pages 19-35 for a full listing of Fund securities. All investments are subject to risk, including the possible loss of principal. In the past several years, financial markets have experienced increased volatility, depressed valuations, decreased liquidity and heightened uncertainty. These conditions may continue, recur, worsen or spread. All investments are subject to risk, including the possible loss of principal. The Fund has the ability to invest in a wide variety of securities and asset classes. In addition, the Fund is non-diversified, which means it can invest a higher percentage of its assets in the securities of any one or more issuers. This will increase the Fund's potential risk exposure. 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 employ leverage through the use of derivatives, which increases the volatility of investment returns and subjects the Fund to magnified losses if the Fund 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 and some of the underlying funds may employ short selling, a speculative strategy. Unlike the possible loss on a security that is purchased, there is no limit to the amount of loss on an appreciating security that is sold short. 8 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 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. The Fund may invest in commodity-linked derivatives. The value of commodity-linked derivatives may be affected by changes in overall market movements, commodity index volatility, changes in interest rates, factors affecting a particular industry or commodity, international economic, political and regulatory developments, supply and demand, and governmental regulatory policies. Investments in equity securities are subject to price fluctuation. Small-and mid-cap stocks involve greater risks and volatility than large-cap stocks. International investments are subject to special risks, including currency fluctuations, and 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 will generally fall. Prepayment risk is the chance that an issuer may exercise its right to repay 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. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 9 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 prepayments. High-yield bonds possess greater price volatility, illiquidity, and possibility of default. 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. 10 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 Portfolio Summary | 4/30/16 Sector Distribution -------------------------------------------------------------------------------- (As a percentage of total long-term holdings) [THE FOLLOWING DATA WAS REPRESENTED AS A PIE CHART IN THE PRINTED MATERIAL] Financials 28.8% Industrials 17.2% Health Care 15.9% Consumer Discretionary 6.9% Materials 6.5% Government 5.8% Information Technology 4.9% Energy 4.9% Consumer Staples 3.6% Exchange Traded Funds 3.4% Utilities 1.2% Telecommunication Services 0.9% Portfolio Diversification* -------------------------------------------------------------------------------- (As a percentage of total investment portfolio) [THE FOLLOWING DATA WAS REPRESENTED AS A PIE CHART IN THE PRINTED MATERIAL] International Common Stocks 34.1% U.S. Common Stocks 29.9% Foreign Government Bonds 13.2% International Corporate Bonds 8.2% Exchange Traded Fund 4.1% U.S. Corporate Bonds 3.8% Depositary Receipts for International Stocks 3.0% Exchange Traded Funds 2.8% Senior Secured Loans 0.6% Collateralized Mortgage Obligations 0.3% U.S. Preferred Stocks 0.0%+ * Includes investments in insurance-linked Securities totaling 0.1% of total investment portfolio. + Amount rounds to less than 0.1%. 10 Largest Holdings -------------------------------------------------------------------------------- (As a percentage of total long-term holdings)** 1. Russian Foreign Bond - Eurobond, 3.5%, 1/16/19 3.07% -------------------------------------------------------------------------------- 2. Indonesia Government International Bond, 5.875%, 1/15/24 2.57 -------------------------------------------------------------------------------- 3. ProShares S&P 500 Dividend Aristocrats ETF 1.59 -------------------------------------------------------------------------------- 4. Mexico Government International Bond, 4.0%, 10/2/23 1.28 -------------------------------------------------------------------------------- 5. Mexico Government International Bond, 3.6%, 1/30/25 1.27 -------------------------------------------------------------------------------- 6. Safran SA 1.14 -------------------------------------------------------------------------------- 7. Bristol-Myers Squibb Co. 1.13 -------------------------------------------------------------------------------- 8. AngloGold Ashanti Holdings Plc, 5.125%, 8/1/22 1.08 -------------------------------------------------------------------------------- 9. Mexican Bonos, 5.75%, 3/5/26 1.05 -------------------------------------------------------------------------------- 10. Aberdeen Asia-Pacific Income Fund, Inc. 1.03 -------------------------------------------------------------------------------- ** 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 Flexible Opportunities Fund | Semiannual Report | 4/30/16 11 Prices and Distributions | 4/30/16 Net Asset Value per Share -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- Class 4/30/16 10/31/15 -------------------------------------------------------------------------------- A $12.03 $12.68 -------------------------------------------------------------------------------- C $11.91 $12.56 -------------------------------------------------------------------------------- R $12.01 $12.69 -------------------------------------------------------------------------------- Y $12.07 $12.72 -------------------------------------------------------------------------------- Distributions per Share: 11/1/15 - 4/30/16 -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- Short-Term Long-Term Class Dividends Capital Gains Capital Gains -------------------------------------------------------------------------------- A $0.1366 $ -- $0.5636 -------------------------------------------------------------------------------- C $0.0940 $ -- $0.5636 -------------------------------------------------------------------------------- R $0.1324 $ -- $0.5636 -------------------------------------------------------------------------------- Y $0.1521 $ -- $0.5636 -------------------------------------------------------------------------------- The Barclays U.S. Treasury TIPS 1-10 Year Index is an unmanaged index comprised of U.S. Treasury Inflation Protected Securities (TIPS) having a maturity of at least 1 year and less than 10 years. Index returns are calculated monthly, 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 13-16. 12 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 Performance Update | 4/30/16 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 Flexible Opportunities Fund at public offering price during the periods shown, compared to that of the Barclays U.S. Treasury TIPS 1-10 Year Index. Average Annual Total Returns (As of April 30, 2016) -------------------------------------------------------------------------------- Barclays Net Public U.S. Treasury Asset Offering TIPS Value Price 1-10 Year Period (NAV) (POP) Index -------------------------------------------------------------------------------- Life of Class (5/3/2010) 6.67% 5.86% 2.58% 5 years 5.23 4.27 1.51 1 year -6.89 -11.08 1.23 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated March 1, 2016) -------------------------------------------------------------------------------- Gross Net -------------------------------------------------------------------------------- 1.29% 1.20% -------------------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment Pioneer Flexible Barclays U.S. Treasury Opportunities Fund TIPS 1-10 Year Index 5/10 $ 9,550 $ 10,000 4/11 $ 11,112 $ 10,789 4/12 $ 11,667 $ 11,546 4/13 $ 13,615 $ 11,853 4/14 $ 13,785 $ 11,376 4/15 $ 15,402 $ 11,487 4/16 $ 14,340 $ 11,629 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 net expense ratio reflects the contractual expense limitation currently in effect through March 1, 2017, for Class A 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 Flexible Opportunities Fund | Semiannual Report | 4/30/16 13 Performance Update | 4/30/16 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 Flexible Opportunities Fund during the periods shown, compared to that of the Barclays U.S. Treasury TIPS 1-10 Year Index. Average Annual Total Returns (As of April 30, 2016) -------------------------------------------------------------------------------- Barclays U.S. Treasury TIPS If If 1-10 Year Period Held Redeemed Index -------------------------------------------------------------------------------- Life of Class (5/3/2010) 5.87% 5.87% 2.58% 5 years 4.45 4.45 1.51 1 year -7.57 -7.57 1.23 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated March 1, 2016) -------------------------------------------------------------------------------- Gross -------------------------------------------------------------------------------- 2.04% -------------------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment Pioneer Flexible Barclays U.S. Treasury Opportunities Fund TIPS 1-10 Year Index 5/10 $ 10,000 $ 10,000 4/11 $ 11,554 $ 10,789 4/12 $ 12,039 $ 11,546 4/13 $ 13,953 $ 11,853 4/14 $ 14,024 $ 11,376 4/15 $ 15,540 $ 11,487 4/16 $ 14,363 $ 11,629 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. 14 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 Performance Update | 4/30/16 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 Flexible Opportunities Fund during the periods shown, compared to that of the Barclays U.S. Treasury TIPS 1-10 Year Index. Average Annual Total Returns (As of April 30, 2016) -------------------------------------------------------------------------------- Barclays Net U.S. Treasury Asset TIPS Value 1-10 Year Period (NAV) Index -------------------------------------------------------------------------------- Life of Class (5/3/2010) 6.41% 2.58% 5 years 4.92 1.51 1 year -7.58 1.23 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated March 1, 2016) -------------------------------------------------------------------------------- Gross -------------------------------------------------------------------------------- 2.04% -------------------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment Pioneer Flexible Barclays U.S. Treasury Opportunities Fund TIPS 1-10 Year Index 5/10 $ 10,000 $ 10,000 4/11 $ 11,633 $ 10,789 4/12 $ 12,214 $ 11,546 4/13 $ 14,254 $ 11,853 4/14 $ 14,417 $ 11,376 4/15 $ 16,002 $ 11,487 4/16 $ 14,789 $ 11,629 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 September 13, 2013, 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 September 13, 2013, 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 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 Flexible Opportunities Fund | Semiannual Report | 4/30/16 15 Performance Update | 4/30/16 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 Flexible Opportunities Fund during the periods shown, compared to that of the Barclays U.S. Treasury TIPS 1-10 Year Index. Average Annual Total Returns (As of April 30, 2016) -------------------------------------------------------------------------------- Barclays Net U.S. Treasury Asset TIPS Value 1-10 Year Period (NAV) Index -------------------------------------------------------------------------------- Life of Class (5/3/2010) 6.99% 2.58% 5 years 5.55 1.51 1 year -6.61 1.23 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated March 1, 2016) -------------------------------------------------------------------------------- Gross Net -------------------------------------------------------------------------------- 1.05% 0.90% -------------------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $5 Million Investment Pioneer Flexible Barclays U.S. Treasury Opportunities Fund TIPS 1-10 Year Index 5/10 $ 5,000,000 $ 5,000,000 4/11 $ 5,832,730 $ 5,394,260 4/12 $ 6,143,064 $ 5,773,026 4/13 $ 7,196,009 $ 5,926,297 4/14 $ 7,306,215 $ 5,688,168 4/15 $ 8,180,260 $ 5,743,708 4/16 $ 7,639,657 $ 5,814,264 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 March 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. 16 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 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 Flexible Opportunities Fund Based on actual returns from November 1, 2015, through April 30, 2016. -------------------------------------------------------------------------------- Share Class A C R Y -------------------------------------------------------------------------------- Beginning Account $1,000.00 $1,000.00 $1,000.00 $1,000.00 Value on 11/1/15 -------------------------------------------------------------------------------- Ending Account $1,005.20 $1,001.60 $1,002.40 $1,006.50 Value (after expenses) on 4/30/16 -------------------------------------------------------------------------------- Expenses Paid $ 5.88 $ 9.60 $ 8.31 $ 4.49 During Period* -------------------------------------------------------------------------------- * Expenses are equal to the Fund's annualized net expense ratio plus the expense ratio of the underlying funds. These combined totals were 1.18%, 1.93%, 1.67% and 0.90% for Class A, Class C, Class R and Class Y shares, respectively. These combined ratios were multiplied by the average account value over the period, and then multiplied by 182/366 (to reflect the one-half year period). Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 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 Flexible Opportunities Fund Based on a hypothetical 5% return per year before expenses, reflecting the period from November 1, 2015, through April 30, 2016. -------------------------------------------------------------------------------- Share Class A C R Y -------------------------------------------------------------------------------- Beginning Account $1,000.00 $1,000.00 $1,000.00 $1,000.00 Value On 11/1/15 -------------------------------------------------------------------------------- Ending Account $1,019.00 $1,015.27 $1,016.56 $1,020.39 Value (after expenses) On 4/30/16 -------------------------------------------------------------------------------- Expenses Paid $ 5.92 $ 9.67 $ 8.37 $ 4.52 During Period* -------------------------------------------------------------------------------- * Expenses are equal to the Fund's annualized net expense ratio plus the expense ratio of the underlying funds. These combined totals were 1.18%, 1.93%, 1.67% and 0.90% for Class A, Class C, Class R and Class Y shares, respectively. These combined ratios were multiplied by the average account value over the period, and then multiplied by 182/366 (to reflect the one-half year period). 18 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 Schedule of Investments | 4/30/16 (unaudited) ----------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value ----------------------------------------------------------------------------------------------------- PREFERRED STOCKS -- 0.0%+ REAL ESTATE -- 0.0%+ Retail REIT -- 0.0%+ 204 Wheeler Real Estate Investment Trust, Inc., 9.0% $ 199,920 --------------- Total Real Estate $ 199,920 ----------------------------------------------------------------------------------------------------- TOTAL PREFERRED STOCKS (Cost $195,245) $ 199,920 ----------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------- Shares ----------------------------------------------------------------------------------------------------- COMMON STOCKS -- 62.5% ENERGY -- 0.9% Oil & Gas Equipment & Services -- 0.9% 30,817 Core Laboratories NV $ 4,119,000 27,610 Halliburton Co. 1,140,569 13,882 Schlumberger, Ltd. 1,115,280 --------------- $ 6,374,849 --------------- Total Energy $ 6,374,849 ----------------------------------------------------------------------------------------------------- MATERIALS -- 0.5% Diversified Chemicals -- 0.1% 94,000 Daicel Corp. $ 1,219,978 ----------------------------------------------------------------------------------------------------- Construction Materials -- 0.4% 8,434 Martin Marietta Materials, Inc. $ 1,427,286 13,130 Vulcan Materials Co. 1,413,182 --------------- $ 2,840,468 --------------- Total Materials $ 4,060,446 ----------------------------------------------------------------------------------------------------- CAPITAL GOODS -- 13.1% Aerospace & Defense -- 5.7% 60,325 Engility Holdings, Inc. $ 1,186,593 38,433 Honeywell International, Inc. 4,391,739 227,503 Leonardo-Finmeccanica S.p.A. 2,873,466 179,867 Magellan Aerospace Corp. 2,531,217 32,471 Northrop Grumman Corp. 6,697,468 54,566 Raytheon Co. 6,894,414 116,892 Safran SA 8,053,937 75,478 Thales SA 6,525,454 12,652 TransDigm Group, Inc. 2,883,011 --------------- $ 42,037,299 ----------------------------------------------------------------------------------------------------- Building Products -- 0.5% 1,997 Geberit AG $ 766,620 225,800 Takasago Thermal Engineering Co., Ltd. 2,917,848 --------------- $ 3,684,468 ----------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 19 Schedule of Investments | 4/30/16 (unaudited) (continued) ----------------------------------------------------------------------------------------------------- Shares Value ----------------------------------------------------------------------------------------------------- Construction & Engineering -- 4.3% 1,750,000 China Communications Construction Co., Ltd. $ 2,111,614 1,128,000 China Railway Group, Ltd. 898,666 2,556,000 China State Construction International Holdings, Ltd. 3,993,596 119,046 Granite Construction, Inc. 5,308,261 792,000 Kajima Corp. 5,083,821 100,000 Maeda Corp. 782,458 4,244,000 Pembangunan Perumahan Persero Tbk PT 1,179,694 457,000 Shimizu Corp. 4,209,633 568,000 Taisei Corp. 3,981,296 24,400 Vinci SA 1,822,834 11,469,600 Waskita Karya Persero Tbk PT 2,039,910 --------------- $ 31,411,783 ----------------------------------------------------------------------------------------------------- Electrical Components & Equipment -- 0.2% 198,000 Zhuzhou CRRC Times Electric Co, Ltd. $ 1,132,034 ----------------------------------------------------------------------------------------------------- Heavy Electrical Equipment -- 0.2% 1,733,000 China High Speed Transmission Equipment Group Co., Ltd. $ 1,347,152 ----------------------------------------------------------------------------------------------------- Industrial Conglomerates -- 0.6% 7,639 Danaher Corp. $ 739,073 102,300 Seibu Holdings, Inc.* 2,239,355 87,200 SM Investments Corp. 1,750,118 --------------- $ 4,728,546 ----------------------------------------------------------------------------------------------------- Construction & Farm Machinery & Heavy Trucks -- 0.1% 62,916 Volvo AB (Class B) $ 736,561 ----------------------------------------------------------------------------------------------------- Agricultural & Farm Machinery -- 0.5% 40,444 The Toro Co. $ 3,496,384 ----------------------------------------------------------------------------------------------------- Industrial Machinery -- 1.0% 3,983 Georg Fischer AG $ 3,234,060 42,200 Hoshizaki Electric Co., Ltd. 3,665,783 6,799 Stanley Black & Decker, Inc. 760,944 --------------- $ 7,660,787 --------------- Total Capital Goods $ 96,235,014 ----------------------------------------------------------------------------------------------------- COMMERCIAL SERVICES & SUPPLIES -- 1.6% Environmental & Facilities Services -- 0.5% 1,291,000 China Everbright International, Ltd. $ 1,451,254 3,588,000 Tianjin Capital Environmental Protection Group Co., Ltd. 2,007,441 --------------- $ 3,458,695 ----------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 20 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 ----------------------------------------------------------------------------------------------------- Shares Value ----------------------------------------------------------------------------------------------------- Security & Alarm Services -- 0.8% 545 dorma+kaba Holding AG* $ 353,335 73,200 Secom Co., Ltd. 5,792,756 --------------- $ 6,146,091 ----------------------------------------------------------------------------------------------------- Research & Consulting Services -- 0.3% 22,296 Teleperformance $ 2,001,642 --------------- Total Commercial Services & Supplies $ 11,606,428 ----------------------------------------------------------------------------------------------------- TRANSPORTATION -- 1.5% Airlines -- 0.3% 1,634,000 China Eastern Airlines Corp, Ltd.* $ 897,351 38,900 Japan Airlines Co., Ltd. 1,440,957 --------------- $ 2,338,308 ----------------------------------------------------------------------------------------------------- Railroads -- 1.0% 16,400 Central Japan Railway Co. $ 2,986,778 307,000 Keisei Electric Railway Co., Ltd. 4,381,399 --------------- $ 7,368,177 ----------------------------------------------------------------------------------------------------- Airport Services -- 0.2% 5,277 Aena SA $ 752,617 648,000 Beijing Capital International Airport Co., Ltd. 697,529 --------------- $ 1,450,146 --------------- Total Transportation $ 11,156,631 ----------------------------------------------------------------------------------------------------- AUTOMOBILES & COMPONENTS -- 1.0% Auto Parts & Equipment -- 0.7% 64,720 Johnson Controls, Inc. $ 2,679,408 4,714 Valeo SA 747,353 2,670,000 Xinyi Glass Holdings, Ltd. 1,827,706 --------------- $ 5,254,467 ----------------------------------------------------------------------------------------------------- Automobile Manufacturers -- 0.3% 380,562 Tata Motors, Ltd. $ 2,337,970 --------------- Total Automobiles & Components $ 7,592,437 ----------------------------------------------------------------------------------------------------- CONSUMER DURABLES & APPAREL -- 0.5% Consumer Electronics -- 0.2% 12,130 Harman International Industries, Inc. $ 931,099 26,500 Sony Corp. 689,847 --------------- $ 1,620,946 ----------------------------------------------------------------------------------------------------- Home Furnishings -- 0.3% 1,715,600 Man Wah Holdings, Ltd. $ 2,003,756 --------------- Total Consumer Durables & Apparel $ 3,624,702 ----------------------------------------------------------------------------------------------------- CONSUMER SERVICES -- 1.4% Casinos & Gaming -- 0.3% 618,000 Galaxy Entertainment Group, Ltd.* $ 2,087,326 ----------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 21 Schedule of Investments | 4/30/16 (unaudited) (continued) ----------------------------------------------------------------------------------------------------- Shares Value ----------------------------------------------------------------------------------------------------- Hotels, Resorts & Cruise Lines -- 0.7% 453,648 Aitken Spence Hotel Holdings Plc $ 195,418 29,450 Hyatt Hotels Corp.* 1,410,066 30,662 Marriott International, Inc. 2,149,100 309,813 NH Hotel Group SA* 1,490,021 --------------- $ 5,244,605 ----------------------------------------------------------------------------------------------------- Education Services -- 0.4% 69,728 New Oriental Education & Technology Group, Inc. (A.D.R.) $ 2,730,548 --------------- Total Consumer Services $ 10,062,479 ----------------------------------------------------------------------------------------------------- MEDIA -- 1.2% Advertising -- 0.4% 65,959 Stroeer SE & Co KGaA* $ 3,247,775 ----------------------------------------------------------------------------------------------------- Broadcasting -- 0.4% 337,395 Sun TV Network, Ltd. $ 1,888,404 120,766 Zee Entertainment Enterprises, Ltd. 754,466 --------------- $ 2,642,870 ----------------------------------------------------------------------------------------------------- Cable & Satellite -- 0.3% 35,616 Comcast Corp. $ 2,164,028 ----------------------------------------------------------------------------------------------------- Movies & Entertainment -- 0.1% 11,227 Loen Entertainment, Inc. $ 758,068 --------------- Total Media $ 8,812,741 ----------------------------------------------------------------------------------------------------- RETAILING -- 1.5% Internet Retail -- 0.3% 180,748 Vipshop Holdings, Ltd. (A.D.R.)* $ 2,465,403 ----------------------------------------------------------------------------------------------------- General Merchandise Stores -- 0.2% 6,700 Ryohin Keikaku Co., Ltd. $ 1,548,883 ----------------------------------------------------------------------------------------------------- Apparel Retail -- 1.0% 92,547 The TJX Companies, Inc. $ 7,016,914 --------------- Total Retailing $ 11,031,200 ----------------------------------------------------------------------------------------------------- FOOD & STAPLES RETAILING -- 1.0% Drug Retail -- 1.0% 17,635 CVS Health Corp. $ 1,772,318 59,500 Sundrug Co., Ltd. 4,393,572 10,600 Tsuruha Holdings, Inc. 1,048,925 --------------- $ 7,214,815 --------------- Total Food & Staples Retailing $ 7,214,815 ----------------------------------------------------------------------------------------------------- FOOD, BEVERAGE & TOBACCO -- 1.6% Packaged Foods & Meats -- 0.2% 19,378 Nestle SA $ 1,444,160 ----------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 22 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 ----------------------------------------------------------------------------------------------------- Shares Value ----------------------------------------------------------------------------------------------------- Tobacco -- 1.4% 55,555 Altria Group, Inc. $ 3,483,854 138,223 Reynolds American, Inc. 6,855,861 --------------- $ 10,339,715 --------------- Total Food, Beverage & Tobacco $ 11,783,875 ----------------------------------------------------------------------------------------------------- HOUSEHOLD & PERSONAL PRODUCTS -- 0.5% Personal Products -- 0.5% 67,800 Kao Corp. $ 3,885,722 --------------- Total Household & Personal Products $ 3,885,722 ----------------------------------------------------------------------------------------------------- HEALTH CARE EQUIPMENT & SERVICES -- 10.1% Health Care Equipment -- 6.0% 9,706 Becton Dickinson and Co. $ 1,565,190 173,774 Boston Scientific Corp.* 3,809,126 31,991 CR Bard, Inc. 6,787,530 66,672 Edwards Lifesciences Corp.* 7,081,233 113,246 Hill-Rom Holdings, Inc. 5,475,444 102,244 Hologic, Inc.* 3,434,376 4,723 Intuitive Surgical, Inc.* 2,958,298 66,921 Medtronic PLC 5,296,797 57,754 NuVasive, Inc.* 3,057,497 39,814 Stryker Corp. 4,340,124 --------------- $ 43,805,615 ----------------------------------------------------------------------------------------------------- Health Care Distributors -- 0.5% 42,295 Cardinal Health, Inc. $ 3,318,466 ----------------------------------------------------------------------------------------------------- Health Care Services -- 0.4% 24,360 Laboratory Corp of America Holdings* $ 3,052,795 ----------------------------------------------------------------------------------------------------- Health Care Facilities -- 2.2% 81,692 HCA Holdings, Inc. $ 6,586,009 43,968 Orpea 3,625,542 97,104 VCA, Inc.* 6,114,639 --------------- $ 16,326,190 ----------------------------------------------------------------------------------------------------- Managed Health Care -- 1.0% 21,522 Aetna, Inc. $ 2,416,275 38,959 UnitedHealth Group, Inc. 5,130,121 --------------- $ 7,546,396 --------------- Total Health Care Equipment & Services $ 74,049,462 ----------------------------------------------------------------------------------------------------- PHARMACEUTICALS, BIOTECHNOLOGY & LIFE SCIENCES -- 5.3% Biotechnology -- 0.8% 1,442,000 3SBio, Inc. $ 1,745,547 22,014 Actelion, Ltd. 3,556,567 31,113 Grifols SA 676,744 --------------- $ 5,978,858 ----------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 23 Schedule of Investments | 4/30/16 (unaudited) (continued) ----------------------------------------------------------------------------------------------------- Shares Value ----------------------------------------------------------------------------------------------------- Pharmaceuticals -- 2.8% 110,419 Bristol-Myers Squibb Co. $ 7,970,043 41,600 Ono Pharmaceutical Co, Ltd. 1,940,541 1,330,500 Shanghai Fosun Pharmaceutical Group Co, Ltd. 3,619,078 67,100 Shionogi & Co., Ltd. 3,548,192 60,512 Shire Plc 3,766,550 --------------- $ 20,844,404 ----------------------------------------------------------------------------------------------------- Life Sciences Tools & Services -- 1.7% 97,834 Agilent Technologies, Inc. $ 4,003,367 26,525 Gerresheimer AG 1,972,473 131,927 INC Research Holdings, Inc. 6,349,647 --------------- $ 12,325,487 --------------- Total Pharmaceuticals, Biotechnology & Life Sciences $ 39,148,749 ----------------------------------------------------------------------------------------------------- BANKS -- 1.8% Diversified Banks -- 1.3% 382,965 Banco de Sabadell SA $ 731,912 254,529 Hatton National Bank Plc 360,256 44,598 HDFC Bank, Ltd. 756,433 159,300 Kasikornbank PCL 757,268 415,480 Metropolitan Bank & Trust Co. 717,716 98,400 Sumitomo Mitsui Financial Group, Inc. 3,147,066 199,475 Yes Bank, Ltd. 2,825,693 --------------- $ 9,296,344 ----------------------------------------------------------------------------------------------------- Regional Banks -- 0.5% 136,577 Banregio Grupo Financiero SAB de CV $ 819,684 41,946 First Republic Bank 2,949,643 --------------- $ 3,769,327 --------------- Total Banks $ 13,065,671 ----------------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 1.6% Multi-Sector Holdings -- 0.4% 46,735 GT Capital Holdings, Inc. $ 1,358,281 13,252 Wendel SA 1,531,144 --------------- $ 2,889,425 ----------------------------------------------------------------------------------------------------- Consumer Finance -- 1.0% 65,049 Discover Financial Services, Inc. $ 3,660,307 123,257 Synchrony Financial 3,767,966 --------------- $ 7,428,273 ----------------------------------------------------------------------------------------------------- Asset Management & Custody Banks -- 0.2% 41,777 The Blackstone Group LP $ 1,146,361 --------------- Total Diversified Financials $ 11,464,059 ----------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 24 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 ----------------------------------------------------------------------------------------------------- Shares Value ----------------------------------------------------------------------------------------------------- INSURANCE -- 3.5% Life & Health Insurance -- 1.3% 123,800 AIA Group, Ltd. $ 745,312 619,066 Poste Italiane S.p.A. 4,728,313 16,905 Swiss Life Holding AG 4,265,896 --------------- $ 9,739,521 ----------------------------------------------------------------------------------------------------- Multi-line Insurance -- 0.8% 33,294 Allianz SE* $ 5,652,025 ----------------------------------------------------------------------------------------------------- Property & Casualty Insurance -- 1.4% 53,187 Chubb, Ltd. $ 6,268,620 67,132 The Allstate Corp. 4,366,937 --------------- $ 10,635,557 --------------- Total Insurance $ 26,027,103 ----------------------------------------------------------------------------------------------------- REAL ESTATE -- 7.8% Diversified REIT -- 1.0% 742,930 Green Real Estate Investment Trust plc* $ 1,216,543 403,841 Hibernia Real Estate Investment Trust plc 596,545 4,592,100 Mapletree Greater China Commercial Trust 3,517,150 190,041 Merlin Properties Socimi SA 2,208,802 --------------- $ 7,539,040 ----------------------------------------------------------------------------------------------------- Industrial REIT -- 0.3% 1,015,400 Ascendas Real Estate Investment Trust $ 1,857,439 ----------------------------------------------------------------------------------------------------- Mortgage REIT -- 0.3% 124,311 Starwood Property Trust, Inc. $ 2,406,661 ----------------------------------------------------------------------------------------------------- Hotel & Resort REIT -- 2.8% 362,018 DiamondRock Hospitality Co. $ 3,225,580 236 Hoshino Resorts Real Estate Investment Trust, Inc. 2,905,908 5,233 Japan Hotel Real Estate Investment Trust Investment Corp. 4,805,641 105,220 LaSalle Hotel Properties 2,514,758 127,979 Pebblebrook Hotel Trust 3,537,340 69,442 Ryman Hospitality Properties, Inc. 3,578,346 --------------- $ 20,567,573 ----------------------------------------------------------------------------------------------------- Office REIT -- 0.4% 3,953,300 Keppel Real Estate Investment Trust $ 3,086,678 ----------------------------------------------------------------------------------------------------- Health Care REIT -- 0.2% 1,224,900 First Real Estate Investment Trust $ 1,138,552 ----------------------------------------------------------------------------------------------------- Residential REIT's -- 0.1% 30,288 Colony Starwood Homes $ 738,119 ----------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 25 Schedule of Investments | 4/30/16 (unaudited) (continued) ----------------------------------------------------------------------------------------------------- Shares Value ----------------------------------------------------------------------------------------------------- Retail REIT -- 0.3% 342,100 CapitaLand Retail China Trust $ 375,221 9,137 Simon Property Group, Inc. 1,838,090 74,022 Wheeler Real Estate Investment Trust, Inc. 104,371 --------------- $ 2,317,682 ----------------------------------------------------------------------------------------------------- Diversified Real Estate Activities -- 1.5% 1,569,100 Ayala Land, Inc. $ 1,155,933 479,000 CapitaLand, Ltd. 1,107,741 406,600 City Developments, Ltd. 2,521,597 308,700 Takara Leben Co., Ltd. 2,059,639 283,100 Tokyo Tatemono Co., Ltd. 3,867,870 --------------- $ 10,712,780 ----------------------------------------------------------------------------------------------------- Real Estate Operating Companies -- 0.5% 1,751,200 Ascendas India Trust $ 1,243,602 5,759,000 SM Prime Holdings, Inc. 2,773,283 --------------- $ 4,016,885 ----------------------------------------------------------------------------------------------------- Real Estate Development -- 0.4% 296,100 China Vanke Co, Ltd. $ 742,054 919,600 Frasers Centrepoint, Ltd.* 1,141,978 740,000 Longfor Properties Co., Ltd. 1,041,730 --------------- $ 2,925,762 --------------- Total Real Estate $ 57,307,171 ----------------------------------------------------------------------------------------------------- SOFTWARE & SERVICES -- 3.1% Internet Software & Services -- 1.1% 11,405 Alibaba Group Holding, Ltd. (A.D.R.) $ 877,501 5,166 Alphabet, Inc. (Class A) 3,656,908 16,296 Facebook, Inc.* 1,916,084 88,300 Tencent Holdings, Ltd. 1,808,778 --------------- $ 8,259,271 ----------------------------------------------------------------------------------------------------- IT Consulting & Other Services -- 0.6% 15,442 Capgemini SA $ 1,441,665 53,357 Leidos Holdings, Inc. 2,647,041 --------------- $ 4,088,706 ----------------------------------------------------------------------------------------------------- Data Processing & Outsourced Services -- 1.4% 24,552 Amadeus IT Holding SA $ 1,117,270 58,649 MasterCard, Inc. 5,688,367 49,140 Visa, Inc. 3,795,574 --------------- $ 10,601,211 --------------- Total Software & Services $ 22,949,188 ----------------------------------------------------------------------------------------------------- TECHNOLOGY HARDWARE & EQUIPMENT -- 0.9% Communications Equipment -- 0.5% 44,785 Harris Corp. $ 3,583,248 ----------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 26 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 ----------------------------------------------------------------------------------------------------- Shares Value ----------------------------------------------------------------------------------------------------- Electronic Equipment Manufacturers -- 0.4% 2,656,000 China Railway Signal & Communication Corp, Ltd. $ 1,578,446 57,814 FLIR Systems, Inc.* 1,746,561 --------------- $ 3,325,007 --------------- Total Technology Hardware & Equipment $ 6,908,255 ----------------------------------------------------------------------------------------------------- SEMICONDUCTORS & SEMICONDUCTOR EQUIPMENT -- 0.7% Semiconductors -- 0.7% 37,521 Broadcom, Ltd. $ 5,468,686 --------------- Total Semiconductors & Semiconductor Equipment $ 5,468,686 ----------------------------------------------------------------------------------------------------- TELECOMMUNICATION SERVICES -- 0.2% Wireless Telecommunication Services -- 0.2% 276,290 Bharti Airtel, Ltd. $ 1,514,372 --------------- Total Telecommunication Services $ 1,514,372 ----------------------------------------------------------------------------------------------------- UTILITIES -- 1.2% Electric Utilities -- 0.1% 115,000 Cheung Kong Infrastructure Holdings, Ltd. $ 1,087,423 ----------------------------------------------------------------------------------------------------- Water Utilities -- 0.7% 3,882,000 Beijing Enterprises Water Group, Ltd. $ 2,327,068 3,682,000 CT Environmental Group, Ltd.* 1,077,483 1,096,000 Guangdong Investment, Ltd. 1,554,189 --------------- $ 4,958,740 ----------------------------------------------------------------------------------------------------- Independent Power Producers & Energy Traders -- 0.2% 748,097 China Resources Power Holdings Co, Ltd. $ 1,267,225 ----------------------------------------------------------------------------------------------------- Renewable Electricity -- 0.2% 135,010 Saeta Yield SA $ 1,437,780 --------------- Total Utilities $ 8,751,168 ----------------------------------------------------------------------------------------------------- TOTAL COMMON STOCKS (Cost $427,007,573) $ 460,095,223 ----------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) ----------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- 1.0% BANKS -- 1.0% Thrifts & Mortgage Finance -- 1.0% 3,000,000 COMM 2006-C8 Mortgage Trust, 5.377%, 12/10/46 $ 2,892,583 2,384,000 6.15 JP Morgan Chase Commercial Mortgage Securities Trust 2006-LDP7, Floating Rate Note, 4/17/45 1,764,160 The accompanying notes are an integral part of these financial statements. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 27 Schedule of Investments | 4/30/16 (unaudited) (continued) ----------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value ----------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 3,000,000 5.57 Morgan Stanley Capital I Trust 2007-TOP25, Floating Rate Note, 11/12/49 $ 2,954,928 --------------- $ 7,611,671 --------------- Total Banks $ 7,611,671 ----------------------------------------------------------------------------------------------------- TOTAL COLLATERALIZED MORTGAGE OBLIGATIONS (Cost $8,249,944) $ 7,611,671 ----------------------------------------------------------------------------------------------------- CORPORATE BONDS -- 12.9% ENERGY -- 3.0% Integrated Oil & Gas -- 1.5% 5,682,000 Lukoil International Finance BV, 6.125%, 4,500,000 11/9/20 (144A) $ 6,074,342 Lukoil International Finance BV, 7.25%, 11/5/19 (144A) 4,991,985 --------------- $ 11,066,327 ----------------------------------------------------------------------------------------------------- Oil & Gas Exploration & Production -- 1.5% 6,687,000 Gazprom OAO Via Gaz Capital SA, 3.85%, 4,000,000 2/6/20 (144A) $ 6,592,580 Gazprom OAO Via Gaz Capital SA, 6.51%, 3/7/22 (144A) 4,327,720 $ 10,920,300 --------------- Total Energy $ 21,986,627 ----------------------------------------------------------------------------------------------------- MATERIALS -- 7.0% Construction Materials -- 0.5% 3,000,000 Vulcan Materials Co., 7.5%, 6/15/21 $ 3,615,000 ----------------------------------------------------------------------------------------------------- Metal & Glass Containers -- 0.2% 1,586,000 Ball Corp., 4.0%, 11/15/23 $ 1,569,744 ----------------------------------------------------------------------------------------------------- Paper Packaging -- 0.4% 3,000,000 Sealed Air Corp., 5.125%, 12/1/24 (144A) $ 3,142,500 ----------------------------------------------------------------------------------------------------- Diversified Metals & Mining -- 0.9% 6,971,000 Gold Fields Orogen Holdings BVI, Ltd., 4.875%, 10/7/20 (144A) $ 6,517,885 ----------------------------------------------------------------------------------------------------- Gold -- 4.4% 7,500,000 AngloGold Ashanti Holdings Plc, 5.125%, 8/1/22 $ 7,593,750 5,500,000 AngloGold Ashanti Holdings Plc, 8.5%, 7/30/20 5,923,500 3,000,000 AngloGold Ashanti Holdings Plc, 8.5%, 7/30/20 3,231,000 5,840,000 Kinross Gold Corp., 5.125%, 9/1/21 5,781,600 5,925,000 Kinross Gold Corp., 5.125%, 9/1/21 5,865,750 4,350,000 Kinross Gold Corp., 5.95%, 3/15/24 4,099,875 --------------- $ 32,495,475 ----------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 28 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 ----------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value ----------------------------------------------------------------------------------------------------- Steel -- 0.6% 4,000,000 ArcelorMittal, 5.5%, 2/25/17 $ 4,130,000 --------------- Total Materials $ 51,470,604 ----------------------------------------------------------------------------------------------------- CAPITAL GOODS -- 0.5% Building Products -- 0.5% 3,000,000 USG Corp., 9.75%, 1/15/18 $ 3,367,500 --------------- Total Capital Goods $ 3,367,500 ----------------------------------------------------------------------------------------------------- CONSUMER DURABLES & APPAREL -- 0.3% Apparel, Accessories & Luxury Goods -- 0.3% 1,943,000 Hanesbrands, Inc., 6.375%, 12/15/20 $ 2,011,005 --------------- Total Consumer Durables & Apparel $ 2,011,005 ----------------------------------------------------------------------------------------------------- CONSUMER SERVICES -- 0.8% Casinos & Gaming -- 0.8% 5,523,000 MGM Resorts International, 6.625%, 12/15/21 $ 5,881,995 --------------- Total Consumer Services $ 5,881,995 ----------------------------------------------------------------------------------------------------- FOOD, BEVERAGE & TOBACCO -- 0.4% Packaged Foods & Meats -- 0.4% 1,500,000 Smithfield Foods, Inc., 5.875%, 8/1/21 (144A) $ 1,563,750 1,500,000 Smithfield Foods, Inc., 6.625%, 8/15/22 1,586,250 --------------- $ 3,150,000 --------------- Total Food, Beverage & Tobacco $ 3,150,000 ----------------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 0.4% Consumer Finance -- 0.4% 3,000,000 First Cash Financial Services, Inc., 6.75%, 4/1/21 $ 2,985,000 --------------- Total Diversified Financials $ 2,985,000 ----------------------------------------------------------------------------------------------------- INSURANCE -- 0.1% Reinsurance -- 0.1% 1,000,000 7.48 Northshore Re, Ltd., Floating Rate Note, 7/5/16 (Cat Bond) (144A) $ 1,003,400 --------------- Total Insurance $ 1,003,400 ----------------------------------------------------------------------------------------------------- REAL ESTATE -- 0.2% Real Estate Development -- 0.2% 1,400,000 Sunac China Holdings, Ltd., 9.375%, 4/5/18 $ 1,463,000 --------------- Total Real Estate $ 1,463,000 ----------------------------------------------------------------------------------------------------- TELECOMMUNICATION SERVICES -- 0.2% Wireless Telecommunication Services -- 0.2% 1,500,000 Sprint Communications, Inc., 6.0%, 12/1/16 $ 1,507,500 --------------- Total Telecommunication Services $ 1,507,500 ----------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 29 Schedule of Investments | 4/30/16 (unaudited) (continued) ----------------------------------------------------------------------------------------------------- Floating Principal Rate (b) Amount ($) (unaudited) Value ----------------------------------------------------------------------------------------------------- TOTAL CORPORATE BONDS (Cost $91,743,835) $ 94,826,631 ----------------------------------------------------------------------------------------------------- FOREIGN GOVERNMENT BONDS -- 12.8% AUD 9,530,000 Australia Government Bond, 1.75%, 11/21/20 $ 7,165,165 15,870,000 Indonesia Government International Bond, 5.875%, 1/15/24 (144A) 18,059,505 3,796,000 Indonesia Government International Bond, 6.75%, 1/15/44 (144A) 4,648,639 IDR 25,355,000,000 Indonesia Treasury Bond, 7.0%, 5/15/27 1,810,907 IDR 44,544,000,000 Indonesia Treasury Bond, 8.375%, 9/15/26 3,534,804 MXN 128,693,400 Mexican Bonos, 5.75%, 3/5/26 7,420,432 8,804,000 Mexico Government International Bond, 3.6%, 1/30/25 8,947,065 8,582,000 Mexico Government International Bond, 4.0%, 10/2/23 8,989,645 NZD 5,134,000 New Zealand Government Bond, 3.0%, 4/15/20 3,688,038 PHP 165,000,000 Philippine Government Bond, 3.625%, 9/9/25 3,484,357 RUB 304,576,000 Russian Federal Bond - OFZ, 7.6%, 7/20/22 4,444,049 21,400,000 Russian Foreign Bond - Eurobond, 3.5%, 1/16/19 (144A) 21,638,603 ----------------------------------------------------------------------------------------------------- TOTAL FOREIGN GOVERNMENT BONDS (Cost $89,658,285) $ 93,831,209 ----------------------------------------------------------------------------------------------------- SENIOR FLOATING RATE LOAN INTEREST -- 0.0%+** TECHNOLOGY HARDWARE & EQUIPMENT -- 0.0% Communications Equipment -- 0.0%+ 91,030 3.31 CommScope, Inc., Tranche 4 Term Loan, 1/14/18 $ 91,000 --------------- Total Technology Hardware & Equipment $ 91,000 ----------------------------------------------------------------------------------------------------- TOTAL SENIOR FLOATING RATE LOAN INTERESTS (Cost $91,030) $ 91,000 ----------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------- Shares ----------------------------------------------------------------------------------------------------- CLOSED-END FUNDS -- 0.2% 62,300 BlackRock Munivest Fund, Inc. $ 671,594 44,100 BlackRock Muniyield Fund, Inc. 693,693 --------------- $ 1,365,287 ----------------------------------------------------------------------------------------------------- TOTAL CLOSED-END FUNDS (Cost $1,140,036) $ 1,365,287 ----------------------------------------------------------------------------------------------------- MUTUAL FUNDS -- 5.1% 1,443,597 Aberdeen Asia-Pacific Income Fund, Inc. $ 7,275,729 32,883 Guggenheim S&P Global Water Index ETF 962,485 The accompanying notes are an integral part of these financial statements. 30 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 ----------------------------------------------------------------------------------------------------- Shares Value ----------------------------------------------------------------------------------------------------- MUTUAL FUNDS - (continued) 62,296 PowerShares International BuyBack Achievers Portfolio $ 1,762,977 211,883 ProShares S&P 500 Dividend Aristocrats ETF 11,174,709 177,729 SPDR S&P Euro Dividend Aristocrats UCITS ETF 4,182,284 19,163 SPDR S&P Global Dividend Aristocrats ETF 594,451 210,227 SPDR S&P UK Dividend Aristocrats UCITS ETF 3,640,666 118,579 SPDR S&P US Dividend Aristocrats UCITS ETF 5,102,454 209,556 VanEck Vectors Vietnam ETF 3,021,798 ----------------------------------------------------------------------------------------------------- TOTAL MUTUAL FUNDS (Cost $38,196,922) $ 37,717,553 ----------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------- Number of Strike Expiration Contracts Description Counterparty Price Date ----------------------------------------------------------------------------------------------------- PUT OPTIONS PURCHASED -- 0.4% 625 Deutsche Boerse AG German Stock Index Barclays 9,900 6/17/16 $ 1,541,591 1,000 Hong Kong Stock Exchange Barclays 9,000 6/29/16 1,398,719 ----------------------------------------------------------------------------------------------------- TOTAL PUT OPTIONS PURCHASED $ 2,940,310 --------------- (Cost $2,273,557) $ 2,940,310 ----------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------- Principal Amount ($) ----------------------------------------------------------------------------------------------------- TEMPORARY CASH INVESTMENTS -- 0.7% Commercial Paper -- 0.7% 1,780,000 Barclays, Floating Rate Note, 5/2/16 (c) $ 1,779,955 1,780,000 BNP Paribas, Commercial Papar, 5/2/16 (c) 1,779,944 1,780,000 Total CP, Floating Rate Note, 5/2/16 (c) 1,779,950 --------------- $ 5,339,849 ----------------------------------------------------------------------------------------------------- TOTAL TEMPORARY CASH INVESTMENTS (Cost $5,339,952) $ 5,339,849 ----------------------------------------------------------------------------------------------------- TOTAL INVESTMENT IN SECURITIES -- 95.6% (Cost $663,896,379) (a) $ 704,018,653 ----------------------------------------------------------------------------------------------------- OTHER ASSETS & LIABILITIES -- 4.4% $ 32,476,232 ----------------------------------------------------------------------------------------------------- TOTAL NET ASSETS -- 100.0% $ 736,494,885 ===================================================================================================== The accompanying notes are an integral part of these financial statements. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 31 Schedule of Investments | 4/30/16 (unaudited) (continued) * Non-income producing security. + Amount rounds to less than 0.1%. (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 April 30, 2016, the value of these securities amounted to $78,560,909 or 10.7% of total net assets. (A.D.R.) American Depositary Receipts. REIT Real Estate Investment Trust. (Cat Bond) Catastrophe or event-linked bond. At April 30, 2016, the value of these securities amounted to $1,003,400 or 0.1% of total net assets. See Notes to Financial Statements -- Note 1I. ** 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 U.S. banks, (iii) the 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 April 30, 2016, the net unrealized appreciation on investments based on cost for federal income tax purposes of $670,643,003 was as follows: Aggregate gross unrealized appreciation for all investments in which there is an excess of value over tax cost $ 47,119,031 Aggregate gross unrealized depreciation for all investments in which there is an excess of tax cost over value (13,743,381) --------------- Net unrealized appreciation $ 33,375,650 =============== (b) Debt obligation with a variable interest rate. Rate shown is rate at period end. (c) Security issued with a zero coupon. Income is earned through accretion of discount. NOTE: Principal amounts are denominated in U.S. Dollars unless otherwise noted: AUD Australian Dollar IDR Indonesian Rupiah MXN Mexican Peso NZD New Zealand Dollar PHP Philippine Peso RUB Russian Ruble Purchases and sales of securities (excluding temporary cash investments) for the six months ended April 30, 2016 were as follows: -------------------------------------------------------------------------------- Purchases Sales -------------------------------------------------------------------------------- Long-Term U.S. Government $ -- $ -- Other Long-Term Securities 659,539,295 717,274,228 The accompanying notes are an integral part of these financial statements. 32 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 TOTAL RETURN SWAP AGREEMENTS -------------------------------------------------------------------------------------------------------- Net Unrealized Notional Pay/ Obligation Expiration Appreciation Principal Counterparty Receive Entity/Index Coupon Date (Depreciation) -------------------------------------------------------------------------------------------------------- 2,391 Citibank NA Pay BI Macau/China 3M Libor + 3/24/17 $ (21,032) Gaming Market 40 bps Competitive Peer Group Index 2,955 Citibank NA Pay BI Macau/China 3M Libor + 3/24/17 (22,524) Gaming Market 40 bps Competitive Peer Group Index 18,227 Citibank NA Pay BI Macau/China 3M Libor + 3/24/17 (125,640) Gaming Market 40 bps Competitive Peer Group Index IDR 7,003,517 Citibank NA Pay MSCI Indonesia 3M Libor 2/15/17 (9,144) Index PHP 21,231 Citibank NA Pay Philippine Stock 3M Libor 2/15/17 206,731 Exchange PSEi Index 155,416 Citibank NA Pay PureFunds ISE 3M Libor + 6/10/16 147,526 Cyber Security 40 bps ETF 10 Goldman Sach Pay Pioneer Custom 3M Libor + 11/20/16 87 Basket (Basket 39 bps Comprised of Exchange Traded Equity Securities) EUR 1,172 Societe Pay Solactive 3M EURIBOR 6/13/16 (2,214) Generale SA European + 25 bps Buyback Index EUR 1,253 Societe Pay Solactive 3M EURIBOR 10/17/16 (17,654) Generale SA European + 25 bps Buyback Index JPY 184,624 Societe Pay Solactive 3M Libor + 6/14/16 71,359 Generale SA European 70 bps Buyback Index JPY 160,444 Societe Pay Solactive 3M Libor + 4/4/17 (38,091) Generale SA European 50 bps Buyback Index ======================================================================================================== $ 189,404 ======================================================================================================== NOTE: Principal amounts are denominated in U.S. Dollars unless otherwise noted: EUR Euro JPY Japanese Yen IDR Indonesian Rupiah PHP Philippine Peso The accompanying notes are an integral part of these financial statements. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 33 Schedule of Investments | 4/30/16 (unaudited) (continued) 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 April 30, 2016, in valuing the Fund's investments: ---------------------------------------------------------------------------------------------- Level 1 Level 2 Level 3 Total ---------------------------------------------------------------------------------------------- Preferred Stock $ -- $ 199,920 $ -- $ 199,920 Common Stocks* 460,095,223 -- -- 460,095,223 Collateralized Mortgage Obligations -- 7,611,671 -- 7,611,671 Corporate Bonds -- 94,826,631 -- 94,826,631 Foreign Government Bonds -- 93,831,209 -- 93,831,209 Senior Floating Rate Loan Interest -- 91,000 -- 91,000 Closed-End Funds 1,365,287 -- -- 1,365,287 Mutual Funds 37,717,553 -- -- 37,717,553 Put Options Purchased 2,940,310 -- -- 2,940,310 Commercial Paper 5,339,849 -- -- 5,339,849 ---------------------------------------------------------------------------------------------- Total $ 507,458,222 $ 196,560,431 $ -- $704,018,653 ============================================================================================== Other Financial Instruments Net unrealized appreciation on futures contracts $ 986,826 $ -- $ -- $ 986,826 Net unrealized appreciation on total return swap contracts -- 189,404 -- 189,404 ---------------------------------------------------------------------------------------------- Total Other Financial Instruments $ 986,826 $ 189,404 $ -- $ 1,176,230 ============================================================================================== The following is a reconciliation of assets valued using significant unobservable inputs (Level 3): ---------------------------------------------------------------------------------------------- Common Stocks ---------------------------------------------------------------------------------------------- Balance as of 10/31/15 $ 3,981,510 Realized gain (loss)(1) 150,246 Change in unrealized appreciation (depreciation)(2) -- Purchases -- Sales (4,131,756) Transfers in to Level 3* -- Transfers out of Level 3* -- Transfers in and out of Level 3 activity -- ---------------------------------------------------------------------------------------------- Balance as of 4/30/16 $ -- ============================================================================================== (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 April 30, 2016, there were no transfers between Levels 1, 2 and 3. Net change in unrealized appreciation (depreciation) of investments still held as of 4/30/16 $ -- ------------ The accompanying notes are an integral part of these financial statements. 34 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 The following is a summary of the fair valuation of certain Fund's assets and liabilities as of April 30, 2016. ---------------------------------------------------------------------------------------------- Level 1 Level 2 Level 3 Total ---------------------------------------------------------------------------------------------- Assets: Restricted cash $ -- $3,816,014 $ -- $3,816,014 Foreign currencies, at value -- 5,506,323 -- 5,506,323 Liabilities: Variation margin for futures contracts (496,765) -- -- (496,765) ---------------------------------------------------------------------------------------------- Total: $ (496,765) $9,322,337 $ -- $8,825,572 ============================================================================================== The accompanying notes are an integral part of these financial statements. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 35 Statement of Assets and Liabilities | 4/30/16 (Consolidated) (unaudited) ASSETS: Investment in securities, at value (cost $663,896,379) $704,018,653 Cash 10,809,075 Restricted cash* 3,816,014 Foreign currencies, at value (cost $3,821,140) 5,506,323 Receivables -- Investment securities sold 16,801,865 Fund shares sold 2,380,495 Dividends 903,918 Interest 3,046,038 Due from Pioneer Investment Management, Inc. 38,635 Net unrealized appreciation on swap contracts 189,404 Other assets 116,498 -------------------------------------------------------------------------------------- Total assets $747,626,918 ====================================================================================== LIABILITIES: Payables -- Investment securities purchased $ 6,565,852 Fund shares repurchased 3,519,612 Trustee fees 3,345 Distributions 285 Futures payable 83,627 Variation margin on futures contracts 496,765 Reserve for repatriation taxes 94,609 Due to affiliates 170,094 Accrued expenses 197,844 -------------------------------------------------------------------------------------- Total liabilities $ 11,132,033 ====================================================================================== NET ASSETS: Paid-in capital $729,389,935 Distributions in excess of net investment income (2,235,453) Accumulated net realized loss on investments, futures contracts, swap contracts, written options and foreign currency transactions (31,920,618) Net unrealized appreciation on investments 40,122,274 Net unrealized appreciation on futures contracts 986,826 Net unrealized appreciation on swap contracts 189,404 Net unrealized depreciation on forward foreign currency contracts and other assets and liabilities denominated in foreign currencies (37,483) -------------------------------------------------------------------------------------- Total net assets $736,494,885 ====================================================================================== NET ASSET VALUE PER SHARE: (No par value, unlimited number of shares authorized) Class A (based on $187,729,903/15,599,742 shares) $ 12.03 Class C (based on $199,945,838/16,792,313 shares) $ 11.91 Class R (based on $289,933/24,131 shares) $ 12.01 Class Y (based on $348,529,211/28,865,142 shares) $ 12.07 MAXIMUM OFFERING PRICE: Class A ($12.03 / 95.5%) $ 12.60 ====================================================================================== * Represents restricted cash deposited at the custodian and/or counterparty for derivative contracts. The accompanying notes are an integral part of these financial statements. 36 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 Statement of Operations (Consolidated) (unaudited) For the Six Months Ended 4/30/16 INVESTMENT INCOME: Dividends (net of foreign taxes withheld of $175,384) $ 4,330,914 Interest 5,213,156 ------------------------------------------------------------------------------------------------ Total investment income $ 9,544,070 ------------------------------------------------------------------------------------------------ EXPENSES: Management fees $ 2,543,024 Transfer agent fees Class A 11,897 Class C 7,959 Class R 57 Class Y 10,882 Distribution fees Class A 235,871 Class C 993,977 Class R 558 Shareholder communications expense 312,383 Administrative expense 130,201 Custodian fees 169,543 Registration fees 53,021 Professional fees 37,018 Printing expense 19,005 Fees and expenses of nonaffiliated Trustees 17,553 Pricing expense 5,692 Miscellaneous 51,452 ------------------------------------------------------------------------------------------------ Total expenses $ 4,600,093 Less fees waived and expenses reimbursed by Pioneer Investment Management, Inc. (41,309) ------------------------------------------------------------------------------------------------ Net expenses $ 4,558,784 ------------------------------------------------------------------------------------------------ Net investment income $ 4,985,286 ------------------------------------------------------------------------------------------------ REALIZED AND UNREALIZED GAIN (LOSS) ON INVESTMENTS, FUTURES CONTRACTS, WRITTEN OPTIONS, SWAP CONTRACTS AND FOREIGN CURRENCY TRANSACTIONS: Net realized gain (loss) on: Investments (net of foreign capital gains taxes of $134,105) $ (7,780,304) Futures contracts (11,405,996) Written options (8,219,949) Swap contracts (1,716,148) Forward foreign currency contracts and other assets and liabilities denominated in foreign currencies 170,361 $ (28,952,036) ------------------------------------------------------------------------------------------------ Change in net unrealized appreciation (depreciation) on: Investments $ 21,781,940 Futures contracts 2,157,481 Swap contracts (293,250) Forward foreign currency contracts and other assets and liabilities denominated in foreign currencies 493,832 $ 24,140,003 ------------------------------------------------------------------------------------------------ Net realized and unrealized gain (loss) on investments, futures contracts, written options, swap contracts and foreign currency transactions $ (4,812,033) ------------------------------------------------------------------------------------------------ Net increase in net assets resulting from operations $ 173,253 ================================================================================================ The accompanying notes are an integral part of these financial statements. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 37 Statements of Changes in Net Assets (Consolidated) ------------------------------------------------------------------------------------------------ Six Months Ended 4/30/16 Year Ended (unaudited) 10/31/15 ------------------------------------------------------------------------------------------------ FROM OPERATIONS: Net investment income $ 4,985,286 $ 9,929,235 Net realized gain (loss) on investments, futures contracts, written options, swap contracts and foreign currency transactions (28,952,036) 32,959,343 Change in net unrealized appreciation (depreciation) on investments, futures contracts, written options, swap contracts and foreign currency transactions 24,140,003 (30,526,506) ------------------------------------------------------------------------------------------------ Net increase in net assets resulting from operations $ 173,253 $ 12,362,072 ------------------------------------------------------------------------------------------------ DISTRIBUTIONS TO SHAREOWNERS: Net investment income: Class A ($0.14 and $0.30 per share, respectively) $ (2,277,507) $ (4,787,767) Class C ($0.09 and $0.16 per share, respectively) (1,654,873) (2,796,710) Class R ($0.13 and $0.15 per share, respectively) (2,520) (557) Class Y ($0.15 and $0.33 per share, respectively) (4,499,058) (9,305,033) Class Z* ($0.00 and $0.19 per share, respectively) -- (2,220) Net realized gain: Class A ($0.56 and $0.33 per share, respectively) (9,239,156) (5,521,118) Class C ($0.56 and $0.33 per share, respectively) (9,649,365) (5,791,481) Class R ($0.56 and $0.33 per share, respectively) (7,412) (1,460) Class Y ($0.56 and $0.33 per share, respectively) (16,206,495) (9,576,515) Class Z* ($0.00 and $0.33 per share, respectively) -- (3,857) ------------------------------------------------------------------------------------------------ Total distributions to shareowners $ (43,536,386) $ (37,786,718) ================================================================================================ FROM FUND SHARE TRANSACTIONS: Net proceeds from sale of shares $ 126,649,706 $ 300,297,276 Reinvestment of distributions 37,067,953 31,631,974 Cost of shares repurchased (190,471,657) (366,871,843) ------------------------------------------------------------------------------------------------ Net decrease in net assets resulting from Fund share transactions $ (26,753,998) $ (34,942,593) ------------------------------------------------------------------------------------------------ Net decrease in net assets $ (70,117,131) $ (60,367,239) NET ASSETS: Beginning of period $ 806,612,016 $ 866,979,255 ------------------------------------------------------------------------------------------------ End of period $ 736,494,885 $ 806,612,016 ------------------------------------------------------------------------------------------------ Undistributed (distributions in excess of) net investment income $ (2,235,453) $ 1,213,219 ================================================================================================ * Class Z shares converted to Class Y shares on August 7, 2015. The accompanying notes are an integral part of these financial statements. 38 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 ---------------------------------------------------------------------------------------- Six Months Six Months Ended Ended 4/30/16 4/30/16 Year Ended Year Ended Shares Amount 10/31/15 10/31/15 (unaudited) (unaudited) Shares Amount ---------------------------------------------------------------------------------------- Class A Shares sold 1,725,476 $ 20,098,209 5,975,840 $ 79,431,258 Reinvestment of distributions 904,082 10,735,894 702,485 8,981,329 Less shares repurchased (3,509,563) (40,589,005) (7,754,295) (99,574,530) ---------------------------------------------------------------------------------------- Net decrease (880,005) $ (9,754,902) (1,075,970) $ (11,161,943) ======================================================================================== Class C Shares sold 1,719,639 $ 19,698,533 3,551,007 $ 46,008,975 Reinvestment of distributions 769,622 9,054,160 541,062 6,808,756 Less shares repurchased (3,105,615) (35,657,165) (5,311,858) (67,275,117) ---------------------------------------------------------------------------------------- Net decrease (616,354) $ (6,904,472) (1,219,789) $ (14,457,386) ======================================================================================== Class R Shares sold 22,759 $ 261,639 6,047 $ 74,816 Reinvestment of distributions 547 6,495 139 1,773 Less shares repurchased (8,642) (98,007) (2,453) (31,093) ---------------------------------------------------------------------------------------- Net increase 14,664 $ 170,127 3,733 $ 45,496 ======================================================================================== Class Y Shares sold 7,417,861 $ 86,591,325 13,280,661 $ 174,740,739 Reinvestment of distributions 1,450,285 17,271,404 1,234,446 15,834,274 Less shares repurchased (9,786,056) (114,127,480) (15,663,576) (199,789,697) ---------------------------------------------------------------------------------------- Net decrease (917,910) $ (10,264,751) (1,148,469) $ (9,214,684) ======================================================================================== Class Z* Shares sold -- $ -- 3,096 $ 41,488 Reinvestment of distributions -- -- 461 5,842 Less shares repurchased -- -- (15,449) (201,406) ---------------------------------------------------------------------------------------- Net (decrease) -- $ -- (11,892) $ (154,076) ======================================================================================== * Class Z shares converted to Class Y shares on August 7, 2015. The accompanying notes are an integral part of these financial statements. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 39 Financial Highlights (Consolidated) -------------------------------------------------------------------------------------------------------------------------------- Six Months Ended Year Year Year Year Year 4/30/16 Ended Ended Ended Ended Ended (unaudited) 10/31/15 10/31/14 10/31/13 10/31/12 10/31/11 -------------------------------------------------------------------------------------------------------------------------------- Class A Net asset value, beginning of period $ 12.68 $ 12.94 $ 13.33 $ 11.76 $ 11.25 $ 10.63 -------------------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income (loss) $ 0.08(b) $ 0.17(b) $ 0.27 $ 0.21 $ 0.20 $ 0.19 Net realized and unrealized gain (loss) on investments (0.03) 0.20 (0.09) 1.51 0.67 0.51 -------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ 0.05 $ 0.37 $ 0.18 $ 1.72 $ 0.87 $ 0.70 -------------------------------------------------------------------------------------------------------------------------------- Distribution to shareowners: Net investment income $ (0.14) $ (0.30) $ (0.08) $ (0.15) $ (0.36) $ (0.08) Net realized gain (0.56) (0.33) (0.49) -- -- -- -------------------------------------------------------------------------------------------------------------------------------- Total distributions $ (0.70) $ (0.63) $ (0.57) $ (0.15) $ (0.36) $ (0.08) -------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ (0.65) $ (0.26) $ (0.39) $ 1.57 $ 0.51 $ 0.62 -------------------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 12.03 $ 12.68 $ 12.94 $ 13.33 $ 11.76 $ 11.25 ================================================================================================================================ Total return* 0.52% 2.85% 1.45% 14.72% 8.01% 6.60% Ratio of net expenses to average net assets (a) 1.18%** 1.20% 1.23% 1.20% 1.20% 1.20% Ratio of net investment income (loss) to average net assets 1.45%** 1.33% 1.60% 1.82% 2.19% 2.05% Portfolio turnover rate 188%** 295% 383% 288% 175% 191% Net assets, end of period (in thousands) $187,730 $209,001 $227,251 $335,398 $147,163 $87,316 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 (a) 1.18%** 1.26% 1.23% 1.23% 1.22% 1.24% Net investment income (loss) to average net assets 1.45%** 1.27% 1.60% 1.79% 2.17% 2.01% ================================================================================================================================ * 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) Includes interest expense of 0.00%, 0.00%, 0.05%, 0.00%, 0.00% and 0.00%. (b) The per-share data presented above is based on the average shares outstanding for the period presented. The accompanying notes are an integral part of these financial statements. 40 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 ----------------------------------------------------------------------------------------------------------------------------------- Six Months Ended Year Year Year Year Year 4/30/16 Ended Ended Ended Ended Ended (unaudited) 10/31/15 10/31/14 10/31/13 10/31/12 10/31/11 ----------------------------------------------------------------------------------------------------------------------------------- Class C Net asset value, beginning of period $ 12.56 $ 12.78 $ 13.21 $ 11.66 $ 11.15 $ 10.60 ----------------------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income (loss) $ 0.04(b) $ 0.07(b) $ 0.13 $ 0.12 $ 0.11 $ 0.08 Net realized and unrealized gain (loss) on investments (0.04) 0.20 (0.05) 1.50 0.67 0.52 ----------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ -- $ 0.27 $ 0.08 $ 1.62 $ 0.78 $ 0.60 ----------------------------------------------------------------------------------------------------------------------------------- Distribution to shareowners: Net investment income $ (0.09) $ (0.16) $ (0.02) $ (0.07) $ (0.27) $ (0.05) Net realized gain (0.56) (0.33) (0.49) -- -- -- ----------------------------------------------------------------------------------------------------------------------------------- Total distributions $ (0.65) $ (0.49) $ (0.51) $ (0.07) $ (0.27) $ (0.05) ----------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ (0.65) $ (0.22) $ (0.43) $ 1.55 $ 0.51 $ 0.55 ----------------------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 11.91 $ 12.56 $ 12.78 $ 13.21 $ 11.66 $ 11.15 =================================================================================================================================== Total return* 0.16% 2.12% 0.60% 13.93% 7.18% 5.69% Ratio of net expenses to average net assets (a) 1.93%** 2.01% 1.97% 1.98% 1.95% 2.00% Ratio of net investment income (loss) to average net assets 0.70%** 0.52% 0.89% 1.05% 1.43% 1.25% Portfolio turnover rate 188%** 295% 383% 288% 175% 191% Net assets, end of period (in thousands) $ 199,946 $218,597 $238,164 $251,889 $104,709 $58,471 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 (a) 1.93%** 2.01% 1.97% 1.98% 1.95% 2.00% Net investment income (loss) to average net assets 0.70%** 0.52% 0.89% 1.05% 1.43% 1.25% =================================================================================================================================== * 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) Includes interest expense of 0.00%, 0.00%, 0.05%, 0.00%, 0.00% and 0.00%. (b) The per-share data presented above is based on the average shares outstanding for the period presented. The accompanying notes are an integral part of these financial statements. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 41 Financial Highlights (Consolidated) (continued) ------------------------------------------------------------------------------------------------------------------------ Six Months Ended Year Year 4/30/16 Ended Ended 9/13/13 to (unaudited) 10/31/15 10/31/14 10/31/13 ------------------------------------------------------------------------------------------------------------------------ Class R Net asset value, beginning of period $ 12.69 $ 12.92 $ 13.32 $ 12.87(a) ------------------------------------------------------------------------------------------------------------------------ Increase (decrease) from investment operations: Net investment income (loss) $ 0.06(d) $ 0.06(d) $ 0.15 $ 0.05 Net realized and unrealized gain (loss) on investments (0.05) 0.19 0.00(b) 0.44 ------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) from investment operations $ 0.01 $ 0.25 $ 0.15 $ 0.49 ------------------------------------------------------------------------------------------------------------------------ Distribution to shareowners: Net investment income $ (0.13) $ (0.15) $ (0.06) $ (0.04) Net realized gain (0.56) (0.33) (0.49) -- ------------------------------------------------------------------------------------------------------------------------ Total distributions $ (0.69) $ (0.48) $ (0.55) $ (0.04) ------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) in net asset value $ (0.68) $ (0.23) $ (0.40) $ 0.45 ------------------------------------------------------------------------------------------------------------------------ Net asset value, end of period $ 12.01 $ 12.69 $ 12.92 $ 13.32 ======================================================================================================================== Total return* 0.24% 1.90% 1.19% 4.76%*** Ratio of net expenses to average net assets (c) 1.67%** 2.01% 1.55% 1.36%** Ratio of net investment income (loss) to average net assets 1.03%** 0.47% 1.40% 2.96%** Portfolio turnover rate 188%** 295% 383% 288%*** Net assets, end of period (in thousands) $ 290 $ 120 $ 74 $ 10 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 (c) 1.67%** 2.01% 1.55% 1.36%** Net investment income (loss) to average net assets 1.03%** 0.47% 1.40% 2.96%** ======================================================================================================================== * 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. *** Not annualized. (a) Class R shares beginning capital was recorded on inception date at $10.00 per share. (b) Amount rounds to less than $0.01 or $(0.01) per share. (c) Includes interest expense of 0.00%, 0.00%, 0.05% and 0.00%. (d) The per-share data presented above is based on the average shares outstanding for the period presented. The accompanying notes are an integral part of these financial statements. 42 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 --------------------------------------------------------------------------------------------------------------------------------- Six Months Ended Year Year Year Year Year 4/30/16 Ended Ended Ended Ended Ended (unaudited) 10/31/15 10/31/14 10/31/13 10/31/12 10/31/11 --------------------------------------------------------------------------------------------------------------------------------- Class Y Net asset value, beginning of period $ 12.72 $ 12.97 $ 13.37 $ 11.79 $ 11.29 $ 10.65 --------------------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income (loss) $ 0.10(b) $ 0.21(b) $ 0.27 $ 0.25 $ 0.24 $ 0.15 Net realized and unrealized gain (loss) on investments (0.04) 0.20 (0.05) 1.52 0.66 0.58 --------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ 0.06 $ 0.41 $ 0.22 $ 1.77 $ 0.90 $ 0.73 --------------------------------------------------------------------------------------------------------------------------------- Distribution to shareowners: Net investment income $ (0.15) $ (0.33) $ (0.13) $ (0.19) $ (0.40) $ (0.09) Net realized gain (0.56) (0.33) (0.49) -- -- -- --------------------------------------------------------------------------------------------------------------------------------- Total distributions $ (0.71) $ (0.66) $ (0.62) $ (0.19) $ (0.40) $ (0.09) --------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ (0.65) $ (0.25) $ (0.40) $ 1.58 $ 0.50 $ 0.64 --------------------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 12.07 $ 12.72 $ 12.97 $ 13.37 $ 11.79 $ 11.29 ================================================================================================================================= Total return* 0.65% 3.20% 1.70% 15.07% 8.33% 6.89% Ratio of net expenses to average net assets (a) 0.90%** 0.90% 0.95% 0.90% 0.90% 0.90% Ratio of net investment income (loss) to average net assets 1.73%** 1.63% 1.92% 2.11% 2.49% 2.35% Portfolio turnover rate 188%** 295% 383% 288% 175% 191% Net assets, end of period (in thousands) $348,529 $378,895 $401,336 $427,190 $185,648 $119,744 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 (a) 0.93%** 1.02% 1.00% 0.98% 0.91% 0.98% Net investment income (loss) to average net assets 1.70%** 1.52% 1.92% 2.03% 2.48% 2.67% ================================================================================================================================= * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions and the complete redemption of the investment at net asset value at the end of each period. ** Annualized. (a) Includes interest expense of 0.00%, 0.00%, 0.05%, 0.00%, 0.00% and 0.00%. (b) The per-share data presented above is based on the average shares outstanding for the period presented. The accompanying notes are an integral part of these financial statements. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 43 Notes to Financial Statements | 4/30/16 (Consolidated) (unaudited) 1. Organization and Significant Accounting Policies Pioneer Flexible Opportunities Fund, (formerly Pioneer Multi Asset Real Return Fund) (the Fund), is one of two portfolios comprising Pioneer Series Trust VI, 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 total return. The Fund offers four classes of shares designated as Class A, Class C, Class R and Class Y shares. Class A, Class C and Class Y shares commenced operations on May 3, 2010. Class R shares commenced operations on September 13, 2013. Class Z shares 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 of Trustees 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 consolidated financial statements of the Fund include the accounts of the Subsidiary. All intercompany accounts and transactions have been eliminated. The Subsidiary, a Cayman Islands exempted company, was incorporated on February 10, 2010, and is wholly-owned and controlled by the Fund. The Fund is the sole shareholder of the Subsidiary. It is intended that the Fund will remain the sole shareholder and will continue to control the Subsidiary. The Fund and the Subsidiary are both managed by Pioneer Investment Management, Inc. (PIM). The Subsidiary acts as an investment vehicle for the Fund in order to effect certain investments on behalf of the Fund. As of April 30, 2016, the Subsidiary represented $22,617,062, or approximately 3.07%, of the net assets of the Fund. 44 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 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 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. Equity securities that have traded on an exchange are valued by using the last sale price on the principal exchange where they are traded. Equity securities that have not traded on the date of valuation, or securities for which sale prices are not available, generally are valued using the mean between the last bid and asked prices or, if both last bid and asked prices are not available, at the last quoted bid price. Last sale and bid and asked prices are provided by independent third party pricing services. In the case of equity securities not traded on an exchange, prices are typically determined by independent third party pricing services using a variety of techniques and methods. Foreign securities are valued in U.S. dollars based on foreign currency exchange rate quotations supplied by a third party pricing service. Trading in non-U.S. equity 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. The fund may use a fair value model developed by an independent pricing service to value non-U.S. equity securities. Fixed-income securities are valued by using 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, or may use a pricing matrix or other fair value methods or techniques to provide an estimated value of the security or instrument. A pricing matrix is a means of valuing a debt security on the basis of current market prices for other debt securities, historical trading patterns in the market for fixed income securities and/or other factors. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 45 Valuations may be supplemented by dealers and other sources, as required. Non-U.S. debt securities that are listed on an exchange will be valued at the bid price obtained from an independent third party pricing service. Loan interests 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 third party 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 or catastrophe bonds are valued at the bid price obtained from an independent third party pricing service. Other insurance linked securities (including sidecars, collateralized reinsurance and industry loss warranties) 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. Swap contracts, including interest rate swaps, caps and floors (other than centrally cleared swap contracts) are valued at the dealer quotations obtained from reputable International Swap Dealer association members. Centrally cleared swaps are valued at the daily settlement price provided by the central clearing counterparty. Futures contracts are generally valued at the closing settlement price established by the exchange on which they are traded. Options contracts are generally valued at the mean between the last bid and ask prices on the principal exchange where they are traded. Over-the- counter ("OTC") options and options on swaps ("swaptions") are valued using 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, or may use a pricing matrix or other fair value methods or techniques to provide an estimated value of the security or instrument. At April 30, 2016, there were no securities that were valued using fair value methods (other than securities valued using prices supplied by independent pricing services or broker-dealers). 46 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 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 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 is recorded on the accrual basis. All discounts/premiums on purchase prices of debt securities are accreted/amortized into interest income for financial reporting purposes. Security transactions are recorded as of trade date. 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 gain or loss on investments. D. 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. The amount of cash deposited with the broker as collateral at April 30, 2016 was Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 47 $3,463,493. 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 gains or losses. 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 changes in value of the underlying securities. With futures, there is minimal counterparty credit risk to the Fund since futures are exchange-traded and the exchange's clearinghouse, as counterparty to all exchange-traded futures, guarantees the futures against default. The average value of contracts open during the six months ended April 30, 2016 was $(50,774,727). At April 30, 2016, open futures contracts were as follows: ---------------------------------------------------------------------------------------------- Number of Unrealized Contracts Settlement Appreciation/ Type Counterparty Long/(Short) Month Value (Depreciation) ---------------------------------------------------------------------------------------------- JPY FX Futures Citibank N.A. (150) 6/16 $(17,583,750) $ (730,936) EUR FX Futures Citibank N.A. (100) 6/16 (14,331,250) (157,708) Copper Futures Citibank N.A. 124 6/16 7,069,550 190,650 Soybean Futures Citibank N.A. (15) 5/16 (765,750) 1,338 Soybean Futures Citibank N.A. 40 7/16 2,059,500 12,287 Palladium Futures Citibank N.A. 124 6/16 7,782,860 681,990 Gold 100oz Futures Citibank N.A. (108) 6/16 (13,937,400) (650,046) WTI Crude Future Citibank N.A. 649 12/18 32,969,200 1,639,251 ---------------------------------------------------------------------------------------------- Total $ 3,262,960 $ 986,826 ============================================================================================== E. 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 is 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 5). F. 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 48 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 its shareowners. Therefore, no federal income tax provision is required. As of October 31, 2015, the Fund did not accrue any interest or penalties with respect to unrecognized 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 during the year ended October 31, 2015 was as follows: --------------------------------------------------------------------------- 2015 --------------------------------------------------------------------------- Distributions paid from: Ordinary income $16,892,287 Long-term capital gain 20,894,431 --------------------------------------------------------------------------- Total $37,786,718 --------------------------------------------------------------------------- The following shows the components of distributable earnings on a federal income tax basis at October 31, 2015: --------------------------------------------------------------------------- 2015 --------------------------------------------------------------------------- Distributable earnings: Undistributed ordinary income $ 2,662,581 Undistributed long-term capital gain 35,258,195 Net unrealized appreciation 12,547,307 --------------------------------------------------------------------------- Total $50,468,083 --------------------------------------------------------------------------- The difference between book-basis and tax-basis net unrealized appreciation is attributable to the tax deferral of losses on wash-sales, the tax treatment on passive foreign investment company (PFIC) holdings, adjustments relating to catastrophe bonds, tax basis adjustments on partnerships and the mark-to-market of forward foreign currency contracts, future contracts and options and the tax basis adjustments on partnerships. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 49 G. 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 $22,477 in underwriting commissions on the sale of Class A shares during the six months ended April 30, 2016. H. 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 Fund's transfer agent 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. I. Insurance Linked Securities (ILS) The Fund invests in event-link 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 occurs, as defined within the terms of an event-linked bond, 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. 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 50 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 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"). A traditional ILW takes the form of a bilateral reinsurance contract, but there are also products that take the form of derivatives, collateralized structures, or exchange-traded instruments. Structured reinsurance investments, including quota share instruments, collateralized reinsurance investments and ILWs, generally are subject to the same risks as event-linked bonds. In addition, where the instruments are based on the performance 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 structured reinsurance investments and therefore the Fund's assets are placed at greater risk of loss than if PIM had more complete information. Structured reinsurance instruments generally will be considered illiquid securities by the Fund. These securities may be difficult to purchase, sell or unwind. Illiquid securities also may be difficult to value. If the Fund is forced to sell an illiquid asset, the Fund may be forced to sell at a loss. J. Risks The value of securities held by the fund may go up or down, sometimes rapidly or unpredictably, due to general market conditions, such as real or perceived adverse economic, political or regulatory conditions, inflation, changes in interest rates, lack of liquidity in the bond markets or adverse investor sentiment. In the past several years, financial markets have experienced increased volatility, depressed valuations, decreased liquidity and heightened uncertainty. These conditions may continue, recur, worsen or spread. Investing in foreign and/or emerging markets securities involves risks relating to interest rates, currency exchange rates and economic and political conditions. 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. The Fund may gain exposure to commodities (such as oil and precious metals) through investment in commodity-related investments, including commodity-linked derivatives, ETFs and leveraged or unleveraged Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 51 commodity-linked notes (derivative debt instruments with principal and/or coupon payments linked to the performance of commodity indices). The Fund also may invest in equity securities of issuers in commodity-related industries. The Fund's investments in commodity-related investments may subject the Fund to greater market price volatility than investments in traditional securities. The value of commodity-related investments may be affected by changes in overall market movements, commodity index volatility, changes in interest rates, or factors affecting particular industries or commodities, such as weather, disease, embargoes, acts of war or terrorism, or political and regulatory developments. Commodity-related investments may be more volatile than the underlying commodities. In addition, commodity-linked investments are subject to counterparty risk due to there being a relatively small number of issuers. The Fund gains exposure to commodity-related investments by investing in the Pioneer Cayman Commodity Fund, Ltd. (the Subsidiary), a foreign entity that is treated as a controlled foreign corporation for U.S. federal income tax purposes. The Fund may invest up to 25% of its total assets in the Subsidiary. The Fund's ability to invest in commodity-related investments, and the means through which any such investments may be made, is limited by tax considerations. The Fund may invest in REIT securities, the value of which can fall for a variety of reasons, such as declines in rental income, fluctuating interest rates, poor property management, environmental liabilities, uninsured damage, increased competition, or changes in real estate tax laws. Interest rates in the U.S. recently have been historically low, so the Fund faces a heightened risk that interest rates may rise. A general rise in interest rates may cause investors to move out of fixed income securities on a large scale, which could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions from the Fund. Certain securities in which the Fund invests, including floating rate loans, once sold, may not settle for an extended period (for example, several weeks or even longer). The Fund will not receive its sale proceeds until that time, which may constrain the Fund's ability to meet its obligations (including obligations to redeeming shareholders). K. 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 52 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 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. As of and for the six months ended April 30, 2016, the Fund had no open repurchase agreements. L. Option Writing The Fund may write put and covered call options to seek to increase total return. When an option is written, the Fund receives a premium and becomes obligated to purchase or sell the underlying security at a fixed price, upon the exercise of the option. When the Fund writes an option, an amount equal to the premium received by the Fund is recorded as a liability and is subsequently adjusted to the current value of the option written. Premiums received from writing options that expire unexercised are treated by the Fund on the expiration date as realized gains from investments. The difference between the premium and the amount paid on effecting a closing purchase transaction, including brokerage commissions, is also treated as a realized gain, or, if the premium is less than the amount paid for the closing purchase transaction, as a realized loss. If a call option is exercised, the premium is added to the proceeds from the sale of the underlying security in determining whether the Fund has realized a gain or loss. The Fund, as writer of an option, bears the market risk of an unfavorable change in the price of the security underlying the written option. The average value of contracts open during the six months ended April 30, 2016 was $(2,199,619). There were no written option contracts outstanding as of April 30, 2016. Transactions in written options for the six months ended April 30, 2016 are summarized as follows: ---------------------------------------------------------------------------------- Number of Contracts Premium Received ---------------------------------------------------------------------------------- Options open at beginning of period (--) $ (--) Options opened (62,300) (31,976,409) Options exercised 62,300 31,976,409 Options closed -- -- Options expired -- -- ---------------------------------------------------------------------------------- Options open at end of period (--) $ (--) ================================================================================== Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 53 M. Purchased Options The Fund may purchase put and call options to seek to 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 marked-to-market daily, and any unrealized appreciation or depreciation 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 contracts open during the six months ended April 30, 2016 was $9,036,366. Purchased options open at period end are listed in the Fund's Schedule of Investments. N. 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. 54 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 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. There were no open credit default swap contracts at April 30, 2016. The average value of swap contracts open during the six months ended April 30, 2016 was $134,617. O. Total Return Swap Agreements The Fund may enter into a total return swap to attempt to manage and/or gain exposure to a security or market. Pursuant to a total return swap agreement, the Fund negotiates with a counterparty to exchange a periodic stream of payments. One party makes payments based on the total return of a reference asset (such as a security or a basket of securities or securities index), and in return receives fixed or floating rate interest payments. The total return of the reference asset typically includes appreciation or depreciation on the reference asset, plus any interest or dividend payments. To the extent that the total return of the reference asset exceeds or falls short of the offsetting interest rate obligation, the Fund will receive a payment from or make a payment to the counterparty. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 55 Total return 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 are recorded as realized gains or losses in the Statement of Operations. Total return swap contracts are subject to counterparty risk and unanticipated movements in value of exchange rates, interest rates, securities or the index. The amount of cash deposited with the broker as collateral at April 30, 2016 was $566,691 and is recorded within "Restricted cash" in the Statement of Assets and Liabilities. Open total return swap contracts at April 30, 2016 are listed at the end of the Schedule of Investments. The average value of swap contracts open during the six months ended April 30, 2016 was $(121,747). 2. Management Agreement PIM, a wholly owned indirect subsidiary of UniCredit, manages the Fund's portfolio. Management fees are calculated daily at an annual rate of 0.70% of the average daily net assets of the Fund, excluding assets invested in the Subsidiary and on which the Subsidiary pays a management fee. The Subsidiary has entered into a separate management contract with PIM, pursuant to which PIM manages the assets of the Subsidiary. As compensation for its management services to the Subsidiary and expenses incurred with respect to the Subsidiary, the Subsidiary pays PIM a fee at the annual rate of 0.70% of the Subsidiary's average daily net assets. PIM has contractually agreed to limit ordinary operating expenses to the extent required to reduce Fund expenses to 1.20% and 0.90% of the average daily net assets attributable to Class A and Class Y shares, respectively. These expense limitations are in effect through March 1, 2017. Fees waived and expenses reimbursed during the six months ended April 30, 2016 are reflected on the Statement of Operations. Fees and expenses of other investment companies in which the Fund may invest are not included in the expense limitations noted above. 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 $67,472 in management fees, administrative costs and certain other reimbursements payable to PIM at April 30, 2016. 56 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 3. Transfer Agent Prior to November 2, 2015, Pioneer Investment Management Shareholder Services, Inc. (PIMSS), a wholly owned indirect subsidiary of UniCredit, provided substantially all transfer agent and shareowner services to the Fund at negotiated rates. Effective November 2, 2015, Boston Financial Data Services, Inc. serves as the transfer agent to the Fund at negotiated rates. For the six months ended April 30, 2016, such out-of-pocket expenses by class of shares were as follows: -------------------------------------------------------------------------------- Shareholder Communications: -------------------------------------------------------------------------------- Class A $ 78,097 Class C 86,280 Class R 307 Class Y 147,699 -------------------------------------------------------------------------------- Total $312,383 ================================================================================ Included in "Due to affiliates" reflected on the Statement of Assets and Liabilities is $82,208 in transfer agent fees and out-of-pocket reimbursements payable to the transfer agent at April 30, 2016. 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 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. Included in "Due to affiliates" reflected on the Statement of Assets and Liabilities is $20,414 in distribution fees payable to PFD at April 30, 2016. 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 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. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 57 In addition, redemptions of each class of shares (except 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 R or Class Y shares. Proceeds from the CDSCs are paid to PFD. For the six months ended April 30, 2016, CDSCs in the amount of $16,209 were paid to PFD. 5. Forward Foreign Currency Contracts At April 30, 2016, 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 forward foreign currency contracts open during the six months ended April 30, 2016 was $(310). There were no open forward foreign currency contracts as of April 30, 2016. 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. For the period from June 9, 2015, to February 9, 2016, the facility was in the amount of $240 million. Effective February 10, 2016, the facility is in the amount of $220 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 April 30, 2016, the Fund had no borrowings under the credit facility. 58 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 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 an event of 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 payable by the Fund under the applicable transactions, if any. However, the Fund's right to set off may be restricted or prohibited by the bankruptcy or insolvency laws of the particular jurisdiction to which a specific ISDA counterparty 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, with the exception of forward foreign currency contracts, which are shown on a gross basis. The following charts show gross assets and liabilities of the Fund as of April 30, 2016. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 59 ------------------------------------------------------------------------------------------------------------ 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) ------------------------------------------------------------------------------------------------------------ Citibank NA $ 354,257 $ (178,340) $-- $-- $ 175,917 Goldman Sachs International 87 -- -- -- 87 Societe Generale SA 71,359 (57,959) -- -- 13,400 ------------------------------------------------------------------------------------------------------------ $ 425,703 $ (236,299) $-- $-- $ 189,404 ============================================================================================================ ------------------------------------------------------------------------------------------------------------ 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) Liabilities (c) ------------------------------------------------------------------------------------------------------------ Citibank NA $ 178,340 $ (178,340) $-- $ 566,691 $ 566,691 Goldman Sachs International -- -- -- -- -- Societe Generale SA 57,959 (57,959) -- -- -- ------------------------------------------------------------------------------------------------------------ $ 236,299 $ (236,299) $-- $ 566,691 $ 566,691 ============================================================================================================ (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. (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. 60 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 The fair value of open derivative instruments (not considered to be hedging instruments for accounting disclosure purposes) by risk exposure at April 30, 2016 was as follows: ------------------------------------------------------------------------------------------------- Statement of Assets and Liabilities Foreign Interest Credit Exchange Equity Commodity Rate Risk Risk Rate Risk Risk ------------------------------------------------------------------------------------------------- Assets Net unrealized appreciation on futures contracts $-- $-- $ (888,644) $ 1,875,470 $-- ------------------------------------------------------------------------------------------------- Net unrealized appreciation on swap contracts -- -- -- 189,404 -- ------------------------------------------------------------------------------------------------- Total Value $-- $-- $ (888,644) $ 2,064,874 $-- ================================================================================================= The effect of derivative instruments (not considered to be hedging instruments for accounting disclosure purposes) on the Statement of Operations by risk exposure at April 30, 2016, was as follows: -------------------------------------------------------------------------------------------------- Statement of Operations Foreign Interest Credit Exchange Equity Commodity Rate Risk Risk Rate Risk Risk Risk -------------------------------------------------------------------------------------------------- Net realized gain (loss) on Swap contracts $ -- $(275,810) $ -- $ (1,440,338) $ -- Futures contracts (1,243,725) -- (478,071) (7,659,790) (2,024,410) Written options -- -- -- (6,344,505) (1,875,444) Forward foreign currency contracts -- -- 14,546 -- -- -------------------------------------------------------------------------------------------------- Total Value $(1,243,725) $(275,810) $(463,525) $(15,444,633) $(3,899,854) ================================================================================================== -------------------------------------------------------------------------------------------------- Foreign Interest Credit Exchange Equity Commodity Rate Risk Risk Rate Risk Risk Risk -------------------------------------------------------------------------------------------------- Change in net unrealized appreciation (depreciation) on Swap contracts $ -- $-- $ -- $ (293,250) $ -- Futures contracts 282,824 -- (1,479,707) 2,611,189 743,175 -------------------------------------------------------------------------------------------------- Total Value $ 282,824 $-- $(1,479,707) $2,317,939 $743,175 ================================================================================================== Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 61 ADDITIONAL INFORMATION PIM, the Fund's investment adviser, is currently an indirect, wholly owned subsidiary of 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 previously announced by UniCredit, 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 PIM. 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. Under the Investment Company Act of 1940, completion of the Transaction will cause the Fund's current investment advisory agreement with PIM to terminate. Accordingly, the Fund's Board of Trustees will be asked to approve a new investment advisory agreement. If approved by the Board, the Fund's new investment advisory agreement will be submitted to the shareholders of the Fund for their approval. 62 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 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 Shareowner Services and 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. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 63 This page for your notes. 64 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 This page for your notes. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 65 This page for your notes. 66 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 This page for your notes. Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 67 This page for your notes. 68 Pioneer Flexible Opportunities Fund | Semiannual Report | 4/30/16 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: -------------------------------------------------------------------------------- Pioneer Funds 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) 2016 Pioneer Investments 24879-05-0616 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 VI By (Signature and Title)* /s/ Lisa M. Jones Lisa M. Jones, President & Chief Executive Officer Date June 28, 2016 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 June 28, 2016 By (Signature and Title)* /s/ Mark E. Bradley Mark E. Bradley, Treasurer & Chief Accounting & Financial Officer Date June 28, 2016 * Print the name and title of each signing officer under his or her signature.