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 811-02864 Pioneer Bond Fund (Exact name of registrant as specified in charter) 60 State Street, Boston, MA 02109 (Address of principal executive offices) (ZIP code) Terrence J. Cullen, Amundi Pioneer Asset 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: June 30 Date of reporting period: July 1, 2018 through December 31, 2018 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 Bond Fund -------------------------------------------------------------------------------- Semiannual Report | December 31, 2018 -------------------------------------------------------------------------------- Ticker Symbols: Class A PIOBX Class C PCYBX Class K PBFKX Class R PBFRX Class Y PICYX Beginning in February 2021, as permitted by regulations adopted by the Securities and Exchange Commission, paper copies of the Fund's shareholder reports like this one will no longer be sent by mail, unless you specifically request paper copies of the reports from the Fund or from your financial intermediary, such as a broker-dealer, bank or insurance company. Instead, the reports will be made available on the Fund's website, and you will be notified by mail each time a report is posted and provided with a website link to access the report. If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications electronically by contacting your financial intermediary or, if you invest directly with the Fund, by calling 1-800-225-6292. You may elect to receive all future reports in paper free of charge. If you invest directly with the Fund, you can inform the Fund that you wish to continue receiving paper copies of your shareholder reports by calling 1-800-225-6292. If you invest through a financial intermediary, you can contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. Your election to receive reports in paper will apply to all funds held in your account if you invest through your financial intermediary or all funds held with the Pioneer funds complex if you invest directly. [LOGO] Amundi Pioneer ============== ASSET MANAGEMENT visit us: www.amundipioneer.com Table of Contents President's Letter 2 Portfolio Management Discussion 4 Portfolio Summary 10 Prices and Distributions 11 Performance Update 12 Comparing Ongoing Fund Expenses 17 Schedule of Investments 19 Financial Statements 91 Notes to Financial Statements 100 Additional Information 116 Approval of Investment Management Agreement 118 Trustees, Officers and Service Providers 123 Pioneer Bond Fund | Semiannual Report | 12/31/18 1 President's Letter Since 1928, active portfolio management based on in-depth, fundamental research, has been the foundation of Amundi Pioneer's investment approach. We believe an active management investment strategy is a prudent approach to investing, especially during periods of market volatility, which can result from any number of risk factors, including slow U.S. economic growth, rising interest rates, and geopolitical factors. Of course, in today's global economy, risk factors extend well beyond U.S. borders, and political and economic issues on the international front can also cause or contribute to volatility in U.S. markets. At Amundi Pioneer, each security under consideration is researched by our team of experienced investment professionals, who visit companies and meet with their management teams. At the end of this research process, if we have conviction in a company's business model and management team, and regard the security as a potentially solid investment opportunity, an Amundi Pioneer portfolio manager makes an active decision to invest in that security. The portfolio resulting from these decisions represents an expression of his or her convictions, and strives to balance overall risk and return opportunity. As an example, the Standard & Poor's 500 Index -- the predominant benchmark for many U.S. Large-Cap Core Equity funds -- has 500 stocks. An Amundi Pioneer portfolio manager chooses to invest in only those companies that he or she believes can offer the most attractive opportunities to pursue the fund's investment objective, thus potentially benefiting the fund's shareowners. This process results in a portfolio that does not own all 500 stocks, but a much narrower universe. The same active decision to invest in a company is also applied when we decide to sell a security, either due to changing fundamentals, valuation concerns, or market risks. We apply this active decision-making across all of our equity, fixed-income, and global portfolios. Today, as investors, we have many options. It is our view that active management can serve shareholders well not only when markets are thriving, but also during periods of market volatility and uncertainty, thus making it a compelling investment choice. As you consider the many choices today, 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. 2 Pioneer Bond Fund | Semiannual Report | 12/31/18 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 Head of the Americas, President and CEO of U.S. Amundi Pioneer Asset Management USA, Inc. December 31, 2018 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 Bond Fund | Semiannual Report | 12/31/18 3 Portfolio Management Discussion | 12/31/18 In the following interview, Brad Komenda discusses the factors that affected the performance of Pioneer Bond Fund during the six-month period ended December 31, 2018. Mr. Komenda, Senior Vice President, Deputy Director of Investment-Grade Corporates, and a portfolio manager at Amundi Pioneer Asset Management, Inc. ("Amundi Pioneer"), is responsible for the day-to-day management of the Portfolio, along with Kenneth J. Taubes, Executive Vice President and Chief Investment Officer, U.S., and a portfolio manager at Amundi Pioneer, and Timothy Rowe, Managing Director, Deputy Director of Multisector Fixed Income, and a portfolio manager at Amundi Pioneer. Q How did the Fund perform during the six-month period ended December 31, 2018? A Pioneer Bond Fund's Class A shares returned 0.66% at net asset value during the six-month period ended December 31, 2018, while the Fund's benchmark, the Bloomberg Barclays U.S. Aggregate Bond Index (the Bloomberg Barclays Index), returned 1.65%. During the same period, the average return of the 1,061 mutual funds in Morningstar's Intermediate-Term Bond Funds Category was 1.08%. Q How would you describe the investment environment in the fixed-income markets during the six-month period ended December 31, 2018? A Entering the period, robust economic data and corporate earnings results boosted credit-market sentiment, outweighing concerns over trade disputes between the U.S. and some of its major trading partners. The markets continued to focus heavily on economic growth and inflation indicators in the effort to glean the likely path of the U.S. Federal Reserve's (the Fed's) monetary policy. Expectations were for two additional quarter-point increases in the federal funds rate by year-end, bringing the total number of rate hikes to four in 2018. Treasury yields rose in advance of the Fed's September 25 meeting, at which the upper band for the benchmark overnight lending rate was raised from 2.00% to 2.25%. Investment-grade corporate bonds led performance within the Fund's benchmark, the Bloomberg Barclays Index, in the third quarter of 2018, while high-yield corporate bonds outperformed the investment-grade market during that same three-month period, given the "risk-on" tone in the markets. 4 Pioneer Bond Fund | Semiannual Report | 12/31/18 The positive market conditions reversed in the fourth quarter of 2018, however, with much of the damage coming in December. Investors' appetite for risk had weakened entering the quarter as concerns about the outlook for the Fed's continued tightening of monetary policy, the escalating U.S./China trade dispute, and mounting evidence of slowing economic growth overseas dampened enthusiasm. In early October, the equity markets began a downward spiral that would persist essentially through year-end. The price of oil, too, slid significantly at that time due to an unfavorable supply/demand outlook. Nonetheless, the Fed met market expectations and raised short-term rates by a quarter-point in December, moving its federal funds target into the 2.25% to 2.50% range, while signaling the likelihood of two additional rate hikes in 2019. Volatility in the "risk-asset" markets spiked on fears that the Fed would raise rates by too much, given the uncertain outlook for global economic growth. The 10-year Treasury yield declined from 3.05% to 2.69% over the fourth quarter, driven by a global flight-to-safety trade. U.S. Treasuries led performance within the Bloomberg Barclays Index over the fourth quarter of 2018 as longer-term interest rates declined. Securitized assets, including mortgage-backed securities (MBS), asset-backed securities (ABS), and commercial-mortgage backed securities (CMBS), were rewarded for their generally high-quality profiles and posted positive returns as well. Investment-grade corporate bonds were the biggest laggards within the investment-grade universe as credit spreads widened. (Credit spreads are commonly defined as the differences in yield between Treasuries and other types of fixed-income securities with similar maturities.) High-yield corporate bonds notably lagged their investment-grade counterparts over the final three months of the period, while returns for floating-rate bank loans were also firmly in negative territory for the fourth quarter. For the full six-month period ended December 31, 2018, securitized assets and Treasuries led performance within the benchmark Bloomberg Barclays Index. The investment-grade corporate bond market posted a small positive return of 0.79%, as measured by the Bloomberg Barclays U.S. Corporate Bond Index, while high-yield securities were negative, returning -2.34%, as measured by the ICE Bank of America Merrill Lynch U.S. High Yield Index. Pioneer Bond Fund | Semiannual Report | 12/31/18 5 Q What factors influenced the Fund's performance relative to the Bloomberg Barclays Index during the six-month period ended December 31, 2018? A The biggest detractor from the Fund's benchmark-relative performance over the six-month period was an approximate 5% non-benchmark portfolio allocation to Treasury Inflation-Protected Securities (TIPS). The performance of TIPS badly lagged that of nominal Treasuries as inflation expectations declined in late 2018. In addition, declining interest rates in the fourth quarter did not benefit TIPS to the same degree as comparable-maturity Treasuries. The Fund's positioning with respect to interest rates was a modest detractor from benchmark-relative performance during the six-month period. In particular, the Fund was slightly underweight versus the benchmark in overall portfolio duration, which limited returns as the 10-year Treasury yield declined late in the period. (Duration is a measure of the sensitivity of the price, or the value of principal, of a fixed-income investment to a change in interest rates, expressed as a number of years.) After having taken a short-duration stance versus the benchmark for the past several years, the increase in interest rates we witnessed over 2018, coupled with the federal funds rate approaching neutral and the flattening of the yield curve, we had moved the portfolio to an essentially neutral-duration stance relative to the Bloomberg Barclays Index as of period-end. Asset allocation decisions, in aggregate, also hurt the Fund's benchmark-relative performance for the six-month period. In broad terms, the Fund's overweighting of credit-sensitive investments -- or debt instruments more subject to default risk -- compared with the benchmark weighed on relative returns as the market moved to a "risk-off" tone in late 2018 and investors sought out "safe-haven" assets such as Treasuries. Detractors from the Fund's benchmark-relative returns within credit-sensitive debt included the portfolio's exposures to both investment-grade corporate credit as well as modest, out-of-benchmark positions in high-yield corporates and floating-rate bank loans. By the same token, the Fund's underweight to U.S. Treasuries constrained benchmark-relative returns as the flat-to-lower movement out on the yield curve supported Treasury performance. The 6 Pioneer Bond Fund | Semiannual Report | 12/31/18 Fund continues to hold a large underweight to nominal Treasuries versus the Bloomberg Barclays Index, as our economic outlook for 2019 remains relatively strong, and we continue to favor allocations to both securitized and credit-sensitive sectors, market segments we believe are poised to rebound in light of their significant underperformance at the end of 2018. On the positive side, the Fund's overweighting of securitized assets, including ABS, contributed modestly to benchmark-relative results, as strong consumer fundamentals supported a favorable view of the asset category. The Fund maintains a modest, strategic exposure to insurance-linked securities (ILS), which are sponsored by insurance companies looking to transfer some of the risk of having to payout claims following a natural disaster. We believe ILS investments can offer the portfolio a valuable source of diversification* and incremental income potential. The Fund's ILS allocation was essentially a neutral factor with regard to benchmark-relative performance for the six-month period, despite the insurance claims generated by the extremely damaging California wildfires late in the year. Q Did the Fund have any investments in derivative securities during the six-month period ended December 31, 2018? If so, did the derivatives have any material impact on benchmark-relative performance? A Yes, we invested the Fund in Treasury futures and credit-default swaps (CDS) during the period. We invest in Treasury futures as part of our duration management for the portfolio. We believe the use of Treasury futures allows us to express our views on duration and yield-curve positioning in the most efficient manner. Investments in CDS are used to either gain or reduce the portfolio's exposure to corporate bonds very quickly, as cash-bond transactions take a little more time. The use of derivatives did not materially impact the Fund's benchmark-relative performance during the period, as they were used as hedging instruments. Q What factors affected the Fund's yield during the six-month period ended December 31, 2018? A The overall rise in Treasury yields contributed to a higher Fund yield, as did the widening of credit spreads over the six-month period. * Diversification does not assure a profit nor protected against loss. Pioneer Bond Fund | Semiannual Report | 12/31/18 7 Q What is your investment outlook and how is the Fund positioned heading into the second half of its fiscal year? A We anticipate 2019 will see the U.S. economy continue to expand, albeit at a more moderate pace. While we reduced the Fund's credit-market exposures through mid-2018, the significant spread-widening, particularly in December, created the opportunity for us to start selectively adding back credit risk, both in investment-grade and high-yield corporates. In particular, we increased the portfolio's holdings of economically sensitive issues in the "BBB" quality range (the lower end of investment grade), which we viewed as having been unduly punished during the year-end market rout. Given the advanced stage of the credit cycle, we are generally avoiding investments in industrial sectors that have seen an increase in merger-and-acquisition activity and shareholder-friendly measures such as increased dividends** and share buybacks, as the increased leverage associated with such activity has resulted in credit downgrades to "BBB-". The Fund has exposure to bank issues in developed Europe, which appear attractive from a relative-valuation standpoint. The Fund remains overweight to securitized assets, including ABS, CMBS, and non-agency MBS, as we view the category as featuring favorable risk/return profiles given our outlook for continued low default rates. We have maintained the portfolio's non-benchmark position in long-duration TIPS, which is designed to help protect the Fund should inflation exceed expectations. Entering 2019, we view TIPS valuations as reflecting an unduly pessimistic outlook for both economic growth and inflation. Other non-benchmark exposures in the portfolio as of year-end include holdings of floating-rate bank loans, where we find valuations are more attractive following December's credit-market sell-off. We are seeking to maintain a high-quality focus within the bank-loan segment, as it has been subject to some of the same stepped-up leveraging we've seen within lower-rated corporates. Given our view that the Fed is now at the neutral federal funds rate, as noted earlier, we have moved the portfolio to a neutral-duration stance versus the Bloomberg Barclays Index, and have positioned the Fund with a modest underweight in the middle of the yield curve, with an overweight on the long end. ** Dividends are not guaranteed. 8 Pioneer Bond Fund | Semiannual Report | 12/31/18 Please refer to the Schedule of Investments on pages 19-90 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. When interest rates rise, the prices of fixed-income securities in the Fund will generally fall. Conversely, when interest rates fall, the prices of fixed-income securities in the Fund will generally rise. Investments in the Fund are subject to possible loss due to the financial failure of the issuers of the underlying securities and their inability to meet their debt obligations. Prepayment risk is the chance that an issuer may exercise its right to prepay its security, if falling interest rates prompt the issuer to do so. Forced to reinvest the unanticipated proceeds at lower interest rates, the Fund would experience a decline in income and lose the opportunity for additional price appreciation. Investments in high-yield or lower-rated securities are subject to greater-than-average price volatility, illiquidity and possibility of default. The securities issued by U.S. Government-sponsored entities (i.e., Fannie Mae, Freddie Mac) are neither guaranteed nor issued by the U.S. Government. The portfolio may invest in mortgage-backed securities, which during times of fluctuating interest rates may increase or decrease more than other fixed-income securities. Mortgage-backed securities are also subject to pre-payments. At times, the Fund's investments may represent industries or industry sectors that are interrelated or have common risks, making the Fund more susceptible to any economic, political, or regulatory developments or other risks affecting those industries and sectors. These risks may increase share price volatility. Before investing, consider the product's investment objectives, risks, charges and expenses. Contact your advisor or Amundi Pioneer Asset Management, Inc., 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 Bond Fund | Semiannual Report | 12/31/18 9 Portfolio Summary | 12/31/18 Portfolio Diversification -------------------------------------------------------------------------------- (As a percentage of total investments)* [THE FOLLOWING DATA WAS REPRESENTED AS A PIE CHART IN THE PRINTED MATERIAL] U.S. Government And Agency Obligations 29.9% Corporate Bonds 29.0% Collateralized Mortgage Obligations 24.2% Asset Backed Securities 7.3% Insurance-Linked Securities 4.1% Municipal Bonds 2.4% Senior Secured Floating Rate Loan Interests 2.3% Convertible Preferred Stocks 0.5% Foreign Government Bonds 0.3% 10 Largest Holdings -------------------------------------------------------------------------------- (As a percentage of total investments)* 1. U.S. Treasury Inflation Indexed Bonds, 1.0%, 2/15/46 1.45% ------------------------------------------------------------------------------------------------------------- 2. U.S. Treasury Inflation Indexed Bonds, 1.0%, 2/15/48 1.23 ------------------------------------------------------------------------------------------------------------- 3. U.S. Treasury Inflation Indexed Bonds, 0.75%, 2/15/45 1.20 ------------------------------------------------------------------------------------------------------------- 4. U.S. Treasury Inflation Indexed Bonds, 0.875%, 2/15/47 1.19 ------------------------------------------------------------------------------------------------------------- 5. U.S. Treasury Notes, 2.5%, 6/30/20 0.92 ------------------------------------------------------------------------------------------------------------- 6. Canadian Imperial Bank of Commerce, 2.874% (3 Month USD LIBOR + 32 bps), 2/2/21 0.44 ------------------------------------------------------------------------------------------------------------- 7. Commonwealth of Pennsylvania, 1st Series, 4.0%, 1/1/29 0.37 ------------------------------------------------------------------------------------------------------------- 8. Fannie Mae, 3.5%, 8/1/47 0.37 ------------------------------------------------------------------------------------------------------------- 9. Liberty Mutual Insurance Co., 7.697%, 10/15/97 (144A) 0.36 ------------------------------------------------------------------------------------------------------------- 10. Williams Cos., Inc., 5.75%, 6/24/44 0.35 ------------------------------------------------------------------------------------------------------------- * Excludes temporary cash investments and all derivative contracts except for options purchased. 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. 10 Pioneer Bond Fund | Semiannual Report | 12/31/18 Prices and Distributions | 12/31/18 Net Asset Value per Share -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- Class 12/31/18 6/30/18 -------------------------------------------------------------------------------- A $9.35 $9.45 -------------------------------------------------------------------------------- C $9.25 $9.35 -------------------------------------------------------------------------------- K $9.35 $9.45 -------------------------------------------------------------------------------- R $9.44 $9.54 -------------------------------------------------------------------------------- Y $9.27 $9.36 -------------------------------------------------------------------------------- Distributions per Share: 7/1/18-12/31/18 -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- Net Investment Short-Term Long-Term Class Income Capital Gains Capital Gains -------------------------------------------------------------------------------- A $0.1613 $ -- $ -- -------------------------------------------------------------------------------- C $0.1251 $ -- $ -- -------------------------------------------------------------------------------- K $0.1803 $ -- $ -- -------------------------------------------------------------------------------- R $0.1507 $ -- $ -- -------------------------------------------------------------------------------- Y $0.1734 $ -- $ -- -------------------------------------------------------------------------------- Index Definition -------------------------------------------------------------------------------- The Bloomberg Barclays U.S. Aggregate Bond Index is an unmanaged measure of the U.S. bond market. 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 12-16. Pioneer Bond Fund | Semiannual Report | 12/31/18 11 Performance Update | 12/31/18 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 Bond Fund at public offering price during the periods shown, compared to that of the Bloomberg Barclays U.S. Aggregate Bond Index. Average Annual Total Returns (As of December 31, 2018) --------------------------------------------------------- Bloomberg Net Public Barclays U.S. Asset Offering Aggregate Value Price Bond Period (NAV) (POP) Index --------------------------------------------------------- 10 years 5.34% 4.86% 3.48% 5 years 2.63 1.69 2.52 1 year -0.88 -5.34 0.01 --------------------------------------------------------- Expense Ratio (Per prospectus dated November 1, 2018) --------------------------------------------------------- Gross --------------------------------------------------------- 0.85% --------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment Bloomberg Barclays U.S. Pioneer Bond Fund Aggregate Bond Index 12/08 $ 9,550 $10,000 12/09 $11,240 $10,593 12/10 $12,301 $11,286 12/11 $12,926 $12,171 12/12 $14,045 $12,684 12/13 $14,113 $12,427 12/14 $14,949 $13,169 12/15 $14,947 $13,241 12/16 $15,572 $13,592 12/17 $16,210 $14,073 12/18 $16,067 $14,075 Call 1-800-225-6292 or visit www.amundipioneer.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. NAV returns would have been lower had sales charges been reflected. POP returns reflect deduction of maximum 4.50% sales charge. All results are historical and assume the reinvestment of dividends and capital gains. Other share classes are available for which performance and expenses will differ. Performance results reflect any applicable expense waivers in effect during the periods shown. Without such waivers Fund performance would be lower. Waivers may not be in effect for all funds. Certain fee waivers are contractual through a specified period. Otherwise, fee waivers can be rescinded at any time. See the prospectus and financial statements for more information. The performance table and graph do not reflect the deduction of fees and taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. Please refer to the financial highlights for a more current expense ratio. 12 Pioneer Bond Fund | Semiannual Report | 12/31/18 Performance Update | 12/31/18 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 Bond Fund during the periods shown, compared to that of the Bloomberg Barclays U.S. Aggregate Bond Index. Average Annual Total Returns (As of December 31, 2018) --------------------------------------------------------- Bloomberg Barclays U.S. Aggregate If If Bond Period Held Redeemed Index --------------------------------------------------------- 10 years 4.47% 4.47% 3.48% 5 years 1.86 1.86 2.52 1 year -1.55 -1.55 0.01 --------------------------------------------------------- Expense Ratio (Per prospectus dated November 1, 2018) --------------------------------------------------------- Gross --------------------------------------------------------- 1.49% --------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment Bloomberg Barclays U.S. Pioneer Bond Fund Aggregate Bond Index 12/08 $10,000 $10,000 12/09 $11,664 $10,593 12/10 $12,644 $11,286 12/11 $13,172 $12,171 12/12 $14,341 $12,684 12/13 $14,123 $12,427 12/14 $14,838 $13,169 12/15 $14,719 $13,241 12/16 $15,224 $13,592 12/17 $15,732 $14,073 12/18 $15,487 $14,075 Call 1-800-225-6292 or visit www.amundipioneer.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 you paid a 1% sales charge, your returns would be lower than those shown above. "If Held" results represent the percent change in net asset value per share. NAV 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. Please refer to the financial highlights for a more current expense ratio. Pioneer Bond Fund | Semiannual Report | 12/31/18 13 Performance Update | 12/31/18 Class K Shares Investment Returns -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $5 million investment made in Class K shares of Pioneer Bond Fund during the periods shown, compared to that of the Bloomberg Barclays U.S. Aggregate Bond Index. Average Annual Total Returns (As of December 31, 2018) --------------------------------------------------------- Bloomberg Net Barclays U.S. Asset Aggregate Value Bond Period (NAV) Index --------------------------------------------------------- 10 years 5.57% 3.48% 5 years 3.01 2.52 1 year -0.48 0.01 --------------------------------------------------------- Expense Ratio (Per prospectus dated November 1, 2018) --------------------------------------------------------- Gross --------------------------------------------------------- 0.35% --------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $5 Million Investment Bloomberg Barclays U.S. Pioneer Bond Fund Aggregate Bond Index 12/08 $5,000,000 $5,000,000 12/09 $5,884,971 $5,296,520 12/10 $6,440,518 $5,643,003 12/11 $6,767,641 $6,085,518 12/12 $7,346,858 $6,342,012 12/13 $7,412,444 $6,213,669 12/14 $7,867,360 $6,584,358 12/15 $7,904,802 $6,620,569 12/16 $8,266,509 $6,795,848 12/17 $8,638,271 $7,036,545 12/18 $8,596,964 $7,037,344 Call 1-800-225-6292 or visit www.amundipioneer.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. The performance shown for Class K shares for the period prior to the commencement of operations of Class K shares on December 20, 2012, is the net asset value performance of the Fund's Class A shares, which has not been restated to reflect any differences in expenses, including Rule 12b-1 fees applicable to Class A shares. Since fees for Class A shares generally are higher than those of Class K shares, the performance of Class K shares prior to their inception would have been higher than the performance shown. 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. 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. Please refer to the financial highlights for a more current expense ratio. 14 Pioneer Bond Fund | Semiannual Report | 12/31/18 Performance Update | 12/31/18 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 Bond Fund during the periods shown, compared to that of the Bloomberg Barclays U.S. Aggregate Bond Index. Average Annual Total Returns (As of December 31, 2018) --------------------------------------------------------- Bloomberg Net Barclays U.S. Asset Aggregate Value Bond Period (NAV) Index --------------------------------------------------------- 10 years 5.01% 3.48% 5 years 2.38 2.52 1 year -1.09 0.01 --------------------------------------------------------- Expense Ratio (Per prospectus dated November 1, 2018) --------------------------------------------------------- Gross --------------------------------------------------------- 1.10% --------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment Bloomberg Barclays U.S. Pioneer Bond Fund Aggregate Bond Index 12/08 $10,000 $10,000 12/09 $11,731 $10,593 12/10 $12,796 $11,286 12/11 $13,396 $12,171 12/12 $14,479 $12,684 12/13 $14,494 $12,427 12/14 $15,314 $13,169 12/15 $15,277 $13,241 12/16 $15,874 $13,592 12/17 $16,481 $14,073 12/18 $16,302 $14,075 Call 1-800-225-6292 or visit www.amundipioneer.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 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. Please refer to the financial highlights for a more current expense ratio. Pioneer Bond Fund | Semiannual Report | 12/31/18 15 Performance Update | 12/31/18 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 Bond Fund during the periods shown, compared to that of the Bloomberg Barclays U.S. Aggregate Bond Index. Average Annual Total Returns (As of December 31, 2018) --------------------------------------------------------- Bloomberg Net Barclays U.S. Asset Aggregate Value Bond Period (NAV) Index --------------------------------------------------------- 10 years 5.61% 3.48% 5 years 2.92 2.52 1 year -0.53 0.01 --------------------------------------------------------- Expense Ratio (Per prospectus dated November 1, 2018) --------------------------------------------------------- Gross --------------------------------------------------------- 0.47% --------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $5 Million Investment Bloomberg Barclays U.S. Pioneer Bond Fund Aggregate Bond Index 12/08 $5,000,000 $5,000,000 12/09 $5,897,611 $5,296,520 12/10 $6,472,825 $5,643,003 12/11 $6,818,480 $6,085,518 12/12 $7,420,415 $6,342,012 12/13 $7,469,208 $6,213,669 12/14 $7,931,859 $6,584,358 12/15 $7,951,262 $6,620,569 12/16 $8,307,445 $6,795,848 12/17 $8,672,405 $7,036,545 12/18 $8,626,732 $7,037,344 Call 1-800-225-6292 or visit www.amundipioneer.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. Class Y shares are not subject to sales charges and are available for limited groups of eligible investors, including institutional investors. All results are historical and assume the reinvestment of dividends and capital gains. Other share classes are available for which performance and expenses will differ. Performance results reflect any applicable expense waivers in effect during the periods shown. Without such waivers Fund performance would be lower. Waivers may not be in effect for all funds. Certain fee waivers are contractual through a specified period. Otherwise, fee waivers can be rescinded at any time. See the prospectus and financial statements for more information. The performance table and graph do not reflect the deduction of fees and taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. Please refer to the financial highlights for a more current expense ratio. 16 Pioneer Bond Fund | Semiannual Report | 12/31/18 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 Bond Fund Based on actual returns from July 1, 2018 through December 31, 2018. ---------------------------------------------------------------------------------------------- Share Class A C K R Y ---------------------------------------------------------------------------------------------- Beginning $1,000.00 $1,000.00 $1,000.00 $1,000.00 $1,000.00 Account Value on 7/1/18 ---------------------------------------------------------------------------------------------- Ending Account $1,006.60 $1,002.70 $1,008.70 $1,005.50 $1,009.10 Value (after expenses) on 12/31/18 ---------------------------------------------------------------------------------------------- Expenses Paid $ 4.30 $ 7.77 $ 2.03 $ 5.56 $ 2.63 During Period* ---------------------------------------------------------------------------------------------- * Expenses are equal to the Fund's annualized net expense ratio of 0.85%, 1.54%, 0.40%, 1.10% and 0.52% for Class A, Class C, Class K, Class R and Class Y shares, respectively, multiplied by the average account value over the period, multiplied by 184/365 (to reflect the one-half year period). Pioneer Bond Fund | Semiannual Report | 12/31/18 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 Bond Fund Based on a hypothetical 5% per year return before expenses, reflecting the period from July 1, 2018 through December 31, 2018. ---------------------------------------------------------------------------------------------- Share Class A C K R Y ---------------------------------------------------------------------------------------------- Beginning $1,000.00 $1,000.00 $1,000.00 $1,000.00 $1,000.00 Account Value on 7/1/18 ---------------------------------------------------------------------------------------------- Ending Account $1,020.92 $1,017.44 $1,023.19 $1,019.66 $1,022.58 Value (after expenses) on 12/31/18 ---------------------------------------------------------------------------------------------- Expenses Paid $ 4.33 $ 7.83 $ 2.04 $ 5.60 $ 2.65 During Period* ---------------------------------------------------------------------------------------------- * Expenses are equal to the Fund's annualized net expense ratio of 0.85%, 1.54%, 0.40%, 1.10% and 0.52% for Class A, Class C, Class K, Class R and Class Y shares, respectively, multiplied by the average account value over the period, multiplied by 184/365 (to reflect the one-half year period). 18 Pioneer Bond Fund | Semiannual Report | 12/31/18 Schedule of Investments | 12/31/18 (unaudited) --------------------------------------------------------------------------------------------------------------------------------- Shares Value --------------------------------------------------------------------------------------------------------------------------------- UNAFFILIATED ISSUERS -- 99.7% CONVERTIBLE PREFERRED STOCKS -- 0.6% of Net Assets Banks -- 0.6% 10,964(a) Bank of America Corp., 7.25% $ 13,732,410 10,209(a) Wells Fargo & Co., 7.5% 12,883,452 -------------- Total Banks $ 26,615,862 --------------------------------------------------------------------------------------------------------------------------------- TOTAL CONVERTIBLE PREFERRED STOCKS (Cost $24,688,188) $ 26,615,862 --------------------------------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) --------------------------------------------------------------------------------------------------------------------------------- ASSET BACKED SECURITIES -- 7.3% of Net Assets 765,269(b) 321 Henderson Receivables I LLC, Series 2005-1A, Class A1, 2.685% (1 Month USD LIBOR + 23 bps), 11/15/40 (144A) $ 728,776 500,000 321 Henderson Receivables III LLC, Series 2008-1A, Class B, 8.37%, 1/15/46 (144A) 591,502 2,743,019 ACC Trust, Series 2018-1, Class A, 3.7%, 12/21/20 (144A) 2,744,260 4,300,000 Access Point Funding I LLC, Series 2017-A, Class B, 3.97%, 4/15/29 (144A) 4,292,023 4,641,250 Applebee's Funding LLC/IHOP Funding LLC, Series 2014-1, Class A2, 4.277%, 9/5/44 (144A) 4,630,437 1,500,000 Ascentium Equipment Receivables Trust, Series 2016-2A, Class D, 4.2%, 9/12/22 (144A) 1,506,927 2,100,000 Ascentium Equipment Receivables Trust, Series 2017-2A, Class D, 3.56%, 10/10/25 (144A) 2,074,789 1,100,000 Ascentium Equipment Receivables Trust, Series 2018-1A, Class D, 3.99%, 12/11/23 (144A) 1,110,389 1,750,000 Avid Automobile Receivables Trust, Series 2018-1, Class B, 3.85%, 7/15/24 (144A) 1,740,070 800,000 Axis Equipment Finance Receivables IV LLC, Series 2018-1A, Class C, 3.74%, 4/22/24 (144A) 799,773 1,249,999 Axis Equipment Finance Receivables IV LLC, Series 2018-1A, Class D, 3.98%, 4/22/24 (144A) 1,249,455 1,675,000 Axis Equipment Finance Receivables VI LLC, Series 2018-2A, Class C, 4.27%, 1/20/23 (144A) 1,705,531 5,784,000 Axis Equipment Finance Receivables VI LLC, Series 2018-2A, Class D, 4.45%, 6/20/23 (144A) 5,887,772 5,590,487(c) Bayview Koitere Fund Trust, Series 2017-RT4, Class A, 3.5%, 7/28/57 (144A) 5,541,364 1,416,000 BCC Funding XIV LLC, Series 2018-1A, Class B, 3.39%, 8/21/23 (144A) 1,417,370 126,127(b) Bear Stearns Asset Backed Securities Trust, Series 2006-SD2, Class A3, 2.996% (1 Month USD LIBOR + 49 bps), 6/25/36 126,126 1,126,280 BXG Receivables Note Trust, Series 2015-A, Class A, 2.88%, 5/2/30 (144A) 1,110,870 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 19 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- ASSET BACKED SECURITIES -- (continued) 6,977,881 Cazenovia Creek Funding II LLC, Series 2018-1A, Class A, 3.561%, 7/15/30 (144A) $ 6,982,397 1,400,000 CIG Auto Receivables Trust, Series 2017-1A, Class B, 3.81%, 5/15/23 (144A) 1,384,749 6,635,269(c) Citigroup Mortgage Loan Trust, Inc., Series 2017-RP2, Class A1, 3.25%, 7/25/67 (144A) 6,510,971 1,582,039(b) Commonbond Student Loan Trust, Series 2017-BGS, Class A2, 3.156% (1 Month USD LIBOR + 65 bps), 9/25/42 (144A) 1,559,087 5,500,000 Commonbond Student Loan Trust, Series 2018-CGS, Class A1, 3.87%, 2/25/46 (144A) 5,549,112 3,000,000 CoreVest American Finance Trust, Series 2017-1, Class C, 3.756%, 10/15/49 (144A) 2,899,854 1,500,000 Credit Acceptance Auto Loan Trust, Series 2016-2A, Class C, 4.29%, 11/15/24 (144A) 1,507,603 380,184 CRG Issuer, Series 2015-1, Class A, 4.07%, 7/10/22 (144A) 378,283 445,116(b) DRB Prime Student Loan Trust, Series 2016-B, Class A1, 4.306% (1 Month USD LIBOR + 180 bps), 6/25/40 (144A) 459,857 3,750,000 Drive Auto Receivables Trust, Series 2018-1, Class C, 3.22%, 3/15/23 3,742,397 235,687(b) Drug Royalty II LP 2, Series 2014-1, Class A1, 5.286% (3 Month USD LIBOR + 285 bps), 7/15/23 (144A) 237,196 4,497,212 Elm Trust, Series 2018-2A, Class A2, 4.605%, 10/20/27 (144A) 4,570,659 1,300,000 Engs Commercial Finance Trust, Series 2016-1A, Class B, 3.45%, 3/22/22 (144A) 1,269,997 1,900,000 Engs Commercial Finance Trust, Series 2016-1A, Class D, 5.22%, 1/22/24 (144A) 1,856,549 2,000,000 Engs Commercial Finance Trust, Series 2018-1A, Class B, 3.8%, 2/22/23 (144A) 2,013,863 1,400,000 Engs Commercial Finance Trust, Series 2018-1A, Class C, 4.05%, 2/22/23 (144A) 1,411,214 1,500,000 Exeter Automobile Receivables Trust, Series 2018-1A, Class C, 3.03%, 1/17/23 (144A) 1,490,482 2,182,409(b) Fieldstone Mortgage Investment Trust, Series 2005-3, Class 1A, 2.805% (1 Month USD LIBOR + 49 bps), 2/25/36 2,164,075 4,314,000(c) Finance of America Structured Securities Trust, Series 2017-HB1, Class M1, 2.84%, 11/25/27 (144A) 4,282,076 1,454,295 First Investors Auto Owner Trust, Series 2014-3A, Class C, 2.97%, 11/16/20 (144A) 1,453,709 300,000 First Investors Auto Owner Trust, Series 2017-2A, Class C, 3.0%, 8/15/23 (144A) 296,969 1,140,000 Ford Credit Auto Owner Trust /Ford Credit, Series 2018-2, Class A, 3.47%, 1/15/30 (144A) 1,150,404 The accompanying notes are an integral part of these financial statements. 20 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- ASSET BACKED SECURITIES -- (continued) 4,200,000 Four Seas LP, Series 2017-1A, Class A2, 5.927%, 8/28/27 (144A) $ 4,082,039 1,000,000 Foursight Capital Automobile Receivables Trust, Series 2018-1, Class D, 4.19%, 11/15/23 (144A) 1,007,265 1,770,928(b) Fremont Home Loan Trust, Series 2006-2, Class 1A1, 2.666% (1 Month USD LIBOR + 16 bps), 2/25/36 1,735,231 415,000 GLS Auto Receivables Trust, Series 2017-1A, Class B, 2.98%, 12/15/21 (144A) 413,537 59,996(d) GMAT Trust, Series 2013-1A, Class A, 6.967%, 11/25/43 (144A) 60,017 863,200(b) GSRPM Mortgage Loan Trust, Series 2003-2, Class M1, 3.856% (1 Month USD LIBOR + 135 bps), 6/25/33 858,197 111,197(b) GSRPM Mortgage Loan Trust, Series 2006-2, Class A2, 2.806% (1 Month USD LIBOR + 30 bps), 9/25/36 (144A) 111,071 4,882,763 Hardee's Funding LLC, Series 2018-1A, Class A2II, 4.959%, 6/20/48 (144A) 4,972,849 2,250,000(b) Hertz Fleet Lease Funding LP, Series 2016-1, Class E, 5.887% (1 Month USD LIBOR + 350 bps), 4/10/30 (144A) 2,258,569 1,850,000 Hertz Fleet Lease Funding LP, Series 2018-1, Class C, 3.77%, 5/10/32 (144A) 1,867,328 2,800,000 Hertz Fleet Lease Funding LP, Series 2018-1, Class D, 4.17%, 5/10/32 (144A) 2,827,042 2,790,750 HOA Funding LLC, Series 2014-1A, Class A2, 4.846%, 8/20/44 (144A) 2,779,308 6,360,149(b) Home Partners of America Trust, Series 2018-1, Class A, 3.355% (1 Month USD LIBOR + 90 bps), 7/17/37 (144A) 6,306,570 782,184 Icon Brand Holdings LLC, Series 2012-1A, Class A, 4.229%, 1/25/43 (144A) 540,113 213,490 Icon Brand Holdings LLC, Series 2013-1A, Class A2, 4.352%, 1/25/43 (144A) 120,915 3,650,000(b) Invitation Homes Trust, Series 2018-SFR1, Class C, 3.705% (1 Month USD LIBOR + 125 bps), 3/17/37 (144A) 3,609,420 3,971,992 JG Wentworth XLI LLC, Series 2018-1A, Class A, 3.74%, 10/17/72 (144A) 3,948,065 374,100 JG Wentworth XXII LLC, Series 2010-3A, Class A, 3.82%, 12/15/48 (144A) 378,635 3,750,000 Kabbage Asset Securitization LLC, Series 2017-1, Class A, 4.571%, 3/15/22 (144A) 3,775,034 1,200,000 Kabbage Asset Securitization LLC, Series 2017-1, Class B, 5.794%, 3/15/22 (144A) 1,211,387 16,286 Lehman ABS Manufactured Housing Contract Trust, Series 2001-B, Class A1, 3.01%, 4/15/40 16,293 5,818,372 Marlette Funding Trust, Series 2018-3A, Class A, 3.2%, 9/15/28 (144A) 5,811,292 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 21 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- ASSET BACKED SECURITIES -- (continued) 1,750,000 Marlin Receivables LLC, Series 2018-1A, Class C, 3.7%, 6/20/23 (144A) $ 1,760,374 3,383,000(c) Mill City Mortgage Loan Trust, Series 2017-1, Class M2, 3.25%, 11/25/58 (144A) 3,209,440 14,000,000(c) Mill City Mortgage Loan Trust, Series 2018-2, Class M1, 3.75%, 5/25/58 (144A) 13,409,943 11,108,973(c) Mill City Mortgage Loan Trust, Series 2018-3, Class A1, 3.5%, 8/25/58 (144A) 11,020,520 2,645,000(c) Nationstar HECM Loan Trust, Series 2018-3A, Class M3, 4.353%, 11/25/28 (144A) 2,644,999 2,170,693(b) New Century Home Equity Loan Trust, Series 2005-2, Class M2, 3.181% (1 Month USD LIBOR + 68 bps), 6/25/35 2,169,461 2,850,000 New Residential Advance Receivables Trust Advance Receivables Backed Notes, Series 2016-T2, Class BT2, 3.02%, 10/15/49 (144A) 2,827,742 3,619,080(b) Newtek Small Business Loan Trust, Series 2017-1, Class A, 4.506% (1 Month USD LIBOR + 200 bps), 2/15/43 (144A) 3,616,134 2,149,242(b) NovaStar Mortgage Funding Trust, Series 2005-3, Class M1, 3.181% (1 Month USD LIBOR + 68 bps), 1/25/36 2,140,981 1,775,000 Ocwen Master Advance Receivables Trust, Series 2016-T2, Class BT2, 3.265%, 8/16/49 (144A) 1,769,888 5,305,000 OneMain Financial Issuance Trust, Series 2015-2A, Class D, 5.64%, 7/18/25 (144A) 5,343,444 1,176,572(b) Option One Mortgage Loan Trust, Series 2005-3, Class M2, 3.241% (1 Month USD LIBOR + 74 bps), 8/25/35 1,172,841 834,164 Oxford Finance Funding LLC, Series 2016-1A, Class A, 3.968%, 6/17/24 (144A) 836,749 3,250,000 Progress Residential Trust, Series 2018-SFR2, Class E, 4.656%, 8/17/35 (144A) 3,233,219 5,810,000 Progress Residential Trust, Series 2018-SFR3, Class E, 4.873%, 10/17/35 (144A) 5,884,205 2,000,000 Purchasing Power Funding LLC, Series 2018-A, Class A, 3.34%, 8/15/22 (144A) 1,993,831 3,306(b) RAAC Trust, Series 2006-RP2, Class A, 2.756% (1 Month USD LIBOR + 25 bps), 2/25/37 (144A) 3,305 1,745,840(d) RCO Mortgage LLC, Series 2017-1, Class A1, 3.375%, 8/25/22 (144A) 1,735,589 1,859,896 SCF Equipment Leasing LLC, Series 2017-2A, Class A, 3.41%, 12/20/23 (144A) 1,856,386 2,250,000 SCF Equipment Leasing LLC, Series 2018-1A, Class C, 4.21%, 4/20/27 (144A) 2,296,337 152,231 SCF Equipment Trust LLC, Series 2016-1A, Class A, 3.62%, 11/20/21 (144A) 151,948 3,126,030 Spirit Master Funding LLC, Series 2014-4A, Class A2, 4.629%, 1/20/45 (144A) 3,151,336 The accompanying notes are an integral part of these financial statements. 22 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- ASSET BACKED SECURITIES -- (continued) 1,472,500 STORE Master Funding I LLC, Series 2015-1A, Class A1, 3.75%, 4/20/45 (144A) $ 1,456,279 7,188(d) Structured Asset Securities Corp., Series 2004-19XS, Class A6B, 4.971%, 10/25/34 7,310 163,339(d) Terwin Mortgage Trust, Series 2005-16HE, Class AF2, 4.761%, 9/25/36 163,156 3,200,000 Tidewater Auto Receivables Trust, Series 2018-AA, Class C, 3.84%, 11/15/24 (144A) 3,215,973 1,078,000 Tidewater Auto Receivables Trust, Series 2018-AA, Class D, 4.3%, 11/15/24 (144A) 1,085,199 1,767,847 Tidewater Sales Finance Master Trust, Series 2017-AA, Class A, 4.55%, 4/15/21 (144A) 1,765,038 686,270 TLF National Tax Lien Trust, Series 2017-1A, Class B, 3.84%, 12/15/29 (144A) 686,263 1,195,000(c) Towd Point Mortgage Trust, Series 2015-2, Class 1M1, 3.25%, 11/25/60 (144A) 1,165,289 9,375,000(c) Towd Point Mortgage Trust, Series 2015-5, Class M1, 3.5%, 5/25/55 (144A) 9,285,468 10,011,000(c) Towd Point Mortgage Trust, Series 2016-3, Class M1, 3.5%, 4/25/56 (144A) 9,878,370 9,130,000(c) Towd Point Mortgage Trust, Series 2016-4, Class M1, 3.25%, 7/25/56 (144A) 8,775,445 3,000,000(c) Towd Point Mortgage Trust, Series 2016-5, Class M1, 3.375%, 10/25/56 (144A) 2,882,360 4,985,000(c) Towd Point Mortgage Trust, Series 2017-4, Class A2, 3.0%, 6/25/57 (144A) 4,675,921 11,500,000(c) Towd Point Mortgage Trust, Series 2017-6, Class A2, 3.0%, 10/25/57 (144A) 10,658,837 6,572,097(c) Towd Point Mortgage Trust, Series 2018-3, Class A1, 3.75%, 5/25/58 (144A) 6,567,969 3,250,000(c) Towd Point Mortgage Trust, Series 2018-3, Class A2, 3.875%, 5/25/58 (144A) 3,187,031 8,498,157(c) Towd Point Mortgage Trust, Series 2018-4, Class A1, 3.0%, 6/25/58 (144A) 8,262,066 11,489,050(c) Towd Point Mortgage Trust, Series 2018-6, Class A1A, 3.75%, 3/25/58 (144A) 11,495,367 11,860,000(c) Towd Point Mortgage Trust, Series 2018-SJ1, Class A1, 4.0%, 10/25/58 (144A) 11,857,818 3,000,000(b) Trafigura Securitisation Finance Plc, Series 2017-1A, Class A1, 3.305% (1 Month USD LIBOR + 85 bps), 12/15/20 (144A) 3,007,500 8,500,000 Tricon American Homes Trust, Series 2017-SFR2, Class B, 3.275%, 1/17/36 (144A) 8,237,569 44,053 United States Small Business Administration, 6.14%, 1/1/22 45,250 194,437 United States Small Business Administration, Series 2005-20B, Class 1, 4.625%, 2/1/25 199,815 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 23 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- ASSET BACKED SECURITIES -- (continued) 172,505 United States Small Business Administration, Series 2005-20E, Class 1, 4.84%, 5/1/25 $ 177,921 249,626 United States Small Business Administration, Series 2008-20D, Class 1, 5.37%, 4/1/28 263,647 266,407 United States Small Business Administration, Series 2008-20H, Class 1, 6.02%, 8/1/28 285,833 171,604 United States Small Business Administration, Series 2008-20J, Class 1, 5.63%, 10/1/28 183,962 147,008 United States Small Business Administration, Series 2008-20L, Class 1, 6.22%, 12/1/28 160,048 66,348 United States Small Business Administration, Series 2009-20A, Class 1, 5.72%, 1/1/29 71,183 160,191 United States Small Business Administration, Series 2009-20I, Class 1, 4.2%, 9/1/29 166,584 5,945,980 Upstart Securitization Trust, Series 2018-2, Class A, 3.33%, 12/22/25 (144A) 5,936,599 702,809 Welk Resorts LLC, Series 2015-AA, Class A, 2.79%, 6/16/31 (144A) 693,314 2,353,570 Welk Resorts LLC, Series 2017-AA, Class B, 3.41%, 6/15/33 (144A) 2,314,763 1,671,711 Westgate Resorts LLC, Series 2016-1A, Class B, 4.5%, 12/20/28 (144A) 1,664,461 1,226,688 Westgate Resorts LLC, Series 2017-1A, Class A, 3.05%, 12/20/30 (144A) 1,218,275 6,762,674 Westgate Resorts LLC, Series 2018-1A, Class C, 4.1%, 12/20/31 (144A) 6,772,623 1,000,000 Westlake Automobile Receivables Trust, Series 2017-2A, Class C, 2.59%, 12/15/22 (144A) 992,136 1,970,000 Westlake Automobile Receivables Trust, Series 2018-1A, Class E, 4.53%, 5/15/23 (144A) 1,964,390 1,900,000 Westlake Automobile Receivables Trust, Series 2018-2A, Class D, 4.0%, 1/16/24 (144A) 1,917,196 6,530,000 Westlake Automobile Receivables Trust, Series 2018-3A, Class B, 3.32%, 10/16/23 (144A) 6,543,629 3,870,000 Westlake Automobile Receivables Trust, Series 2018-3A, Class E, 4.9%, 12/15/23 (144A) 3,908,838 2,500,000 WRG Debt Funding II LLC, Series 2017-1, Class A, 4.458%, 3/15/26 (144A) 2,482,031 --------------------------------------------------------------------------------------------------------------------------------- TOTAL ASSET BACKED SECURITIES (Cost $358,559,120) $ 357,626,512 --------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- 24.1% of Net Assets 3,190,000 A10 Term Asset Financing LLC, Series 2017-1A, Class B, 3.15%, 3/15/36 (144A) $ 3,093,702 4,028,789(c) Agate Bay Mortgage Trust, Series 2015-1, Class A13, 3.5%, 1/25/45 (144A) 3,951,808 4,004,242(c) Agate Bay Mortgage Trust, Series 2015-7, Class B3, 3.766%, 10/25/45 (144A) 3,844,346 The accompanying notes are an integral part of these financial statements. 24 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 16,795(b) Alternative Loan Trust, Series 2003-14T1, Class A9, 2.956% (1 Month USD LIBOR + 45 bps), 8/25/18 $ 10,512 2,800,000 American Homes 4 Rent, Series 2014-SFR3, Class C, 4.596%, 12/17/36 (144A) 2,917,863 700,000 American Homes 4 Rent, Series 2014-SFR3, Class D, 5.04%, 12/17/36 (144A) 738,320 1,300,000 American Homes 4 Rent, Series 2015-SFR1, Class C, 4.11%, 4/17/52 (144A) 1,321,871 5,200,000(b) Arbor Realty Commercial Real Estate Notes, Ltd., Series 2017-FL1, Class B, 4.955% (1 Month USD LIBOR + 250 bps), 4/15/27 (144A) 5,356,000 1,149,596 B2R Mortgage Trust, Series 2015-1, Class A1, 2.524%, 5/15/48 (144A) 1,136,993 5,900,000(b) BAMLL Commercial Mortgage Securities Trust, Series 2014-FL1, Class B, 4.507% (1 Month USD LIBOR + 220 bps), 12/15/31 (144A) 5,901,857 3,500,000(c) BAMLL Commercial Mortgage Securities Trust, Series 2016-FR14, Class A, 3.012%, 2/27/48 (144A) 3,445,057 7,460,000 BANK, Series 2017-BNK5, Class AS, 3.624%, 6/15/60 7,359,698 9,000,000 BANK, Series 2017-BNK7, Class AS, 3.748%, 9/15/60 8,914,094 6,869,884(c) Bayview Opportunity Master Fund IVb Trust, Series 2017-RT2, Class A, 3.5%, 8/28/57 (144A) 6,809,407 3,125,771(c) Bayview Opportunity Master Fund IVb Trust, Series 2017-SPL4, Class A, 3.5%, 1/28/55 (144A) 3,098,072 686,066(c) Bear Stearns Commercial Mortgage Securities Trust, Series 2005-PWR7, Class B, 5.214%, 2/11/41 682,176 3,657,457(b) Bellemeade Re, Ltd., Series 2017-1, Class M1, 4.206% (1 Month USD LIBOR + 170 bps), 10/25/27 (144A) 3,673,583 6,440,000(b) Bellemeade Re, Ltd., Series 2018-1A, Class M1B, 4.106% (1 Month USD LIBOR + 160 bps), 4/25/28 (144A) 6,439,992 5,430,000(b) Bellemeade Re, Ltd., Series 2018-2A, Class M1B, 3.856% (1 Month USD LIBOR + 135 bps), 8/25/28 (144A) 5,404,322 4,320,000(b) Bellemeade Re, Ltd., Series 2018-3A, Class M1B, 4.356% (1 Month USD LIBOR + 185 bps), 10/25/27 (144A) 4,313,126 7,000,000 Benchmark Mortgage Trust, Series 2018-B2, Class A4, 3.615%, 2/15/51 7,018,331 4,200,000 Benchmark Mortgage Trust, Series 2018-B5, Class A3, 3.944%, 7/15/51 4,282,057 7,400,000 Benchmark Mortgage Trust, Series 2018-B8, Class A4, 3.963%, 1/15/52 7,528,872 4,700,000(b) BTH-13 Mortgage Backed Securities Trust, Series 2018-13, Class A, 4.807% (1 Month USD LIBOR + 250 bps), 8/18/21 (144A) 4,700,382 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 25 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 4,187,548(c) Cascade Funding Mortgage Trust, Series 2018-RM2, Class A, 4.0%, 10/25/68 (144A) $ 4,209,365 3,250,000 CCRESG Commercial Mortgage Trust, Series 2016-HEAT, Class A, 3.357%, 4/10/29 (144A) 3,250,739 3,675,000 CD Mortgage Trust, Series 2018-CD7, Class A3, 4.013%, 8/15/51 3,762,121 4,000,000 CFCRE Commercial Mortgage Trust, Series 2016-C3, Class A2, 3.597%, 1/10/48 3,989,672 173,621(c) CHL Mortgage Pass-Through Trust, Series 2003-56, Class 4A2, 4.542%, 12/25/33 177,201 5,117,488(c) CIM Trust, Series 2018-J1, Class A10, 3.5%, 3/25/48 (144A) 5,059,703 3,400,000(c) Citigroup Commercial Mortgage Trust, Series 2014-GC19, Class B, 4.805%, 3/10/47 3,546,727 6,000,000(c) Citigroup Commercial Mortgage Trust, Series 2014-GC25, Class B, 4.345%, 10/10/47 6,135,721 3,100,000 Citigroup Commercial Mortgage Trust, Series 2015-GC27, Class A5, 3.137%, 2/10/48 3,046,986 6,052,000(c) Citigroup Commercial Mortgage Trust, Series 2015-GC33, Class B, 4.569%, 9/10/58 6,213,208 4,621,000 Citigroup Commercial Mortgage Trust, Series 2016-P5, Class D, 3.0%, 10/10/49 (144A) 3,739,291 1,007,654(c) Citigroup Mortgage Loan Trust, Series 2014-J1, Class A1, 3.5%, 6/25/44 (144A) 995,590 10,998,099(c) Citigroup Mortgage Loan Trust, Series 2018-RP2, Class A1, 3.5%, 2/25/58 (144A) 11,026,694 9,314,141(c) Citigroup Mortgage Loan Trust, Inc., Series 2018-RP1, Class A1, 3.0%, 9/25/64 (144A) 9,236,423 2,037,137 Colony American Finance, Ltd., Series 2015-1, Class A, 2.896%, 10/15/47 (144A) 2,024,639 2,400,000(d) Colony American Finance, Ltd., Series 2016-1, Class D, 5.972%, 6/15/48 (144A) 2,424,041 2,400,000(d) Colony American Finance, Ltd., Series 2016-2, Class D, 5.028%, 11/15/48 (144A) 2,385,904 1,556,526(b) Colony Starwood Homes Trust, Series 2016-2A, Class B, 4.205% (1 Month USD LIBOR + 175 bps), 12/17/33 (144A) 1,557,007 4,186,968(c) COLT Mortgage Loan Trust, Series 2018-3, Class A1, 3.692%, 10/26/48 (144A) 4,182,495 2,090,000 COMM Mortgage Trust, Series 2012-CR2, Class AM, 3.791%, 8/15/45 2,126,673 2,940,633 COMM Mortgage Trust, Series 2012-CR3, Class A3, 2.822%, 10/15/45 2,894,543 5,000,000(c) COMM Mortgage Trust, Series 2013-CR11, Class C, 5.166%, 8/10/50 (144A) 5,120,788 1,900,000 COMM Mortgage Trust, Series 2013-LC6, Class A4, 2.941%, 1/10/46 1,880,369 The accompanying notes are an integral part of these financial statements. 26 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 2,500,000(c) COMM Mortgage Trust, Series 2014-CR16, Class C, 4.901%, 4/10/47 $ 2,550,048 7,325,000(c) COMM Mortgage Trust, Series 2014-CR20, Class C, 4.502%, 11/10/47 7,253,374 296,318(b) COMM Mortgage Trust, Series 2014-FL5, Class B, 3.693% (1 Month USD LIBOR + 215 bps), 10/15/31 (144A) 295,666 6,600,000 COMM Mortgage Trust, Series 2014-UBS3, Class A3, 3.546%, 6/10/47 6,653,347 4,500,000(c) COMM Mortgage Trust, Series 2014-UBS3, Class C, 4.781%, 6/10/47 4,466,056 4,100,000 COMM Mortgage Trust, Series 2014-UBS4, Class A4, 3.42%, 8/10/47 4,105,252 5,200,000 COMM Mortgage Trust, Series 2015-3BP, Class A, 3.178%, 2/10/35 (144A) 5,121,882 4,000,000(c) COMM Mortgage Trust, Series 2015-CR23, Class CMD, 3.685%, 5/10/48 (144A) 3,951,364 3,104,000(c) COMM Mortgage Trust, Series 2015-CR25, Class B, 4.544%, 8/10/48 3,194,194 6,300,000 COMM Mortgage Trust, Series 2015-CR26, Class A3, 3.359%, 10/10/48 6,251,104 4,500,000(c) COMM Mortgage Trust, Series 2015-DC1, Class B, 4.035%, 2/10/48 4,497,746 7,120,000(c) CSAIL Commercial Mortgage Trust, Series 2016-C5, Class C, 4.537%, 11/15/48 7,150,746 2,090,000 CSAIL Commercial Mortgage Trust, Series 2016-C6, Class A5, 3.09%, 1/15/49 2,020,647 8,493,289(c) CSMC Trust, Series 2013-6, Class 2A3, 3.5%, 8/25/43 (144A) 8,359,881 4,309,848(c) CSMC Trust, Series 2013-IVR3, Class A1, 2.5%, 5/25/43 (144A) 4,064,264 3,847,037(c) CSMC Trust, Series 2013-IVR3, Class A3, 1.55%, 5/25/43 (144A) 3,703,065 3,590,690(c) CSMC Trust, Series 2013-IVR3, Class B2, 3.452%, 5/25/43 (144A) 3,563,022 2,695,585(c) CSMC Trust, Series 2013-IVR3, Class B4, 3.452%, 5/25/43 (144A) 2,552,490 2,858,767(c) CSMC Trust, Series 2013-IVR5, Class B4, 3.651%, 10/25/43 (144A) 2,815,669 8,228,254(c) CSMC Trust, Series 2013-TH1, Class A1, 2.13%, 2/25/43 (144A) 7,671,765 4,553,651(c) CSMC Trust, Series 2017-HL2, Class A1, 3.5%, 10/25/47 (144A) 4,466,954 6,908,159(c) CSMC Trust, Series 2017-HL2, Class A3, 3.5%, 10/25/47 (144A) 6,813,013 16,533,880(c) CSMC Trust, Series 2018-J1, Class A11, 3.5%, 2/25/48 (144A) 15,955,473 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 27 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 6,000,000 DBJPM Mortgage Trust, Series 2016-C3, Class A5, 2.89%, 8/10/49 $ 5,724,985 1,851,352(c) Deephaven Residential Mortgage Trust, Series 2017-3A, Class A1, 2.577%, 10/25/47 (144A) 1,827,757 4,435,946(c) Deephaven Residential Mortgage Trust, Series 2018-1A, Class A1, 2.976%, 12/25/57 (144A) 4,393,480 5,470,000(b) Eagle Re, Ltd., Series 2018-1, Class M1, 3.98% (1 Month USD LIBOR + 170 bps), 11/25/28 (144A) 5,462,419 4,087,634(c) EverBank Mortgage Loan Trust, Series 2013-2, Class A, 3.0%, 6/25/43 (144A) 3,942,251 2,257,767(b) Fannie Mae Connecticut Avenue Securities, Series 2018-C01, Class 1M1, 3.106% (1 Month USD LIBOR + 60 bps), 7/25/30 2,249,737 1,072,491(b) Fannie Mae Connecticut Avenue Securities, Series 2018-C04, Class 2M1, 3.256% (1 Month USD LIBOR + 75 bps), 12/25/30 1,071,656 7,205,366(b) Fannie Mae Connecticut Avenue Securities, Series 2018-C05, Class 1M1, 3.226% (1 Month USD LIBOR + 72 bps), 1/25/31 7,188,288 571,357(c) Fannie Mae Grantor Trust, Series 2004-T2, Class 2A, 4.371%, 7/25/43 600,326 23,482(b) Federal Home Loan Mortgage Corp. REMICS, Series 3780, Class FE, 2.855% (1 Month USD LIBOR + 40 bps), 12/15/20 23,542 1,426,911 Federal Home Loan Mortgage Corp. Whole Loan Securities Trust, Series 2017-SC02, Class 2A1, 3.5%, 5/25/47 1,424,053 6 Federal National Mortgage Association REMICS, Series 1989-19, Class B, 10.3%, 4/25/19 6 270,901 Federal National Mortgage Association REMICS, Series 2009-36, Class HX, 4.5%, 6/25/29 278,116 997,386 Federal National Mortgage Association REMICS, Series 2013-128, Class DV, 3.0%, 6/25/23 993,975 2,197,000(c) FirstKey Mortgage Trust, Series 2015-1, Class B4, 3.924%, 3/25/45 (144A) 2,032,225 10,010,778(c) Flagstar Mortgage Trust, Series 2018-1, Class A3, 3.5%, 3/25/48 (144A) 9,804,165 5,455,113(c) Flagstar Mortgage Trust, Series 2018-2, Class A14, 3.5%, 4/25/48 (144A) 5,202,748 7,853,452(c) Flagstar Mortgage Trust, Series 2018-2, Class B1, 4.076%, 4/25/48 (144A) 7,967,471 9,360,805(c) Flagstar Mortgage Trust, Series 2018-3INV, Class A3, 4.0%, 5/25/48 (144A) 9,373,115 4,686,013(c) Flagstar Mortgage Trust, Series 2018-3INV, Class B1, 4.518%, 5/25/48 (144A) 4,874,650 4,853,406(c) Flagstar Mortgage Trust, Series 2018-3INV, Class B3, 4.518%, 5/25/48 (144A) 4,840,246 The accompanying notes are an integral part of these financial statements. 28 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 6,906,687(c) Flagstar Mortgage Trust, Series 2018-5, Class A7, 4.0%, 9/25/48 (144A) $ 6,928,543 8,670,000(b) Freddie Mac Stacr Trust, Series 2018-HQA2, Class M1, 3.256% (1 Month USD LIBOR + 75 bps), 10/25/48 (144A) 8,649,383 2,695,000(b) Freddie Mac Structured Agency Credit Risk Debt Notes, Series 2016-DNA4, Class M2, 3.806% (1 Month USD LIBOR + 130 bps), 3/25/29 2,697,976 3,719,791(b) Freddie Mac Structured Agency Credit Risk Debt Notes, Series 2018-HQA1, Class M1, 3.206% (1 Month USD LIBOR + 70 bps), 9/25/30 3,711,080 3,503,145(c) Freddie Mac Structured Agency Credit Risk Debt Notes, Series 2018-SPI3, Class M1, 4.167%, 8/25/48 (144A) 3,511,975 890,000(c) FREMF Mortgage Trust, Series 2010-K9, Class B, 5.207%, 9/25/45 (144A) 917,349 2,060,000(c) FREMF Mortgage Trust, Series 2012-K710, Class B, 3.817%, 6/25/47 (144A) 2,058,514 902,511(b) FREMF Mortgage Trust, Series 2014-KF05, Class B, 6.347% (1 Month USD LIBOR + 400 bps), 9/25/22 (144A) 934,552 2,653,276(b) FREMF Mortgage Trust, Series 2014-KS02, Class B, 7.347% (1 Month USD LIBOR + 500 bps), 8/25/23 (144A) 2,726,453 3,700,000(c) FREMF Mortgage Trust, Series 2015-K51, Class B, 3.953%, 10/25/48 (144A) 3,664,387 5,987,422(c) FRESB Mortgage Trust, Series 2018-SB52, Class A7F, 3.39%, 6/25/25 6,077,840 4,630,000(c) GAHR Commercial Mortgage Trust, Series 2015-NRF, Class CFX, 3.382%, 12/15/34 (144A) 4,589,944 1,055,607 Government National Mortgage Association, Series 2005-61, Class UZ, 5.25%, 8/16/35 1,111,292 601,767 Government National Mortgage Association, Series 2012-130, Class PA, 3.0%, 4/20/41 600,078 669,612 Government National Mortgage Association, Series 2013-169, Class TE, 3.25%, 4/16/27 668,592 38,827,615(c)(e) Government National Mortgage Association, Series 2017-21, Class IO, 0.795%, 10/16/58 2,869,877 3,698,022 Government National Mortgage Association, Series 2018-20, Class A, 2.5%, 9/16/49 3,626,240 1,000,000 GS Mortgage Securities Corp. II, Series 2013-GC10, Class B, 3.682%, 2/10/46 (144A) 995,362 5,030,000(c) GS Mortgage Securities Trust, Series 2013-GC12, Class C, 4.179%, 6/10/46 4,919,945 6,500,000 GS Mortgage Securities Trust, Series 2015-GC28, Class A5, 3.396%, 2/10/48 6,463,545 3,603,131(c) GS Mortgage-Backed Securities Trust, Series 2014-EB1A, Class B3, 3.116%, 7/25/44 (144A) 3,604,358 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 29 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 2,475,026 GS Mortgage-Backed Securities Trust, Series 2018-RPL1, Class A1A, 3.75%, 10/25/57 (144A) $ 2,483,949 750,000(b) Home Partners of America Trust, Series 2017-1, Class B, 3.805% (1 Month USD LIBOR + 135 bps), 7/17/34 (144A) 746,741 2,270,000(b) Home Re, Ltd., Series 2018-1, Class M1, 4.106% (1 Month USD LIBOR + 160 bps), 10/25/28 (144A) 2,272,765 251,157(b) JP Morgan Chase Commercial Mortgage Securities Trust, Series 2006-LDP9, Class A3SF, 2.61% (1 Month USD LIBOR + 16 bps), 5/15/47 251,157 901,860 JP Morgan Chase Commercial Mortgage Securities Trust, Series 2011-C5, Class A3, 4.171%, 8/15/46 919,941 1,900,000(c) JP Morgan Chase Commercial Mortgage Securities Trust, Series 2012-C8, Class B, 3.977%, 10/15/45 (144A) 1,906,769 4,555,234 JP Morgan Chase Commercial Mortgage Securities Trust, Series 2012-LC9, Class A5, 2.84%, 12/15/47 4,475,951 5,925,000(c) JP Morgan Chase Commercial Mortgage Securities Trust, Series 2018-BCON, Class C, 3.756%, 1/5/31 (144A) 5,931,570 6,700,000 JP Morgan Chase Commercial Mortgage Securities Trust, Series 2018-WPT, Class AFX, 4.248%, 7/5/33 (144A) 6,956,185 7,353,064(c) JP Morgan Mortgage Trust, Series 2013-1, Class 2A2, 2.5%, 3/25/43 (144A) 7,091,972 2,619,156(c) JP Morgan Mortgage Trust, Series 2013-1, Class 2A3, 3.0%, 3/25/43 (144A) 2,575,932 4,907,215(c) JP Morgan Mortgage Trust, Series 2016-3, Class 2A1, 3.0%, 10/25/46 (144A) 4,829,720 7,347,507(c) JP Morgan Mortgage Trust, Series 2016-4, Class A13, 3.5%, 10/25/46 (144A) 7,225,539 8,273,635(c) JP Morgan Mortgage Trust, Series 2016-5, Class AM, 2.649%, 12/25/46 (144A) 8,164,608 5,569,050(c) JP Morgan Mortgage Trust, Series 2016-5, Class B1, 2.648%, 12/25/46 (144A) 5,545,575 1,886,770(c) JP Morgan Mortgage Trust, Series 2017-1, Class A3, 3.5%, 1/25/47 (144A) 1,861,538 10,555,000(c) JP Morgan Mortgage Trust, Series 2017-1, Class A6, 3.5%, 1/25/47 (144A) 10,318,769 2,485,273(c) JP Morgan Mortgage Trust, Series 2017-2, Class A4, 3.0%, 5/25/47 (144A) 2,397,024 13,789,615(c) JP Morgan Mortgage Trust, Series 2017-2, Class A6, 3.0%, 5/25/47 (144A) 13,414,648 1,418,547(c) JP Morgan Mortgage Trust, Series 2017-2, Class B1, 3.742%, 5/25/47 (144A) 1,384,583 4,970,341(c) JP Morgan Mortgage Trust, Series 2017-3, Class 1A13, 3.5%, 8/25/47 (144A) 4,886,669 The accompanying notes are an integral part of these financial statements. 30 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 4,828,699(c) JP Morgan Mortgage Trust, Series 2017-3, Class 1A3, 3.5%, 8/25/47 (144A) $ 4,737,732 3,745,252(c) JP Morgan Mortgage Trust, Series 2017-3, Class 1A5, 3.5%, 8/25/47 (144A) 3,697,414 4,278,425(c) JP Morgan Mortgage Trust, Series 2017-3, Class 1A6, 3.0%, 8/25/47 (144A) 4,136,721 8,926,283(c) JP Morgan Mortgage Trust, Series 2017-3, Class 2A2, 2.5%, 8/25/47 (144A) 8,587,012 3,659,464(c) JP Morgan Mortgage Trust, Series 2017-4, Class A3, 3.5%, 11/25/48 (144A) 3,590,707 7,760,358(c) JP Morgan Mortgage Trust, Series 2017-4, Class A5, 3.5%, 11/25/48 (144A) 7,661,235 15,376,451(c) JP Morgan Mortgage Trust, Series 2017-4, Class A6, 3.0%, 11/25/48 (144A) 15,185,929 4,703,658(c) JP Morgan Mortgage Trust, Series 2017-5, Class A1A, 3.0%, 10/26/48 (144A) 4,676,074 1,680,312(c) JP Morgan Mortgage Trust, Series 2017-5, Class A2, 3.176%, 10/26/48 (144A) 1,663,481 4,428,297(c) JP Morgan Mortgage Trust, Series 2017-5, Class B1, 3.176%, 10/26/48 (144A) 4,349,959 2,946,644(c) JP Morgan Mortgage Trust, Series 2017-6, Class A13, 3.5%, 12/25/48 (144A) 2,830,271 13,108,284(c) JP Morgan Mortgage Trust, Series 2017-6, Class A5, 3.5%, 12/25/48 (144A) 12,932,987 97,085(c) JP Morgan Mortgage Trust, Series 2017-6, Class A6, 3.0%, 12/25/48 (144A) 94,381 10,089,368(c) JP Morgan Mortgage Trust, Series 2017-6, Class B1, 3.849%, 12/25/48 (144A) 9,975,775 2,944,160(c) JP Morgan Mortgage Trust, Series 2018-1, Class B1, 3.768%, 6/25/48 (144A) 2,857,633 9,273,701(c) JP Morgan Mortgage Trust, Series 2018-3, Class A5, 3.5%, 9/25/48 (144A) 9,149,452 3,838,715(c) JP Morgan Mortgage Trust, Series 2018-3, Class B1, 3.782%, 9/25/48 (144A) 3,727,875 13,815,000(c) JP Morgan Mortgage Trust, Series 2018-4, Class A17, 3.5%, 10/25/48 (144A) 13,506,318 740,728(c) JP Morgan Mortgage Trust, Series 2018-4, Class A5, 3.5%, 10/25/48 (144A) 730,803 5,207,215(c) JP Morgan Mortgage Trust, Series 2018-4, Class B2, 3.797%, 10/25/48 (144A) 4,950,862 12,049,350(c) JP Morgan Mortgage Trust, Series 2018-6, Class 2A2, 3.0%, 12/25/48 (144A) 11,844,607 8,910,123(c) JP Morgan Mortgage Trust, Series 2018-9, Class A3, 4.0%, 2/25/49 (144A) 8,936,131 3,801,385(c) JP Morgan Mortgage Trust, Series 2018-9, Class A5, 4.0%, 2/25/49 (144A) 3,821,281 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 31 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 3,952,630(c) JP Morgan Trust, Series 2015-3, Class A6, 3.0%, 5/25/45 (144A) $ 3,902,206 4,239,986(c) JP Morgan Trust, Series 2015-3, Class B3, 3.678%, 5/25/45 (144A) 4,073,217 7,850,000 JPMBB Commercial Mortgage Securities Trust, Series 2015-C32, Class A4, 3.329%, 11/15/48 7,776,064 3,450,000(c) JPMDB Commercial Mortgage Securities Trust, Series 2016-C2, Class B, 3.99%, 6/15/49 3,390,271 6,650,000 JPMDB Commercial Mortgage Securities Trust, Series 2016-C4, Class A3, 3.141%, 12/15/49 6,439,538 2,000,000(c) JPMDB Commercial Mortgage Securities Trust, Series 2016-C4, Class D, 3.093%, 12/15/49 (144A) 1,626,639 7,640,000 JPMDB Commercial Mortgage Securities Trust, Series 2018-C8, Class A4, 4.211%, 6/15/51 7,934,770 45,714,000(c)(e) JPMDB Commercial Mortgage Securities Trust, Series 2018-C8, Class XB, 0.113%, 6/15/51 524,550 1,878,399 La Hipotecaria El Salvadorian Mortgage Trust, Series 2016-1A, Class A, 3.358%, 1/15/46 (144A) 1,831,541 936,322(b) La Hipotecaria Panamanian Mortgage Trust, Series 2010-1GA, Class A, 2.5% (Panamanian Mortgage Reference Rate + 300 bps), 9/8/39 (144A) 905,891 2,848,379(b) La Hipotecaria Panamanian Mortgage Trust, Series 2014-1A, Class A1, 3.258% (Panamanian Mortgage Reference Rate + 224 bps), 11/24/42 (144A) 2,765,598 3,690,000(c) LSTAR Commercial Mortgage Trust, Series 2015-3, Class AS, 3.128%, 4/20/48 (144A) 3,601,318 2,173,067(b) LSTAR Securities Investment, Ltd., Series 2017-7, Class A, 4.099% (1 Month USD LIBOR + 175 bps), 10/1/22 (144A) 2,184,368 3,486,576(b) LSTAR Securities Investment, Ltd., Series 2018-1, Class A, 3.849% (1 Month USD LIBOR + 200 bps), 4/1/21 (144A) 3,482,963 7,774,845(c) Mello Mortgage Capital Acceptance, Series 2018-MTG1, Class A1, 3.5%, 5/25/48 (144A) 7,676,920 6,607,577(c) Mill City Mortgage Loan Trust, Series 2017-3, Class M2, 3.25%, 1/25/61 (144A) 6,252,125 5,113,071 Morgan Stanley Bank of America Merrill Lynch Trust, Series 2012-C6, Class A4, 2.858%, 11/15/45 5,040,048 6,900,000 Morgan Stanley Capital I Trust, Series 2018-MP, Class A, 4.418%, 7/11/40 (144A) 7,230,354 404,549(b) MRFC Mortgage Pass-Through Trust, Series 2000-TBC3, Class A1, 2.895% (1 Month USD LIBOR + 44 bps), 12/15/30 389,852 5,661,586(b) New Residential Mortgage Loan Trust, Series 2018-4A, Class A1S, 3.256% (1 Month USD LIBOR + 75 bps), 1/25/48 (144A) 5,631,792 The accompanying notes are an integral part of these financial statements. 32 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 4,068,562(c) New Residential Mortgage Loan Trust, Series 2018-5A, Class A1, 4.75%, 12/25/57 (144A) $ 4,169,225 122,459(c) New Residential Mortgage Loan Trust, Series 2018-RPL1, Class A1, 3.5%, 12/25/57 (144A) 121,881 5,682,656(c) NRP Mortgage Trust, Series 2013-1, Class B1, 3.315%, 7/25/43 (144A) 5,613,485 4,370,876(c) NRP Mortgage Trust, Series 2013-1, Class B2, 3.315%, 7/25/43 (144A) 4,294,064 2,969,102(c) OBX Trust, Series 2018-EXP1, Class 1A6, 4.5%, 4/25/48 (144A) 3,011,087 452,692(b) Pepper Residential Securities Trust No. 18, Series 18A, Class A1UA, 3.371% (1 Month USD LIBOR + 95 bps), 3/12/47 (144A) 451,772 12,384,462(c) PMT Loan Trust, Series 2013-J1, Class A1, 3.5%, 9/25/43 (144A) 12,201,543 8,947,142(c) PMT Loan Trust, Series 2013-J1, Class A11, 3.5%, 9/25/43 (144A) 8,852,009 4,800,000 Progress Residential Trust, Series 2017-SFR1, Class B, 3.017%, 8/17/34 (144A) 4,701,075 700,000 Progress Residential Trust, Series 2017-SFR1, Class D, 3.565%, 8/17/34 (144A) 688,671 5,135,000 Progress Residential Trust, Series 2017-SFR2, Class B, 3.196%, 12/17/34 (144A) 5,052,138 6,404,038(c) PSMC Trust, Series 2018-1, Class A3, 3.5%, 2/25/48 (144A) 6,322,240 7,848,442(c) PSMC Trust, Series 2018-3, Class A3, 4.0%, 8/25/48 (144A) 7,893,096 5,430,000(b) Radnor Re, Ltd., Series 2018-1, Class M1, 3.906% (1 Month USD LIBOR + 140 bps), 3/25/28 (144A) 5,418,434 464,548(b) RESIMAC Premier, Series 2017-1A, Class A1A, 3.35% (1 Month USD LIBOR + 95 bps), 9/11/48 (144A) 463,044 5,072,982 Seasoned Credit Risk Transfer Trust, Series 2018-2, Class MT, 3.5%, 11/25/57 5,013,531 10,464,393 Seasoned Credit Risk Transfer Trust, Series 2018-4, Class MT, 3.5%, 11/25/57 10,341,761 2,675,199(c) Sequoia Mortgage Trust, Series 2012-6, Class A2, 1.808%, 12/25/42 2,500,486 2,821,043(c) Sequoia Mortgage Trust, Series 2012-6, Class B3, 3.733%, 12/25/42 2,794,145 3,715,711(c) Sequoia Mortgage Trust, Series 2013-2, Class A, 1.874%, 2/25/43 3,321,443 7,174,567(c) Sequoia Mortgage Trust, Series 2013-4, Class A1, 2.325%, 4/25/43 6,663,099 7,506,415(c) Sequoia Mortgage Trust, Series 2013-5, Class A1, 2.5%, 5/25/43 (144A) 6,995,915 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 33 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 15,415,642(c) Sequoia Mortgage Trust, Series 2013-5, Class A2, 3.0%, 5/25/43 (144A) $ 14,809,676 7,558,793(c) Sequoia Mortgage Trust, Series 2013-6, Class A1, 2.5%, 5/25/43 7,171,703 11,429,851(c) Sequoia Mortgage Trust, Series 2013-6, Class A2, 3.0%, 5/25/43 11,000,786 8,448,157(c) Sequoia Mortgage Trust, Series 2013-7, Class A1, 2.5%, 6/25/43 7,868,277 10,413,539(c) Sequoia Mortgage Trust, Series 2013-7, Class A2, 3.0%, 6/25/43 10,009,264 10,428,902(c) Sequoia Mortgage Trust, Series 2013-8, Class A1, 3.0%, 6/25/43 10,063,484 7,987,103 Sequoia Mortgage Trust, Series 2013-9, Class A1, 3.5%, 7/25/43 (144A) 7,889,449 9,931,616(c) Sequoia Mortgage Trust, Series 2013-10, Class A1, 3.5%, 8/25/43 (144A) 9,810,187 6,341,209(c) Sequoia Mortgage Trust, Series 2013-10, Class B1, 3.56%, 8/25/43 (144A) 6,314,598 3,711,474(c) Sequoia Mortgage Trust, Series 2015-1, Class A2, 3.0%, 1/25/45 (144A) 3,578,264 4,677,550(c) Sequoia Mortgage Trust, Series 2017-3, Class A1, 3.5%, 4/25/47 (144A) 4,583,817 3,500,537(c) Sequoia Mortgage Trust, Series 2017-4, Class A4, 3.5%, 7/25/47 (144A) 3,466,327 8,087,292(c) Sequoia Mortgage Trust, Series 2017-5, Class A1, 3.5%, 8/25/47 (144A) 7,947,977 7,887,251(c) Sequoia Mortgage Trust, Series 2017-7, Class A1, 3.5%, 10/25/47 (144A) 7,734,128 2,438,396(c) Sequoia Mortgage Trust, Series 2017-CH2, Class A1, 4.0%, 12/25/47 (144A) 2,464,411 11,478,187(c) Sequoia Mortgage Trust, Series 2018-3, Class A4, 3.5%, 3/25/48 (144A) 11,370,848 11,735,431(c) Sequoia Mortgage Trust, Series 2018-6, Class A22, 4.0%, 7/25/48 (144A) 11,932,697 9,580,477(c) Sequoia Mortgage Trust, Series 2018-8, Class A4, 4.0%, 11/25/48 (144A) 9,618,598 4,514,395(c) Sequoia Mortgage Trust, Series 2018-CH1, Class A1, 4.0%, 2/25/48 (144A) 4,557,072 5,300,684(c) Sequoia Mortgage Trust, Series 2018-CH3, Class A1, 4.5%, 8/25/48 (144A) 5,396,751 4,295,390(c) Sequoia Mortgage Trust, Series 2018-CH4, Class A10, 4.5%, 10/25/48 (144A) 4,379,502 6,721,676(c) Shellpoint Co-Originator Trust, Series 2015-1, Class A9, 3.5%, 8/25/45 (144A) 6,640,298 6,222,170(c) Shellpoint Co-Originator Trust, Series 2017-1, Class A1, 3.5%, 4/25/47 (144A) 6,116,539 The accompanying notes are an integral part of these financial statements. 34 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 12,005,724(c) Shellpoint Co-Originator Trust, Series 2017-2, Class A1, 3.5%, 10/25/47 (144A) $ 11,723,121 2,519,918(c) Shellpoint Co-Originator Trust, Series 2017-2, Class B1, 3.736%, 10/25/47 (144A) 2,468,117 2,765,821(c) Sofi Mortgage Trust, Series 2016-1A, Class 1A4, 3.0%, 11/25/46 (144A) 2,567,317 4,880,000(b) STACR Trust, Series 2018-DNA3, Class M1, 3.256% (1 Month USD LIBOR + 75 bps), 9/25/48 (144A) 4,870,593 6,450,000(b) STACR Trust, Series 2018-HRP2, Class M3, 4.906% (1 Month USD LIBOR + 240 bps), 2/25/47 (144A) 6,412,949 2,950,000(b) Starwood Waypoint Homes Trust, Series 2017-1, Class B, 3.625% (1 Month USD LIBOR + 117 bps), 1/17/35 (144A) 2,926,544 106,921(c) TIAA Bank Mortgage Loan Trust, Series 2018-2, Class A1, 3.5%, 7/25/48 (144A) 104,801 5,891,486 Toro Mortgage Funding Trust, Series 2017-RJ1, 4.0%, 4/25/74 5,819,683 7,540,000(c) Towd Point Mortgage Trust, Series 2015-6, Class M1, 3.75%, 4/25/55 (144A) 7,524,014 5,000,000(c) Towd Point Mortgage Trust, Series 2017-1, Class M1, 3.75%, 10/25/56 (144A) 4,909,145 12,015,000(c) Towd Point Mortgage Trust, Series 2017-2, Class A2, 3.25%, 4/25/57 (144A) 11,682,472 10,055,000(c) Towd Point Mortgage Trust, Series 2017-3, Class A2, 3.0%, 7/25/57 (144A) 9,538,933 7,045,826(c) Towd Point Mortgage Trust, Series 2017-5, Class XA, 3.5%, 2/25/57 (144A) 6,952,457 227,908 Vendee Mortgage Trust, Series 2008-1, Class GD, 5.25%, 1/15/32 233,334 401,281 Vendee Mortgage Trust, Series 2010-1, Class DA, 4.25%, 2/15/35 406,503 4,500,000 Wells Fargo Commercial Mortgage Trust, Series 2014-LC16, Class ASB, 3.477%, 8/15/50 4,526,693 3,810,000 Wells Fargo Commercial Mortgage Trust, Series 2015-NXS3, Class A4, 3.617%, 9/15/57 3,830,979 8,200,000 Wells Fargo Commercial Mortgage Trust, Series 2016-C32, Class A3, 3.294%, 1/15/59 8,083,815 10,000,000 Wells Fargo Commercial Mortgage Trust, Series 2016-LC24, Class A3, 2.684%, 10/15/49 9,394,681 173,196(b) Wells Fargo Credit Risk Transfer Securities Trust, Series 2015-WF1, Class 2M1, 5.356% (1 Month USD LIBOR + 285 bps), 11/25/25 (144A) 173,528 4,200,000(c) WFRBS Commercial Mortgage Trust, Series 2013-C12, Class D, 4.419%, 3/15/48 (144A) 3,848,296 6,200,000 WFRBS Commercial Mortgage Trust, Series 2013-C16, Class A4, 4.136%, 9/15/46 6,419,440 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 35 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 3,319,516(c) WinWater Mortgage Loan Trust, Series 2014-1, Class A1, 3.832%, 6/20/44 (144A) $ 3,302,747 2,898,096(c) WinWater Mortgage Loan Trust, Series 2014-2, Class B4, 4.101%, 9/20/44 (144A) 2,826,848 3,575,467(c) WinWater Mortgage Loan Trust, Series 2016-1, Class 1A5, 3.5%, 1/20/46 (144A) 3,524,809 --------------------------------------------------------------------------------------------------------------------------------- TOTAL COLLATERALIZED MORTGAGE OBLIGATIONS (Cost $1,201,481,566) $1,186,634,745 --------------------------------------------------------------------------------------------------------------------------------- CORPORATE BONDS -- 28.9% of Net Assets Aerospace & Defense -- 0.6% 3,625,000 Embraer Netherlands Finance BV, 5.4%, 2/1/27 $ 3,742,849 2,499,000 Leonardo US Holdings, Inc., 6.25%, 1/15/40 (144A) 2,324,070 13,470,000 Rockwell Collins, Inc., 3.2%, 3/15/24 12,971,751 7,910,000 United Technologies Corp., 4.125%, 11/16/28 7,836,447 -------------- Total Aerospace & Defense $ 26,875,117 --------------------------------------------------------------------------------------------------------------------------------- Agriculture -- 0.5% 12,540,000 Philip Morris International, Inc., 3.25%, 11/10/24 $ 12,238,102 14,708,000 Reynolds American, Inc., 4.45%, 6/12/25 14,181,963 -------------- Total Agriculture $ 26,420,065 --------------------------------------------------------------------------------------------------------------------------------- Airlines -- 0.2% 6,921,000 Air Canada 2017-1 Class AA Pass Through Trust, 3.3%, 1/15/30 (144A) $ 6,604,657 2,475,000 Delta Air Lines, Inc., 2.875%, 3/13/20 2,458,558 -------------- Total Airlines $ 9,063,215 --------------------------------------------------------------------------------------------------------------------------------- Auto Manufacturers -- 0.8% 2,300,000 General Motors Financial Co., Inc., 3.7%, 11/24/20 $ 2,290,700 10,710,000 General Motors Financial Co., Inc., 4.0%, 1/15/25 10,018,314 12,300,000 Hyundai Capital Services, Inc., 3.0%, 8/29/22 (144A) 11,900,988 3,590,000 Nissan Motor Acceptance Corp., 2.15%, 7/13/20 (144A) 3,503,872 7,495,000 Nissan Motor Acceptance Corp., 3.15%, 3/15/21 (144A) 7,389,022 7,040,000 Volkswagen Group of America Finance LLC, 4.0%, 11/12/21 (144A) 7,035,628 -------------- Total Auto Manufacturers $ 42,138,524 --------------------------------------------------------------------------------------------------------------------------------- Banks -- 4.5% 1,150,000 Bank of America Corp., 4.2%, 8/26/24 $ 1,140,570 10,345,000(b) Bank of New York Mellon Corp., 3.57% (3 Month USD LIBOR + 105 bps), 10/30/23 10,363,225 6,525,000(a)(c) Barclays Plc, 7.75% (5 Year USD Swap Rate + 484 bps) 6,276,528 1,915,000 BBVA Bancomer SA, 6.5%, 3/10/21 (144A) 1,986,812 The accompanying notes are an integral part of these financial statements. 36 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- Banks -- (continued) 13,040,000(a)(c) BNP Paribas SA, 7.625% (5 Year USD Swap Rate + 631 bps) (144A) $ 13,284,500 6,900,000 BPCE SA, 2.25%, 1/27/20 6,809,299 3,860,000 BPCE SA, 4.875%, 4/1/26 (144A) 3,802,555 21,955,000(b) Canadian Imperial Bank of Commerce, 2.874% (3 Month USD LIBOR + 32 bps), 2/2/21 21,730,059 3,435,000 Cooperatieve Rabobank UA, 3.875%, 2/8/22 3,472,956 7,175,000 Cooperatieve Rabobank UA, 3.95%, 11/9/22 7,151,594 11,725,000(a)(c) Credit Suisse Group AG, 7.125% (5 Year USD Swap Rate + 511 bps) 11,578,437 7,300,000 Credit Suisse Group Funding Guernsey, Ltd., 3.8%, 9/15/22 7,246,744 4,700,000(a)(c) Danske Bank AS, 6.125% (USD Swap Rate + 390 bps) 4,100,750 8,840,000(c) DBS Group Holdings, Ltd., 4.52% (5 Year USD 1100 Run ICE Swap Rate + 159 bps), 12/11/28 (144A) 9,032,279 7,891,000(c) Goldman Sachs Group, Inc., 3.272% (3 Month USD LIBOR + 120 bps), 9/29/25 7,396,807 6,335,000(c) Goldman Sachs Group, Inc., 4.223% (3 Month USD LIBOR + 130 bps), 5/1/29 6,096,730 1,305,000 HSBC Bank Plc, 7.65%, 5/1/25 1,504,070 2,400,000(b) HSBC Holdings Plc, 3.64% (3 Month USD LIBOR + 100 bps), 5/18/24 2,337,206 11,106,000(a)(c) ING Groep NV, 6.5% (5 Year USD Swap Rate + 445 bps) 10,289,709 7,378,000 KeyCorp, 5.1%, 3/24/21 7,652,100 8,675,000 Lloyds Banking Group Plc, 4.65%, 3/24/26 8,156,138 3,400,000(a)(c) Lloyds Banking Group Plc, 7.5% (5 Year USD Swap Rate + 450 bps) 3,281,680 5,450,000 Morgan Stanley, 4.1%, 5/22/23 5,457,872 300,000 Morgan Stanley, 4.875%, 11/1/22 309,148 4,500,000 Nordea Bank Abp, 4.25%, 9/21/22 (144A) 4,523,025 8,524,000 Nordea Bank Abp, 4.875%, 5/13/21 (144A) 8,669,667 10,505,000(a)(c) Royal Bank of Scotland Group Plc, 8.625% (5 Year USD Swap Rate + 760 bps) 10,872,675 11,500,000(a)(c) Societe Generale SA, 7.375% (5 Year USD Swap Rate + 624 bps) (144A) 11,198,125 12,575,000 SunTrust Bank, 2.45%, 8/1/22 12,123,059 2,250,000(c) Turkiye Garanti Bankasi AS, 6.125% (5 Year USD Swap Rate + 422 bps), 5/24/27 (144A) 1,921,230 4,900,000 UBS AG, 7.625%, 8/17/22 5,218,500 4,497,000(a)(c) UBS Group Funding Switzerland AG, 7.125% (5 Year USD Swap Rate + 588 bps) 4,560,534 -------------- Total Banks $ 219,544,583 --------------------------------------------------------------------------------------------------------------------------------- Beverages -- 0.5% 4,350,000(b) Anheuser-Busch InBev Finance, Inc., 3.819% (3 Month USD LIBOR + 126 bps), 2/1/21 $ 4,373,816 7,630,000 Bacardi, Ltd., 5.3%, 5/15/48 (144A) 6,888,106 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 37 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- Beverages -- (continued) 5,300,000 Pernod Ricard SA, 4.25%, 7/15/22 (144A) $ 5,376,514 6,869,000 Pernod Ricard SA, 4.45%, 1/15/22 (144A) 7,006,060 -------------- Total Beverages $ 23,644,496 --------------------------------------------------------------------------------------------------------------------------------- Biotechnology -- 0.6% 3,990,000 Baxalta, Inc., 3.6%, 6/23/22 $ 3,959,739 3,550,000 Biogen, Inc., 3.625%, 9/15/22 3,559,301 11,735,000 Biogen, Inc., 5.2%, 9/15/45 12,116,629 9,846,000 Celgene Corp., 4.55%, 2/20/48 8,532,495 -------------- Total Biotechnology $ 28,168,164 --------------------------------------------------------------------------------------------------------------------------------- Building Materials -- 0.8% 5,197,000 American Woodmark Corp., 4.875%, 3/15/26 (144A) $ 4,599,345 11,000,000 CRH America, Inc., 3.875%, 5/18/25 (144A) 10,572,171 7,680,000 Fortune Brands Home & Security, Inc., 3.0%, 6/15/20 7,616,678 3,250,000 Fortune Brands Home & Security, Inc., 4.0%, 9/21/23 3,215,549 5,675,000 Owens Corning, 3.4%, 8/15/26 5,182,364 5,150,000 Owens Corning, 4.2%, 12/1/24 5,109,048 4,385,000 Standard Industries, Inc., 5.5%, 2/15/23 (144A) 4,297,300 -------------- Total Building Materials $ 40,592,455 --------------------------------------------------------------------------------------------------------------------------------- Chemicals -- 0.6% 1,180,000 CF Industries, Inc., 4.95%, 6/1/43 $ 914,500 4,930,000 CF Industries, Inc., 5.375%, 3/15/44 3,993,300 6,365,000 Chemours Co., 7.0%, 5/15/25 6,412,737 12,505,000 DowDuPont, Inc., 4.205%, 11/15/23 12,781,983 5,135,000 NOVA Chemicals Corp., 4.875%, 6/1/24 (144A) 4,634,338 -------------- Total Chemicals $ 28,736,858 --------------------------------------------------------------------------------------------------------------------------------- Commercial Services -- 0.4% 3,950,000 ERAC USA Finance LLC, 3.3%, 12/1/26 (144A) $ 3,712,537 1,300,000 ERAC USA Finance LLC, 3.8%, 11/1/25 (144A) 1,274,724 4,600,000 ERAC USA Finance LLC, 4.5%, 2/15/45 (144A) 4,327,583 2,400,000 Moody's Corp., 3.25%, 6/7/21 2,390,743 2,600,000 President & Fellows of Harvard College, 2.3%, 10/1/23 2,533,662 5,942,000 Verisk Analytics, Inc., 5.5%, 6/15/45 6,014,765 -------------- Total Commercial Services $ 20,254,014 --------------------------------------------------------------------------------------------------------------------------------- Diversified Financial Services -- 0.9% 800,000(b) AIG Global Funding, 3.277% (3 Month USD LIBOR + 48 bps), 7/2/20 (144A) $ 799,513 2,980,000 Cantor Fitzgerald LP, 7.875%, 10/15/19 (144A) 3,067,732 1,465,000 Capital One Bank USA NA, 8.8%, 7/15/19 1,505,131 9,675,000 Capital One Financial Corp., 3.75%, 4/24/24 9,436,107 5,200,000 Capital One Financial Corp., 4.25%, 4/30/25 5,161,461 The accompanying notes are an integral part of these financial statements. 38 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- Diversified Financial Services -- (continued) 4,031,000 GE Capital International Funding Co. Unlimited Co., 2.342%, 11/15/20 $ 3,890,138 2,350,000 GTP Acquisition Partners I LLC, 2.35%, 6/15/20 (144A) 2,312,156 6,200,000 TD Ameritrade Holding Corp., 3.3%, 4/1/27 5,930,041 11,625,000 USAA Capital Corp., 2.45%, 8/1/20 (144A) 11,513,313 4,550,000 Visa, Inc., 2.2%, 12/14/20 4,500,572 -------------- Total Diversified Financial Services $ 48,116,164 --------------------------------------------------------------------------------------------------------------------------------- Electric -- 2.3% 2,850,000 Calpine Corp., 5.25%, 6/1/26 (144A) $ 2,600,625 6,925,000 Calpine Corp., 5.75%, 1/15/25 6,336,375 8,385,000 Consolidated Edison Co. of New York, Inc., 4.625%, 12/1/54 8,198,401 6,728,000 Dominion Energy, Inc., 2.579%, 7/1/20 6,622,717 2,700,000 Dominion Energy, Inc., 2.75%, 1/15/22 2,629,942 925,000 Edison International, 2.4%, 9/15/22 872,260 2,150,000(a)(c) Electricite de France SA, 5.25% (USD Swap Rate + 371 bps) (144A) 2,031,750 2,320,000(c) Enel S.p.A., 8.75% (5 Year USD Swap Rate + 588 bps), 9/24/73 (144A) 2,366,400 6,365,000 Exelon Corp., 2.85%, 6/15/20 6,314,564 4,655,000 Iberdrola International BV, 6.75%, 7/15/36 5,523,172 2,725,000 Indiana Michigan Power Co., 4.55%, 3/15/46 2,745,106 4,000,000 Israel Electric Corp., Ltd., 4.25%, 8/14/28 (144A) 3,799,680 5,450,000 Israel Electric Corp., Ltd., 5.0%, 11/12/24 (144A) 5,489,676 779,000 Israel Electric Corp., Ltd., 7.25%, 1/15/19 (144A) 779,327 610,000 Israel Electric Corp., Ltd., 9.375%, 1/28/20 (144A) 645,990 517,782 Kiowa Power Partners LLC, 5.737%, 3/30/21 (144A) 526,895 6,536,000 NextEra Energy Capital Holdings, Inc., 2.3%, 4/1/19 6,521,010 10,270,000 NextEra Energy Capital Holdings, Inc., 3.55%, 5/1/27 9,800,101 2,327,000 NRG Energy, Inc., 5.75%, 1/15/28 2,233,920 195,567 OrCal Geothermal, Inc., 6.21%, 12/30/20 (144A) 193,455 11,910,000 PPL Capital Funding, Inc, 3.1%, 5/15/26 11,163,359 1,675,000 San Diego Gas & Electric Co., 1.914%, 2/1/22 1,643,558 9,720,000 Sempra Energy, 3.4%, 2/1/28 8,881,152 3,312,500 Southern California Edison Co., 1.845%, 2/1/22 3,221,772 4,348,000(a)(c) Southern California Edison Co., 6.25% (3 Month USD LIBOR + 420 bps) 4,141,470 11,475,000 Southwestern Electric Power Co., 3.9%, 4/1/45 10,331,655 -------------- Total Electric $ 115,614,332 --------------------------------------------------------------------------------------------------------------------------------- Electronics -- 0.3% 8,412,000 Amphenol Corp., 3.125%, 9/15/21 $ 8,336,587 3,065,000 Amphenol Corp., 3.2%, 4/1/24 2,971,948 5,780,000 Flex, Ltd., 4.75%, 6/15/25 5,662,254 -------------- Total Electronics $ 16,970,789 --------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 39 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- Energy-Alternate Sources -- 0.0%+ 416,249 Alta Wind Holdings LLC, 7.0%, 6/30/35 (144A) $ 451,842 -------------- Total Energy-Alternate Sources $ 451,842 --------------------------------------------------------------------------------------------------------------------------------- Environmental Control -- 0.1% 2,678,000 Republic Services, Inc., 2.9%, 7/1/26 $ 2,525,975 -------------- Total Environmental Control $ 2,525,975 --------------------------------------------------------------------------------------------------------------------------------- Food -- 0.7% 12,410,000 Conagra Brands, Inc., 3.8%, 10/22/21 $ 12,414,376 4,119,000 Mondelez International Holdings Netherlands BV, 2.0%, 10/28/21 (144A) 3,946,554 2,500,000 Smithfield Foods, Inc., 2.65%, 10/3/21 (144A) 2,389,259 7,555,000 Smithfield Foods, Inc., 2.7%, 1/31/20 (144A) 7,452,713 3,430,000(b) Tyson Foods, Inc., 3.096% (3 Month USD LIBOR + 45 bps), 8/21/20 3,385,588 3,075,000(b) Tyson Foods, Inc., 3.288% (3 Month USD LIBOR + 55 bps), 6/2/20 3,058,197 -------------- Total Food $ 32,646,687 --------------------------------------------------------------------------------------------------------------------------------- Forest Products & Paper -- 0.1% 1,275,000 International Paper Co., 4.8%, 6/15/44 $ 1,143,177 2,575,000 International Paper Co., 6.0%, 11/15/41 2,712,560 -------------- Total Forest Products & Paper $ 3,855,737 --------------------------------------------------------------------------------------------------------------------------------- Gas -- 0.1% 3,060,000 Boston Gas Co., 3.15%, 8/1/27 (144A) $ 2,919,095 1,931,530 Nakilat, Inc., 6.267%, 12/31/33 (144A) 2,115,412 -------------- Total Gas $ 5,034,507 --------------------------------------------------------------------------------------------------------------------------------- Healthcare-Products -- 0.6% 4,155,000 Abbott Laboratories, 3.75%, 11/30/26 $ 4,103,463 4,700,000(b) Becton Dickinson & Co., 3.678% (3 Month USD LIBOR + 88 bps), 12/29/20 4,652,762 10,340,000 Boston Scientific Corp., 4.0%, 3/1/28 10,036,335 11,200,000 Thermo Fisher Scientific, Inc., 3.0%, 4/15/23 10,896,347 -------------- Total Healthcare-Products $ 29,688,907 --------------------------------------------------------------------------------------------------------------------------------- Healthcare-Services -- 0.5% 6,585,000 Anthem, Inc., 3.35%, 12/1/24 $ 6,415,076 4,506,000 Anthem, Inc., 3.65%, 12/1/27 4,305,152 1,140,000 Anthem, Inc., 4.101%, 3/1/28 1,117,356 6,225,000 Cigna Corp., 4.375%, 10/15/28 (144A) 6,259,741 3,630,000 Humana, Inc., 3.95%, 3/15/27 3,546,452 2,400,000 NYU Hospitals Center, 4.428%, 7/1/42 2,423,339 -------------- Total Healthcare-Services $ 24,067,116 --------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 40 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- Home Builders -- 0.3% 5,120,000 Lennar Corp., 4.75%, 4/1/21 $ 5,075,200 5,215,000 Meritage Homes Corp., 6.0%, 6/1/25 4,915,137 5,391,000 TRI Pointe Group, Inc., 5.25%, 6/1/27 4,203,363 -------------- Total Home Builders $ 14,193,700 --------------------------------------------------------------------------------------------------------------------------------- Household Products & Wares -- 0.3% 8,203,000 Church & Dwight Co., Inc., 2.45%, 8/1/22 $ 7,927,866 5,235,000 Church & Dwight Co., Inc., 3.15%, 8/1/27 4,924,250 -------------- Total Household Products & Wares $ 12,852,116 --------------------------------------------------------------------------------------------------------------------------------- Insurance -- 2.1% 7,000,000 Aflac, Inc., 3.625%, 11/15/24 $ 6,994,546 2,335,000 AXA SA, 8.6%, 12/15/30 2,888,605 9,100,000 CNA Financial Corp., 4.5%, 3/1/26 9,174,334 1,850,000 Delphi Financial Group, Inc., 7.875%, 1/31/20 1,936,337 9,610,000(c) Farmers Insurance Exchange, 4.747% (3 Month USD LIBOR + 323 bps), 11/1/57 (144A) 8,494,885 5,045,000 Great-West Lifeco Finance 2018 LP, 4.581%, 5/17/48 (144A) 5,073,691 13,040,000 Liberty Mutual Insurance Co., 7.697%, 10/15/97 (144A) 17,600,096 13,250,000 MassMutual Global Funding II, 2.75%, 6/22/24 (144A) 12,699,096 6,200,000 MassMutual Global Funding II, 2.95%, 1/11/25 (144A) 5,953,930 2,425,000 Principal Life Global Funding II, 1.5%, 4/18/19 (144A) 2,413,916 10,395,000 Protective Life Corp., 4.3%, 9/30/28 (144A) 10,304,043 4,250,000 Protective Life Corp., 7.375%, 10/15/19 4,368,804 3,680,000 Protective Life Global Funding, 2.615%, 8/22/22 (144A) 3,576,968 1,090,000 Prudential Financial, Inc., 4.5%, 11/16/21 1,124,966 690,000 Teachers Insurance & Annuity Association of America, 6.85%, 12/16/39 (144A) 897,147 9,065,000 Torchmark Corp., 4.55%, 9/15/28 9,210,448 -------------- Total Insurance $ 102,711,812 --------------------------------------------------------------------------------------------------------------------------------- Internet -- 0.8% 9,595,000 Alibaba Group Holding, Ltd., 3.4%, 12/6/27 $ 8,872,100 3,265,000 Amazon.com, Inc., 2.8%, 8/22/24 3,173,441 7,170,000 Booking Holdings, Inc., 3.55%, 3/15/28 6,754,351 1,925,000 Booking Holdings, Inc., 3.6%, 6/1/26 1,870,227 7,875,000 Booking Holdings, Inc., 3.65%, 3/15/25 7,668,809 4,125,000 Expedia Group, Inc., 3.8%, 2/15/28 3,740,690 5,900,000 Expedia Group, Inc., 4.5%, 8/15/24 5,907,542 950,000 Expedia Group, Inc., 5.0%, 2/15/26 959,642 -------------- Total Internet $ 38,946,802 --------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 41 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- Iron & Steel -- 0.1% 3,550,000 Commercial Metals Co., 4.875%, 5/15/23 $ 3,354,750 1,525,000 Commercial Metals Co., 5.75%, 4/15/26 (144A) 1,414,438 -------------- Total Iron & Steel $ 4,769,188 --------------------------------------------------------------------------------------------------------------------------------- Media -- 0.5% 7,745,000 Comcast Corp., 4.15%, 10/15/28 $ 7,864,525 6,455,000 Comcast Corp., 4.25%, 10/15/30 6,527,991 5,013,000 Sky, Ltd., 3.75%, 9/16/24 (144A) 4,994,621 3,450,000 Videotron, Ltd., 5.375%, 6/15/24 (144A) 3,415,500 -------------- Total Media $ 22,802,637 --------------------------------------------------------------------------------------------------------------------------------- Mining -- 0.2% 1,325,000 Anglo American Capital Plc, 4.0%, 9/11/27 (144A) $ 1,198,938 2,750,000 Anglo American Capital Plc, 4.75%, 4/10/27 (144A) 2,633,753 6,600,000 Anglo American Capital Plc, 4.875%, 5/14/25 (144A) 6,482,610 -------------- Total Mining $ 10,315,301 --------------------------------------------------------------------------------------------------------------------------------- Miscellaneous Manufacturers -- 0.1% 1,368,000 Amsted Industries, Inc., 5.0%, 3/15/22 (144A) $ 1,330,380 3,485,000 Amsted Industries, Inc., 5.375%, 9/15/24 (144A) 3,284,612 1,392,000 General Electric Co., 5.3%, 2/11/21 1,393,726 -------------- Total Miscellaneous Manufacturers $ 6,008,718 --------------------------------------------------------------------------------------------------------------------------------- Multi-National -- 0.1% 2,230,000 Banque Ouest Africaine de Developpement, 5.0%, 7/27/27 (144A) $ 2,086,656 4,450,000 Banque Ouest Africaine de Developpement, 5.5%, 5/6/21 (144A) 4,518,664 -------------- Total Multi-National $ 6,605,320 --------------------------------------------------------------------------------------------------------------------------------- Oil & Gas -- 0.9% 6,360,000 BP Capital Markets Plc, 3.062%, 3/17/22 $ 6,302,124 5,275,000 CNOOC Nexen Finance 2014 ULC, 4.25%, 4/30/24 5,347,621 5,138,000 Continental Resources, Inc., 4.375%, 1/15/28 4,833,634 215,000 Motiva Enterprises LLC, 5.75%, 1/15/20 (144A) 218,768 1,770,000 Newfield Exploration Co., 5.375%, 1/1/26 1,734,600 1,400,000 Newfield Exploration Co., 5.625%, 7/1/24 1,417,500 4,750,000 Sinopec Group Overseas Development 2014, Ltd., 4.375%, 4/10/24 (144A) 4,849,565 10,050,000 Sinopec Group Overseas Development 2015, Ltd., 2.5%, 4/28/20 (144A) 9,926,505 8,468,000 Valero Energy Corp., 6.625%, 6/15/37 9,277,853 -------------- Total Oil & Gas $ 43,908,170 --------------------------------------------------------------------------------------------------------------------------------- Oil & Gas Services -- 0.1% 2,250,000 Halliburton Co., 7.6%, 8/15/96 (144A) $ 2,881,775 -------------- Total Oil & Gas Services $ 2,881,775 --------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 42 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- Pharmaceuticals -- 1.5% 12,975,000 AbbVie, Inc., 4.875%, 11/14/48 $ 12,105,609 4,900,000 Bayer US Finance II LLC, 4.25%, 12/15/25 (144A) 4,768,978 12,950,000 Cardinal Health, Inc., 3.079%, 6/15/24 12,160,794 650,000 CVS Health Corp., 2.25%, 8/12/19 646,816 5,050,000 CVS Health Corp., 4.1%, 3/25/25 4,999,613 487,194 CVS Pass-Through Trust, 5.298%, 1/11/27 (144A) 495,769 2,571,521 CVS Pass-Through Trust, 5.773%, 1/10/33 (144A) 2,703,501 1,775,492 CVS Pass-Through Trust, 5.926%, 1/10/34 (144A) 1,912,225 3,279,855 CVS Pass-Through Trust, 6.036%, 12/10/28 3,491,771 4,733,440 CVS Pass-Through Trust, 8.353%, 7/10/31 (144A) 5,724,595 1,391,000 Perrigo Finance Unlimited Co., 3.5%, 3/15/21 1,367,358 4,570,000 Perrigo Finance Unlimited Co., 3.9%, 12/15/24 4,228,977 11,181,000 Perrigo Finance Unlimited Co., 4.375%, 3/15/26 10,147,156 3,084,000 Shire Acquisitions Investments Ireland, DAC, 3.2%, 9/23/26 2,790,779 7,150,000 Takeda Pharmaceutical Co., Ltd., 4.0%, 11/26/21 (144A) 7,247,519 -------------- Total Pharmaceuticals $ 74,791,460 --------------------------------------------------------------------------------------------------------------------------------- Pipelines -- 3.9% 9,940,000 Andeavor Logistics LP/Tesoro Logistics Finance Corp., 4.25%, 12/1/27 $ 9,383,411 5,595,000 Cheniere Energy Partners LP, 5.25%, 10/1/25 5,217,337 750,000 DCP Midstream Operating LP, 5.35%, 3/15/20 (144A) 752,813 3,450,000 DCP Midstream Operating LP, 5.375%, 7/15/25 3,372,375 4,025,000 DCP Midstream Operating LP, 5.6%, 4/1/44 3,481,625 8,361,000 Enable Midstream Partners LP, 3.9%, 5/15/24 8,020,175 3,629,000 Enable Midstream Partners LP, 4.4%, 3/15/27 3,388,542 6,080,000 Enable Midstream Partners LP, 4.95%, 5/15/28 5,755,450 10,550,000 Enbridge, Inc., 3.7%, 7/15/27 9,992,373 1,149,000 Energy Transfer LP, 5.5%, 6/1/27 1,120,275 5,130,000 Energy Transfer Operating LP, 6.0%, 6/15/48 4,995,657 4,207,000 Energy Transfer Operating LP, 6.5%, 2/1/42 4,198,690 2,981,000 EnLink Midstream Partners LP, 5.45%, 6/1/47 2,410,811 3,573,000 Enterprise Products Operating LLC, 2.8%, 2/15/21 3,535,512 11,775,000 Enterprise Products Operating LLC, 4.15%, 10/16/28 11,715,669 10,830,000 Kinder Morgan, Inc., 5.05%, 2/15/46 9,889,271 15,125,000 Kinder Morgan, Inc., 5.55%, 6/1/45 14,979,334 2,182,000 MPLX LP, 4.0%, 3/15/28 2,045,081 4,725,000 MPLX LP, 4.125%, 3/1/27 4,498,737 3,875,000 MPLX LP, 4.875%, 12/1/24 3,944,482 3,045,000 MPLX LP, 4.875%, 6/1/25 3,072,900 6,920,000 MPLX LP, 5.5%, 2/15/49 6,731,176 12,125,000 Phillips 66 Partners LP, 3.75%, 3/1/28 11,198,108 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 43 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- Pipelines -- (continued) 2,295,000 Phillips 66 Partners LP, 4.9%, 10/1/46 $ 2,103,912 10,675,000 Sabine Pass Liquefaction LLC, 5.0%, 3/15/27 10,710,652 6,730,000 Sunoco Logistics Partners Operations LP, 5.35%, 5/15/45 5,956,959 10,876,000 Sunoco Logistics Partners Operations LP, 5.4%, 10/1/47 9,855,898 786,000 Sunoco Logistics Partners Operations LP, 6.1%, 2/15/42 759,340 2,713,000 Targa Resources Partners LP/Targa Resources Partners Finance Corp., 5.0%, 1/15/28 2,455,265 8,870,000 Texas Eastern Transmission LP, 3.5%, 1/15/28 (144A) 8,374,398 17,007,000 Williams Cos., Inc., 5.75%, 6/24/44 17,092,534 2,475,000 Williams Cos., Inc., 7.75%, 6/15/31 2,989,704 -------------- Total Pipelines $ 193,998,466 --------------------------------------------------------------------------------------------------------------------------------- REITS -- 1.6% 2,681,000 Alexandria Real Estate Equities, Inc., 2.75%, 1/15/20 $ 2,660,048 2,768,000 Alexandria Real Estate Equities, Inc., 3.9%, 6/15/23 2,784,755 1,350,000 Alexandria Real Estate Equities, Inc., 3.95%, 1/15/27 1,309,938 3,415,000 Alexandria Real Estate Equities, Inc., 4.6%, 4/1/22 3,515,571 3,450,000 Duke Realty LP, 3.625%, 4/15/23 3,447,336 8,560,000 Duke Realty LP, 3.75%, 12/1/24 8,495,403 9,500,000 Essex Portfolio LP, 3.5%, 4/1/25 9,233,158 1,480,000 Essex Portfolio LP, 3.625%, 5/1/27 1,426,574 6,805,000 Healthcare Trust of America Holdings LP, 3.5%, 8/1/26 6,396,094 4,675,000 Healthcare Trust of America Holdings LP, 3.75%, 7/1/27 4,451,270 2,032,000 Highwoods Realty LP, 3.2%, 6/15/21 2,007,168 3,390,000 Highwoods Realty LP, 3.625%, 1/15/23 3,350,021 7,105,000 Highwoods Realty LP, 4.125%, 3/15/28 6,951,679 1,800,000 SBA Tower Trust, 2.877%, 7/9/21 (144A) 1,766,987 6,975,000 SBA Tower Trust, 3.869%, 10/8/24 (144A) 6,920,351 1,520,000 UDR, Inc., 2.95%, 9/1/26 1,401,082 6,077,000 UDR, Inc., 4.0%, 10/1/25 6,058,139 5,300,000 UDR, Inc., 4.4%, 1/26/29 5,345,593 -------------- Total REITS $ 77,521,167 --------------------------------------------------------------------------------------------------------------------------------- Retail -- 0.4% 7,040,000 Alimentation Couche-Tard, Inc., 3.55%, 7/26/27 (144A) $ 6,573,065 3,994,000 AutoZone, Inc., 2.5%, 4/15/21 3,905,607 7,505,000 Walmart, Inc., 3.4%, 6/26/23 7,582,335 -------------- Total Retail $ 18,061,007 --------------------------------------------------------------------------------------------------------------------------------- Software -- 0.2% 5,501,000 Fiserv, Inc., 3.8%, 10/1/23 $ 5,535,256 5,650,000 salesforce.com, Inc., 3.7%, 4/11/28 5,679,858 -------------- Total Software $ 11,215,114 --------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 44 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- Telecommunications -- 0.2% 5,227,000 CommScope Technologies LLC, 5.0%, 3/15/27 (144A) $ 4,233,870 3,989,000 Level 3 Financing, Inc., 5.375%, 1/15/24 3,799,522 1,500,000 Unison Ground Lease Funding LLC, 2.981%, 3/15/20 (144A) 1,489,643 -------------- Total Telecommunications $ 9,523,035 --------------------------------------------------------------------------------------------------------------------------------- Transportation -- 0.4% 6,650,000 TTX Co., 3.6%, 1/15/25 (144A) $ 6,617,041 3,250,000 TTX Co., 4.2%, 7/1/46 (144A) 3,114,507 13,715,000 Union Pacific Corp., 3.375%, 2/1/35 12,002,907 -------------- Total Transportation $ 21,734,455 --------------------------------------------------------------------------------------------------------------------------------- Trucking & Leasing -- 0.1% 4,825,000 Penske Truck Leasing Co. LP/PTL Finance Corp., 3.375%, 2/1/22 (144A) $ 4,771,137 -------------- Total Trucking & Leasing $ 4,771,137 --------------------------------------------------------------------------------------------------------------------------------- TOTAL CORPORATE BONDS (Cost $1,467,779,037) $1,422,020,927 --------------------------------------------------------------------------------------------------------------------------------- FOREIGN GOVERNMENT BONDS -- 0.3% of Net Assets Mexico -- 0.2% 13,425,000 Mexico Government International Bond, 4.6%, 2/10/48 $ 11,914,687 -------------- Total Mexico $ 11,914,687 --------------------------------------------------------------------------------------------------------------------------------- Nigeria -- 0.1% 4,550,000 Africa Finance Corp., 4.375%, 4/29/20 (144A) $ 4,499,577 -------------- Total Nigeria $ 4,499,577 --------------------------------------------------------------------------------------------------------------------------------- TOTAL FOREIGN GOVERNMENT BONDS (Cost $16,890,470) $ 16,414,264 --------------------------------------------------------------------------------------------------------------------------------- INSURANCE-LINKED SECURITIES -- 4.0% of Net Assets(k) CATASTROPHE LINKED BONDS -- 1.4% Earthquakes -- California -- 0.2% 2,800,000(b) Golden State Re II, 4.637% (3 Month U.S. Treasury Bill + 220 bps), 1/8/19 (144A) $ 2,800,000 2,700,000(b) Ursa Re, 3.5% (ZERO + 350 bps), 5/27/20 (144A) 2,663,010 3,000,000(b) Ursa Re, 4.0% (ZERO + 400 bps), 12/10/19 (144A) 2,934,000 800,000(b) Ursa Re, 8.452% (3 Month U.S. Treasury Bill + 600 bps), 5/27/20 (144A) 788,000 -------------- $ 9,185,010 --------------------------------------------------------------------------------------------------------------------------------- Earthquakes -- Chile -- 0.0%+ 1,500,000(b) International Bank for Reconstruction & Development, 4.916% (3 Month USD LIBOR + 250 bps), 2/15/21 (144A) $ 1,491,150 --------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 45 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- Earthquakes -- Colombia -- 0.0%+ 1,250,000(b) International Bank for Reconstruction & Development, 5.416% (3 Month USD LIBOR + 300 bps), 2/15/21 (144A) $ 1,237,875 --------------------------------------------------------------------------------------------------------------------------------- Earthquakes -- Mexico -- 0.0%+ 1,050,000(b) International Bank for Reconstruction & Development, 4.916% (3 Month USD LIBOR + 250 bps), 2/14/20 (144A) $ 1,041,180 --------------------------------------------------------------------------------------------------------------------------------- Earthquakes -- U.S. -- 0.0%+ 650,000(b) Acorn Re, 4.986% (3 Month USD LIBOR + 275 bps), 11/10/21 (144A) $ 640,510 700,000(b) Kilimanjaro Re, 6.195% (3 Month U.S. Treasury Bill + 375 bps), 11/25/19 (144A) 687,470 -------------- $ 1,327,980 --------------------------------------------------------------------------------------------------------------------------------- Health -- U.S. -- 0.1% 2,000,000(b) Vitality Re V, 4.202% (3 Month U.S. Treasury Bill + 175 bps), 1/7/19 (144A) $ 2,000,000 2,900,000(b) Vitality Re VII, 4.602% (3 Month U.S. Treasury Bill + 215 bps), 1/7/20 (144A) 2,911,020 1,000,000(b) Vitality Re VII, 5.102% (3 Month U.S. Treasury Bill + 265 bps), 1/7/20 (144A) 1,006,700 -------------- $ 5,917,720 --------------------------------------------------------------------------------------------------------------------------------- Hurricane -- Gulf Region -- 0.1% 4,150,000(b) Alamo Re, 6.832% (3 Month U.S. Treasury Bill + 439 bps), 6/7/19 (144A) $ 4,156,225 --------------------------------------------------------------------------------------------------------------------------------- Multiperil -- U.S. -- 0.5% 2,000,000(b) Bowline Re, 6.945% (3 Month U.S. Treasury Bill + 450 bps), 5/23/22 (144A) $ 1,939,000 1,350,000(b) Caelus Re IV, 7.972% (3 Month U.S. Treasury Bill + 553 bps), 3/6/20 (144A) 1,296,000 1,000,000(b) Caelus Re V, 2.942% (1 Month U.S. Treasury Bill + 50 bps), 6/5/20 (144A) 180,000 750,000(b) Caelus Re V, 5.652% (3 Month U.S. Treasury Bill + 321 bps), 6/5/20 (144A) 650,475 2,000,000(b) Kilimanjaro Re, 6.858% (3 Month USD LIBOR + 465 bps), 5/6/22 (144A) 1,932,800 3,000,000(b) Kilimanjaro Re, 9.195% (3 Month U.S. Treasury Bill + 675 bps), 12/6/19 (144A) 2,990,700 1,500,000(b) Kilimanjaro Re, 11.695% 3 Month U.S. Treasury Bill + 925 bps), 12/6/19 (144A) 1,490,700 2,600,000(b) Kilimanjaro II Re, 8.293% (6 Month USD LIBOR + 572 bps), 4/20/21 (144A) 2,578,420 3,500,000(b) Kilimanjaro II Re, 9.713% (6 Month USD LIBOR + 714 bps), 4/20/21 (144A) 3,466,750 1,250,000+(b) Panthera Re, 5.945% (3 Month U.S. Treasury Bill + 350 bps), 3/9/20 (144A) 1,267,750 The accompanying notes are an integral part of these financial statements. 46 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- Multiperil -- U.S. -- (continued) 2,500,000(b) Residential Reinsurance 2016, 6.272% (3 Month U.S. Treasury Bill + 382 bps), 12/6/20 (144A) $ 2,488,250 1,600,000(b) Sanders Re, 5.644% (6 Month USD LIBOR + 307 bps), 12/6/21 (144A) 1,575,360 1,000,000(b) Skyline Re, 4.942% (3 Month U.S. Treasury Bill + 250 bps), 1/6/20 (144A) 1,004,000 -------------- $ 22,860,205 --------------------------------------------------------------------------------------------------------------------------------- Multiperil -- U.S. Regional -- 0.1% 750,000(b) First Coast Re, 6.298% (3 Month U.S. Treasury Bill + 382 bps), 6/7/19 (144A) $ 750,750 2,500,000(b) Long Point Re III, 5.195% (3 Month U.S. Treasury Bill + 275 bps), 6/1/22 (144A) 2,482,750 -------------- $ 3,233,500 --------------------------------------------------------------------------------------------------------------------------------- Multiperil -- Worldwide -- 0.2% 1,300,000(b) Galilei Re, 6.84% (6 Month USD LIBOR + 466 bps), 1/8/20 (144A) $ 1,295,580 1,500,000(b) Galilei Re, 6.86% (6 Month USD LIBOR + 466 bps), 1/8/21 (144A) 1,470,000 1,300,000(b) Galilei Re, 7.63% (6 Month USD LIBOR + 545 bps), 1/8/20 (144A) 1,287,260 1,200,000(b) Galilei Re, 7.65% (6 Month USD LIBOR + 545 bps), 1/8/21 (144A) 1,175,760 1,400,000(b) Galilei Re, 8.71% (6 Month USD LIBOR + 653 bps), 1/8/20 (144A) 1,385,580 1,500,000(b) Galilei Re, 8.73% (6 Month USD LIBOR + 653 bps), 1/8/21 (144A) 1,469,700 2,100,000+(f) Sector Re V, Series 8, Class C, 12/1/23 (144A) 2,113,117 400,000+(f) Sector Re V, Series 8, Class D, 12/1/23 (144A) 402,499 -------------- $ 10,599,496 --------------------------------------------------------------------------------------------------------------------------------- Pandemic -- Worldwide -- 0.1% 1,700,000(b) International Bank for Reconstruction & Development, 9.365% (6 Month USD LIBOR + 690 bps), 7/15/20 (144A) $ 1,704,760 --------------------------------------------------------------------------------------------------------------------------------- Windstorm -- Florida -- 0.0%+ 1,400,000(b) Casablanca Re, 6.415% (6 Month USD LIBOR + 393 bps), 6/4/20 (144A) $ 1,413,300 --------------------------------------------------------------------------------------------------------------------------------- Windstorm -- Japan -- 0.0%+ 500,000(b) Aozora Re, 4.681% (6 Month USD LIBOR + 224 bps), 4/7/20 (144A) $ 495,800 --------------------------------------------------------------------------------------------------------------------------------- Windstorm -- Texas -- 0.0%+ 1,700,000(b) Alamo Re, 7.292% (3 Month U.S. Treasury Bill + 485 bps), 6/8/20 (144A) $ 1,690,820 --------------------------------------------------------------------------------------------------------------------------------- Windstorm -- U.S. Multistate -- 0.0%+ 1,000,000(b) Citrus Re, 2.942% (1 Month U.S. Treasury Bill + 50 bps), 4/9/20 (144A) $ 935,000 --------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 47 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- Windstorm -- Worldwide -- 0.1% 2,000,000(b) Queen Street XI Re, 8.602% (3 Month U.S. Treasury Bill + 615 bps), 6/7/19 (144A) $ 1,996,400 -------------- Total Catastrophe Linked Bonds $ 69,286,421 --------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED REINSURANCE -- 0.6% Earthquakes -- California -- 0.2% 2,200,000+(g) Resilience Re, Variable Rate Notes, 1/8/19 (144A) $ 2,200,000 3,600,000+(g) Resilience Re, Variable Rate Notes, 1/8/19 (144A) 3,600,000 1,600,000+(g) Resilience Re, Variable Rate Notes, 10/8/19 1,699,360 -------------- $ 7,499,360 --------------------------------------------------------------------------------------------------------------------------------- Hurricane -- U.S. -- 0.0%+ 1,200,000+(g) Oakmont Re 2018-2, Variable Rate Notes, 4/30/19 $ 27,120 --------------------------------------------------------------------------------------------------------------------------------- Multiperil -- Massachusetts -- 0.1% 5,000,000+(g) Denning Re 2018, Variable Rate Notes, 7/15/19 $ 4,970,892 --------------------------------------------------------------------------------------------------------------------------------- Multiperil -- U.S. -- 0.0%+ 2,800,000+(g) Kingsbarns Re 2017, Variable Rate Notes, 5/15/19 $ 428,960 --------------------------------------------------------------------------------------------------------------------------------- Multiperil -- U.S. Regional -- 0.0%+ 1,000,000+(g) EC0012 Re, Variable Rate Notes, 6/15/19 $ 976,000 --------------------------------------------------------------------------------------------------------------------------------- Multiperil -- Worldwide -- 0.2% 4,918,415+(g) Kilarney Re 2018, Variable Rate Notes, 4/15/19 $ 4,436,410 600,000+(g) Limestone Re 2016-1, Variable Rate Notes, 8/31/21 689,100 1,750,000+(g) Limestone Re 2016-1, Variable Rate Notes, 8/31/21 2,009,875 1,500,000+(g) Resilience Re, Variable Rate Notes, 4/8/19 1,518,300 2,000,000+(g) Resilience Re, Variable Rate Notes, 4/8/19 2,015,800 3,600,000+(g) Resilience Re, Variable Rate Notes, 5/1/19 36,000 567,400+(g) Seminole Re 2018, Variable Rate Notes, 1/15/20 504,248 553,333+(g) Walton Health Re 2018, Variable Rate Notes, 6/15/19 276,667 -------------- $ 11,486,400 --------------------------------------------------------------------------------------------------------------------------------- Windstorm -- Florida -- 0.0%+ 1,500,000+(g) Formby Re 2018, Variable Rate Notes, 6/15/19 $ 1,506,803 511,212+(g) Formby Re 2018-2, Variable Rate Notes, 3/31/19 522,459 -------------- $ 2,029,262 --------------------------------------------------------------------------------------------------------------------------------- Windstorm -- U.S. Regional -- 0.1% 2,022,204+(g) Hillside Re 2018, Variable Rate Notes, 7/1/19 $ 35,389 1,000,000+(g) Oakmont Re 2017, Variable Rate Notes, 4/15/19 11,500 815,825+(g) Oakmont Re 2018, Variable Rate Notes, 4/15/19 760,920 2,600,000+(g) Promissum Re 2018, Variable Rate Notes, 6/15/19 2,600,000 250,000+(g) Resilience Re, Variable Rate Notes, 6/15/19 258,850 -------------- $ 3,666,659 -------------- Total Collateralized Reinsurance $ 31,084,653 --------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 48 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- INDUSTRY LOSS WARRANTIES -- 0.2% Multiperil -- U.S. -- 0.2% 4,257,500+(g) Cypress Re 2018, Variable Rate Notes, 4/15/19 $ 3,980,337 1,244,707+(g) Laytown Re, Variable Rate Notes, 4/15/19 1,210,104 5,343,100+(g) Pinehurst Re 2018, Variable Rate Notes, 4/15/19 5,032,131 -------------- Total Industry Loss Warranties $ 10,222,572 --------------------------------------------------------------------------------------------------------------------------------- REINSURANCE SIDECARS -- 1.8% Multiperil -- U.S. -- 0.2% 3,000,000+(g) Carnoustie Re 2015, Variable Rate Notes, 7/1/19 $ 9,600 3,600,000+(g) Carnoustie Re 2016, Variable Rate Notes, 11/30/20 97,200 4,500,000+(g) Carnoustie Re 2017, Variable Rate Notes, 11/30/21 1,143,900 2,000,000+(g) Carnoustie Re 2018, Variable Rate Notes, 12/31/21 1,938,950 1,139,928+(g) Carnoustie Re 2019, Variable Rate Notes, 12/31/22 1,139,928 1,300,000+(g) Castle Stuart Housing Association Re 2018, Variable Rate Notes, 12/1/21 1,096,420 2,000,000+(g) Harambee Re 2018, Variable Rate Notes, 12/31/21 1,803,000 3,609,302+(g) Harambee Re 2019, Variable Rate Notes, 12/31/22 3,609,302 1,000,000+(g) Prestwick Re 2015-1, Variable Rate Notes, 7/1/19 17,000 1,200,007+(g) Sector Re V, Series 7, Class G, Variable Rate Notes, 3/1/22 (144A) 864,482 -------------- $ 11,719,782 --------------------------------------------------------------------------------------------------------------------------------- Multiperil -- Worldwide -- 1.6% 1,100,000+(g) Alturas Re 2019-1, Variable Rate Notes, 3/10/23 $ 1,100,000 2,800,000+(g) Alturas Re 2019-2, Variable Rate Notes, 3/10/22 2,800,000 900,000+(g) Arlington Re 2015, Variable Rate Notes, 2/1/19 43,740 750,000+(g) Arlington Re 2016, Variable Rate Notes, 2/28/19 97,875 2,000,000+(g) Berwick Re 2017-1, Variable Rate Notes, 2/1/19 66,200 10,192,268+(g) Berwick Re 2018-1, Variable Rate Notes, 12/31/21 9,692,123 7,846,828+(g) Berwick Re 2019-1, Variable Rate Notes, 12/31/22 7,846,828 1,250,000+(g) Blue Lotus Re 2018, Variable Rate Notes, 12/31/21 1,315,000 397,500+(g) Eden Re II, Variable Rate Notes, 3/22/21 (144A) 81,964 841,500+(g) Eden Re II, Variable Rate Notes, 3/22/21 166,785 3,717,000+(g) Eden Re II, Variable Rate Notes, 3/22/22 (144A) 3,933,329 600,000+(g) Eden Re II, Variable Rate Notes, 3/22/23 (144A) 600,000 2,500,000+(g) Eden Re II, Variable Rate Notes, 3/22/22 (144A) 2,647,000 3,500,000+(g) Gleneagles Re 2016, Variable Rate Notes, 11/30/20 217,000 1,000,000+(g) Gleneagles Re 2018, Variable Rate Notes, 12/31/21 1,005,100 886,832+(g) Gleneagles Re 2019, Variable Rate Notes, 12/31/22 886,832 2,118,314+(g) Gullane Re 2018, Variable Rate Notes, 12/31/21 1,842,933 2,500,000+(g) Limestone Re 2018, Variable Rate Notes, 3/1/22 2,550,750 500,000+(g) Lion Rock Re 2019, Variable Rate Notes, 1/31/20 500,000 3,000,000+(g) Lorenz Re 2017, Variable Rate Notes, 3/31/20 435,300 5,000,000+(g) Lorenz Re 2018, Variable Rate Notes, 7/1/21 3,552,000 2,000,000+(g) Madison Re 2016, Variable Rate Notes, 3/31/19 55,600 1,500,000+(g) Madison Re 2017, Variable Rate Notes, 12/31/19 395,850 2,000,000+(g) Madison Re 2018, Variable Rate Notes, 12/31/21 2,075,800 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 49 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- Multiperil -- Worldwide -- (continued) 7,000,000+(g) Merion Re 2018-2, Variable Rate Notes, 12/31/21 $ 6,826,890 1,000,000+(g) NCM Re 2019, Variable Rate Notes, 12/31/22 1,000,000 3,600,000+(g) Pangaea Re 2015-1, Variable Rate Notes, 2/1/19 6,480 4,000,000+(g) Pangaea Re 2015-2, Variable Rate Notes, 11/30/19 9,600 4,500,000+(g) Pangaea Re 2016-1, Variable Rate Notes, 11/30/20 22,050 3,000,000+(g) Pangaea Re 2016-2, Variable Rate Notes, 11/30/20 16,200 3,800,000+(g) Pangaea Re 2018-1, Variable Rate Notes, 12/31/21 3,336,400 6,500,000+(g) Pangaea Re 2018-3, Variable Rate Notes, 7/1/22 5,546,450 300,000+(g) Sector Re V, Series 7, Class C, Variable Rate Notes, 12/1/22 (144A) 289,131 300,000+(g) Sector Re V, Series 7, Class C, Variable Rate Notes, 12/1/22 (144A) 289,131 500,000+(g) Sector Re V, Series 8, Class F, Variable Rate Notes, 3/1/23 (144A) 520,079 1,199,993+(g) Sector Re V, Series 8, Class G, Variable Rate Notes, 3/1/23 (144A) 1,248,182 2,000,000+(g) Silverton Re, Variable Rate Notes, 9/16/19 (144A) 81,600 3,000,000+(g) St. Andrews Re 2017-1, Variable Rate Notes, 2/1/19 203,400 1,737,984+(g) St. Andrews Re 2017-4, Variable Rate Notes, 6/1/19 171,018 500,000+(g) Thopas Re 2018, Variable Rate Notes, 12/31/21 443,300 2,686,501+(g) Thopas Re 2019, Variable Rate Notes, 12/31/22 2,686,501 4,000,000+(g) Versutus Re 2016-1, Variable Rate Notes, 11/30/20 18,800 4,000,000+(g) Versutus Re 2017-A, Variable Rate Notes, 11/30/21 2,000 2,000,000+(g) Versutus Re 2018-A, Variable Rate Notes, 12/31/21 1,975,000 1,715,899+(g) Versutus Re 2019-B, Variable Rate Notes, 12/31/21 1,715,899 1,000,000+(g) Viribus Re 2018, Variable Rate Notes, 12/31/21 930,000 3,225,387+(g) Viribus Re 2019, Variable Rate Notes, 12/31/22 3,225,387 1,623,326+(g) Woburn Re 2018, Variable Rate Notes, 12/31/21 1,266,194 -------------- $ 75,737,701 -------------- Total Reinsurance Sidecars $ 87,457,483 --------------------------------------------------------------------------------------------------------------------------------- TOTAL INSURANCE-LINKED SECURITIES (Cost $204,874,256) $ 198,051,129 --------------------------------------------------------------------------------------------------------------------------------- MUNICIPAL BONDS -- 2.4% of Net Assets(h) Municipal General -- 0.3% 3,220,000 Fairfax County Economic Development Authority, Series A, 2.875%, 4/1/34 $ 2,987,291 4,075,000 JobsOhio Beverage System, Ohio Taxable Senior Lien, Series B, 3.985%, 1/1/29 4,199,043 1,035,000 JobsOhio Beverage System, Ohio Taxable Senior Lien, Series B, 4.532%, 1/1/35 1,104,583 2,830,000 Virginia Commonwealth Transportation Board, Transportation Capital Projects, 3.0%, 5/15/39 2,567,206 2,325,000 Virginia Commonwealth Transportation Board, Transportation Capital Projects, 4.0%, 5/15/31 2,464,267 2,335,000 Virginia Commonwealth Transportation Board, Transportation Capital Projects, 4.0%, 5/15/32 2,466,507 -------------- Total Municipal General $ 15,788,897 --------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 50 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- Municipal General Obligation -- 0.5% 16,795,000(i) Commonwealth of Pennsylvania, 1st Series, 4.0%, 1/1/29 $ 17,980,895 2,425,000(i) State of Florida, Capital Outlay, Series C, 4.0%, 6/1/31 2,647,397 3,150,000(i) State of Texas, Transportation Commission Mobility Fund, Series A, 4.0%, 10/1/44 3,213,095 -------------- Total Municipal General Obligation $ 23,841,387 --------------------------------------------------------------------------------------------------------------------------------- Municipal Higher Education -- 1.1% 525,000 Amherst College, 3.794%, 11/1/42 $ 510,840 1,025,000 Baylor University, Series A, 4.313%, 3/1/42 1,043,593 7,425,000 Massachusetts Development Finance Agency, Harvard University, Series A, 5.0%, 7/15/40 9,493,160 10,400,000 New York State Dormitory Authority, Columbia University, Series A-2, 5.0%, 10/1/46 13,596,336 8,345,000 Rhode Island Health & Educational Building Corp., Brown University, Series A, 4.0%, 9/1/47 8,622,555 16,810,000 University of California, Series AX, 3.063%, 7/1/25 16,590,293 3,100,000 University of Virginia, Revenue, Refunding General Green, Series A-2, 5.0%, 4/1/45 3,488,089 -------------- Total Municipal Higher Education $ 53,344,866 --------------------------------------------------------------------------------------------------------------------------------- Municipal Medical -- 0.2% 4,775,000 Illinois Finance Authority, Northwestern Memorial Healthcare, 4.0%, 7/15/47 $ 4,807,375 1,695,000 Massachusetts Development Finance Agency, Partners Healthcare System, 4.0%, 7/1/36 1,753,291 2,910,000 Massachusetts Development Finance Agency, Partners Healthcare System, 4.0%, 7/1/41 2,947,335 1,765,000 Ohio Higher Educational Facility Commission, Cleveland Clinic Health, Series A-1, 5.0%, 1/1/42 1,908,000 -------------- Total Municipal Medical $ 11,416,001 --------------------------------------------------------------------------------------------------------------------------------- Municipal School District -- 0.1% 2,800,000(i) Frisco Independent School District, Refunding School Building, 4.0%, 8/15/40 $ 2,862,468 1,750,000(i) Frisco Independent School District, Refunding School Building, 4.0%, 8/15/45 1,782,287 -------------- Total Municipal School District $ 4,644,755 --------------------------------------------------------------------------------------------------------------------------------- Municipal Transportation -- 0.1% 2,350,000 Central Florida Expressway Authority, 5.0%, 7/1/38 $ 2,649,413 600,000 Port Authority of New York & New Jersey, Consolidated-174TH, 4.458%, 10/1/62 610,446 -------------- Total Municipal Transportation $ 3,259,859 --------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 51 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- Municipal Water -- 0.1% 2,410,000 JEA Water & Sewer System Revenue, Series A, 4.0%, 10/1/35 $ 2,557,854 2,435,000 JEA Water & Sewer System Revenue, Series A, 4.0%, 10/1/39 2,527,798 -------------- Total Municipal Water $ 5,085,652 --------------------------------------------------------------------------------------------------------------------------------- TOTAL MUNICIPAL BONDS (Cost $119,600,372) $ 117,381,417 --------------------------------------------------------------------------------------------------------------------------------- SENIOR SECURED FLOATING RATE LOAN INTERESTS -- 2.3% of Net Assets*(b) Automobile -- 0.3% 613,855 Allison Transmission, Inc., New Term Loan, 4.26% (LIBOR + 175 bps), 9/23/22 $ 607,103 4,119,375 American Axle & Manufacturing, Inc., Tranche B Term Loan, 4.752% (LIBOR + 225 bps), 4/6/24 3,922,675 1,354,032 Cooper-Standard Automotive, Inc., Additional Term B-1 Loan, 4.522% (LIBOR + 200 bps), 11/2/23 1,289,716 1,968,085 CWGS Group LLC (aka Camping World, Inc.), Term Loan, 5.129% (LIBOR + 275 bps), 11/8/23 1,784,807 1,396,667 Goodyear Tire & Rubber Co., Second Lien Term Loan, 4.455% (LIBOR + 200 bps), 3/3/25 1,338,705 733,182 Navistar, Inc., Tranche B Term Loan, 5.89% (LIBOR + 350 bps), 11/6/24 705,687 1,424,519 TI Group Automotive Systems LLC, Initial US Term Loan, 5.022% (LIBOR + 250 bps), 6/30/22 1,362,196 -------------- Total Automobile $ 11,010,889 --------------------------------------------------------------------------------------------------------------------------------- Beverage, Food & Tobacco -- 0.1% 1,673,075 Darling Ingredients, Inc. (fka Darling International, Inc.), Term B Loan, 4.57% (LIBOR + 200 bps/ PRIME + 100 bps), 12/18/24 $ 1,658,436 4,036,427 JBS USA Lux SA (fka JBS USA LLC), Initial Term Loan, 5.26% (LIBOR + 250 bps), 10/30/22 3,891,366 -------------- Total Beverage, Food & Tobacco $ 5,549,802 --------------------------------------------------------------------------------------------------------------------------------- Broadcasting & Entertainment -- 0.0%+ 408,127 UPC Financing Partnership, Facility AR, 4.955% (LIBOR + 250 bps), 1/15/26 $ 389,506 -------------- Total Broadcasting & Entertainment $ 389,506 --------------------------------------------------------------------------------------------------------------------------------- Buildings & Real Estate -- 0.0%+ 417,880 Builders FirstSource, Inc., Refinancing Term Loan, 5.803% (LIBOR + 300 bps), 2/29/24 $ 393,644 1,600,800 Communications Sales & Leasing, Inc. (CSL Capital LLC), Shortfall Term Loan, 5.522% (LIBOR + 300 bps), 10/24/22 1,442,053 -------------- Total Buildings & Real Estate $ 1,835,697 --------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 52 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- Chemicals -- 0.0%+ 411,308 Allnex (Luxembourg) & Cy SCA (fka AI Chem & Cy SCA), Tranche B-2 Term Loan, 5.956% (LIBOR + 325 bps), 9/13/23 $ 404,624 309,889 Allnex (Luxembourg) & Cy SCA (fka AI Chem & Cy SCA), Tranche B-3 Term Loan, 5.956% (LIBOR + 325 bps), 9/13/23 304,853 -------------- Total Chemicals $ 709,477 --------------------------------------------------------------------------------------------------------------------------------- Chemicals, Plastics & Rubber -- 0.1% 491,250 Berry Global, Inc. (fka Berry Plastics Corp.), Term R Loan, 4.387% (LIBOR + 200 bps), 1/19/24 $ 478,662 385,788 Infiltrator Water Technologies LLC, First Lien Term B-2 Loan, 5.803% (LIBOR + 300 bps), 5/27/22 376,143 621,818 MacDermid, Inc. (Platform Specialty Products Corp.), Tranche B-6 Term Loan, 5.522% (LIBOR + 300 bps), 6/7/23 612,491 585,116 Nexeo Solutions LLC, Term B-1 Loan, 5.926% (LIBOR + 325 bps), 6/9/23 577,071 517,929 Omnova Solutions, Inc., Term B-2 Loan, 5.772% (LIBOR + 325 bps), 8/25/23 506,275 236,398(j) Platform Specialty Products Corp., Term Loan, 11/14/25 229,306 478,884 Tronox Blocked Borrower LLC, First Lien Blocked Dollar Term Loan, 5.522% (LIBOR + 300 bps), 9/23/24 466,826 1,105,116 Tronox Finance LLC, First Lien Initial Dollar Term Loan, 5.522% (LIBOR + 300 bps), 9/23/24 1,077,291 140,809 W.R. Grace & Co-CONN, Term B-1 Loan, 4.553% (LIBOR + 175 bps), 4/3/25 136,878 241,386 W.R. Grace & Co-CONN, Term B-2 Loan, 4.553% (LIBOR + 175 bps), 4/3/25 234,647 -------------- Total Chemicals, Plastics & Rubber $ 4,695,590 --------------------------------------------------------------------------------------------------------------------------------- Computers & Electronics -- 0.1% 1,065,722 Energy Acquisition LP (aka Electrical Components International), First Lien Initial Term Loan, 7.053% (LIBOR + 425 bps), 6/26/25 $ 1,039,079 3,359,598 Microchip Technology, Inc., Initial Term Loan, 4.53% (LIBOR + 200 bps), 5/29/25 3,195,818 798,040 ON Semiconductor Corp., 2018 New Replacement Term B-3 Loan, 4.272% (LIBOR + 175 bps), 3/31/23 772,353 312,891 Rocket Software, Inc., First Lien Initial Term Loan, 6.772% (LIBOR + 425 bps), 11/28/25 307,415 -------------- Total Computers & Electronics $ 5,314,665 --------------------------------------------------------------------------------------------------------------------------------- Diversified & Conglomerate Manufacturing -- 0.0%+ 318,384 Ranpak Corp., Tranche B-1 USD Term Loan, 5.772% (LIBOR + 325 bps), 10/1/21 $ 315,996 -------------- Total Diversified & Conglomerate Manufacturing $ 315,996 --------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 53 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- Diversified & Conglomerate Service -- 0.2% 568,039 Bright Horizons Family Solutions LLC (fka Bright Horizons Family Solutions, Inc.), Term B Loan, 4.272% (LIBOR + 175 bps), 11/7/23 $ 548,631 1,251,250 Change Healthcare Holdings, Inc. (fka Emdeon, Inc.), Closing Date Term Loan, 5.272% (LIBOR + 275 bps), 3/1/24 1,192,076 640,250 Constellis Holdings LLC, First Lien Term B Loan, 7.522% (LIBOR + 500 bps), 4/21/24 616,240 501,592 Filtration Group Corp., Initial Dollar Term Loan, 5.522% (LIBOR + 300 bps), 3/29/25 484,663 508,250 Iqvia, Inc. (Quintiles IMS), Term B-1 Dollar Loan, 4.803% (LIBOR + 200 bps), 3/7/24 492,621 2,339,848 NVA Holdings, Inc., First Lien Term B-3 Loan, 5.272% (LIBOR + 275 bps), 2/2/25 2,213,106 1,080,750 Team Health Holdings, Inc., Initial Term Loan, 5.272% (LIBOR + 275 bps), 2/6/24 975,377 -------------- Total Diversified & Conglomerate Service $ 6,522,714 --------------------------------------------------------------------------------------------------------------------------------- Electric & Electrical -- 0.0%+ 225,515 Micron Technology, Inc., Term Loan, 4.28% (LIBOR + 175 bps), 4/26/22 $ 222,085 462,955 Rackspace Hosting, Inc., First Lien Term B Loan, 5.582% (LIBOR + 300 bps), 11/3/23 408,326 -------------- Total Electric & Electrical $ 630,411 --------------------------------------------------------------------------------------------------------------------------------- Electronics -- 0.4% 323,467 Avast Software BV, 2018 Refinancing Dollar Term Loan, 5.303% (LIBOR + 250 bps), 9/29/23 $ 313,898 844,089 First Data Corp., 2022D New Dollar Term Loan, 4.504% (LIBOR + 200 bps), 7/8/22 811,732 6,591,848 First Data Corp., 2024-A New Dollar Term Loan, 4.504% (LIBOR + 200 bps), 4/26/24 6,315,814 3,129,898 Rovi Solutions Corp./Rovi Guides, Inc., Term B Loan, 5.03% (LIBOR + 250 bps), 7/2/21 2,981,228 4,973,240 Scientific Games International, Inc., Initial Term B-5 Loan, 5.25% (LIBOR + 275 bps), 8/14/24 4,682,305 1,083,722 Sensata Technologies BV (Sensata Technologies Finance Co., LLC), Sixth Amendment Term Loan, 4.209% (LIBOR + 175 bps), 10/14/21 1,073,336 83,620 WESCO Distribution, Inc., Tranche B-1 Term Loan, 7.5% (PRIME + 200 bps), 12/12/19 83,201 -------------- Total Electronics $ 16,261,514 --------------------------------------------------------------------------------------------------------------------------------- Entertainment & Leisure -- 0.0%+ 2,033,382 Live Nation Entertainment, Inc., Term B-3 Loan, 4.313% (LIBOR + 175 bps), 10/31/23 $ 1,992,714 -------------- Total Entertainment & Leisure $ 1,992,714 --------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 54 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- Environmental Services -- 0.0%+ 960,441 GFL Environmental, Inc., Effective Date Incremental Term Loan, 5.522% (LIBOR + 300 bps), 5/30/25 $ 900,414 -------------- Total Environmental Services $ 900,414 --------------------------------------------------------------------------------------------------------------------------------- Finance -- 0.0%+ 1,399,799 Trans Union LLC, 2017 Replacement Term B-3 Loan, 4.522% (LIBOR + 200 bps), 4/10/23 $ 1,351,855 -------------- Total Finance $ 1,351,855 --------------------------------------------------------------------------------------------------------------------------------- Financial Services -- 0.1% 2,452,782 RPI Finance Trust, Initial Term Loan B-6, 4.522% (LIBOR + 200 bps), 3/27/23 $ 2,381,242 -------------- Total Financial Services $ 2,381,242 --------------------------------------------------------------------------------------------------------------------------------- Healthcare & Pharmaceuticals -- 0.2% 721,530 Alkermes, Inc., 2023 Term Loan, 4.64% (LIBOR + 225 bps), 3/27/23 $ 707,099 493,750 Alphabet Holding Co., Inc. (aka Nature's Bounty), First Lien Initial Term Loan, 6.022% (LIBOR + 350 bps), 9/26/24 448,901 1,053,281 CHS/Community Health Systems, Inc., Incremental 2021 Term H Loan, 5.957% (LIBOR + 325 bps), 1/27/21 1,011,939 242,262 DaVita, Inc. (fka DaVita HealthCare Partners, Inc.), Tranche B Term Loan, 5.272% (LIBOR + 275 bps), 6/24/21 240,218 5,021,763 Endo Luxembourg Finance Co. I S.a r.l., Initial Term Loan, 6.813% (LIBOR + 425 bps), 4/29/24 4,745,566 400,951 Gentiva Health Services, Inc., First Lien Closing Date Initial Term Loan, 6.313% (LIBOR + 375 bps), 7/2/25 390,927 712,312 Grifols Worldwide Operations, Ltd., Tranche B Term Loan, 4.669% (LIBOR + 225 bps), 1/31/25 684,710 1,416,158 HCA, Inc., Tranche B-11 Term Loan, 4.272% (LIBOR + 175 bps), 3/17/23 1,385,180 722,759 Sterigenics-Nordion Holdings LLC, Incremental Term Loan, 5.522% (LIBOR + 300 bps), 5/15/22 693,849 -------------- Total Healthcare & Pharmaceuticals $ 10,308,389 --------------------------------------------------------------------------------------------------------------------------------- Healthcare, Education & Childcare -- 0.1% 780,000 Alliance HealthCare Services, Inc., First Lien Initial Term Loan, 7.022% (LIBOR + 450 bps), 10/24/23 $ 768,300 600,673 Bausch Health Cos., Inc. (fka Valeant Pharmaceuticals International, Inc.), Initial Term Loan, 5.379% (LIBOR + 300 bps), 6/2/25 576,646 1,490,815 Catalent Pharma Solutions, Inc. (fka Cardinal Health 409, Inc.), Dollar Term Loan, 4.772% (LIBOR + 225 bps), 5/20/24 1,451,681 257,034 Kinetic Concepts, Inc., Dollar Term Loan, 6.053% (LIBOR + 325 bps), 2/2/24 248,038 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 55 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- Healthcare, Education & Childcare -- (continued) 2,205,085 KUEHG Corp. (fka KC MergerSub, Inc.) (aka KinderCare), Term B-3 Loan, 6.553% (LIBOR + 375 bps), 2/21/25 $ 2,132,317 1,145,780 Select Medical Corp., Tranche B Term Loan, 4.962% (LIBOR + 250 bps/PRIME + 150 bps), 3/6/25 1,097,084 586,207 Vizient, Inc., Term B-4 Loan, 5.272% (LIBOR + 275 bps), 2/13/23 571,795 -------------- Total Healthcare, Education & Childcare $ 6,845,861 --------------------------------------------------------------------------------------------------------------------------------- Home & Office Furnishings -- 0.0%+ 1,265,473 Serta Simmons Bedding LLC, First Lien Initial Term Loan, 5.891% (LIBOR + 350 bps), 11/8/23 $ 1,056,670 -------------- Total Home & Office Furnishings $ 1,056,670 --------------------------------------------------------------------------------------------------------------------------------- Hotel, Gaming & Leisure -- 0.0%+ 1,678,902 1011778 BC Unlimited Liability Co. (New Red Finance, Inc.) (aka Burger King/Tim Hortons), Term B-3 Loan, 4.772% (LIBOR + 225 bps), 2/16/24 $ 1,601,938 -------------- Total Hotel, Gaming & Leisure $ 1,601,938 --------------------------------------------------------------------------------------------------------------------------------- Insurance -- 0.1% 3,848,778 Asurion LLC (fka Asurion Corp.), New B-7 Term Loan, 5.522% (LIBOR + 300 bps), 11/3/24 $ 3,685,205 436,335 MPH Acquisition Holdings LLC, Initial Term Loan, 5.553% (LIBOR + 275 bps), 6/7/23 412,664 839,375 USI, Inc. (fka Compass Investors, Inc.), 2017 New Term Loan, 5.803% (LIBOR + 300 bps), 5/16/24 794,888 -------------- Total Insurance $ 4,892,757 --------------------------------------------------------------------------------------------------------------------------------- Leasing -- 0.1% 1,370,597 Avolon TLB Borrower 1 (US) LLC, Term B-3 Loan, 4.47% (LIBOR + 200 bps), 1/15/25 $ 1,322,937 2,729,375 IBC Capital I, Ltd. (aka Goodpack, Ltd.), First Lien Tranche B-1 Term Loan, 6.551% (LIBOR + 375 bps), 9/11/23 2,640,670 -------------- Total Leasing $ 3,963,607 --------------------------------------------------------------------------------------------------------------------------------- Leisure & Entertainment -- 0.0%+ 554,516 AMC Entertainment Holdings, Inc. (fka AMC Entertainment, Inc.), Initial Term Loan, 4.705% (LIBOR + 225 bps), 12/15/22 $ 535,801 398,227 Fitness International LLC, Term B Loan, 5.772% (LIBOR + 325 bps), 4/18/25 380,306 1,292,915 Six Flags Theme Parks, Inc., Tranche B Term Loan, 4.26% (LIBOR + 175 bps), 6/30/22 1,269,481 -------------- Total Leisure & Entertainment $ 2,185,588 --------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 56 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- Machinery -- 0.1% 1,165,942 NN, Inc., Tranche B Term Loan, 6.272% (LIBOR + 375 bps), 10/19/22 $ 1,136,794 -------------- Total Machinery $ 1,136,794 --------------------------------------------------------------------------------------------------------------------------------- Metals & Mining -- 0.0%+ 503,333 BWay Holding Co., Initial Term Loan, 5.658% (LIBOR + 325 bps), 4/3/24 $ 475,335 6,880 Zekelman Industries, Inc. (fka JMC Steel Group, Inc.), Term Loan, 4.862% (LIBOR + 225 bps), 6/14/21 6,672 -------------- Total Metals & Mining $ 482,007 --------------------------------------------------------------------------------------------------------------------------------- Oil & Gas -- 0.0%+ 1,110,467 Energy Transfer Equity LP, Refinanced Term Loan, 4.522% (LIBOR + 200 bps), 2/2/24 $ 1,085,655 -------------- Total Oil & Gas $ 1,085,655 --------------------------------------------------------------------------------------------------------------------------------- Printing & Publishing -- 0.0%+ 1,280,500 Nielsen Finance LLC (VNU, Inc.), Class B-4 Term Loan, 4.387% (LIBOR + 200 bps), 10/4/23 $ 1,243,685 -------------- Total Printing & Publishing $ 1,243,685 --------------------------------------------------------------------------------------------------------------------------------- Professional & Business Services -- 0.0%+ 590,531 GW Honos Security Corp. (Garda World Security Corp.), Term B Loan, 6.241% (LIBOR + 350 bps/PRIME + 250 bps), 5/24/24 $ 564,696 992,500 Lamar Media Corp., Term B Loan, 4.313% (LIBOR + 175 bps), 3/14/25 966,447 -------------- Total Professional & Business Services $ 1,531,143 --------------------------------------------------------------------------------------------------------------------------------- Retail -- 0.0%+ 2,673,000 Staples, Inc., Closing Date Term Loan, 6.541% (LIBOR + 400 bps), 9/12/24 $ 2,567,751 -------------- Total Retail $ 2,567,751 --------------------------------------------------------------------------------------------------------------------------------- Retail Store -- 0.1% 5,836 PetSmart, Inc., Tranche B-2 Term Loan, 5.38% (LIBOR + 300 bps), 3/11/22 $ 4,625 -------------- Total Retail Store $ 4,625 --------------------------------------------------------------------------------------------------------------------------------- Telecommunications -- 0.2% 3,716,842 CenturyLink, Inc., Initial Term B Loan, 5.272% (LIBOR + 275 bps), 1/31/25 $ 3,481,053 900,000 Ciena Corp., Refinancing Term Loan, 4.47% (LIBOR + 200 bps), 9/26/25 861,750 1,168,784 GCI Holdings, Inc., New Term B Loan, 4.772% (LIBOR + 225 bps), 2/2/22 1,133,721 1,205,310 Go Daddy Operating Co., LLC (GD Finance Co., Inc.), Tranche B-1 Term Loan, 4.772% (LIBOR + 225 bps), 2/15/24 1,155,591 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 57 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- Telecommunications -- (continued) 1,200,000 Level 3 Financing, Inc., Tranche B 2024 Term Loan, 4.754% (LIBOR + 225 bps), 2/22/24 $ 1,137,000 1,277,250 Sprint Communications, Inc., Initial Term Loan, 5.063% (LIBOR + 250 bps), 2/2/24 1,222,967 -------------- Total Telecommunications $ 8,992,082 --------------------------------------------------------------------------------------------------------------------------------- Utilities -- 0.1% 960,164 Eastern Power LLC (Eastern Covert Midco LLC) (aka TPF II LC LLC), Term Loan, 6.272% (LIBOR + 375 bps), 10/2/23 $ 941,259 927,855 NRG Energy, Inc., Term Loan, 4.272% (LIBOR + 175 bps), 6/30/23 895,251 2,182,026 Vistra Operations Co., LLC (fka Tex Operations Co., LLC), Initial Term Loan, 4.522% (LIBOR + 200 bps), 8/4/23 2,108,983 -------------- Total Utilities $ 3,945,493 --------------------------------------------------------------------------------------------------------------------------------- TOTAL SENIOR SECURED FLOATING RATE LOAN INTERESTS (Cost $116,201,379) $ 111,706,531 --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- 29.8% of Net Assets 1,147,151 Fannie Mae, 2.5%, 7/1/30 $ 1,121,823 1,167,524 Fannie Mae, 2.5%, 7/1/30 1,143,189 2,004,308 Fannie Mae, 2.5%, 7/1/30 1,962,564 227,562 Fannie Mae, 2.5%, 12/1/42 215,390 237,662 Fannie Mae, 2.5%, 12/1/42 225,424 221,660 Fannie Mae, 2.5%, 1/1/43 210,248 89,431 Fannie Mae, 2.5%, 2/1/43 84,827 114,016 Fannie Mae, 2.5%, 2/1/43 107,688 2,431,918 Fannie Mae, 2.5%, 2/1/43 2,306,715 335,032 Fannie Mae, 2.5%, 3/1/43 317,783 121,139 Fannie Mae, 2.5%, 4/1/43 114,902 302,778 Fannie Mae, 2.5%, 8/1/43 287,190 230,415 Fannie Mae, 2.5%, 12/1/43 218,552 164,693 Fannie Mae, 2.5%, 3/1/44 156,214 211,325 Fannie Mae, 2.5%, 4/1/45 199,589 309,107 Fannie Mae, 2.5%, 4/1/45 291,940 443,180 Fannie Mae, 2.5%, 4/1/45 418,565 445,586 Fannie Mae, 2.5%, 4/1/45 420,841 511,425 Fannie Mae, 2.5%, 4/1/45 483,370 530,069 Fannie Mae, 2.5%, 4/1/45 500,629 1,206,447 Fannie Mae, 2.5%, 4/1/45 1,139,448 1,425,791 Fannie Mae, 2.5%, 4/1/45 1,346,614 71,193 Fannie Mae, 2.5%, 5/1/45 67,240 79,630 Fannie Mae, 2.5%, 7/1/45 75,208 The accompanying notes are an integral part of these financial statements. 58 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 253,440 Fannie Mae, 2.5%, 8/1/45 $ 239,366 87,665 Fannie Mae, 2.5%, 1/1/46 82,801 219,929 Fannie Mae, 3.0%, 12/1/21 222,817 3,234,104 Fannie Mae, 3.0%, 9/1/28 3,236,249 2,896,218 Fannie Mae, 3.0%, 10/1/30 2,898,159 1,162,886 Fannie Mae, 3.0%, 4/1/31 1,160,797 15,523,809 Fannie Mae, 3.0%, 8/1/42 15,273,486 3,665,208 Fannie Mae, 3.0%, 9/1/42 3,604,734 1,146,615 Fannie Mae, 3.0%, 12/1/42 1,126,896 2,254,150 Fannie Mae, 3.0%, 2/1/43 2,215,589 620,003 Fannie Mae, 3.0%, 5/1/43 609,412 8,502,874 Fannie Mae, 3.0%, 5/1/43 8,355,905 583,192 Fannie Mae, 3.0%, 7/1/43 573,050 1,442,121 Fannie Mae, 3.0%, 8/1/43 1,417,095 4,050,956 Fannie Mae, 3.0%, 9/1/43 3,980,658 747,432 Fannie Mae, 3.0%, 3/1/45 732,357 6,327,255 Fannie Mae, 3.0%, 6/1/45 6,205,030 633,065 Fannie Mae, 3.0%, 5/1/46 620,263 835,033 Fannie Mae, 3.0%, 5/1/46 816,335 4,590,444 Fannie Mae, 3.0%, 9/1/46 4,476,980 8,440,661 Fannie Mae, 3.0%, 10/1/46 8,232,031 8,457,837 Fannie Mae, 3.0%, 11/1/46 8,248,776 7,308,046 Fannie Mae, 3.0%, 1/1/47 7,160,257 2,607,630 Fannie Mae, 3.0%, 3/1/47 2,543,145 583,002 Fannie Mae, 3.5%, 4/1/26 590,126 361,667 Fannie Mae, 3.5%, 9/1/26 366,153 856,686 Fannie Mae, 3.5%, 12/1/26 867,156 2,403,924 Fannie Mae, 3.5%, 6/1/28 2,441,830 992,647 Fannie Mae, 3.5%, 11/1/40 1,000,391 510,574 Fannie Mae, 3.5%, 10/1/41 514,561 433,606 Fannie Mae, 3.5%, 6/1/42 436,960 2,688,253 Fannie Mae, 3.5%, 7/1/42 2,709,198 2,753,123 Fannie Mae, 3.5%, 8/1/42 2,774,615 221,879 Fannie Mae, 3.5%, 11/1/42 223,611 478,284 Fannie Mae, 3.5%, 12/1/42 482,017 517,368 Fannie Mae, 3.5%, 12/1/42 521,405 4,839,234 Fannie Mae, 3.5%, 2/1/44 4,862,228 2,535,590 Fannie Mae, 3.5%, 9/1/44 2,545,172 5,238,849 Fannie Mae, 3.5%, 2/1/45 5,264,742 1,568,441 Fannie Mae, 3.5%, 4/1/45 1,574,371 6,035,864 Fannie Mae, 3.5%, 6/1/45 6,058,064 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 59 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 2,306,217 Fannie Mae, 3.5%, 8/1/45 $ 2,313,862 7,425,299 Fannie Mae, 3.5%, 8/1/45 7,491,326 5,502,169 Fannie Mae, 3.5%, 9/1/45 5,503,997 6,671,153 Fannie Mae, 3.5%, 9/1/45 6,695,002 1,405,778 Fannie Mae, 3.5%, 10/1/45 1,410,732 11,441,877 Fannie Mae, 3.5%, 11/1/45 11,540,079 2,311,776 Fannie Mae, 3.5%, 12/1/45 2,317,057 2,458,195 Fannie Mae, 3.5%, 12/1/45 2,463,811 4,417,660 Fannie Mae, 3.5%, 12/1/45 4,432,313 5,031,768 Fannie Mae, 3.5%, 1/1/46 5,047,410 6,727,803 Fannie Mae, 3.5%, 1/1/46 6,749,078 2,819,119 Fannie Mae, 3.5%, 2/1/46 2,827,596 4,576,038 Fannie Mae, 3.5%, 2/1/46 4,590,034 1,883,621 Fannie Mae, 3.5%, 3/1/46 1,889,285 3,948,271 Fannie Mae, 3.5%, 4/1/46 3,960,143 2,435,467 Fannie Mae, 3.5%, 5/1/46 2,444,676 5,725,542 Fannie Mae, 3.5%, 7/1/46 5,735,960 8,455,250 Fannie Mae, 3.5%, 9/1/46 8,477,184 492,813 Fannie Mae, 3.5%, 10/1/46 494,066 993,451 Fannie Mae, 3.5%, 10/1/46 995,772 1,125,014 Fannie Mae, 3.5%, 11/1/46 1,127,410 4,344,964 Fannie Mae, 3.5%, 12/1/46 4,355,113 2,209,872 Fannie Mae, 3.5%, 1/1/47 2,214,581 4,446,848 Fannie Mae, 3.5%, 1/1/47 4,456,323 6,136,559 Fannie Mae, 3.5%, 1/1/47 6,155,972 10,321,051 Fannie Mae, 3.5%, 1/1/47 10,345,175 5,662,903 Fannie Mae, 3.5%, 2/1/47 5,674,969 7,130,017 Fannie Mae, 3.5%, 5/1/47 7,140,793 8,031,874 Fannie Mae, 3.5%, 5/1/47 8,040,695 273,450 Fannie Mae, 3.5%, 7/1/47 273,575 2,681,585 Fannie Mae, 3.5%, 7/1/47 2,685,084 8,166,592 Fannie Mae, 3.5%, 7/1/47 8,175,560 11,044,875 Fannie Mae, 3.5%, 7/1/47 11,053,460 1,368,945 Fannie Mae, 3.5%, 8/1/47 1,369,883 17,900,482 Fannie Mae, 3.5%, 8/1/47 17,909,045 2,993,206 Fannie Mae, 3.5%, 11/1/47 2,997,110 7,165,014 Fannie Mae, 3.5%, 12/1/47 7,165,504 11,902,952 Fannie Mae, 3.5%, 12/1/47 11,903,804 15,610,828 Fannie Mae, 3.5%, 12/1/47 15,624,918 3,966,709 Fannie Mae, 3.5%, 1/1/48 3,967,035 3,074,312 Fannie Mae, 3.5%, 2/1/48 3,074,564 The accompanying notes are an integral part of these financial statements. 60 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 902,364 Fannie Mae, 3.771%, 12/1/20 $ 916,619 14,572 Fannie Mae, 4.0%, 9/1/20 14,922 225,453 Fannie Mae, 4.0%, 4/1/25 230,880 225,832 Fannie Mae, 4.0%, 11/1/34 234,290 2,236,950 Fannie Mae, 4.0%, 4/1/39 2,299,895 5,985,806 Fannie Mae, 4.0%, 10/1/40 6,171,779 1,092,958 Fannie Mae, 4.0%, 12/1/40 1,125,001 646,753 Fannie Mae, 4.0%, 4/1/41 664,963 1,055,446 Fannie Mae, 4.0%, 4/1/41 1,085,269 686,105 Fannie Mae, 4.0%, 5/1/41 701,689 1,378,597 Fannie Mae, 4.0%, 10/1/41 1,419,884 949,538 Fannie Mae, 4.0%, 12/1/41 976,370 348,689 Fannie Mae, 4.0%, 1/1/42 358,527 2,481,969 Fannie Mae, 4.0%, 1/1/42 2,552,094 2,117,109 Fannie Mae, 4.0%, 2/1/42 2,176,926 5,804,938 Fannie Mae, 4.0%, 2/1/42 5,968,929 1,017,792 Fannie Mae, 4.0%, 3/1/42 1,046,545 118,853 Fannie Mae, 4.0%, 4/1/42 122,212 531,662 Fannie Mae, 4.0%, 4/1/42 546,683 2,356,015 Fannie Mae, 4.0%, 4/1/42 2,422,577 4,453,604 Fannie Mae, 4.0%, 5/1/42 4,579,434 93,276 Fannie Mae, 4.0%, 6/1/42 95,378 285,574 Fannie Mae, 4.0%, 6/1/42 291,960 139,944 Fannie Mae, 4.0%, 7/1/42 143,898 3,195,887 Fannie Mae, 4.0%, 7/1/42 3,286,172 6,822,350 Fannie Mae, 4.0%, 8/1/42 7,015,085 1,304,424 Fannie Mae, 4.0%, 10/1/42 1,341,274 4,040,675 Fannie Mae, 4.0%, 8/1/43 4,138,168 4,957,548 Fannie Mae, 4.0%, 9/1/43 5,087,384 9,241,426 Fannie Mae, 4.0%, 10/1/43 9,483,797 3,072,317 Fannie Mae, 4.0%, 11/1/43 3,162,150 3,543,483 Fannie Mae, 4.0%, 12/1/43 3,642,834 110,518 Fannie Mae, 4.0%, 1/1/44 113,070 4,760,708 Fannie Mae, 4.0%, 2/1/44 4,872,722 70,794 Fannie Mae, 4.0%, 6/1/44 72,340 87,231 Fannie Mae, 4.0%, 6/1/44 89,116 242,389 Fannie Mae, 4.0%, 7/1/44 247,519 4,653,409 Fannie Mae, 4.0%, 7/1/44 4,754,653 191,855 Fannie Mae, 4.0%, 8/1/44 195,955 215,018 Fannie Mae, 4.0%, 8/1/44 219,679 1,126,795 Fannie Mae, 4.0%, 8/1/44 1,151,045 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 61 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 3,374,225 Fannie Mae, 4.0%, 8/1/44 $ 3,446,339 36,649 Fannie Mae, 4.0%, 9/1/44 37,438 277,578 Fannie Mae, 4.0%, 9/1/44 283,510 370,136 Fannie Mae, 4.0%, 9/1/44 378,104 6,443,979 Fannie Mae, 4.0%, 9/1/44 6,612,976 1,497,409 Fannie Mae, 4.0%, 10/1/44 1,530,101 87,699 Fannie Mae, 4.0%, 11/1/44 89,574 98,856 Fannie Mae, 4.0%, 11/1/44 100,969 181,221 Fannie Mae, 4.0%, 11/1/44 185,080 4,575,153 Fannie Mae, 4.0%, 11/1/44 4,672,928 35,854 Fannie Mae, 4.0%, 12/1/44 36,621 470,536 Fannie Mae, 4.0%, 12/1/44 480,592 65,023 Fannie Mae, 4.0%, 1/1/45 66,362 184,590 Fannie Mae, 4.0%, 1/1/45 188,534 301,235 Fannie Mae, 4.0%, 1/1/45 307,603 45,218 Fannie Mae, 4.0%, 2/1/45 46,167 161,647 Fannie Mae, 4.0%, 2/1/45 165,234 346,989 Fannie Mae, 4.0%, 2/1/45 354,590 3,788,704 Fannie Mae, 4.0%, 3/1/45 3,868,369 2,749,389 Fannie Mae, 4.0%, 8/1/45 2,821,489 2,513,355 Fannie Mae, 4.0%, 10/1/45 2,565,055 3,834,563 Fannie Mae, 4.0%, 10/1/45 3,913,437 4,442,811 Fannie Mae, 4.0%, 10/1/45 4,534,433 64,809 Fannie Mae, 4.0%, 11/1/45 66,113 3,153,200 Fannie Mae, 4.0%, 11/1/45 3,217,879 7,651,238 Fannie Mae, 4.0%, 11/1/45 7,862,928 5,392,919 Fannie Mae, 4.0%, 12/1/45 5,504,129 2,092,523 Fannie Mae, 4.0%, 1/1/46 2,135,353 5,699,054 Fannie Mae, 4.0%, 2/1/46 5,819,938 1,437,462 Fannie Mae, 4.0%, 4/1/46 1,466,445 4,916,215 Fannie Mae, 4.0%, 6/1/46 5,015,309 5,239,895 Fannie Mae, 4.0%, 7/1/46 5,344,984 7,096,407 Fannie Mae, 4.0%, 7/1/46 7,238,908 4,093,513 Fannie Mae, 4.0%, 8/1/46 4,175,382 5,083,192 Fannie Mae, 4.0%, 8/1/46 5,184,869 1,427,139 Fannie Mae, 4.0%, 11/1/46 1,455,620 12,180,315 Fannie Mae, 4.0%, 1/1/47 12,429,379 400,747 Fannie Mae, 4.0%, 2/1/47 409,060 3,094,375 Fannie Mae, 4.0%, 4/1/47 3,165,542 3,163,445 Fannie Mae, 4.0%, 4/1/47 3,225,927 4,764,922 Fannie Mae, 4.0%, 4/1/47 4,875,103 521,664 Fannie Mae, 4.0%, 6/1/47 533,727 1,877,930 Fannie Mae, 4.0%, 6/1/47 1,921,355 The accompanying notes are an integral part of these financial statements. 62 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 2,873,048 Fannie Mae, 4.0%, 6/1/47 $ 2,929,794 4,635,114 Fannie Mae, 4.0%, 6/1/47 4,726,427 8,382,111 Fannie Mae, 4.0%, 6/1/47 8,547,023 2,631,694 Fannie Mae, 4.0%, 7/1/47 2,692,549 2,972,336 Fannie Mae, 4.0%, 7/1/47 3,030,891 2,599,361 Fannie Mae, 4.0%, 8/1/47 2,650,568 4,979,241 Fannie Mae, 4.0%, 8/1/47 5,076,948 6,368,723 Fannie Mae, 4.0%, 12/1/47 6,493,540 8,747,539 Fannie Mae, 4.0%, 4/1/48 8,918,903 5,500 Fannie Mae, 4.5%, 11/1/20 5,602 80,598 Fannie Mae, 4.5%, 11/1/20 82,409 159,056 Fannie Mae, 4.5%, 10/1/35 165,016 406,196 Fannie Mae, 4.5%, 8/1/40 425,465 832,189 Fannie Mae, 4.5%, 8/1/40 871,671 1,447,768 Fannie Mae, 4.5%, 11/1/40 1,516,201 145,266 Fannie Mae, 4.5%, 12/1/40 152,156 551,764 Fannie Mae, 4.5%, 2/1/41 577,938 1,323,367 Fannie Mae, 4.5%, 4/1/41 1,386,148 69,328 Fannie Mae, 4.5%, 5/1/41 72,617 1,794,956 Fannie Mae, 4.5%, 5/1/41 1,880,117 2,415,470 Fannie Mae, 4.5%, 5/1/41 2,530,068 3,124,082 Fannie Mae, 4.5%, 5/1/41 3,272,259 883,516 Fannie Mae, 4.5%, 7/1/41 925,432 957,474 Fannie Mae, 4.5%, 7/1/41 1,002,844 1,171,768 Fannie Mae, 4.5%, 7/1/41 1,223,019 3,436,027 Fannie Mae, 4.5%, 1/1/42 3,598,922 4,433,778 Fannie Mae, 4.5%, 1/1/42 4,643,846 445,332 Fannie Mae, 4.5%, 11/1/43 463,679 3,086,716 Fannie Mae, 4.5%, 12/1/43 3,235,933 3,893,418 Fannie Mae, 4.5%, 12/1/43 4,054,114 6,268,162 Fannie Mae, 4.5%, 12/1/43 6,525,779 4,408,569 Fannie Mae, 4.5%, 1/1/44 4,590,519 2,484,189 Fannie Mae, 4.5%, 2/1/44 2,586,525 3,001,733 Fannie Mae, 4.5%, 2/1/44 3,125,540 4,882,125 Fannie Mae, 4.5%, 5/1/46 5,060,008 607,877 Fannie Mae, 4.5%, 1/1/47 629,969 431,095 Fannie Mae, 4.5%, 2/1/47 446,575 3,528,650 Fannie Mae, 4.5%, 2/1/47 3,656,993 10,635 Fannie Mae, 5.0%, 1/1/20 10,820 24,201 Fannie Mae, 5.0%, 1/1/20 24,623 4,197 Fannie Mae, 5.0%, 2/1/20 4,270 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 63 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 56,686 Fannie Mae, 5.0%, 10/1/20 $ 57,674 4,227 Fannie Mae, 5.0%, 2/1/22 4,303 52,579 Fannie Mae, 5.0%, 2/1/22 53,521 48,257 Fannie Mae, 5.0%, 3/1/23 49,220 178,234 Fannie Mae, 5.0%, 5/1/23 185,277 91,840 Fannie Mae, 5.0%, 7/1/34 94,266 149,338 Fannie Mae, 5.0%, 10/1/34 155,317 609,763 Fannie Mae, 5.0%, 2/1/39 647,386 458,699 Fannie Mae, 5.0%, 6/1/40 486,654 529,410 Fannie Mae, 5.0%, 6/1/40 561,975 359,081 Fannie Mae, 5.0%, 7/1/40 381,170 510,437 Fannie Mae, 5.0%, 7/1/40 541,836 815,542 Fannie Mae, 5.0%, 7/1/40 865,702 627,604 Fannie Mae, 5.0%, 8/1/40 666,211 2,279,301 Fannie Mae, 5.0%, 2/1/41 2,419,603 8,618,077 Fannie Mae, 5.0%, 12/1/44 9,160,531 26,368 Fannie Mae, 5.5%, 9/1/19 26,393 15,333 Fannie Mae, 5.5%, 6/1/33 16,470 69,060 Fannie Mae, 5.5%, 7/1/33 74,240 432,825 Fannie Mae, 5.5%, 7/1/34 466,055 240,234 Fannie Mae, 5.5%, 3/1/36 258,401 83,731 Fannie Mae, 5.5%, 5/1/36 88,829 130,428 Fannie Mae, 5.5%, 6/1/36 140,450 46,085 Fannie Mae, 5.72%, 11/1/28 46,550 24,667 Fannie Mae, 5.72%, 6/1/29 24,693 21,208 Fannie Mae, 5.9%, 11/1/27 21,235 70,848 Fannie Mae, 5.9%, 4/1/28 72,037 671 Fannie Mae, 6.0%, 9/1/29 731 2,937 Fannie Mae, 6.0%, 1/1/32 3,200 11,916 Fannie Mae, 6.0%, 2/1/32 12,977 4,153 Fannie Mae, 6.0%, 3/1/32 4,531 2,839 Fannie Mae, 6.0%, 8/1/32 3,097 333 Fannie Mae, 6.0%, 9/1/32 363 37,381 Fannie Mae, 6.0%, 10/1/32 40,777 5,913 Fannie Mae, 6.0%, 2/1/33 6,346 54,333 Fannie Mae, 6.0%, 3/1/33 59,249 57,951 Fannie Mae, 6.0%, 4/1/33 62,183 75,482 Fannie Mae, 6.0%, 7/1/33 81,011 107,097 Fannie Mae, 6.0%, 7/1/33 114,972 24,404 Fannie Mae, 6.0%, 11/1/33 26,610 92,154 Fannie Mae, 6.0%, 8/1/34 100,504 4,928 Fannie Mae, 6.0%, 9/1/34 5,373 17,879 Fannie Mae, 6.0%, 9/1/34 19,374 The accompanying notes are an integral part of these financial statements. 64 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 28,686 Fannie Mae, 6.0%, 9/1/34 $ 30,949 87,050 Fannie Mae, 6.0%, 9/1/34 93,479 9,012 Fannie Mae, 6.0%, 10/1/34 9,831 8,065 Fannie Mae, 6.0%, 11/1/34 8,797 117,655 Fannie Mae, 6.0%, 11/1/34 126,335 2,876 Fannie Mae, 6.0%, 2/1/35 3,132 6,704 Fannie Mae, 6.0%, 2/1/35 7,275 129,154 Fannie Mae, 6.0%, 4/1/35 140,854 18,939 Fannie Mae, 6.0%, 5/1/35 20,322 82,173 Fannie Mae, 6.0%, 10/1/35 88,227 151,844 Fannie Mae, 6.0%, 12/1/35 165,231 16,565 Fannie Mae, 6.0%, 12/1/37 18,004 184,409 Fannie Mae, 6.0%, 6/1/38 199,456 29,398 Fannie Mae, 6.0%, 7/1/38 31,545 6,181 Fannie Mae, 6.5%, 7/1/29 6,637 1,512 Fannie Mae, 6.5%, 1/1/31 1,624 1,767 Fannie Mae, 6.5%, 4/1/31 1,919 3,544 Fannie Mae, 6.5%, 5/1/31 3,806 63,355 Fannie Mae, 6.5%, 6/1/31 68,034 8,051 Fannie Mae, 6.5%, 8/1/31 8,645 3,068 Fannie Mae, 6.5%, 9/1/31 3,306 4,021 Fannie Mae, 6.5%, 9/1/31 4,318 2,529 Fannie Mae, 6.5%, 10/1/31 2,715 116,260 Fannie Mae, 6.5%, 12/1/31 124,978 4,337 Fannie Mae, 6.5%, 2/1/32 4,658 36,584 Fannie Mae, 6.5%, 3/1/32 39,480 78,802 Fannie Mae, 6.5%, 7/1/32 86,737 65,696 Fannie Mae, 6.5%, 10/1/32 70,548 27,208 Fannie Mae, 6.5%, 7/1/34 29,217 83,015 Fannie Mae, 6.5%, 11/1/37 93,831 20,352 Fannie Mae, 6.5%, 11/1/47 21,216 597 Fannie Mae, 7.0%, 12/1/30 614 6,199 Fannie Mae, 7.0%, 12/1/30 6,788 5,935 Fannie Mae, 7.0%, 4/1/31 6,854 7,147 Fannie Mae, 7.0%, 9/1/31 8,108 14,658 Fannie Mae, 7.0%, 12/1/31 14,858 13,283 Fannie Mae, 7.0%, 1/1/32 15,202 2,473,427 Federal Home Loan Mortgage Corp., 3.0%, 8/1/29 2,476,332 2,329,554 Federal Home Loan Mortgage Corp., 3.0%, 10/1/29 2,332,291 919,203 Federal Home Loan Mortgage Corp., 3.0%, 9/1/42 904,144 5,989,190 Federal Home Loan Mortgage Corp., 3.0%, 11/1/42 5,890,989 689,149 Federal Home Loan Mortgage Corp., 3.0%, 2/1/43 676,994 1,746,234 Federal Home Loan Mortgage Corp., 3.0%, 2/1/43 1,716,609 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 65 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 2,012,917 Federal Home Loan Mortgage Corp., 3.0%, 5/1/43 $ 1,977,359 1,470,678 Federal Home Loan Mortgage Corp., 3.0%, 5/1/45 1,441,661 1,188,385 Federal Home Loan Mortgage Corp., 3.0%, 8/1/45 1,161,912 4,759,703 Federal Home Loan Mortgage Corp., 3.0%, 6/1/46 4,651,274 3,798,370 Federal Home Loan Mortgage Corp., 3.0%, 9/1/46 3,706,535 1,290,074 Federal Home Loan Mortgage Corp., 3.0%, 12/1/46 1,260,685 1,908,552 Federal Home Loan Mortgage Corp., 3.0%, 12/1/46 1,861,944 5,525,460 Federal Home Loan Mortgage Corp., 3.0%, 2/1/47 5,391,378 764,536 Federal Home Loan Mortgage Corp., 3.0%, 3/1/47 745,627 359,613 Federal Home Loan Mortgage Corp., 3.0%, 7/1/47 350,607 205,624 Federal Home Loan Mortgage Corp., 3.5%, 3/1/26 208,278 1,433,789 Federal Home Loan Mortgage Corp., 3.5%, 4/1/42 1,444,424 2,515,662 Federal Home Loan Mortgage Corp., 3.5%, 8/1/43 2,534,186 6,098,895 Federal Home Loan Mortgage Corp., 3.5%, 7/1/44 6,135,159 706,083 Federal Home Loan Mortgage Corp., 3.5%, 8/1/44 710,081 525,669 Federal Home Loan Mortgage Corp., 3.5%, 9/1/44 528,795 2,144,964 Federal Home Loan Mortgage Corp., 3.5%, 10/1/44 2,155,892 106,817 Federal Home Loan Mortgage Corp., 3.5%, 11/1/44 107,240 5,646,182 Federal Home Loan Mortgage Corp., 3.5%, 12/1/44 5,670,141 2,762,177 Federal Home Loan Mortgage Corp., 3.5%, 3/1/45 2,771,551 678,957 Federal Home Loan Mortgage Corp., 3.5%, 4/1/45 681,261 6,796,235 Federal Home Loan Mortgage Corp., 3.5%, 6/1/45 6,825,611 181,331 Federal Home Loan Mortgage Corp., 3.5%, 7/1/45 182,157 5,904,908 Federal Home Loan Mortgage Corp., 3.5%, 10/1/45 5,930,433 6,659,083 Federal Home Loan Mortgage Corp., 3.5%, 10/1/45 6,681,682 6,851,087 Federal Home Loan Mortgage Corp., 3.5%, 11/1/45 6,874,337 3,581,644 Federal Home Loan Mortgage Corp., 3.5%, 3/1/46 3,593,428 5,916,070 Federal Home Loan Mortgage Corp., 3.5%, 5/1/46 5,933,091 6,029,460 Federal Home Loan Mortgage Corp., 3.5%, 7/1/46 6,062,056 8,586,167 Federal Home Loan Mortgage Corp., 3.5%, 8/1/46 8,633,939 8,965,744 Federal Home Loan Mortgage Corp., 3.5%, 8/1/46 8,991,539 10,692,279 Federal Home Loan Mortgage Corp., 3.5%, 8/1/46 10,771,553 3,486,949 Federal Home Loan Mortgage Corp., 3.5%, 12/1/46 3,493,786 10,403,173 Federal Home Loan Mortgage Corp., 3.5%, 12/1/46 10,432,030 2,086,022 Federal Home Loan Mortgage Corp., 3.5%, 1/1/47 2,089,710 662,686 Federal Home Loan Mortgage Corp., 3.5%, 6/1/47 663,807 1,918,978 Federal Home Loan Mortgage Corp., 3.5%, 6/1/47 1,920,141 3,830,974 Federal Home Loan Mortgage Corp., 3.5%, 6/1/47 3,834,039 9,078,863 Federal Home Loan Mortgage Corp., 3.5%, 7/1/47 9,084,368 8,491,688 Federal Home Loan Mortgage Corp., 3.5%, 8/1/47 8,493,548 10,268,033 Federal Home Loan Mortgage Corp., 3.5%, 10/1/47 10,266,205 3,466,242 Federal Home Loan Mortgage Corp., 3.5%, 11/1/47 3,465,591 4,687,760 Federal Home Loan Mortgage Corp., 3.5%, 11/1/47 4,688,786 The accompanying notes are an integral part of these financial statements. 66 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 3,271,656 Federal Home Loan Mortgage Corp., 3.5%, 1/1/48 $ 3,270,948 6,755,951 Federal Home Loan Mortgage Corp., 3.5%, 1/1/48 6,754,620 8,498,943 Federal Home Loan Mortgage Corp., 4.0%, 11/1/41 8,764,392 275,363 Federal Home Loan Mortgage Corp., 4.0%, 6/1/42 282,907 98,358 Federal Home Loan Mortgage Corp., 4.0%, 7/1/42 101,205 3,760,563 Federal Home Loan Mortgage Corp., 4.0%, 10/1/42 3,865,497 58,958 Federal Home Loan Mortgage Corp., 4.0%, 11/1/42 60,303 1,457,054 Federal Home Loan Mortgage Corp., 4.0%, 1/1/44 1,491,108 460,223 Federal Home Loan Mortgage Corp., 4.0%, 2/1/44 471,855 4,166,969 Federal Home Loan Mortgage Corp., 4.0%, 5/1/44 4,259,198 3,866,874 Federal Home Loan Mortgage Corp., 4.0%, 6/1/44 3,952,461 850,241 Federal Home Loan Mortgage Corp., 4.0%, 7/1/44 871,730 1,257,501 Federal Home Loan Mortgage Corp., 4.0%, 7/1/44 1,289,280 1,757,454 Federal Home Loan Mortgage Corp., 4.0%, 7/1/44 1,801,870 5,590,958 Federal Home Loan Mortgage Corp., 4.0%, 7/1/44 5,714,707 2,222,397 Federal Home Loan Mortgage Corp., 4.0%, 9/1/44 2,271,588 5,807,195 Federal Home Loan Mortgage Corp., 4.0%, 9/1/44 5,953,964 1,526,577 Federal Home Loan Mortgage Corp., 4.0%, 12/1/44 1,560,298 1,090,409 Federal Home Loan Mortgage Corp., 4.0%, 4/1/45 1,114,204 4,225,936 Federal Home Loan Mortgage Corp., 4.0%, 12/1/45 4,314,084 1,554,549 Federal Home Loan Mortgage Corp., 4.0%, 1/1/46 1,587,007 226,041 Federal Home Loan Mortgage Corp., 4.0%, 5/1/46 230,485 540,707 Federal Home Loan Mortgage Corp., 4.0%, 5/1/46 551,993 3,673,040 Federal Home Loan Mortgage Corp., 4.0%, 6/1/46 3,749,754 4,504,919 Federal Home Loan Mortgage Corp., 4.0%, 7/1/46 4,598,895 4,031,075 Federal Home Loan Mortgage Corp., 4.0%, 8/1/46 4,115,119 55,921 Federal Home Loan Mortgage Corp., 4.0%, 10/1/46 57,020 1,169,403 Federal Home Loan Mortgage Corp., 4.0%, 3/1/47 1,193,484 2,127,848 Federal Home Loan Mortgage Corp., 4.0%, 4/1/47 2,176,958 3,200,362 Federal Home Loan Mortgage Corp., 4.0%, 4/1/47 3,274,223 6,343,326 Federal Home Loan Mortgage Corp., 4.0%, 4/1/47 6,473,456 7,002,128 Federal Home Loan Mortgage Corp., 4.0%, 4/1/47 7,163,727 9,820,481 Federal Home Loan Mortgage Corp., 4.0%, 4/1/47 10,022,705 11,768,440 Federal Home Loan Mortgage Corp., 4.0%, 5/1/47 12,018,947 1,317,205 Federal Home Loan Mortgage Corp., 4.0%, 6/1/47 1,343,820 3,054,365 Federal Home Loan Mortgage Corp., 4.0%, 7/1/47 3,116,318 6,845,496 Federal Home Loan Mortgage Corp., 4.0%, 10/1/47 6,982,052 23,961 Federal Home Loan Mortgage Corp., 4.5%, 3/1/20 24,403 64,170 Federal Home Loan Mortgage Corp., 4.5%, 10/1/20 65,355 2,312,418 Federal Home Loan Mortgage Corp., 4.5%, 11/1/40 2,421,237 1,443,115 Federal Home Loan Mortgage Corp., 4.5%, 3/1/42 1,511,005 3,370,574 Federal Home Loan Mortgage Corp., 4.5%, 3/1/42 3,529,171 126,431 Federal Home Loan Mortgage Corp., 4.5%, 11/1/43 131,085 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 67 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 6,013,468 Federal Home Loan Mortgage Corp., 4.5%, 5/1/47 $ 6,230,211 130,320 Federal Home Loan Mortgage Corp., 5.0%, 10/1/20 130,956 6,159 Federal Home Loan Mortgage Corp., 5.0%, 12/1/21 6,213 8,909 Federal Home Loan Mortgage Corp., 5.0%, 11/1/34 9,461 83,359 Federal Home Loan Mortgage Corp., 5.0%, 6/1/35 87,284 247,431 Federal Home Loan Mortgage Corp., 5.0%, 9/1/38 261,926 237,514 Federal Home Loan Mortgage Corp., 5.0%, 10/1/38 251,398 153,276 Federal Home Loan Mortgage Corp., 5.5%, 9/1/33 165,242 8,623 Federal Home Loan Mortgage Corp., 5.5%, 1/1/34 9,294 9,450 Federal Home Loan Mortgage Corp., 5.5%, 11/1/34 9,979 77,530 Federal Home Loan Mortgage Corp., 5.5%, 11/1/34 83,657 89,483 Federal Home Loan Mortgage Corp., 5.5%, 8/1/35 96,173 18,416 Federal Home Loan Mortgage Corp., 5.5%, 11/1/35 19,854 828,491 Federal Home Loan Mortgage Corp., 5.5%, 6/1/41 893,786 43,124 Federal Home Loan Mortgage Corp., 6.0%, 1/1/33 46,396 75,419 Federal Home Loan Mortgage Corp., 6.0%, 1/1/33 81,738 3,391 Federal Home Loan Mortgage Corp., 6.0%, 2/1/33 3,693 35,137 Federal Home Loan Mortgage Corp., 6.0%, 2/1/33 38,372 22,805 Federal Home Loan Mortgage Corp., 6.0%, 3/1/33 24,535 110,073 Federal Home Loan Mortgage Corp., 6.0%, 3/1/33 120,146 76,751 Federal Home Loan Mortgage Corp., 6.0%, 9/1/33 83,812 12,013 Federal Home Loan Mortgage Corp., 6.0%, 11/1/33 13,118 30,155 Federal Home Loan Mortgage Corp., 6.0%, 11/1/33 32,581 8,413 Federal Home Loan Mortgage Corp., 6.0%, 12/1/33 9,051 113,021 Federal Home Loan Mortgage Corp., 6.0%, 12/1/33 121,595 21,699 Federal Home Loan Mortgage Corp., 6.0%, 1/1/34 23,690 33,632 Federal Home Loan Mortgage Corp., 6.0%, 1/1/34 36,184 123,186 Federal Home Loan Mortgage Corp., 6.0%, 5/1/34 132,532 330,642 Federal Home Loan Mortgage Corp., 6.0%, 5/1/34 361,167 60,774 Federal Home Loan Mortgage Corp., 6.0%, 8/1/34 65,384 14,970 Federal Home Loan Mortgage Corp., 6.0%, 4/1/35 16,106 45,060 Federal Home Loan Mortgage Corp., 6.0%, 6/1/35 48,479 49,529 Federal Home Loan Mortgage Corp., 6.0%, 4/1/36 53,287 7,873 Federal Home Loan Mortgage Corp., 6.0%, 7/1/36 8,595 32,092 Federal Home Loan Mortgage Corp., 6.0%, 7/1/36 34,526 27,632 Federal Home Loan Mortgage Corp., 6.0%, 12/1/36 30,154 48,943 Federal Home Loan Mortgage Corp., 6.0%, 1/1/38 53,389 54,382 Federal Home Loan Mortgage Corp., 6.0%, 7/1/38 58,754 297 Federal Home Loan Mortgage Corp., 6.5%, 11/1/30 322 145 Federal Home Loan Mortgage Corp., 6.5%, 1/1/31 158 325 Federal Home Loan Mortgage Corp., 6.5%, 3/1/31 352 1,191 Federal Home Loan Mortgage Corp., 6.5%, 3/1/31 1,292 4,809 Federal Home Loan Mortgage Corp., 6.5%, 5/1/31 5,220 The accompanying notes are an integral part of these financial statements. 68 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 5,315 Federal Home Loan Mortgage Corp., 6.5%, 5/1/31 $ 5,860 500 Federal Home Loan Mortgage Corp., 6.5%, 8/1/31 551 3,692 Federal Home Loan Mortgage Corp., 6.5%, 8/1/31 4,007 132 Federal Home Loan Mortgage Corp., 6.5%, 6/1/32 144 8,337 Federal Home Loan Mortgage Corp., 6.5%, 7/1/32 9,364 109 Federal Home Loan Mortgage Corp., 6.5%, 1/1/33 119 27,109 Federal Home Loan Mortgage Corp., 6.5%, 10/1/33 30,706 8,424 Federal Home Loan Mortgage Corp., 7.0%, 8/1/22 8,429 47,407 Federal Home Loan Mortgage Corp., 7.0%, 9/1/22 48,761 2,108 Federal Home Loan Mortgage Corp., 7.0%, 11/1/30 2,374 1,752 Federal Home Loan Mortgage Corp., 7.0%, 6/1/31 1,753 73,049 Federal Home Loan Mortgage Corp., 7.0%, 10/1/46 74,946 7,257,741 Government National Mortgage Association I, 3.5%, 11/15/41 7,344,007 5,614,839 Government National Mortgage Association I, 3.5%, 7/15/42 5,701,073 1,305,751 Government National Mortgage Association I, 3.5%, 10/15/42 1,323,850 786,999 Government National Mortgage Association I, 3.5%, 1/15/44 793,431 8,887,954 Government National Mortgage Association I, 3.5%, 1/15/45 8,953,560 2,414,106 Government National Mortgage Association I, 3.5%, 8/15/46 2,431,925 7,434 Government National Mortgage Association I, 4.0%, 5/15/39 7,623 3,240 Government National Mortgage Association I, 4.0%, 6/15/39 3,322 5,140 Government National Mortgage Association I, 4.0%, 8/15/40 5,300 219,966 Government National Mortgage Association I, 4.0%, 8/15/40 225,533 5,504 Government National Mortgage Association I, 4.0%, 9/15/40 5,676 94,155 Government National Mortgage Association I, 4.0%, 9/15/40 96,538 5,373 Government National Mortgage Association I, 4.0%, 10/15/40 5,509 5,951 Government National Mortgage Association I, 4.0%, 11/15/40 6,102 33,826 Government National Mortgage Association I, 4.0%, 11/15/40 34,778 16,190 Government National Mortgage Association I, 4.0%, 1/15/41 16,639 53,957 Government National Mortgage Association I, 4.0%, 1/15/41 55,618 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 69 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 7,822 Government National Mortgage Association I, 4.0%, 2/15/41 $ 8,066 47,714 Government National Mortgage Association I, 4.0%, 6/15/41 49,177 118,646 Government National Mortgage Association I, 4.0%, 7/15/41 122,325 2,135 Government National Mortgage Association I, 4.0%, 9/15/41 2,189 328,273 Government National Mortgage Association I, 4.0%, 9/15/41 338,482 5,369 Government National Mortgage Association I, 4.0%, 10/15/41 5,505 6,196 Government National Mortgage Association I, 4.0%, 10/15/41 6,368 3,239 Government National Mortgage Association I, 4.0%, 11/15/41 3,321 3,328 Government National Mortgage Association I, 4.0%, 11/15/41 3,421 5,324 Government National Mortgage Association I, 4.0%, 12/15/41 5,489 18,268 Government National Mortgage Association I, 4.0%, 2/15/42 18,774 207,777 Government National Mortgage Association I, 4.0%, 2/15/42 213,036 997,826 Government National Mortgage Association I, 4.0%, 8/15/43 1,028,807 18,796 Government National Mortgage Association I, 4.0%, 11/15/43 19,313 9,943 Government National Mortgage Association I, 4.0%, 3/15/44 10,194 178,359 Government National Mortgage Association I, 4.0%, 3/15/44 182,873 618,088 Government National Mortgage Association I, 4.0%, 3/15/44 633,732 3,305,989 Government National Mortgage Association I, 4.0%, 3/15/44 3,389,667 3,335 Government National Mortgage Association I, 4.0%, 4/15/44 3,419 22,650 Government National Mortgage Association I, 4.0%, 4/15/44 23,228 2,411,266 Government National Mortgage Association I, 4.0%, 4/15/44 2,472,298 318,471 Government National Mortgage Association I, 4.0%, 8/15/44 326,531 56,723 Government National Mortgage Association I, 4.0%, 9/15/44 58,169 192,130 Government National Mortgage Association I, 4.0%, 9/15/44 196,993 The accompanying notes are an integral part of these financial statements. 70 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 246,389 Government National Mortgage Association I, 4.0%, 9/15/44 $ 252,625 426,358 Government National Mortgage Association I, 4.0%, 9/15/44 438,250 2,103,452 Government National Mortgage Association I, 4.0%, 9/15/44 2,156,692 91,140 Government National Mortgage Association I, 4.0%, 10/15/44 93,635 411,356 Government National Mortgage Association I, 4.0%, 11/15/44 421,768 1,603,419 Government National Mortgage Association I, 4.0%, 12/15/44 1,644,003 400,370 Government National Mortgage Association I, 4.0%, 1/15/45 412,941 1,114,090 Government National Mortgage Association I, 4.0%, 1/15/45 1,142,415 1,136,631 Government National Mortgage Association I, 4.0%, 1/15/45 1,165,400 1,962,084 Government National Mortgage Association I, 4.0%, 1/15/45 2,011,747 777,733 Government National Mortgage Association I, 4.0%, 2/15/45 797,418 1,310,982 Government National Mortgage Association I, 4.0%, 2/15/45 1,344,164 129,009 Government National Mortgage Association I, 4.0%, 3/15/45 132,274 1,501,566 Government National Mortgage Association I, 4.0%, 3/15/45 1,539,572 2,950,949 Government National Mortgage Association I, 4.0%, 4/15/45 3,025,943 1,386,280 Government National Mortgage Association I, 4.0%, 5/15/45 1,421,369 4,306,853 Government National Mortgage Association I, 4.0%, 6/15/45 4,415,864 632,441 Government National Mortgage Association I, 4.0%, 7/15/45 648,449 548,656 Government National Mortgage Association I, 4.0%, 8/15/45 563,130 580 Government National Mortgage Association I, 4.5%, 6/15/19 591 696 Government National Mortgage Association I, 4.5%, 8/15/19 711 3,972 Government National Mortgage Association I, 4.5%, 12/15/19 4,080 3,532 Government National Mortgage Association I, 4.5%, 4/15/20 3,631 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 71 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 157,159 Government National Mortgage Association I, 4.5%, 6/15/25 $ 163,735 43,377 Government National Mortgage Association I, 4.5%, 7/15/33 45,177 142,485 Government National Mortgage Association I, 4.5%, 9/15/33 150,148 140,685 Government National Mortgage Association I, 4.5%, 10/15/33 145,677 156,741 Government National Mortgage Association I, 4.5%, 10/15/33 163,243 21,833 Government National Mortgage Association I, 4.5%, 2/15/34 22,624 15,193 Government National Mortgage Association I, 4.5%, 3/15/35 15,732 52,672 Government National Mortgage Association I, 4.5%, 3/15/35 54,542 19,718 Government National Mortgage Association I, 4.5%, 4/15/35 20,417 137,863 Government National Mortgage Association I, 4.5%, 4/15/35 143,403 9,591 Government National Mortgage Association I, 4.5%, 9/15/35 9,931 72,332 Government National Mortgage Association I, 4.5%, 10/15/35 75,340 46,642 Government National Mortgage Association I, 4.5%, 4/15/38 48,297 855,875 Government National Mortgage Association I, 4.5%, 12/15/39 893,796 312,619 Government National Mortgage Association I, 4.5%, 1/15/40 326,773 180,297 Government National Mortgage Association I, 4.5%, 9/15/40 188,346 744,620 Government National Mortgage Association I, 4.5%, 10/15/40 777,861 354,532 Government National Mortgage Association I, 4.5%, 4/15/41 369,918 775,681 Government National Mortgage Association I, 4.5%, 5/15/41 809,897 714,846 Government National Mortgage Association I, 4.5%, 6/15/41 746,224 257,707 Government National Mortgage Association I, 4.5%, 7/15/41 269,074 753,151 Government National Mortgage Association I, 4.5%, 8/15/41 786,350 396 Government National Mortgage Association I, 5.0%, 2/15/19 395 The accompanying notes are an integral part of these financial statements. 72 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 123 Government National Mortgage Association I, 5.0%, 7/15/19 $ 127 4,774 Government National Mortgage Association I, 5.0%, 7/15/19 4,772 51,425 Government National Mortgage Association I, 5.0%, 7/15/33 54,418 58,655 Government National Mortgage Association I, 5.0%, 9/15/33 62,149 61,947 Government National Mortgage Association I, 5.0%, 4/15/34 65,631 349,311 Government National Mortgage Association I, 5.0%, 4/15/35 371,466 151,964 Government National Mortgage Association I, 5.0%, 7/15/40 159,031 79 Government National Mortgage Association I, 5.5%, 4/15/19 78 5,382 Government National Mortgage Association I, 5.5%, 8/15/19 5,385 6,048 Government National Mortgage Association I, 5.5%, 8/15/19 6,052 10,454 Government National Mortgage Association I, 5.5%, 9/15/19 10,460 4,943 Government National Mortgage Association I, 5.5%, 10/15/19 4,957 25,541 Government National Mortgage Association I, 5.5%, 11/15/19 25,594 45,014 Government National Mortgage Association I, 5.5%, 1/15/29 47,796 11,089 Government National Mortgage Association I, 5.5%, 6/15/33 11,965 50,887 Government National Mortgage Association I, 5.5%, 7/15/33 55,086 51,916 Government National Mortgage Association I, 5.5%, 7/15/33 55,993 14,802 Government National Mortgage Association I, 5.5%, 8/15/33 16,012 23,854 Government National Mortgage Association I, 5.5%, 8/15/33 25,806 118,543 Government National Mortgage Association I, 5.5%, 8/15/33 128,103 41,282 Government National Mortgage Association I, 5.5%, 9/15/33 43,834 47,609 Government National Mortgage Association I, 5.5%, 9/15/33 50,576 40,855 Government National Mortgage Association I, 5.5%, 10/15/33 43,516 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 73 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 46,331 Government National Mortgage Association I, 5.5%, 10/15/33 $ 50,112 249,220 Government National Mortgage Association I, 5.5%, 7/15/34 269,653 22,525 Government National Mortgage Association I, 5.5%, 10/15/34 24,108 293,873 Government National Mortgage Association I, 5.5%, 11/15/34 317,920 99,587 Government National Mortgage Association I, 5.5%, 1/15/35 107,685 18,668 Government National Mortgage Association I, 5.5%, 2/15/35 19,833 36,421 Government National Mortgage Association I, 5.5%, 2/15/35 38,671 29,517 Government National Mortgage Association I, 5.5%, 6/15/35 31,341 342,851 Government National Mortgage Association I, 5.5%, 7/15/35 379,564 40,486 Government National Mortgage Association I, 5.5%, 10/15/35 43,103 118,817 Government National Mortgage Association I, 5.5%, 10/15/35 128,601 28,885 Government National Mortgage Association I, 5.5%, 2/15/37 31,177 8,588 Government National Mortgage Association I, 5.72%, 4/15/29 9,141 6,838 Government National Mortgage Association I, 6.0%, 9/15/19 6,845 90,820 Government National Mortgage Association I, 6.0%, 12/15/23 95,803 8,009 Government National Mortgage Association I, 6.0%, 1/15/24 8,593 29,037 Government National Mortgage Association I, 6.0%, 4/15/28 31,606 117,664 Government National Mortgage Association I, 6.0%, 9/15/28 127,070 5,793 Government National Mortgage Association I, 6.0%, 10/15/28 6,215 49,910 Government National Mortgage Association I, 6.0%, 2/15/29 54,293 56,177 Government National Mortgage Association I, 6.0%, 2/15/29 60,460 51,820 Government National Mortgage Association I, 6.0%, 6/15/31 55,595 16,090 Government National Mortgage Association I, 6.0%, 11/15/31 17,486 1,001 Government National Mortgage Association I, 6.0%, 3/15/32 1,087 The accompanying notes are an integral part of these financial statements. 74 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 4,865 Government National Mortgage Association I, 6.0%, 8/15/32 $ 5,290 53,076 Government National Mortgage Association I, 6.0%, 9/15/32 56,942 85,191 Government National Mortgage Association I, 6.0%, 9/15/32 91,397 121,816 Government National Mortgage Association I, 6.0%, 9/15/32 130,690 10,123 Government National Mortgage Association I, 6.0%, 10/15/32 10,860 28,055 Government National Mortgage Association I, 6.0%, 10/15/32 30,265 5,972 Government National Mortgage Association I, 6.0%, 11/15/32 6,406 6,430 Government National Mortgage Association I, 6.0%, 11/15/32 6,898 7,829 Government National Mortgage Association I, 6.0%, 12/15/32 8,399 8,355 Government National Mortgage Association I, 6.0%, 12/15/32 8,999 61,483 Government National Mortgage Association I, 6.0%, 12/15/32 65,961 112,418 Government National Mortgage Association I, 6.0%, 12/15/32 120,607 153,564 Government National Mortgage Association I, 6.0%, 12/15/32 164,750 183,270 Government National Mortgage Association I, 6.0%, 12/15/32 196,620 274,030 Government National Mortgage Association I, 6.0%, 12/15/32 294,505 18,620 Government National Mortgage Association I, 6.0%, 1/15/33 19,976 31,945 Government National Mortgage Association I, 6.0%, 1/15/33 34,624 114,932 Government National Mortgage Association I, 6.0%, 1/15/33 126,506 22,382 Government National Mortgage Association I, 6.0%, 2/15/33 24,357 65,002 Government National Mortgage Association I, 6.0%, 2/15/33 69,737 69,708 Government National Mortgage Association I, 6.0%, 2/15/33 76,155 98,219 Government National Mortgage Association I, 6.0%, 2/15/33 106,920 40,074 Government National Mortgage Association I, 6.0%, 3/15/33 43,526 47,817 Government National Mortgage Association I, 6.0%, 3/15/33 51,301 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 75 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 71,862 Government National Mortgage Association I, 6.0%, 3/15/33 $ 77,935 72,668 Government National Mortgage Association I, 6.0%, 3/15/33 77,962 82,186 Government National Mortgage Association I, 6.0%, 3/15/33 89,431 97,013 Government National Mortgage Association I, 6.0%, 3/15/33 105,712 173,660 Government National Mortgage Association I, 6.0%, 3/15/33 188,868 275,960 Government National Mortgage Association I, 6.0%, 3/15/33 303,282 14,325 Government National Mortgage Association I, 6.0%, 4/15/33 15,369 17,126 Government National Mortgage Association I, 6.0%, 4/15/33 18,373 33,814 Government National Mortgage Association I, 6.0%, 4/15/33 36,278 17,321 Government National Mortgage Association I, 6.0%, 5/15/33 18,583 103,829 Government National Mortgage Association I, 6.0%, 5/15/33 112,000 9,099 Government National Mortgage Association I, 6.0%, 6/15/33 9,900 12,583 Government National Mortgage Association I, 6.0%, 9/15/33 13,547 14,223 Government National Mortgage Association I, 6.0%, 9/15/33 15,259 42,632 Government National Mortgage Association I, 6.0%, 9/15/33 46,359 36,661 Government National Mortgage Association I, 6.0%, 10/15/33 39,800 91,481 Government National Mortgage Association I, 6.0%, 11/15/33 98,145 166,301 Government National Mortgage Association I, 6.0%, 3/15/34 184,270 38,235 Government National Mortgage Association I, 6.0%, 6/15/34 41,078 29,085 Government National Mortgage Association I, 6.0%, 8/15/34 31,656 43,204 Government National Mortgage Association I, 6.0%, 8/15/34 46,351 22,860 Government National Mortgage Association I, 6.0%, 9/15/34 24,864 36,129 Government National Mortgage Association I, 6.0%, 9/15/34 38,761 111,093 Government National Mortgage Association I, 6.0%, 9/15/34 120,887 The accompanying notes are an integral part of these financial statements. 76 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 46,111 Government National Mortgage Association I, 6.0%, 10/15/34 $ 49,469 56,766 Government National Mortgage Association I, 6.0%, 10/15/34 60,901 96,687 Government National Mortgage Association I, 6.0%, 10/15/34 103,730 89,037 Government National Mortgage Association I, 6.0%, 11/15/34 96,149 621,857 Government National Mortgage Association I, 6.0%, 9/15/35 675,878 161,711 Government National Mortgage Association I, 6.0%, 8/15/36 175,834 109,829 Government National Mortgage Association I, 6.0%, 10/15/36 119,388 32,638 Government National Mortgage Association I, 6.0%, 11/15/37 35,016 31,247 Government National Mortgage Association I, 6.0%, 8/15/38 33,893 14,253 Government National Mortgage Association I, 6.5%, 10/15/24 15,258 4,729 Government National Mortgage Association I, 6.5%, 2/15/28 5,093 6,144 Government National Mortgage Association I, 6.5%, 4/15/28 6,617 32,633 Government National Mortgage Association I, 6.5%, 4/15/28 35,143 6,663 Government National Mortgage Association I, 6.5%, 6/15/28 7,411 5,507 Government National Mortgage Association I, 6.5%, 8/15/28 5,931 3,081 Government National Mortgage Association I, 6.5%, 10/15/28 3,318 13,353 Government National Mortgage Association I, 6.5%, 10/15/28 14,380 20,441 Government National Mortgage Association I, 6.5%, 1/15/29 22,013 918 Government National Mortgage Association I, 6.5%, 2/15/29 989 4,479 Government National Mortgage Association I, 6.5%, 2/15/29 4,824 11,297 Government National Mortgage Association I, 6.5%, 2/15/29 12,191 5,257 Government National Mortgage Association I, 6.5%, 3/15/29 5,661 6,244 Government National Mortgage Association I, 6.5%, 3/15/29 6,724 9,510 Government National Mortgage Association I, 6.5%, 3/15/29 10,242 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 77 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 16,456 Government National Mortgage Association I, 6.5%, 3/15/29 $ 17,722 69,820 Government National Mortgage Association I, 6.5%, 3/15/29 75,191 1,665 Government National Mortgage Association I, 6.5%, 5/15/29 1,794 3,234 Government National Mortgage Association I, 6.5%, 5/15/29 3,482 44,440 Government National Mortgage Association I, 6.5%, 5/15/29 49,601 22,625 Government National Mortgage Association I, 6.5%, 6/15/29 24,366 48,302 Government National Mortgage Association I, 6.5%, 4/15/31 54,322 11,605 Government National Mortgage Association I, 6.5%, 5/15/31 13,058 12,952 Government National Mortgage Association I, 6.5%, 5/15/31 14,729 35,713 Government National Mortgage Association I, 6.5%, 5/15/31 38,461 5,800 Government National Mortgage Association I, 6.5%, 6/15/31 6,259 12,101 Government National Mortgage Association I, 6.5%, 7/15/31 13,032 33,482 Government National Mortgage Association I, 6.5%, 8/15/31 36,057 16,683 Government National Mortgage Association I, 6.5%, 9/15/31 17,967 4,512 Government National Mortgage Association I, 6.5%, 10/15/31 4,859 12,565 Government National Mortgage Association I, 6.5%, 10/15/31 13,532 57,505 Government National Mortgage Association I, 6.5%, 10/15/31 61,929 2,738 Government National Mortgage Association I, 6.5%, 11/15/31 2,948 40,624 Government National Mortgage Association I, 6.5%, 11/15/31 43,749 17,073 Government National Mortgage Association I, 6.5%, 1/15/32 18,386 76,294 Government National Mortgage Association I, 6.5%, 1/15/32 85,057 7,714 Government National Mortgage Association I, 6.5%, 2/15/32 8,352 12,643 Government National Mortgage Association I, 6.5%, 2/15/32 14,026 15,092 Government National Mortgage Association I, 6.5%, 2/15/32 17,275 The accompanying notes are an integral part of these financial statements. 78 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 18,958 Government National Mortgage Association I, 6.5%, 2/15/32 $ 20,417 27,511 Government National Mortgage Association I, 6.5%, 2/15/32 31,372 9,734 Government National Mortgage Association I, 6.5%, 3/15/32 10,483 73,613 Government National Mortgage Association I, 6.5%, 3/15/32 80,392 4,501 Government National Mortgage Association I, 6.5%, 4/15/32 4,847 8,385 Government National Mortgage Association I, 6.5%, 4/15/32 9,119 8,632 Government National Mortgage Association I, 6.5%, 4/15/32 9,296 52,489 Government National Mortgage Association I, 6.5%, 4/15/32 58,922 4,069 Government National Mortgage Association I, 6.5%, 5/15/32 4,394 5,110 Government National Mortgage Association I, 6.5%, 5/15/32 5,504 8,388 Government National Mortgage Association I, 6.5%, 5/15/32 9,408 8,844 Government National Mortgage Association I, 6.5%, 5/15/32 9,577 9,524 Government National Mortgage Association I, 6.5%, 6/15/32 10,257 9,529 Government National Mortgage Association I, 6.5%, 6/15/32 10,375 12,106 Government National Mortgage Association I, 6.5%, 6/15/32 13,037 8,237 Government National Mortgage Association I, 6.5%, 7/15/32 8,870 9,362 Government National Mortgage Association I, 6.5%, 7/15/32 10,082 99,902 Government National Mortgage Association I, 6.5%, 7/15/32 114,617 3,545 Government National Mortgage Association I, 6.5%, 8/15/32 3,820 28,398 Government National Mortgage Association I, 6.5%, 8/15/32 32,489 41,062 Government National Mortgage Association I, 6.5%, 8/15/32 44,699 14,708 Government National Mortgage Association I, 6.5%, 9/15/32 16,411 36,436 Government National Mortgage Association I, 6.5%, 9/15/32 39,736 38,809 Government National Mortgage Association I, 6.5%, 9/15/32 42,201 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 79 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 39,189 Government National Mortgage Association I, 6.5%, 10/15/32 $ 42,204 39,910 Government National Mortgage Association I, 6.5%, 11/15/32 45,471 243,438 Government National Mortgage Association I, 6.5%, 12/15/32 278,612 2,586 Government National Mortgage Association I, 6.5%, 1/15/33 2,904 262,191 Government National Mortgage Association I, 6.5%, 1/15/33 299,792 28,844 Government National Mortgage Association I, 6.5%, 5/15/33 31,063 1,527 Government National Mortgage Association I, 6.5%, 10/15/33 1,653 3,391 Government National Mortgage Association I, 6.5%, 2/15/34 3,652 104,695 Government National Mortgage Association I, 6.5%, 6/15/34 113,066 3,790 Government National Mortgage Association I, 6.5%, 9/15/34 4,081 38,000 Government National Mortgage Association I, 6.5%, 4/15/35 40,924 6,112 Government National Mortgage Association I, 6.5%, 6/15/35 6,582 17,173 Government National Mortgage Association I, 6.5%, 7/15/35 18,494 61,033 Government National Mortgage Association I, 6.5%, 7/15/35 65,728 1,906 Government National Mortgage Association I, 6.75%, 4/15/26 2,052 12,240 Government National Mortgage Association I, 7.0%, 8/15/23 12,702 39,931 Government National Mortgage Association I, 7.0%, 9/15/24 42,793 15,276 Government National Mortgage Association I, 7.0%, 7/15/25 16,244 5,808 Government National Mortgage Association I, 7.0%, 11/15/26 6,345 14,138 Government National Mortgage Association I, 7.0%, 6/15/27 15,594 15,702 Government National Mortgage Association I, 7.0%, 1/15/28 16,831 12,780 Government National Mortgage Association I, 7.0%, 2/15/28 13,569 11,502 Government National Mortgage Association I, 7.0%, 3/15/28 11,666 The accompanying notes are an integral part of these financial statements. 80 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 4,803 Government National Mortgage Association I, 7.0%, 4/15/28 $ 4,834 11,552 Government National Mortgage Association I, 7.0%, 7/15/28 12,439 977 Government National Mortgage Association I, 7.0%, 8/15/28 1,066 11,883 Government National Mortgage Association I, 7.0%, 11/15/28 13,446 33,804 Government National Mortgage Association I, 7.0%, 11/15/28 37,916 20,483 Government National Mortgage Association I, 7.0%, 4/15/29 20,881 22,955 Government National Mortgage Association I, 7.0%, 4/15/29 24,318 21,036 Government National Mortgage Association I, 7.0%, 5/15/29 21,311 3,251 Government National Mortgage Association I, 7.0%, 6/15/29 3,254 8,016 Government National Mortgage Association I, 7.0%, 7/15/29 8,770 40,721 Government National Mortgage Association I, 7.0%, 11/15/29 43,916 1,839 Government National Mortgage Association I, 7.0%, 12/15/30 1,862 5,936 Government National Mortgage Association I, 7.0%, 12/15/30 6,118 27,024 Government National Mortgage Association I, 7.0%, 12/15/30 30,785 35,638 Government National Mortgage Association I, 7.0%, 12/15/30 35,987 39,890 Government National Mortgage Association I, 7.0%, 1/15/31 40,192 4,938 Government National Mortgage Association I, 7.0%, 3/15/31 5,001 20,464 Government National Mortgage Association I, 7.0%, 6/15/31 23,571 2,461 Government National Mortgage Association I, 7.0%, 7/15/31 2,842 111,362 Government National Mortgage Association I, 7.0%, 8/15/31 127,634 11,078 Government National Mortgage Association I, 7.0%, 9/15/31 11,446 28,156 Government National Mortgage Association I, 7.0%, 9/15/31 30,650 7,610 Government National Mortgage Association I, 7.0%, 11/15/31 7,853 47,150 Government National Mortgage Association I, 7.0%, 3/15/32 51,229 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 81 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 41,875 Government National Mortgage Association I, 7.0%, 4/15/32 $ 45,840 70,384 Government National Mortgage Association I, 7.0%, 5/15/32 81,599 5,408 Government National Mortgage Association I, 7.5%, 3/15/23 5,611 22,031 Government National Mortgage Association I, 7.5%, 10/15/23 23,164 1,196 Government National Mortgage Association I, 7.5%, 6/15/24 1,209 8,203 Government National Mortgage Association I, 7.5%, 8/15/25 8,274 3,602 Government National Mortgage Association I, 7.5%, 9/15/25 3,823 3,347 Government National Mortgage Association I, 7.5%, 12/15/25 3,399 554 Government National Mortgage Association I, 7.5%, 2/15/26 555 9,248 Government National Mortgage Association I, 7.5%, 2/15/27 9,890 25,033 Government National Mortgage Association I, 7.5%, 3/15/27 28,386 34,788 Government National Mortgage Association I, 7.5%, 10/15/27 37,847 14,173 Government National Mortgage Association I, 7.5%, 6/15/29 15,412 2,520 Government National Mortgage Association I, 7.5%, 8/15/29 2,546 7,576 Government National Mortgage Association I, 7.5%, 8/15/29 7,636 15,607 Government National Mortgage Association I, 7.5%, 9/15/29 15,627 5,395 Government National Mortgage Association I, 7.5%, 10/15/29 5,526 7,570 Government National Mortgage Association I, 7.5%, 10/15/29 8,242 13,366 Government National Mortgage Association I, 7.5%, 2/15/31 13,470 14,776 Government National Mortgage Association I, 7.5%, 2/15/31 15,092 6,688 Government National Mortgage Association I, 7.5%, 3/15/31 6,821 40,919 Government National Mortgage Association I, 7.5%, 12/15/31 42,204 2,048 Government National Mortgage Association I, 7.75%, 2/15/30 2,068 1,330 Government National Mortgage Association I, 8.25%, 5/15/20 1,331 The accompanying notes are an integral part of these financial statements. 82 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 1,028 Government National Mortgage Association I, 8.5%, 8/15/21 $ 1,030 120 Government National Mortgage Association I, 9.0%, 12/15/19 120 54 Government National Mortgage Association I, 9.0%, 1/15/20 54 84 Government National Mortgage Association I, 9.0%, 9/15/21 85 1,320 Government National Mortgage Association I, 9.0%, 6/15/22 1,335 592,085 Government National Mortgage Association II, 3.5%, 3/20/45 596,149 499,654 Government National Mortgage Association II, 3.5%, 4/20/45 503,292 844,315 Government National Mortgage Association II, 3.5%, 4/20/45 850,529 1,119,917 Government National Mortgage Association II, 3.5%, 4/20/45 1,126,889 1,447,698 Government National Mortgage Association II, 3.5%, 3/20/46 1,461,003 6,453,006 Government National Mortgage Association II, 4.0%, 7/20/44 6,656,797 174,498 Government National Mortgage Association II, 4.0%, 9/20/44 180,008 1,506,423 Government National Mortgage Association II, 4.0%, 10/20/44 1,547,960 5,938,623 Government National Mortgage Association II, 4.0%, 10/20/46 6,104,067 2,040,684 Government National Mortgage Association II, 4.0%, 2/20/48 2,102,193 2,046,943 Government National Mortgage Association II, 4.0%, 4/20/48 2,108,645 11,385,000 Government National Mortgage Association II, 4.0%, 1/1/49 (TBA) 11,657,173 54,558 Government National Mortgage Association II, 4.5%, 12/20/34 56,833 209,032 Government National Mortgage Association II, 4.5%, 1/20/35 217,800 33,752 Government National Mortgage Association II, 4.5%, 3/20/35 35,217 1,009,169 Government National Mortgage Association II, 4.5%, 9/20/41 1,058,765 5,240,537 Government National Mortgage Association II, 4.5%, 9/20/44 5,405,924 1,482,450 Government National Mortgage Association II, 4.5%, 10/20/44 1,554,419 3,120,732 Government National Mortgage Association II, 4.5%, 11/20/44 3,272,458 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 83 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 8,143,455 Government National Mortgage Association II, 4.5%, 2/20/48 $ 8,450,536 341 Government National Mortgage Association II, 5.0%, 2/20/19 348 3,537 Government National Mortgage Association II, 5.0%, 1/20/20 3,652 14,651 Government National Mortgage Association II, 5.5%, 10/20/19 14,659 148,006 Government National Mortgage Association II, 5.5%, 3/20/34 158,108 127,560 Government National Mortgage Association II, 5.5%, 4/20/34 136,237 89,432 Government National Mortgage Association II, 5.5%, 10/20/37 94,484 137,292 Government National Mortgage Association II, 5.75%, 6/20/33 144,663 23,229 Government National Mortgage Association II, 5.9%, 1/20/28 24,559 58,653 Government National Mortgage Association II, 5.9%, 7/20/28 61,562 2,074 Government National Mortgage Association II, 6.0%, 7/20/19 2,074 14,073 Government National Mortgage Association II, 6.0%, 10/20/31 15,235 68,070 Government National Mortgage Association II, 6.0%, 1/20/33 75,452 74,753 Government National Mortgage Association II, 6.0%, 10/20/33 81,039 42,677 Government National Mortgage Association II, 6.0%, 6/20/34 46,280 45,048 Government National Mortgage Association II, 6.45%, 7/20/32 47,719 78,877 Government National Mortgage Association II, 6.45%, 1/20/33 83,552 15,290 Government National Mortgage Association II, 6.5%, 1/20/24 15,878 31,004 Government National Mortgage Association II, 6.5%, 8/20/28 34,592 1,482 Government National Mortgage Association II, 6.5%, 2/20/29 1,671 592 Government National Mortgage Association II, 6.5%, 3/20/29 664 18,060 Government National Mortgage Association II, 6.5%, 4/20/29 20,236 9,799 Government National Mortgage Association II, 6.5%, 4/20/31 11,161 6,948 Government National Mortgage Association II, 6.5%, 6/20/31 7,924 The accompanying notes are an integral part of these financial statements. 84 Pioneer Bond Fund | Semiannual Report | 12/31/18 --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 33,748 Government National Mortgage Association II, 6.5%, 10/20/32 $ 38,494 43,523 Government National Mortgage Association II, 6.5%, 3/20/34 49,984 5,170 Government National Mortgage Association II, 7.0%, 5/20/26 5,734 13,634 Government National Mortgage Association II, 7.0%, 8/20/27 15,278 15,134 Government National Mortgage Association II, 7.0%, 6/20/28 17,118 49,880 Government National Mortgage Association II, 7.0%, 11/20/28 56,455 52,050 Government National Mortgage Association II, 7.0%, 1/20/29 59,029 5,040 Government National Mortgage Association II, 7.0%, 2/20/29 5,715 1,482 Government National Mortgage Association II, 7.0%, 12/20/30 1,690 7,836 Government National Mortgage Association II, 7.0%, 1/20/31 9,072 3,821 Government National Mortgage Association II, 7.0%, 3/20/31 4,406 20,900 Government National Mortgage Association II, 7.0%, 7/20/31 24,281 8,333 Government National Mortgage Association II, 7.0%, 11/20/31 9,675 8,701 Government National Mortgage Association II, 7.5%, 5/20/30 10,230 2,601 Government National Mortgage Association II, 7.5%, 6/20/30 3,000 6,413 Government National Mortgage Association II, 7.5%, 7/20/30 7,169 9,362 Government National Mortgage Association II, 7.5%, 8/20/30 11,083 4,605 Government National Mortgage Association II, 7.5%, 12/20/30 5,410 15 Government National Mortgage Association II, 8.0%, 5/20/25 16 271 Government National Mortgage Association II, 9.0%, 9/20/21 271 1,597 Government National Mortgage Association II, 9.0%, 3/20/22 1,600 219 Government National Mortgage Association II, 9.0%, 4/20/22 219 1,955 Government National Mortgage Association II, 9.0%, 11/20/24 1,959 648,043 Tennessee Valley Authority, 4.929%, 1/15/21 663,785 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 85 Schedule of Investments | 12/31/18 (unaudited)(continued) --------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value --------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 14,000,000 U.S. Treasury Bonds, 3.125%, 5/15/48 $ 14,265,781 65,658,857 U.S. Treasury Inflation Indexed Bonds, 0.75%, 2/15/45 58,699,703 63,238,978 U.S. Treasury Inflation Indexed Bonds, 0.875%, 2/15/47 58,047,288 74,949,738 U.S. Treasury Inflation Indexed Bonds, 1.0%, 2/15/46 71,050,010 63,452,813 U.S. Treasury Inflation Indexed Bonds, 1.0%, 2/15/48 60,130,628 45,000,000 U.S. Treasury Notes, 2.5%, 6/30/20 44,964,844 12,430,000 U.S. Treasury Notes, 2.875%, 5/15/28 12,620,819 --------------------------------------------------------------------------------------------------------------------------------- TOTAL U.S. GOVERNMENT AND AGENCY OBLIGATIONS (Cost $1,513,038,980) $1,467,134,872 --------------------------------------------------------------------------------------------------------------------------------- TOTAL INVESTMENTS IN UNAFFILIATED ISSUERS -- 99.7% (Cost $5,023,113,368) $4,903,586,259 --------------------------------------------------------------------------------------------------------------------------------- OTHER ASSETS AND LIABILITIES -- 0.3% $ 14,382,282 --------------------------------------------------------------------------------------------------------------------------------- NET ASSETS -- 100.0% $4,917,968,541 ================================================================================================================================= bps Basis Points. FREMF Freddie Mac Multifamily Fixed-Rate Mortgage Loans. FRESB Freddie Mac Multifamily Small Balance Certificates. ICE Intercontinental Exchange. LIBOR London Interbank Offered Rate. PRIME U.S. Federal Funds Rate. REIT Real Estate Investment Trust. REMICS Real Estate Mortgage Investment Conduits. (TBA) "To Be Announced" Securities. ZERO Zero Constant Index. (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 December 31, 2018, the value of these securities amounted to $1,687,177,161, or 34.3% of net assets. + Amount rounds to less than 0.1%. * Senior secured 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, (ii) the prime rate offered by one or more major United States banks, (iii) the rate of a certificate of deposit or (iv) other base lending rates used by commercial lenders. The interest rate shown is the rate accruing at December 31, 2018. + Securities that used significant unobservable inputs to determine their value. (a) Security is perpetual in nature and has no stated maturity date. (b) Floating rate note. Coupon rate, reference index and spread shown at December 31, 2018. The accompanying notes are an integral part of these financial statements. 86 Pioneer Bond Fund | Semiannual Report | 12/31/18 (c) The interest rate is subject to change periodically. The interest rate and/or reference index and spread shown at December 31, 2018. (d) Debt obligation initially issued at one coupon which converts to a higher coupon at a specific date. The rate shown is the rate at December 31, 2018. (e) Security represents the interest-only portion payments on a pool of underlying mortgages or mortgage-backed securities. (f) Security issued with a zero coupon. Income is recognized through accretion of discount. (g) Rate to be determined. (h) Consists of Revenue Bonds unless otherwise indicated. (i) Represents a General Obligation Bond. (j) This term loan will settle after December 31, 2018, at which time the interest rate will be determined. (k) Securities are restricted as to resale. FUTURES CONTRACTS FIXED INCOME INDEX FUTURES CONTRACTS ----------------------------------------------------------------------------------------------- Number of Contracts Expiration Notional Unrealized Long Description Date Amount Market Value Appreciation ----------------------------------------------------------------------------------------------- 1,062 U.S. 2 Year 3/29/19 $223,948,861 $225,475,875 $ 1,527,014 Note (CBT) 4,484 U.S. 5 Year 3/29/19 505,569,844 514,258,750 8,688,906 Note (CBT) ----------------------------------------------------------------------------------------------- $729,518,705 $739,734,625 $10,215,920 =============================================================================================== ----------------------------------------------------------------------------------------------- Number of Contracts Expiration Notional Unrealized Short Description Date Amount Market Value Depreciation ----------------------------------------------------------------------------------------------- 1,548 U.S. 10 Year 3/20/19 $184,241,543 $188,880,187 $ (4,638,644) Note (CBT) 2,381 U.S. 10 Year 3/20/19 302,066,552 309,716,016 (7,649,464) Ultra 442 U.S. Long 3/20/19 61,531,909 64,532,000 (3,000,091) Bond (CBT) 129 U.S. Ultra 3/20/19 19,637,617 20,724,656 (1,087,039) Bond (CBT) ----------------------------------------------------------------------------------------------- $567,477,621 $583,852,859 $(16,375,238) ----------------------------------------------------------------------------------------------- TOTAL FUTURES CONTRACTS $162,041,084 $155,881,766 $ (6,159,318) =============================================================================================== SWAP CONTRACTS CENTRALLY CLEARED CREDIT DEFAULT SWAP CONTRACT -- SELL PROTECTION -------------------------------------------------------------------------------------------------------------------------- Obligation Annual Notional Reference/ Pay/ Fixed Expiration Premiums Unrealized Market Amount ($)(1) Index Receive(2) Rate Date Paid Appreciation Value -------------------------------------------------------------------------------------------------------------------------- 24,481,245 Markit CDX North America High Yield Index Series 31 Receive 5.00% 12/20/23 $378,970 $151,665 $530,635 -------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 87 Schedule of Investments | 12/31/18 (unaudited)(continued) OVER THE COUNTER (OTC) CREDIT DEFAULT SWAP CONTRACTS -- SELL PROTECTION ------------------------------------------------------------------------------------------------------------------------------------ Obligation Annual Notional Reference/ Pay/ Fixed Expiration Premiums Unrealized Market Amount ($)(1) Counterparty Index Receive(2) Rate Date (Received) Appreciation Value ------------------------------------------------------------------------------------------------------------------------------------ 3,979,000 JPMorgan Chase Simon Receive 1.00% 6/20/22 $ (13,137) $ 81,964 $ 68,827 Bank NA Property Group LP 2,851,000 JPMorgan Chase Simon Receive 1.00% 6/20/22 (8,072) 57,386 49,314 Bank NA Property Group LP ------------------------------------------------------------------------------------------------------------------------------------ TOTAL OVER THE COUNTER (OTC) CREDIT DEFAULT SWAP CONTRACTS -- SELL PROTECTION $(21,209) $139,350 $118,141 ------------------------------------------------------------------------------------------------------------------------------------ TOTAL SWAP CONTRACTS $357,761 $291,015 $648,776 ==================================================================================================================================== (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) Receives Quarterly. Purchases and sales of securities (excluding temporary cash investments) for the six months ended December 31, 2018, were as follows: ----------------------------------------------------------------------------------------------------- Purchases Sales ----------------------------------------------------------------------------------------------------- Long-Term U.S. Government Securities $355,878,243 $296,559,938 Other Long-Term Securities $841,595,856 $818,166,589 The Fund is permitted to engage in purchase and sale transactions ("cross trades") with certain funds and accounts for which Amundi Pioneer Asset Management, Inc., (the "Adviser"), serves as the investment adviser, as set forth in Rule 17a-7 under the Investment Company Act of 1940, pursuant to procedures adopted by the Board of Trustees. Under these procedures, cross trades are effected at current market prices. During the six months ended December 31, 2018, the Fund did not engaged in any cross trade activity. At December 31, 2018, the net unrealized depreciation on investments based on cost for federal tax purposes of $5,026,181,878 was as follows: Aggregate gross unrealized appreciation for all investments in which there is an excess of value over tax cost $ 33,770,978 Aggregate gross unrealized depreciation for all investments in which there is an excess of tax cost over value (161,877,139) ------------- Net unrealized depreciation $(128,106,161) ============= Various inputs are used in determining the value of the Fund's investments. These inputs are summarized in the three broad levels 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 risks, 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. 88 Pioneer Bond Fund | Semiannual Report | 12/31/18 The following is a summary of the inputs used as of December 31, 2018, in valuing the Fund's investments. ------------------------------------------------------------------------------------------------------------------------- Level 1 Level 2 Level 3 Total ------------------------------------------------------------------------------------------------------------------------- Convertible Preferred Stocks $26,615,862 $ -- $ -- $ 26,615,862 Asset Backed Securities -- 357,626,512 -- 357,626,512 Collateralized Mortgage Obligations -- 1,186,634,745 -- 1,186,634,745 Corporate Bonds -- 1,422,020,927 -- 1,422,020,927 Foreign Government Bonds -- 16,414,264 -- 16,414,264 Insurance-Linked Securities Catastrophe Linked Bonds Multiperil - U.S. -- 21,592,455 1,267,750 22,860,205 Multiperil - Worldwide -- 8,083,880 2,515,616 10,599,496 Collateralized Reinsurance Earthquakes - California -- -- 7,499,360 7,499,360 Hurricane - U.S. -- -- 27,120 27,120 Multiperil - Massachusetts -- -- 4,970,892 4,970,892 Multiperil - U.S. -- -- 428,960 428,960 Multiperil - U.S. Regional -- -- 976,000 976,000 Multiperil - Worldwide -- -- 11,486,400 11,486,400 Windstorm - Florida -- -- 2,029,262 2,029,262 Windstorm - U.S. Regional -- -- 3,666,659 3,666,659 Industry Loss Warranties Multiperil - U.S. -- -- 10,222,572 10,222,572 Reinsurance Sidecars Multiperil - U.S. -- -- 11,719,782 11,719,782 Multiperil - Worldwide -- -- 75,737,701 75,737,701 All Other Insurance-Linked Securities -- 35,826,720 -- 35,826,720 Municipal Bonds -- 117,381,417 -- 117,381,417 Senior Secured Floating Rate Loan Interests -- 111,706,531 -- 111,706,531 U.S. Government and Agency Obligations -- 1,467,134,872 -- 1,467,134,872 ------------------------------------------------------------------------------------------------------------------------- Total Investments in Securities $26,615,862 $4,744,422,323 $132,548,074 $ 4,903,586,259 ------------------------------------------------------------------------------------------------------------------------- Other Financial Instruments Net unrealized depreciation on futures contracts $(6,159,318) $ -- $ -- $ (6,159,318) Swap contracts, at value -- 648,776 -- 648,776 ------------------------------------------------------------------------------------------------------------------------- Total Other Financial Instruments $(6,159,318) $ 648,776 $ -- $ (5,510,542) ========================================================================================================================= The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 89 Schedule of Investments | 12/31/18 (unaudited)(continued) The following is a reconciliation of assets valued using significant unobservable inputs (Level 3): ------------------------------------------------------------------------------ Insurance- Linked Securities ------------------------------------------------------------------------------ Balance as of 6/30/18(a) $107,644,478 Realized gain (loss)(1) (16,150) Change in unrealized appreciation (depreciation)(2) (3,201,812) Accrued discounts/premiums (57,161) Purchases 45,830,328 Sales (17,651,609) Transfers in to Level 3* -- Transfers out of Level 3* -- ------------------------------------------------------------------------------ Balance as of 12/31/18 $132,548,074 ============================================================================== (a) Securities were classified as Corporate Bonds on the June 30, 2018 financial statements. (1) Realized gain (loss) on these securities is included in the realized gain (loss) from investments on the Statement of Operations. (2) Unrealized appreciation (depreciation) on these securities is included in the change in unrealized appreciation (depreciation) from investments on the Statement of Operations. * Transfers are calculated on the beginning of period value. For the six months ended December 31, 2018, there were no transfers between Levels 1, 2 and 3. Net change in unrealized appreciation (depreciation) of Level 3 investments still held and considered Level 3 at December 31, 2018: $(3,285,291) ----------- The accompanying notes are an integral part of these financial statements. 90 Pioneer Bond Fund | Semiannual Report | 12/31/18 Statement of Assets and Liabilities | 12/31/18 (unaudited) ASSETS: Investments in unaffiliated issuers, at value (cost $5,023,113,368) $4,903,586,259 Futures collateral 4,670,150 Swaps collateral 1,448,074 To be announced securities collateral 565,000 Due from broker for futures 6,159,316 Variation margin for swap contracts 47,491 Swap contracts, at value (net premiums paid $357,761) 648,776 Receivables -- Investment securities sold 78,548,070 Fund shares sold 46,684,989 Dividends 202,583 Interest 26,089,329 Other assets 150,163 ----------------------------------------------------------------------------------------------------------- Total assets $5,068,800,200 =========================================================================================================== LIABILITIES: Payables -- Investment securities purchased $ 80,876,225 Fund shares repurchased 38,744,886 Distributions 1,861,608 Trustees' fees 1,944 Due to Custodian 19,483,266 Due to broker for swaps 528,787 Variation margin for futures contracts 734,220 Net unrealized depreciation on futures contracts 6,159,318 Due to affiliates 329,651 Accrued expenses 2,111,754 ----------------------------------------------------------------------------------------------------------- Total liabilities $ 150,831,659 =========================================================================================================== NET ASSETS: Paid-in capital $5,080,818,147 Distributable earnings (loss) (162,849,606) ----------------------------------------------------------------------------------------------------------- Net assets $4,917,968,541 =========================================================================================================== NET ASSET VALUE PER SHARE: No par value (unlimited number of shares authorized) Class A (based on $968,540,476/103,540,505 shares) $ 9.35 Class C (based on $64,826,698/7,006,410 shares) $ 9.25 Class K (based on $1,029,581,481/110,125,572 shares) $ 9.35 Class R (based on $183,360,078/19,423,959 shares) $ 9.44 Class Y (based on $2,671,659,808/288,285,721 shares) $ 9.27 MAXIMUM OFFERING PRICE PER SHARE: Class A (based on $9.35 net asset value per share/100%-4.50% maximum sales charge) $ 9.79 =========================================================================================================== The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 91 Statement of Operations (unaudited) FOR THE SIX MONTHS ENDED 12/31/18 INVESTMENT INCOME: Interest from unaffiliated issuers $ 92,441,079 Dividends from unaffiliated issuers 1,173,468 ----------------------------------------------------------------------------------------------------------------- Total investment income $ 93,614,547 ================================================================================================================= EXPENSES: Management fees $ 8,635,377 Administrative expense 655,148 Transfer agent fees Class A 1,277,542 Class C 45,144 Class K 2,597 Class R 233,203 Class Y 1,610,498 Distribution fees Class A 1,311,273 Class C 349,241 Class R 460,664 Shareowner communications expense 80,005 Custodian fees 122,069 Registration fees 97,996 Professional fees 155,951 Printing expense 22,830 Pricing expense 133,829 Trustees' fees 111,587 Insurance expense 31,647 Miscellaneous 32,113 ----------------------------------------------------------------------------------------------------------------- Total expenses $ 15,368,714 Less fees waived and expenses reimbursed by the Adviser (290,627) ----------------------------------------------------------------------------------------------------------------- Net expenses $ 15,078,087 ----------------------------------------------------------------------------------------------------------------- Net investment income $ 78,536,460 ----------------------------------------------------------------------------------------------------------------- REALIZED AND UNREALIZED GAIN (LOSS) ON INVESTMENTS: Net realized gain (loss) on: Investments in unaffiliated issuers $(14,722,322) Futures contracts 646,820 Swap contracts 750,239 $(13,325,263) ----------------------------------------------------------------------------------------------------------------- Change in net unrealized appreciation (depreciation) on: Investments in unaffiliated issuers $(23,801,892) Futures contracts (3,837,636) Swap contracts 75,676 Unfunded loan commitments (1,444) $(27,565,296) ----------------------------------------------------------------------------------------------------------------- Net realized and unrealized gain (loss) on investments $(40,890,559) ----------------------------------------------------------------------------------------------------------------- Net increase in net assets resulting from operations $ 37,645,901 ================================================================================================================= The accompanying notes are an integral part of these financial statements. 92 Pioneer Bond Fund | Semiannual Report | 12/31/18 Statements of Changes in Net Assets ----------------------------------------------------------------------------------------------------------------- Six Months Ended 12/31/18 Year Ended (unaudited) 6/30/18 ----------------------------------------------------------------------------------------------------------------- FROM OPERATIONS: Net investment income (loss) $ 78,536,460 $ 143,173,744 Net realized gain (loss) on investments (13,325,263) 10,923,996 Change in net unrealized appreciation (depreciation) on investments (27,565,296) (140,359,697) ----------------------------------------------------------------------------------------------------------------- Net increase in net assets resulting from operations $ 37,645,901 $ 13,738,043 ----------------------------------------------------------------------------------------------------------------- DISTRIBUTIONS TO SHAREOWNERS: Class A ($0.16 and $0.28 per share, respectively) $ (17,672,235) $ (32,824,981)* Class C ($0.13 and $0.20 per share, respectively) (919,554) (1,902,820)* Class K ($0.18 and $0.31 per share, respectively) (19,553,604) (27,240,137)* Class R ($0.15 and $0.25 per share, respectively) (2,910,046) (4,692,437)* Class Y ($0.17 and $0.30 per share, respectively) (49,870,260) (84,440,366)* ----------------------------------------------------------------------------------------------------------------- Total distributions to shareowners $ (90,925,699) $ (151,100,741) ----------------------------------------------------------------------------------------------------------------- FROM FUND SHARE TRANSACTIONS: Net proceeds from sales of shares $ 1,066,649,605 $ 1,964,162,519 Reinvestment of distributions 73,182,017 119,480,660 Cost of shares repurchased (1,156,778,865) (1,674,666,408) ----------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net assets resulting from Fund share transactions $ (16,947,243) $ 408,976,771 ----------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net assets $ (70,227,041) $ 271,614,073 NET ASSETS:** Beginning of period $ 4,988,195,582 $ 4,716,581,509 ----------------------------------------------------------------------------------------------------------------- End of period $ 4,917,968,541 $ 4,988,195,582 ================================================================================================================= * For the year ended June 30, 2018, distributions to shareowners were presented as net investment income. ** For the year ended June 30, 2018, undistributed net investment income was presented as follows: $6,240,063. The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 93 Statements of Changes in Net Assets (continued) ------------------------------------------------------------------------------------------------------------------ Six Months Six Months Ended Ended 12/31/18 12/31/18 Year Ended Year Ended Shares Amount 6/30/18 6/30/18 (unaudited) (unaudited) Shares Amount ------------------------------------------------------------------------------------------------------------------ Class A Shares sold 13,511,206 $ 127,062,964 32,509,729 $ 313,658,795 Reinvestment of distributions 1,355,081 12,706,075 2,370,359 22,839,925 Less shares repurchased (25,679,887) (240,932,617) (39,650,187) (381,172,700) ------------------------------------------------------------------------------------------------------------------ Net decrease (10,813,600) $(101,163,578) (4,770,099) $ (44,673,980) ================================================================================================================== Class C Shares sold 910,247 $ 8,446,638 1,175,621 $ 11,253,310 Reinvestment of distributions 74,816 694,029 152,545 1,453,906 Less shares repurchased (2,462,080) (22,901,406) (2,897,968) (27,587,924) ------------------------------------------------------------------------------------------------------------------ Net decrease (1,477,017) $ (13,760,739) (1,569,802) $ (14,880,708) ================================================================================================================== Class K Shares sold 45,291,489 $ 425,982,589 45,145,368 $ 434,364,284 Reinvestment of distributions 1,645,457 15,419,665 2,183,632 20,998,540 Less shares repurchased (36,230,111) (340,166,485) (22,716,260) (217,864,913) ------------------------------------------------------------------------------------------------------------------ Net increase 10,706,835 $ 101,235,769 24,612,740 $ 237,497,911 ================================================================================================================== Class R Shares sold 2,434,501 $ 23,143,935 6,423,616 $ 62,506,249 Reinvestment of distributions 282,331 2,671,266 411,975 4,003,314 Less shares repurchased (2,131,268) (20,189,637) (6,238,265) (60,823,043) ------------------------------------------------------------------------------------------------------------------ Net increase 585,564 $ 5,625,564 597,326 $ 5,686,520 ================================================================================================================== Class Y Shares sold 51,812,162 $ 482,013,479 119,625,124 $1,142,379,881 Reinvestment of distributions 4,488,201 41,690,982 7,353,829 70,184,975 Less shares repurchased (57,265,923) (532,588,720) (103,621,965) (987,217,828) ------------------------------------------------------------------------------------------------------------------ Net increase (decrease) (965,560) $ (8,884,259) 23,356,988 $ 225,347,028 ================================================================================================================== The accompanying notes are an integral part of these financial statements. 94 Pioneer Bond Fund | Semiannual Report | 12/31/18 Financial Highlights ------------------------------------------------------------------------------------------------------------------------------------ Six Months Ended Year Year Year Year Year 12/31/18 Ended Ended Ended Ended Ended (unaudited) 6/30/18 6/30/17 6/30/16* 6/30/15* 6/30/14* ------------------------------------------------------------------------------------------------------------------------------------ Class A Net asset value, beginning of period $ 9.45 $ 9.71 $ 9.76 $ 9.68 $ 9.88 $ 9.67 ------------------------------------------------------------------------------------------------------------------------------------ Increase (decrease) from investment operations: Net investment income (loss) $ 0.14(a) $ 0.26(a) $ 0.25(a) $ 0.25(a) $ 0.27 $ 0.35 Net realized and unrealized gain (loss) on investments (0.08) (0.24) (0.01) 0.12 (0.14) 0.24 ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) from investment operations $ 0.06 $ 0.02 $ 0.24 $ 0.37 $ 0.13 $ 0.59 ------------------------------------------------------------------------------------------------------------------------------------ Distributions to shareowners: Net investment income $ (0.16) $ (0.28) $ (0.29) $ (0.27) $ (0.29) $ (0.38) Net realized gain -- -- -- (0.02) (0.04) -- ------------------------------------------------------------------------------------------------------------------------------------ Total distributions $ (0.16) $ (0.28) $ (0.29) $ (0.29) $ (0.33) $ (0.38) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) in net asset value $ (0.10) $ (0.26) $ (0.05) $ 0.08 $ (0.20) $ 0.21 ------------------------------------------------------------------------------------------------------------------------------------ Net asset value, end of period $ 9.35 $ 9.45 $ 9.71 $ 9.76 $ 9.68 $ 9.88 ==================================================================================================================================== Total return (b) 0.66%(c) 0.14% 2.48% 3.93% 1.32% 6.19% Ratio of net expenses to average net assets 0.85%(d) 0.85% 0.85% 0.85% 0.85% 0.85% Ratio of net investment income (loss) to average net assets 2.87%(d) 2.71% 2.60% 2.58% 2.68% 3.52% Portfolio turnover rate 23%(c) 45% 44% 43% 81% 41% Net assets, end of period (in thousands) $968,540 $1,081,121 $1,156,940 $1,177,941 $1,044,659 $706,962 Ratios with no waiver of fees and assumption of expense by the Adviser and no reduction for fees paid indirectly: Total expenses to average net assets 0.90%(d) 0.96% 0.99% 0.98% 0.93% 1.00% Net investment income (loss) to average net assets 2.82%(d) 2.60% 2.46% 2.45% 2.60% 3.37% ==================================================================================================================================== * The Fund was audited by an independent registered public accounting firm other than Ernst & Young LLP. (a) The per-share data presented above is based on the average shares outstanding for the period presented. (b) 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. (c) Not annualized. (d) Annualized. The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 95 Financial Highlights (continued) ------------------------------------------------------------------------------------------------------------------------------------ Six Months Ended Year Year Year Year Year 12/31/18 Ended Ended Ended Ended Ended (unaudited) 6/30/18 6/30/17 6/30/16* 6/30/15* 6/30/14* ------------------------------------------------------------------------------------------------------------------------------------ Class C Net asset value, beginning of period $ 9.35 $ 9.60 $ 9.66 $ 9.57 $ 9.77 $ 9.57 ------------------------------------------------------------------------------------------------------------------------------------ Increase (decrease) from investment operations: Net investment income (loss) $ 0.10(a) $ 0.19(a) $ 0.18(a) $ 0.17(a) $ 0.19 $ 0.26 Net realized and unrealized gain (loss) on investments (0.07) (0.24) (0.03) 0.14 (0.14) 0.23 ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) from investment operations $ 0.03 $ (0.05) $ 0.15 $ 0.31 $ 0.05 $ 0.49 ------------------------------------------------------------------------------------------------------------------------------------ Distributions to shareowners: Net investment income $ (0.13) $ (0.20) $ (0.21) $ (0.20) $ (0.21) $ (0.29) Net realized gain -- -- -- (0.02) (0.04) -- ------------------------------------------------------------------------------------------------------------------------------------ Total distributions $ (0.13) $ (0.20) $ (0.21) $ (0.22) $ (0.25) $ (0.29) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) in net asset value $ (0.10) $ (0.25) $ (0.06) $ 0.09 $ (0.20) $ 0.20 ------------------------------------------------------------------------------------------------------------------------------------ Net asset value, end of period $ 9.25 $ 9.35 $ 9.60 $ 9.66 $ 9.57 $ 9.77 ==================================================================================================================================== Total return (b) 0.27%(c) (0.52)% 1.62% 3.28% 0.49% 5.20% Ratio of net expenses to average net assets 1.54%(d) 1.60% 1.59% 1.60% 1.63% 1.73% Ratio of net investment income (loss) to average net assets 2.18%(d) 1.96% 1.84% 1.84% 1.89% 2.69% Portfolio turnover rate 23%(c) 45% 44% 43% 81% 41% Net assets, end of period (in thousands) $64,827 $79,308 $96,547 $134,299 $114,222 $73,224 ==================================================================================================================================== * The Fund was audited by an independent registered public accounting firm other than Ernst & Young LLP. (a) The per-share data presented above is based on the average shares outstanding for the period presented. (b) 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. (c) Not annualized. (d) Annualized. The accompanying notes are an integral part of these financial statements. 96 Pioneer Bond Fund | Semiannual Report | 12/31/18 ------------------------------------------------------------------------------------------------------------------------------------ Six Months Ended Year Year Year Year Year 12/31/18 Ended Ended Ended Ended Ended (unaudited) 6/30/18 6/30/17 6/30/16* 6/30/15* 6/30/14* ------------------------------------------------------------------------------------------------------------------------------------ Class K Net asset value, beginning of period $ 9.45 $ 9.71 $ 9.76 $ 9.68 $ 9.87 $ 9.67 ------------------------------------------------------------------------------------------------------------------------------------ Increase (decrease) from investment operations: Net investment income (loss) $ 0.16(a) $ 0.30(a) $ 0.29(a) $ 0.29(a) $ 0.30 $ 0.40 Net realized and unrealized gain (loss) on investments (0.08) (0.25) (0.01) 0.12 (0.13) 0.20 ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) from investment operations $ 0.08 $ 0.05 $ 0.28 $ 0.41 $ 0.17 $ 0.60 ------------------------------------------------------------------------------------------------------------------------------------ Distributions to shareowners: Net investment income $ (0.18) $ (0.31) $ (0.33) $ (0.31) $ (0.32) $(0.40) Net realized gain -- -- -- (0.02) (0.04) -- ------------------------------------------------------------------------------------------------------------------------------------ Total distributions $ (0.18) $ (0.31) $ (0.33) $ (0.33) $ (0.36) $(0.40) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) in net asset value $ (0.10) $ (0.26) $ (0.05) $ 0.08 $ (0.19) $ 0.20 ------------------------------------------------------------------------------------------------------------------------------------ Net asset value, end of period $ 9.35 $ 9.45 $ 9.71 $ 9.76 $ 9.68 $ 9.87 ==================================================================================================================================== Total return (b) 0.87%(c) 0.54% 2.87% 4.32% 1.80% 6.37% Ratio of net expenses to average net assets 0.40%(d) 0.46% 0.47% 0.47% 0.47% 0.56% Ratio of net investment income (loss) to average net assets 3.32%(d) 3.11% 3.01% 2.98% 3.03% 3.59% Portfolio turnover rate 23%(c) 45% 44% 43% 81% 41% Net assets, end of period (in thousands) $1,029,581 $939,272 $726,063 $340,096 $179,135 $4,398 ==================================================================================================================================== * The Fund was audited by an independent registered public accounting firm other than Ernst & Young LLP. (a) The per-share data presented above is based on the average shares outstanding for the period presented. (b) 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. (c) Not annualized. (d) Annualized. The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 97 Financial Highlights (continued) ------------------------------------------------------------------------------------------------------------------------------------ Six Months Ended Year Year Year Year Year 12/31/18 Ended Ended Ended Ended Ended (unaudited) 6/30/18 6/30/17 6/30/16* 6/30/15* 6/30/14* ------------------------------------------------------------------------------------------------------------------------------------ Class R Net asset value, beginning of period $ 9.54 $ 9.80 $ 9.85 $ 9.77 $ 9.97 $ 9.76 ------------------------------------------------------------------------------------------------------------------------------------ Increase (decrease) from investment operations: Net investment income (loss) $ 0.13(a) $ 0.24(a) $ 0.23(a) $ 0.23(a) $ 0.25 $ 0.32 Net realized and unrealized gain (loss) on investments (0.08) (0.25) (0.01) 0.12 (0.15) 0.23 ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) from investment operations $ 0.05 $ (0.01) $ 0.22 $ 0.35 $ 0.10 $ 0.55 ------------------------------------------------------------------------------------------------------------------------------------ Distributions to shareowners: Net investment income $ (0.15) $ (0.25) $ (0.27) $ (0.25) $ (0.26) $ (0.34) Net realized gain -- -- -- (0.02) (0.04) -- ------------------------------------------------------------------------------------------------------------------------------------ Total distributions $ (0.15) $ (0.25) $ (0.27) $ (0.27) $ (0.30) $ (0.34) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) in net asset value $ (0.10) $ (0.26) $ (0.05) $ 0.08 $ (0.20) $ 0.21 ------------------------------------------------------------------------------------------------------------------------------------ Net asset value, end of period $ 9.44 $ 9.54 $ 9.80 $ 9.85 $ 9.77 $ 9.97 ==================================================================================================================================== Total return (b) 0.55%(c) (0.08)% 2.23% 3.66% 1.06% 5.75% Ratio of net expenses to average net assets 1.10%(d) 1.10% 1.10% 1.10% 1.10% 1.25% Ratio of net investment income (loss) to average net assets 2.63%(d) 2.46% 2.35% 2.33% 2.43% 3.12% Portfolio turnover rate 23%(c) 45% 44% 43% 81% 41% Net assets, end of period (in thousands) $183,360 $179,729 $178,770 $156,110 $116,815 $48,264 Ratios with no waiver of fees and assumption of expense by the Adviser and no reduction for fees paid indirectly: Total expenses to average net assets 1.15%(d) 1.21% 1.24% 1.21% 1.21% 1.32% Net investment income (loss) to average net assets 2.58%(d) 2.35% 2.21% 2.22% 2.32% 3.05% ==================================================================================================================================== * The Fund was audited by an independent registered public accounting firm other than Ernst & Young LLP. (a) The per-share data presented above is based on the average shares outstanding for the period presented. (b) 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. (c) Not annualized. (d) Annualized. The accompanying notes are an integral part of these financial statements. 98 Pioneer Bond Fund | Semiannual Report | 12/31/18 ------------------------------------------------------------------------------------------------------------------------------------ Six Months Ended Year Year Year Year Year 12/31/18 Ended Ended Ended Ended Ended (unaudited) 6/30/18 6/30/17 6/30/16* 6/30/15* 6/30/14* ------------------------------------------------------------------------------------------------------------------------------------ Class Y Net asset value, beginning of period $ 9.36 $ 9.62 $ 9.67 $ 9.59 $ 9.79 $ 9.58 ------------------------------------------------------------------------------------------------------------------------------------ Increase (decrease) from investment operations: Net investment income (loss) $ 0.15(a) $ 0.28(a) $ 0.28(a) $ 0.27(a) $ 0.30 $ 0.36 Net realized and unrealized gain (loss) on investments (0.07) (0.24) (0.02) 0.12 (0.15) 0.24 ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) from investment operations $ 0.08 $ 0.04 $ 0.26 $ 0.39 $ 0.15 $ 0.60 ------------------------------------------------------------------------------------------------------------------------------------ Distributions to shareowners: Net investment income $ (0.17) $ (0.30) $ (0.31) $ (0.29) $ (0.31) $ (0.39) Net realized gain -- -- -- (0.02) (0.04) -- ------------------------------------------------------------------------------------------------------------------------------------ Total distributions $ (0.17) $ (0.30) $ (0.31) $ (0.31) $ (0.35) $ (0.39) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) in net asset value $ (0.09) $ (0.26) $ (0.05) $ 0.08 $ (0.20) $ 0.21 ------------------------------------------------------------------------------------------------------------------------------------ Net asset value, end of period $ 9.27 $ 9.36 $ 9.62 $ 9.67 $ 9.59 $ 9.79 ==================================================================================================================================== Total return (b) 0.91%(c) 0.40% 2.76% 4.22% 1.59% 6.41% Ratio of net expenses to average net assets 0.52%(d) 0.58% 0.58% 0.58% 0.58% 0.66% Ratio of net investment income (loss) to average net assets 3.20%(d) 2.98% 2.87% 2.85% 2.95% 3.72% Portfolio turnover rate 23%(c) 45% 44% 43% 81% 41% Net assets, end of period (in thousands) $2,671,660 $2,708,766 $2,558,262 $2,136,681 $1,644,161 $871,801 Ratios with no waiver of fees and assumption of expense by the Adviser and no reduction for fees paid indirectly: Total expenses to average net assets 0.52%(d) 0.58% 0.59% 0.59% 0.58% 0.66% Net investment income (loss) to average net assets 3.20%(d) 2.98% 2.86% 2.84% 2.95% 3.72% ==================================================================================================================================== * The Fund was audited by an independent registered public accounting firm other than Ernst & Young LLP. (a) The per-share data presented above is based on the average shares outstanding for the period presented. (b) 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. (c) Not annualized. (d) Annualized. The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/18 99 Notes to Financial Statements | 12/31/18 (unaudited) 1. Organization and Significant Accounting Policies Pioneer Bond Fund (the "Fund") is a Delaware statutory trust. The Fund is registered under the Investment Company Act of 1940 as a diversified, open-end management investment company. The investment objective of the Fund is to seek current income consistent with preservation of capital. The Fund offers six classes of shares designated as Class A, Class C, Class K, Class R, Class T and Class Y shares. Class T shares had not commenced operations as of December 31, 2018. 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 shareowner approval. Under per-share voting, each share of a class of the Fund is entitled to one vote. Under dollar-weighted voting, a shareowner'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. Amundi Pioneer Asset Management, Inc., an indirect wholly owned subsidiary of Amundi and Amundi's wholly owned subsidiary, Amundi USA, Inc., serves as the Fund's investment adviser (the "Adviser"). Amundi Pioneer Distributor, Inc., an affiliate of Amundi Pioneer Asset Management, Inc., serves as the Fund's distributor (the "Distributor"). In August 2018, the Securities and Exchange Commission ("SEC") released a Disclosure Update and Simplification Final Rule. The Final Rule amends Regulation S-X disclosures requirements to conform them to U.S. Generally Accepted Accounting Principles ("U.S. GAAP") for investment companies. The Fund's financial statements were prepared in compliance with the new amendments to Regulation S-X. The Fund is an investment company and follows investment company accounting and reporting guidance under U.S. GAAP. U.S. GAAP requires the management of the Fund to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets 100 Pioneer Bond Fund | Semiannual Report | 12/31/18 and liabilities at the date of the financial statements, and the reported amounts of income, expenses and gain or loss 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. 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. 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. When independent third party pricing services are unable to supply prices, or when prices or market quotations are considered to be unreliable, the value of that security may be determined using quotations from one or more broker-dealers. 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 Pioneer Bond Fund | Semiannual Report | 12/31/18 101 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. Repurchase agreements are valued at par. Cash may include overnight time deposits at approved financial institutions. Futures contracts are generally valued at the closing settlement price established by the exchange on which they are traded. 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 Dealers 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 or broker-dealers 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 the Adviser pursuant to procedures adopted by the Fund's Board of Trustees. The Adviser's fair valuation team uses fair value methods approved by the Valuation Committee of the Board of Trustees. The Adviser'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 December 31, 2018, no securities were valued using fair value methods (other than securities valued using prices supplied by independent pricing services, broker-dealers or using a third party insurance industry pricing model). 102 Pioneer Bond Fund | Semiannual Report | 12/31/18 B. Investment Income and Transactions Dividend income is recorded on the ex-dividend date, except that certain dividends from foreign securities where the ex-dividend date may have passed are recorded as soon as the Fund becomes aware of the ex-dividend data in the exercise of reasonable diligence. Interest income, including interest on income-bearing cash accounts, is recorded on the accrual basis. Dividend and interest income are reported net of unrecoverable foreign taxes withheld at the applicable country rates and net of income accrued on defaulted securities. Interest and dividend income payable by delivery of additional shares is reclassified as PIK (payment-in-kind) income upon receipt and is included in interest and dividend income, respectively. Principal amounts of mortgage-backed securities are adjusted for monthly paydowns. Premiums and discounts related to certain mortgage-backed securities are amortized or accreted in proportion to the monthly paydowns. All discounts/premiums on purchase prices of debt securities are accreted/amortized for financial reporting purposes over the life of the respective securities, and such accretion/amortization is included in interest income. 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 provision for federal income taxes is required. As of June 30, 2018, 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 on 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. GAAP. Distributions in excess of net investment income or net realized gains are temporary over distributions for financial statement purposes resulting from differences in the recognition or classification of income or distributions for financial statement and tax Pioneer Bond Fund | Semiannual Report | 12/31/18 103 purposes. Capital accounts within the financial statements are adjusted for permanent book/tax differences to reflect tax character, but are not adjusted for temporary differences. The tax character of current year distributions payable will be determined at the end of the current taxable year. The tax character of distributions paid during the year ended June 30, 2018 was as follows: -------------------------------------------------------------------------- 2018 -------------------------------------------------------------------------- Distributions paid from: Ordinary income $151,100,741 -------------------------------------------------------------------------- Total $151,100,741 ========================================================================== The following shows the components of distributable earnings on a federal income tax basis at June 30, 2018: -------------------------------------------------------------------------- 2018 -------------------------------------------------------------------------- Distributable earnings: Undistributed ordinary income $ 13,924,346 Capital Loss Carryforward (14,858,738) Capital Loss Carryforward Limited (676,688) Current year dividends payable (2,499,401) Net unrealized depreciation (105,459,327) -------------------------------------------------------------------------- Total $(109,569,808) ========================================================================== The difference between book-basis and tax-basis net unrealized appreciation is attributable to the tax deferral of losses on wash sales, adjustments relating to catastrophe bonds, the tax treatment of premium and amortization and the mark-to-market of futures and swap contracts. D. Fund Shares The Fund records sales and repurchases of its shares as of trade date. The Distributor earned $15,873 in underwriting commissions on the sale of Class A shares during the six months ended December 31, 2018. E. Class Allocations Income, common expenses and realized and unrealized gains and losses are calculated at the Fund level and allocated daily to each class of shares based on its respective percentage of adjusted net assets at the beginning of the day. 104 Pioneer Bond Fund | Semiannual Report | 12/31/18 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 K and 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). 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, Class R and Class Y shares can reflect different transfer agent and distribution expense rates. F. 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's investments in foreign markets and countries with limited developing markets may subject the Fund to a greater degree of risk than investments in a developed market. These risks include disruptive political or economic conditions and the imposition of adverse governmental laws or currency exchange restrictions. Interest rates in the U.S. have been historically low and have begun to rise, so the Fund faces a heightened risk that interest rates may continue to rise. A general rise in interest rates could adversely affect the price and liquidity of fixed-income securities and could also result in increased redemptions from the Fund. Pioneer Bond Fund | Semiannual Report | 12/31/18 105 The Fund invests in below investment grade (high yield) debt securities and preferred stocks. Some of these high yield securities may be convertible into equity securities of the issuer. 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. With the increased use of technologies such as the Internet to conduct business, the Fund is susceptible to operational, information security and related risks. While the Fund's Adviser has established business continuity plans in the event of, and risk management systems to prevent, limit or mitigate, such cyber-attacks, there are inherent limitations in such plans and systems including the possibility that certain risks have not been identified. Furthermore, the Fund cannot control the cybersecurity plans and systems put in place by service providers to the Fund such as Brown Brothers Harriman & Co., the Fund's custodian and accounting agent, and DST Asset Manager Solutions, Inc., the Fund's transfer agent. In addition, many beneficial owners of Fund shares hold them through accounts at broker-dealers, retirement platforms and other financial market participants over which neither the Fund nor Amundi Pioneer exercises control. Each of these may in turn rely on service providers to them, which are also subject to the risk of cyber-attacks. Cybersecurity failures or breaches at Amundi Pioneer or the Fund's service providers or intermediaries have the ability to cause disruptions and impact business operations, potentially resulting in financial losses, interference with the Fund's ability to calculate its net asset value, impediments to trading, the inability of Fund shareowners to effect share purchases, redemptions or exchanges, or receive distributions, loss of or unauthorized access to private shareowners information and violations of applicable privacy and other laws, regulatory fines, penalties, reputational damage, or additional compliance costs. Such costs and losses may not be covered under any insurance. In addition, maintaining vigilance against cyber-attacks may involve substantial costs over time, and system enhancements may themselves be subject to cyber-attacks. 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. G. Insurance-Linked Securities ("ILS") The Fund invests in event-linked bonds and other ILS. The Fund could lose a portion or all of the principal it has invested in an ILS, and the right to additional interest payments with respect to the security, upon the occurrence of one or more trigger events, as defined within the terms of an 106 Pioneer Bond Fund | Semiannual Report | 12/31/18 insurance-linked security. Trigger events, generally, are hurricanes, earthquakes, or other natural events of a specific size or magnitude that occur in a designated geographic region during a specified time period, and/or that involve losses or other metrics that exceed a specific amount. There is no way to accurately predict whether a trigger event will occur and, accordingly, ILS carry significant risk. 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, ILS 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. Where the ILS 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 the Adviser 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 the Adviser 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. H. 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 Pioneer Bond Fund | Semiannual Report | 12/31/18 107 held in safekeeping in the customer-only account of the Fund's custodian or a sub-custodian of the Fund. The Adviser 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 December 31, 2018, the Fund had no open repurchase agreements. I. Futures Contracts The Fund may enter into futures transactions in order to attempt to hedge against changes in interest rates, securities prices and currency exchange rates or to seek to increase total return. Futures contracts are types of derivatives. All futures contracts entered into by the Fund are traded on a futures exchange. Upon entering into a futures contract, the Fund is required to deposit with a broker an amount of cash or securities equal to the minimum "initial margin" requirements of the associated futures exchange. The amount of cash deposited with the broker as collateral at December 31, 2018, is recorded as "Futures collateral" on the Statement of Assets and Liabilities. Subsequent payments for futures contracts ("variation margin") are paid or received by the Fund, depending on the daily fluctuation in the value of the contracts, and are recorded by the Fund as unrealized appreciation or depreciation. Cash received from or paid to the broker related to previous margin movement is held in a segregated account at the broker and is recorded as either "Due from broker for futures" or "Due to broker for futures" on the Statement of Assets and Liabilities. 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 reduced 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 market value of contracts open during the six months ended December 31, 2018, was $196,900,913. Open futures contracts outstanding at December 31, 2018 are listed in the Schedule of Investments. 108 Pioneer Bond Fund | Semiannual Report | 12/31/18 J. Credit Default Swap Contracts A credit default swap is a contract between a buyer of protection and a seller of protection against a pre-defined credit event or an underlying reference obligation, which may be a single security or a basket or index of securities. The Fund may buy or sell 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. As a buyer of protection, the Fund 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 within the "Swap contracts, at value" line item on the Statement of Assets and Liabilities. Periodic payments received or paid by the Fund are recorded as realized gains or losses on 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 within the "Swap contracts, at value" line item on 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 on 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 Pioneer Bond Fund | Semiannual Report | 12/31/18 109 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. In addition, obligations under sell protection credit default swaps may be partially offset by net amounts received from settlement of buy protection credit default swaps entered into by the Fund for the same reference obligation with the same counterparty. Certain swap contracts that are cleared through a central clearinghouse are referred to as centrally cleared swaps. All payments made or received by the Fund are pursuant to a centrally cleared swap contract with the central clearing party rather than the original counterparty. Upon entering into a centrally cleared swap contract, the Fund is required to make an initial margin deposit, either in cash or in securities. The daily change in value on open centrally cleared contracts is recorded as "Variation margin for centrally cleared swaps" on the Statement of Assets and Liabilities. Cash received from or paid to the broker related to previous margin movement is held in a segregated account at the broker and is recorded as either "Due from broker for swaps" or "Due to broker for swaps" on the Statement of Assets and Liabilities. The amount of cash deposited with a broker as collateral at December 31, 2018, is recorded as "Swaps collateral" on the Statement of Assets and Liabilities. The average market value of credit default swap contracts open during the six months ended December 31, 2018 was $(4,520,924). Open credit default swap contracts at December 31, 2018 are listed in the Schedule of Investments. 2. Management Agreement The Adviser manages the Fund's portfolio. Effective October 1, 2018, management fees are calculated daily at the annual rate of 0.40% of the Fund's average daily net assets up to $500 million, 0.35% of the next $500 million of the Fund's average daily net assets, 0.30% of the next $1 billion of the Fund's average daily net assets, 0.25% of the next $8 billion of the Fund's average daily net assets, and 0.225% of the Fund's average daily net assets over $10 billion. The fee is accrued daily and paid monthly. Prior to October 1, 2018, the management fee was calculated daily at the annual rate of 0.40% of the Fund's average daily net assets. For the six months ended December 31, 2018, the effective management fee (excluding waivers and/or assumption of expenses) was equivalent to 0.34% (annualized) of the Fund's average daily net assets. The Adviser has contractually agreed to limit ordinary operating expenses (ordinary operating expenses means all fund expenses other than extraordinary expenses, such as litigation, taxes, brokerage commissions and acquired fund fees and expenses) of the Fund to the extent required to reduce Fund expenses to 0.85%, 1.10%, and 0.58% of the average daily net assets 110 Pioneer Bond Fund | Semiannual Report | 12/31/18 attributable to Class A, Class R and Class Y shares, respectively. Fees waived and expenses reimbursed during the six months ended December 31, 2018 are reflected on the Statement of Operations. These expense limitations are in effect through November 1, 2019. There can be no assurance that the Adviser 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 $274,702 in management fees, administrative costs and certain other reimbursements payable to the Adviser at December 31, 2018. 3. Transfer Agent DST Asset Manager Solutions, Inc. serves as the transfer agent to the Fund at negotiated rates. Transfer agent fees and payables shown on the Statement of Operations and the Statement of Assets and Liabilities, respectively, include sub-transfer agent expenses incurred through the Fund's omnibus relationship contracts. In addition, the Fund reimbursed the transfer agent for out-of-pocket expenses incurred by the transfer agent related to shareowner communications activities such as proxy and statement mailings, and outgoing phone calls. For the six months ended December 31, 2018, such out-of-pocket expenses by class of shares were as follows: -------------------------------------------------------------------------------- Shareowner Communications -------------------------------------------------------------------------------- Class A $26,242 Class C 2,632 Class K 7,961 Class R 725 Class Y 42,445 -------------------------------------------------------------------------------- Total $80,005 ================================================================================ 4. Distribution and Service Plans The Fund has adopted a distribution plan (the "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 the Distributor 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 the Distributor 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 Pioneer Bond Fund | Semiannual Report | 12/31/18 111 maintenance services or distribution services with regard to Class C shares. Pursuant to the Plan, the Fund also pays the Distributor 0.50% of the average daily net assets attributable to Class R shares for distribution services. Included in "Due to affiliates" reflected on the Statement of Assets and Liabilities is $54,949 in distribution fees payable to the Distributor at December 31, 2018. The Fund also has adopted a separate service plan for Class R shares (the "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. In addition, redemptions of each class of shares (except Class K, Class R and Class Y shares) may be subject to a contingent deferred sales charge ("CDSC"). A CDSC of 1.00% may be imposed on redemptions of certain net asset value purchases of Class A shares within 12 months of purchase. Redemptions of Class C shares within 12 months of purchase are subject to a CDSC of 1.00%, based on the lower of cost or market value of shares being redeemed. Shares purchased as part of an exchange remain subject to any CDSC that applied to the original purchase of those shares. There is no CDSC for Class K, Class R or Class Y shares. Proceeds from the CDSCs are paid to the Distributor. For the six months ended December 31, 2018, CDSCs in the amount of $2,891 were paid to the Distributor. 5. 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 credit facility or the limits set for borrowing by the Fund's prospectus and the 1940 Act. Prior to August 1, 2018 the credit facility was in the amount of $195 million. Effective August 1, 2018 the Fund participates in a credit facility that is in the amount of $250 million. Under such credit facility, depending on the type of loan, interest on borrowings is payable at the London Interbank Offered Rate ("LIBOR") plus 0.90% 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, or (c) 2% plus the overnight Eurodollar rate on the borrowing date. The Funds pay an annual commitment fee to participate in 112 Pioneer Bond Fund | Semiannual Report | 12/31/18 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 December 31, 2018, the Fund had no borrowings under the credit facility. 6. Master Netting Agreements The Fund has entered into an International Swaps and Derivatives Association, Inc. Master Agreement ("ISDA Master Agreement") or similar agreement with substantially all of its derivative counterparties. An ISDA Master Agreement is a bilateral agreement between the Fund and a counterparty that governs the trading of certain Over the Counter ("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 a 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 setoff may be restricted or prohibited by the bankruptcy or insolvency laws of the particular jurisdiction to which each specific ISDA Master Agreement of each 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 on the Statement of Assets and Liabilities as "Swaps collateral". Securities pledged by the Fund as collateral, if any, are identified as such in the Schedule of Investments. Pioneer Bond Fund | Semiannual Report | 12/31/18 113 Financial instruments subject to an enforceable master netting agreement, such as an ISDA Master Agreement, have been offset on the Statement of Assets and Liabilities. The following charts show gross assets and liabilities of the Fund as of December 31, 2018. ------------------------------------------------------------------------------------------------------------------- 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) ------------------------------------------------------------------------------------------------------------------- JPMorgan Chase Bank NA $139,350 $ -- $ -- $ -- $139,350 ------------------------------------------------------------------------------------------------------------------- Total $139,350 $ -- $ -- $ -- $139,350 =================================================================================================================== ------------------------------------------------------------------------------------------------------------------- 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) ------------------------------------------------------------------------------------------------------------------- JPMorgan Chase Bank NA $ -- $ -- $ -- $ -- $ -- ------------------------------------------------------------------------------------------------------------------- Total $ -- $ -- $ -- $ -- $ -- =================================================================================================================== (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. 7. Additional Disclosures about Derivative Instruments and Hedging Activities The Fund's use of derivatives may enhance or mitigate the Fund's exposure 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 rate 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. 114 Pioneer Bond Fund | Semiannual Report | 12/31/18 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 December 31, 2018 was as follows: ------------------------------------------------------------------------------------------------------------ Foreign Statement of Assets Interest Credit Exchange Equity Commodity and Liabilities Rate Risk Risk Rate Risk Risk Risk ------------------------------------------------------------------------------------------------------------ Assets: Swap contracts, at value $ -- $648,776 $ -- $ -- $ -- ------------------------------------------------------------------------------------------------------------ Total Value $ -- $648,776 $ -- $ -- $ -- ============================================================================================================ Liabilities: Net unrealized depreciation on futures contracts (6,159,318) $ -- -- -- -- ------------------------------------------------------------------------------------------------------------ Total Value $(6,159,318) $ -- $ -- $ -- $ -- ============================================================================================================ The effect of derivative instruments (not considered to be hedging instruments for accounting disclosure purposes) on the Statement of Operations by risk exposure at December 31, 2018 was as follows: ------------------------------------------------------------------------------------------------------------ Foreign Interest Credit Exchange Equity Commodity Statement of Operations Rate Risk Risk Rate Risk Risk Risk ------------------------------------------------------------------------------------------------------------ Net realized gain (loss) on: Futures contracts $ 646,820 $ -- $ -- $ -- $ -- Swap contracts -- 750,239 -- -- -- ------------------------------------------------------------------------------------------------------------ Total Value $ 646,820 $750,239 $ -- $ -- $ -- ============================================================================================================ Change in net unrealized appreciation (depreciation) on: Futures contracts $(3,837,636) $ -- $ -- $ -- $ -- Swap contracts -- 75,676 -- -- -- ------------------------------------------------------------------------------------------------------------ Total Value $(3,837,636) $ 75,676 $ -- $ -- $ -- ============================================================================================================ Pioneer Bond Fund | Semiannual Report | 12/31/18 115 ADDITIONAL INFORMATION (unaudited) Change in Independent Registered Public Accounting Firm Prior to July 3, 2017 Pioneer Investment Management, Inc. (the "Adviser"), the Fund's investment adviser, was an indirect, wholly owned subsidiary of UniCredit S.p.A. ("UniCredit"). On that date, UniCredit completed the sale of its Pioneer Investments business, which includes the Adviser, to Amundi (the "Transaction"). As a result of the Transaction, the Adviser became an indirect, wholly owned subsidiary of Amundi. Amundi is controlled by Credit Agricole S.A. Amundi is headquartered in Paris, France, and, as of September 30, 2016, had more than $1.1 trillion in assets under management worldwide. Deloitte & Touche LLP ("D&T"), the Fund's previous independent registered public accounting firm, informed the Audit Committee and the Board that it would no longer be independent with respect to the Fund upon the completion of the Transaction as a result of certain services being provided to Amundi and Credit Agricole, and, accordingly, that it intended to resign as the Fund's independent registered public accounting firm upon the completion of the Transaction. D&T's resignation was effective on July 3, 2017, when the Transaction was completed. During the periods as to which D&T has served as the Fund's independent registered public accounting firm, D&T's reports on the Fund's financial statements have not contained an adverse opinion or disclaimer of opinion and have not been qualified or modified as to uncertainty, audit scope or accounting principles. Further, there have been no disagreements with D&T on any matter of accounting principles or practices, financial statement disclosure, or auditing scope or procedure, which, if not resolved to the satisfaction of D&T, would have caused D&T to make reference to the subject matter of the disagreement in connection with its report on the financial statements. In addition, there have been no reportable events of the kind described in Item 304(a)(1)(v) of Regulation S-K under the Securities Exchange Act of 1934. Effective immediately following the completion of the Transaction on July 3, 2017, the Board, acting upon the recommendation of the Audit Committee, engaged an independent registered public accounting firm, Ernst & Young LLP ("EY"). Prior to its engagement, EY had advised the Fund's Audit Committee that EY had identified the following matters, in each case relating to services rendered by other member firms of Ernst & Young Global Limited, all of which are located outside the United States, to UniCredit and certain of its subsidiaries during the period commencing July 1, 2016, that it determined to be 116 Pioneer Bond Fund | Semiannual Report | 12/31/18 inconsistent with the auditor independence rules set forth by the Securities and Exchange Commission ("SEC"): (a) project management support services to UniCredit in the Czech Republic, Germany, Italy, Serbia and Slovenia in relation to twenty-two projects, that were determined to be inconsistent with Rule 2-01(c)(4)(vi) of Regulation S-X (management functions); (b) two engagements for UniCredit in Italy where fees were contingent/success based and that were determined to be inconsistent with Rule 2-01(c)(5) of Regulation S-X (contingent fees); (c) four engagements where legal and expert services were provided to UniCredit in the Czech Republic and Germany, and twenty engagements where the legal advisory services were provided to UniCredit in Austria, Czech Republic, Italy and Poland, that were determined to be inconsistent with Rule 2-01(c)(4)(ix) and (x) of Regulation S-X (legal and expert services); and (d) two engagements for UniCredit in Italy involving assistance in the sale of certain assets, that were determined to be inconsistent with Rule 2-01(c)(4)(viii) of Regulation S-X (broker-dealer, investment adviser or investment banking services). None of the foregoing services involved the Fund, any of the other funds in the Pioneer Family of Funds or any other Pioneer entity sold by UniCredit in the Transaction. EY advised the Audit Committee that it had considered the matters described above and had concluded that such matters would not impair EY's ability to exercise objective and impartial judgment in connection with the audits of the financial statements of the Fund under the SEC and Public Company Accounting Oversight Board independence rules, and that a reasonable investor with knowledge of all relevant facts and circumstances would reach the same conclusion. Management and the Audit Committee considered these matters and discussed the matters with EY and, based upon EY's description of the matters and statements made by EY, Management and the Audit Committee believe that EY will be capable of exercising objective and impartial judgment in connection with the audits of the financial statements of the Fund, and Management further believes that a reasonable investor with knowledge of all relevant facts and circumstances would reach the same conclusion. Pioneer Bond Fund | Semiannual Report | 12/31/18 117 Approval of Investment Management Agreement Amundi Pioneer Asset Management, Inc. ("APAM") serves as the investment adviser to Pioneer Bond Fund (the "Fund") pursuant to an investment management agreement between APAM and the Fund. In order for APAM to remain the investment adviser of the Fund, the Trustees of the Fund must determine annually whether to renew the investment management agreement for the Fund. The contract review process began in January 2018 as the Trustees of the Fund agreed on, among other things, an overall approach and timeline for the process. Contract review materials were provided to the Trustees in March 2018, July 2018 and September 2018. In addition, the Trustees reviewed and discussed the Fund's performance at regularly scheduled meetings throughout the year, and took into account other information related to the Fund provided to the Trustees at regularly scheduled meetings, in connection with the review of the Fund's investment management agreement. In March 2018, the Trustees, among other things, discussed the memorandum provided by Fund counsel that summarized the legal standards and other considerations that are relevant to the Trustees in their deliberations regarding the renewal of the investment management agreement, and reviewed and discussed the qualifications of the investment management teams for the Fund, as well as the level of investment by the Fund's portfolio managers in the Fund. In July 2018, the Trustees, among other things, reviewed the Fund's management fees and total expense ratios, the financial statements of APAM and its parent companies, profitability analyses provided by APAM, and analyses from APAM as to possible economies of scale. The Trustees also reviewed the profitability of the institutional business of APAM and APAM's affiliate, Amundi Pioneer Institutional Asset Management, Inc. ("APIAM" and, together with APAM, "Amundi Pioneer"), as compared to that of APAM's fund management business, and considered the differences between the fees and expenses of the Fund and the fees and expenses of APAM's and APIAM's institutional accounts, as well as the different services provided by APAM to the Fund and by APAM and APIAM to the institutional accounts. The Trustees further considered contract review materials, including additional materials received in response to the Trustees' request, in September 2018. At a meeting held on September 18, 2018, based on their evaluation of the information provided by APAM and third parties, the Trustees of the Fund, including the Independent Trustees voting separately, unanimously approved the renewal of the investment management agreement for another year. In approving the renewal of the investment management agreement, the Trustees 118 Pioneer Bond Fund | Semiannual Report | 12/31/18 considered various factors that they determined were relevant, including the factors described below. The Trustees did not identify any single factor as the controlling factor in determining to approve the renewal of the agreement. Nature, Extent and Quality of Services The Trustees considered the nature, extent and quality of the services that had been provided by APAM to the Fund, taking into account the investment objective and strategy of the Fund. The Trustees also reviewed APAM's investment approach for the Fund and its research process. The Trustees considered the resources of APAM and the personnel of APAM who provide investment management services to the Fund. They also reviewed the amount of non-Fund assets managed by the portfolio managers of the Fund. They considered the non-investment resources and personnel of APAM that are involved in APAM's services to the Fund, including APAM's compliance, risk management, and legal resources and personnel. The Trustees noted the substantial attention and high priority given by APAM's senior management to the Pioneer Fund complex. The Trustees considered that APAM supervises and monitors the performance of the Fund's service providers and provides the Fund with personnel (including Fund officers) and other resources that are necessary for the Fund's business management and operations. The Trustees also considered that, as administrator, APAM is responsible for the administration of the Fund's business and other affairs. The Trustees considered the fees paid to APAM for the provision of administration services. Based on these considerations, the Trustees concluded that the nature, extent and quality of services that had been provided by APAM to the Fund were satisfactory and consistent with the terms of the investment management agreement. Performance of the Fund In considering the Fund's performance, the Trustees regularly review and discuss throughout the year data prepared by APAM and information comparing the Fund's performance with the performance of its peer group of funds, as classified by Morningstar, Inc. (Morningstar), and the performance of the Fund's benchmark index. They also discuss the Fund's performance with APAM on a regular basis. The Trustees' regular reviews and discussions were factored into the Trustees' deliberations concerning the renewal of the investment management agreement. Pioneer Bond Fund | Semiannual Report | 12/31/18 119 Management Fee and Expenses The Trustees considered information showing the fees and expenses of the Fund in comparison to the management fees of its peer group of funds as classified by Morningstar and also to the expense ratios of a peer group of funds selected on the basis of criteria determined by the Independent Trustees for this purpose using data provided by Strategic Insight Mutual Fund Research and Consulting, LLC (Strategic Insight), an independent third party. The peer group comparisons referred to below are organized in quintiles. Each quintile represents one-fifth of the peer group. In all peer group comparisons referred to below, first quintile is most favorable to the Fund's shareowners. The Trustees noted that they separately review and consider the impact of the Fund's transfer agency and Fund- and APAM-paid expenses for sub-transfer agency and intermediary arrangements, and that the results of the most recent such review were considered in the consideration of the Fund's expense ratio. The Trustees considered that the Fund's management fee for the most recent fiscal year was in the second quintile relative to the management fees paid by other funds in its Morningstar category for the comparable period. The Trustees considered breakpoints that would be added to the Fund's management fee schedule, effective October 1, 2018. The Trustees considered that the expense ratio of the Fund's Class A shares for the most recent fiscal year was in the fourth quintile relative to its Strategic Insight peer group for the comparable period. The Trustees considered that the expense ratio of the Fund's Class Y shares for the most recent fiscal year was in the fifth quintile relative to its Strategic Insight peer group for the comparable period. The Trustees noted the impact of expenses relating to small accounts and omnibus accounts on transfer and sub-transfer agency expenses generally. The Trustees noted that APAM had agreed to waive fees and/or reimburse expenses in order to limit the ordinary operating expenses of the Fund. The Trustees reviewed management fees charged by APAM and APIAM to institutional and other clients, including publicly offered European funds sponsored by APAM's affiliates, unaffiliated U.S. registered investment companies (in a sub-advisory capacity), and unaffiliated foreign and domestic separate accounts. The Trustees also considered APAM's costs in providing services to the Fund and APAM's and APIAM's costs in providing services to the other clients and considered the differences in management fees and profit margins for fund and non-fund services. In evaluating the fees associated with APAM's and APIAM's client accounts, the Trustees took into account the respective demands, resources and complexity associated with the Fund and other client accounts. The Trustees noted that, in some instances, the fee rates for those clients were lower than the management fee for the Fund and considered that, under the investment management agreement with the Fund, 120 Pioneer Bond Fund | Semiannual Report | 12/31/18 APAM performs additional services for the Fund that it does not provide to those other clients or services that are broader in scope, including oversight of the Fund's other service providers and activities related to compliance and the extensive regulatory and tax regimes to which the Fund is subject. The Trustees also considered the entrepreneurial risks associated with APAM's management of the Fund. The Trustees concluded that the management fee payable by the Fund to APAM was reasonable in relation to the nature and quality of the services provided by APAM. Profitability The Trustees considered information provided by APAM regarding the profitability of APAM with respect to the advisory services provided by APAM to the Fund, including the methodology used by APAM in allocating certain of its costs to the management of the Fund. The Trustees also considered APAM's profit margin in connection with the overall operation of the Fund. They further reviewed the financial results, including the profit margins, realized by APAM and APIAM from non-fund businesses. The Trustees considered APAM's profit margins in comparison to the limited industry data available and noted that the profitability of any adviser was affected by numerous factors, including its organizational structure and method for allocating expenses. The Trustees concluded that APAM's profitability with respect to the management of the Fund was not unreasonable. Economies of Scale The Trustees considered APAM's views relating to economies of scale in connection with the Pioneer Funds as fund assets grow and the extent to which any such economies of scale are shared with the Fund and Fund shareholders. The Trustees noted the breakpoints in the management fee schedule. The Trustees recognize that economies of scale are difficult to identify and quantify, and that, among other factors that may be relevant, are the following: fee levels, expense subsidization, investment by APAM in research and analytical capabilities and APAM's commitment and resource allocation to the Fund. The Trustees noted that profitability also may be an indicator of the availability of any economies of scale, although profitability may vary for other reasons including due to reductions in expenses. The Trustees concluded that economies of scale, if any, were being appropriately shared with the Fund. Pioneer Bond Fund | Semiannual Report | 12/31/18 121 Other Benefits The Trustees considered the other benefits that APAM enjoys from its relationship with the Fund. The Trustees considered the character and amount of fees paid or to be paid by the Fund, other than under the investment management agreement, for services provided by APAM and its affiliates. The Trustees further considered the revenues and profitability of APAM's businesses other than the Fund business. To the extent applicable, the Trustees also considered the benefits to the Fund and to APAM and its affiliates from the use of "soft" commission dollars generated by the Fund to pay for research and brokerage services. The Trustees considered that Amundi Pioneer is the principal U.S. asset management business of Amundi, which is one of the largest asset managers globally. Amundi's worldwide asset management business manages over $1.7 trillion in assets (including the Pioneer Funds). The Trustees considered that APAM's relationship with Amundi creates potential opportunities for APAM, APIAM and Amundi that derive from APAM's relationships with the Fund, including Amundi's ability to market the services of APAM globally. The Trustees noted that APAM has access to additional research and portfolio management capabilities as a result of its relationship with Amundi and Amundi's enhanced global presence that may contribute to an increase in the resources available to APAM. The Trustees considered that APAM and the Fund receive reciprocal intangible benefits from the relationship, including mutual brand recognition and, for the Fund, direct and indirect access to the resources of a large global asset manager. The Trustees concluded that any such benefits received by APAM as a result of its relationship with the Fund were reasonable. Conclusion After consideration of the factors described above as well as other factors, the Trustees, including the Independent Trustees, concluded that the investment management agreement for the Fund, including the fees payable thereunder, was fair and reasonable and voted to approve the proposed renewal of the investment management agreement. 122 Pioneer Bond Fund | Semiannual Report | 12/31/18 Trustees, Officers and Service Providers Trustees Officers Thomas J. Perna, Chairman Lisa M. Jones, President and David R. Bock Chief Executive Officer Benjamin M. Friedman Mark E. Bradley, Treasurer and Margaret B.W. Graham Chief Financial Officer Lisa M. Jones Christopher J. Kelley, Secretary and Lorraine H. Monchak Chief Legal Officer Marguerite A. Piret Fred J. Ricciardi Kenneth J. Taubes Investment Adviser and Administrator Amundi Pioneer Asset Management, Inc. Custodian and Sub-Administrator Brown Brothers Harriman & Co. Principal Underwriter Amundi Pioneer Distributor, Inc. Legal Counsel Morgan, Lewis & Bockius LLP Shareowner Services and Transfer Agent DST Asset Manager Solutions, 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 www.amundipioneer.com. This information is also available on the Securities and Exchange Commission's web site at www.sec.gov. Pioneer Bond Fund | Semiannual Report | 12/31/18 123 This page is for your notes. 124 Pioneer Bond Fund | Semiannual Report | 12/31/18 How to Contact Amundi 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 FactFoneSM for automated fund yields, prices, account information and transactions 1-800-225-4321 Retirement plans information 1-800-622-0176 Write to us: -------------------------------------------------------------------------------- Amundi Pioneer P.O. Box 219427 Kansas City, MO 64121-9427 Our toll-free fax 1-800-225-4240 Our internet e-mail address us.askamundipioneer@amundipioneer.com (for general questions about Amundi Pioneer only) Visit our web site: www.amundipioneer.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 https://www.sec.gov. [LOGO] Amundi Pioneer ============== ASSET MANAGEMENT Amundi Pioneer Asset Management, Inc. 60 State Street Boston, MA 02109 www.amundipioneer.com Securities offered through Amundi Pioneer Distributor, Inc. 60 State Street, Boston, MA 02109 Underwriter of Pioneer Mutual Funds, Member SIPC [C] 2019 Amundi Pioneer Asset Management 18633-13-0219 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)). Mr. David R. Bock, 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 Amudi Pioneer Asset Management, Inc, 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. Disclosure of Securities Lending Activities for Closed-End Management Investment Companies. (a) If the registrant is a closed-end management investment company, provide the following dollar amounts of income and compensation related to the securities lending activities of the registrant during its most recent fiscal year: N/A (1) Gross income from securities lending activities; N/A (2) All fees and/or compensation for each of the following securities lending activities and related services: any share of revenue generated by the securities lending program paid to the securities lending agent(s) (revenue split); fees paid for cash collateral management services (including fees deducted from a pooled cash collateral reinvestment vehicle) that are not included in the revenue split; administrative fees that are not included in the revenue split; fees for indemnification that are not included in the revenue split; rebates paid to borrowers; and any other fees relating to the securities lending program that are not included in the revenue split, including a description of those other fees; N/A (3) The aggregate fees/compensation disclosed pursuant to paragraph (2); and N/A (4) Net income from securities lending activities (i.e., the dollar amount in paragraph (1) minus the dollar amount in paragraph (3)). If a fee for a service is included in the revenue split, state that the fee is included in the revenue split. N/A (b) If the registrant is a closed-end management investment company, describe the services provided to the registrant by the securities lending agent in the registrants most recent fiscal year. N/A ITEM 13. 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 Bond Fund By (Signature and Title)* /s/ Lisa M. Jones Lisa M. Jones, President & Chief Executive Officer Date March 5, 2019 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 March 5, 2019 By (Signature and Title)* /s/ Mark E. Bradley Mark E. Bradley, Treasurer & Chief Accounting & Financial Officer Date March 5, 2019 * Print the name and title of each signing officer under his or her signature.