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 June 30, 2019 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 -------------------------------------------------------------------------------- Annual Report | June 30, 2019 -------------------------------------------------------------------------------- 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 within the Pioneer Fund complex if you invest directly. [LOGO] Amundi Pioneer ============== ASSET MANAGEMENT visit us: www.amundipioneer.com/us 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 90 Notes to Financial Statements 99 Report of Independent Registered Public Accounting Firm 115 Additional Information 117 Trustees, Officers and Service Providers 118 Pioneer Bond Fund | Annual Report | 6/30/19 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. In fact, it's not unusual for political and economic issues on the international front to 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 communicate directly with the management teams of those companies. 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 | Annual Report | 6/30/19 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. June 30, 2019 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 | Annual Report | 6/30/19 3 Portfolio Management Discussion | 6/30/19 In the following interview, Brad Komenda discusses the factors that affected the performance of Pioneer Bond Fund during the 12-month period ended June 30, 2019. 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 Fund, 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, Director of Multisector Fixed Income, and a portfolio manager at Amundi Pioneer. Q How did the Fund perform during the 12-month period ended June 30, 2019? A Pioneer Bond Fund's Class A shares returned 6.93% at net asset value during the 12-month period ended June 30, 2019, while the Fund's benchmark, the Bloomberg Barclays U.S. Aggregate Bond Index (the Bloomberg Barclays Index), returned 7.87%. During the same period, the average return of the 623 mutual funds in Morningstar's Intermediate Core-Plus Bond Funds Category was 7.35%. Q How would you describe the investment environment in the fixed-income markets during the 12-month period ended June 30, 2019? A Entering the period in July 2018, robust economic data and corporate earnings results boosted credit-market sentiment, outweighing concerns over U.S. trade disputes with some of its key trading partners, especially China. The markets continued to focus heavily on economic growth and inflation indicators in the effort to glean future U.S. Federal Reserve (Fed) policy. Expectations at the time were for two additional quarter-point federal funds rate increases by year-end, for a total of four in 2018. Treasury yields rose in advance of the Fed's meeting on September 25, 2018, which resulted in an increase of 0.25% in the upper band for the benchmark overnight lending rate, from 2.00% to 2.25%. Investment-grade corporate bonds led performance within the Fund's benchmark, the Bloomberg Barclays Index, for the third quarter of 2018, though high-yield corporate bonds outperformed the investment grade for that quarter, given the "risk-on" attitude of many market participants. Market conditions reversed dramatically in the fourth quarter of 2018, however, with much of the damage coming in December. Investors' risk sentiment weakened from the outset of the quarter, due to concerns regarding the outlook for continued Fed tightening of monetary policy, the 4 Pioneer Bond Fund | Annual Report | 6/30/19 escalating U.S.-China trade dispute, and mounting evidence of slowing economic growth overseas. In early October, equities embarked on a downward trajectory that would persist essentially through the end of the calendar year. The price of oil also fell on an unfavorable supply/demand outlook. Nonetheless, the Fed in mid-December met expectations and raised short-term interest rates by another quarter-point, up to the 2.25% to 2.50% range, while signaling the likelihood of two additional hikes in 2019. Market volatility for riskier assets spiked as participants feared the Fed would "overshoot" on interest rates, given the uncertain outlook on global economic growth. The 10-year Treasury yield declined from 3.01% to 2.69% in December 2018, driven down by a global flight-to-safety trade. Risk-oriented assets then rebounded sharply in January of 2019 as the Fed pivoted to a less aggressive tone with regard to monetary policy, announcing an early end to its balance-sheet reduction program (a partial unwinding of its quantitative easing bond-purchasing initiatives of years past), while indicating it was leaning toward putting interest-rate increases on pause. In addition, weak economic data out of the euro zone and China led to renewed accommodation from the European Central Bank (ECB) and the People's Bank of China, to go along with the Fed's actions. Modest progress on trade matters, a firming in oil prices, and positive corporate earnings reports also helped boost investor sentiment for credit-sensitive assets. While there was some interim market volatility, credit-sensitive assets generally maintained a firm tone through the end of April 2019, before wavering in May after President Trump's announcement of plans to institute a 25% tariff on some $200 billion worth of Chinese goods. In response to the escalation in the U.S.-China trade dispute, which threatened an already fragile economic growth backdrop, the Fed signaled a willingness to implement one or more cuts in the federal funds rate before the end of 2019, and the policy reversal spurred a strong rally in the bond markets over the final weeks of the period. For the 12 months ended June 30, 2019, the investment-grade corporate bond market posted a positive return of 10.72%, while high-yield corporate bonds returned 7.48% (according to the Bloomberg Barclays U.S. Corporate Bond Index and the Bloomberg Barclays U.S. Corporate High Yield Index, respectively). Treasury bond performance was strong, too, as yields declined along the length of the curve, while modestly trailing corporate credit. Securitized assets, including mortgage-backed securities (MBS), asset-backed securities (ABS), and commercial MBS (CMBS), delivered notable positive returns for the period, while lagging the performance of both corporate bonds and Treasury issues. Pioneer Bond Fund | Annual Report | 6/30/19 5 Q What factors influenced the Fund's performance relative to the Bloomberg Barclays Index during the 12-month period ended June 30, 2019? A The Fund's absolute return was solid for the 12-month period, though it lagged the return of the Bloomberg Barclays Index. Our tactical shifts with respect to the Fund's credit exposure throughout the period made a meaningful, positive contribution to benchmark-relative returns. As credit spreads approached their widest point in late 2018, we began to add risk to the portfolio, both in the investment-grade and high-yield corporate sectors. We continued to add riskier assets into March 2019 as recession fears abated, allowing the Fund's relative returns to benefit from the strong performance of corporate credit. (Credit spreads are commonly defined as the differences in yield between Treasuries and other types of fixed-income securities with similar maturities.) Conversely, a portfolio underweight to U.S. Treasuries and a corresponding overweighting of securitized assets held back the Fund's returns relative to the benchmark, as Treasury performance received a boost from declining rates along the yield curve over the 12-month period. (When Treasury yields decline, the prices of Treasuries typically increase.) Market sentiment with respect to the securitized asset class received support from strong consumer fundamentals over the period, but the sector's performance did not benefit from the decline in interest rates to the same degree as Treasury securities. Another modest detractor from the Fund's benchmark-relative performance during the 12-month period was interest-rate positioning. In particular, the Fund was slightly underweight (or short compared to the benchmark) overall portfolio duration for most of the first half of the period, which limited relative returns as the 10-year Treasury yield declined. (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.) Additionally, a non-benchmark portfolio position in Treasury Inflation- Protected Securities (TIPS) was a drag on the Fund's benchmark-relative returns. The performance of TIPS lagged nominal Treasuries for the period as inflation expectations declined in late 2018. Moreover, similar to the situation with securitized assets, TIPS did not benefit to the same degree as comparable-maturity Treasuries from declining interest rates during the period. Another non-benchmark Fund allocation that detracted from relative performance was a small position in floating-rate bank loans, as the Fed's policy shift from tightening (rate hikes) to potential easing (rate cuts) limited gains for the asset class. (Bank loans have tended to perform well during periods of rising interest rates due to their floating-rate features.) 6 Pioneer Bond Fund | Annual Report | 6/30/19 We have maintained a modest, strategic Fund exposure to insurance-linked securities (ILS). ILS are sponsored by property-and-casualty insurers seeking to transfer some of the risk of having to pay damage claims in the wake of a natural disaster. We believe ILS can offer a valuable source of portfolio diversification* and incremental income. The Fund's allocation to ILS was a modest detractor from benchmark-relative performance over the 12-month period, as initial damage-loss estimates for Typhoon Jebi, which hit Japan in September of 2018, turned out to be greatly understated. In addition, the asset class has experienced some recent outflows, which has led to spread widening. Despite the underperformance over the period, we decided to increase the Fund's ILS exposure on pricing weakness, which created an attractive buying opportunity. Q Did the Fund have any investments in derivative securities during the 12-month period ended June 30, 2019? If so, did the derivatives have any material impact on performance? A Yes, we invested the Fund in Treasury futures and credit-default swaps (CDS) during the period. We typically invest in Treasury futures as part of our duration-management strategy 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. We use CDS investments to either increase or reduce the Fund's exposure to corporate bonds very quickly, as cash-bond transactions take a little more time. The use of derivatives did not have a material impact on the Fund's performance during the period, as they were used as hedging instruments. Q What factors affected the Fund's yield, or distributions** to shareholders, during the 12-month period ended June 30, 2019? A The overall decline in Treasury yields contributed to a lower portfolio yield, as did the tightening of credit spreads over the 12-month period. Q What is your investment outlook, and how is the Fund positioned heading into its new fiscal year? A In our view, the current level of uncertainty, coupled with extended credit valuations, warrants a somewhat conservative investment stance. We are not predicting that a recession is around the corner, but the risks appear to be higher. At the end of June, yields on short-term Treasuries exceeded those on the 10-year Treasury bond. Such an "inversion" of the yield curve * Diversification does not assure a profit nor protect against loss. ** Distributions are not guaranteed. Pioneer Bond Fund | Annual Report | 6/30/19 7 is generally viewed as a sign that investors are pessimistic about the economy's prospects and are thus bidding up prices for longer-term Treasuries as part of a flight to safety. As the second quarter of 2019 progressed, we reduced the Fund's risk profile as spreads approached their earlier tight levels and the yield curve's inversion increased in the wake of the Trump administration's public statements on the trade situation. We trimmed exposure to corporate credit over the second quarter, while increasing the portfolio's allocation to out-of-benchmark securitized sectors, including non-agency MBS and ABS, based on the view that the strong employment backdrop and healthy household balance sheets make the fundamental outlook for consumers favorable, relative to the outlook for companies. While the Fund's allocation to securitized assets has weighed on benchmark-relative performance of late, we believe their low correlation with credit-market performance and their generally higher quality offer a good offset to higher-risk sectors. We saw that scenario play out in the fourth quarter of 2018, in fact, when MBS outperformed most non-government fixed-income asset classes. The Fund ended the month of June slightly underweight versus the benchmark to investment-grade corporates, although it was overweight energy within the sector, based on attractive valuations. Our focus in that area is on midstream issuers, which have tended to be less vulnerable to energy-price volatility. We have reduced the portfolio's floating-rate bank loan position given the outlook for stable-to-declining short-term interest rates, and based on our view that the potential upside for the loan asset class is limited, as current valuations are near par (face) value. Outside the United States, the Fund continues to hold a meaningful position in core European bank issuers, with a tilt toward bonds that are lower in the capital structure. We believe those issues are attractive from a relative-valuation standpoint. Given the recent decline in interest rates, we returned the portfolio to a modest short-duration stance versus the Bloomberg Barclays Index as of period-end. That said, the Fund is overweight at the long end of the yield curve, as the curve is reasonably steep between the 10-year and 30-year maturities. 8 Pioneer Bond Fund | Annual Report | 6/30/19 Please refer to the Schedule of Investments on pages 19-89 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 | Annual Report | 6/30/19 9 Portfolio Summary | 6/30/19 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 32.2% Corporate Bonds 27.5% Collateralized Mortgage Obligations 22.7% Asset Backed Securities 11.8% Insurance-Linked Securities 3.1% Senior Secured Floating Rate Loan Interests 1.7% Convertible Preferred Stocks 0.5% Municipal Bonds 0.3% Foreign Government Bonds 0.2% 10 Largest Holdings -------------------------------------------------------------------------------- (As a percentage of total investments)* 1. U.S. Treasury Bills, 7/23/19 1.80% -------------------------------------------------------------------------------- 2. U.S. Treasury Inflation Indexed Bonds, 1.0%, 2/15/46 1.43 -------------------------------------------------------------------------------- 3. U.S. Treasury Inflation Indexed Bonds, 1.0%, 2/15/48 1.22 -------------------------------------------------------------------------------- 4. U.S. Treasury Inflation Indexed Bonds, 0.875%, 2/15/47 1.17 -------------------------------------------------------------------------------- 5. U.S. Treasury Bills, 7/9/19 1.17 -------------------------------------------------------------------------------- 6. U.S. Treasury Bonds, 3.0%, 2/15/49 1.02 -------------------------------------------------------------------------------- 7. U.S. Treasury Inflation Indexed Bonds, 1.0%, 2/15/49 0.99 -------------------------------------------------------------------------------- 8. Fannie Mae, 5.0%, 7/1/49 (TBA) 0.91 -------------------------------------------------------------------------------- 9. Fannie Mae, 4.0%, 7/1/49 (TBA) 0.80 -------------------------------------------------------------------------------- 10. U.S. Treasury Inflation Indexed Bonds, 0.75%, 2/15/45 0.53 -------------------------------------------------------------------------------- * 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 | Annual Report | 6/30/19 Prices and Distributions | 6/30/19 Net Asset Value per Share -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- Class 6/30/19 6/30/18 -------------------------------------------------------------------------------- A $9.79 $9.45 -------------------------------------------------------------------------------- C $9.68 $9.35 -------------------------------------------------------------------------------- K $9.78 $9.45 -------------------------------------------------------------------------------- R $9.88 $9.54 -------------------------------------------------------------------------------- Y $9.70 $9.36 -------------------------------------------------------------------------------- Distributions per Share: 7/1/18-6/30/19 -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- Net Investment Short-Term Long-Term Class Income Capital Gains Capital Gains -------------------------------------------------------------------------------- A $0.3008 $ -- $ -- -------------------------------------------------------------------------------- C $0.2310 $ -- $ -- -------------------------------------------------------------------------------- K $0.3418 $ -- $ -- -------------------------------------------------------------------------------- R $0.2793 $ -- $ -- -------------------------------------------------------------------------------- Y $0.3279 $ -- $ -- -------------------------------------------------------------------------------- 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 | Annual Report | 6/30/19 11 Performance Update | 6/30/19 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 June 30, 2019) -------------------------------------------------------- Bloomberg Net Public Barclays U.S. Asset Offering Aggregate Value Price Bond Period (NAV) (POP) Index -------------------------------------------------------- 10 years 5.12% 4.64% 3.90% 5 years 2.93 1.99 2.95 1 year 6.93 2.11 7.87 -------------------------------------------------------- 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 6/09 $ 9,550 $10,000 6/10 $10,955 $10,950 6/11 $11,730 $11,377 6/12 $12,423 $12,227 6/13 $12,822 $12,143 6/14 $13,616 $12,674 6/15 $13,795 $12,910 6/16 $14,337 $13,685 6/17 $14,693 $13,641 6/18 $14,715 $13,587 6/19 $15,734 $14,657 Call 1-800-225-6292 or visit www.amundipioneer.com/us 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 | Annual Report | 6/30/19 Performance Update | 6/30/19 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 June 30, 2019) -------------------------------------------------------- Bloomberg Barclays U.S. Aggregate If If Bond Period Held Redeemed Index -------------------------------------------------------- 10 years 4.26% 4.26% 3.90% 5 years 2.17 2.17 2.95 1 year 6.10 6.10 7.87 -------------------------------------------------------- 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 6/09 $10,000 $10,000 6/10 $11,363 $10,950 6/11 $12,052 $11,377 6/12 $12,669 $12,227 6/13 $12,964 $12,143 6/14 $13,638 $12,674 6/15 $13,704 $12,910 6/16 $14,153 $13,685 6/17 $14,383 $13,641 6/18 $14,308 $13,587 6/19 $15,181 $14,657 Call 1-800-225-6292 or visit www.amundipioneer.com/us 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 | Annual Report | 6/30/19 13 Performance Update | 6/30/19 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 June 30, 2019) -------------------------------------------------------- Bloomberg Net Barclays U.S. Asset Aggregate Value Bond Period (NAV) Index -------------------------------------------------------- 10 years 5.36% 3.90% 5 years 3.34 2.95 1 year 7.28 7.87 -------------------------------------------------------- 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 6/09 $5,000,000 $5,000,000 6/10 $5,735,497 $5,474,923 6/11 $6,141,533 $5,688,540 6/12 $6,504,415 $6,113,678 6/13 $6,724,502 $6,071,640 6/14 $7,152,850 $6,337,157 6/15 $7,281,638 $6,454,908 6/16 $7,596,410 $6,842,283 6/17 $7,814,744 $6,820,747 6/18 $7,857,069 $6,793,673 6/19 $8,428,905 $7,328,284 Call 1-800-225-6292 or visit www.amundipioneer.com/us 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 | Annual Report | 6/30/19 Performance Update | 6/30/19 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 June 30, 2019) -------------------------------------------------------- Bloomberg Net Barclays U.S. Asset Aggregate Value Bond Period (NAV) Index -------------------------------------------------------- 10 years 4.78% 3.90% 5 years 2.67 2.95 1 year 6.62 7.87 -------------------------------------------------------- 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 6/09 $10,000 $10,000 6/10 $11,418 $10,950 6/11 $12,179 $11,377 6/12 $12,859 $12,227 6/13 $13,219 $12,143 6/14 $13,979 $12,674 6/15 $14,128 $12,910 6/16 $14,645 $13,685 6/17 $14,971 $13,641 6/18 $14,960 $13,587 6/19 $15,950 $14,657 Call 1-800-225-6292 or visit www.amundipioneer.com/us 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 | Annual Report | 6/30/19 15 Performance Update | 6/30/19 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 June 30, 2019) -------------------------------------------------------- Bloomberg Net Barclays U.S. Asset Aggregate Value Bond Period (NAV) Index -------------------------------------------------------- 10 years 5.39% 3.90% 5 years 3.23 2.95 1 year 7.30 7.87 -------------------------------------------------------- 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 6/09 $5,000,000 $5,000,000 6/10 $5,752,975 $5,474,923 6/11 $6,170,100 $5,688,540 6/12 $6,557,133 $6,113,678 6/13 $6,775,957 $6,071,640 6/14 $7,210,450 $6,337,157 6/15 $7,324,828 $6,454,908 6/16 $7,633,936 $6,842,283 6/17 $7,844,772 $6,820,747 6/18 $7,876,186 $6,793,673 6/19 $8,451,119 $7,328,284 Call 1-800-225-6292 or visit www.amundipioneer.com/us 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 | Annual Report | 6/30/19 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 January 1, 2019 through June 30, 2019. ----------------------------------------------------------------------------------------------- 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 1/1/19 ----------------------------------------------------------------------------------------------- Ending Account $1,069.30 $1,061.00 $1,072.80 $1,066.20 $1,073.00 Value (after expenses) on 6/30/19 ----------------------------------------------------------------------------------------------- Expenses Paid $ 4.35 $ 7.76 $ 1.89 $ 5.62 $ 2.51 During Period* ----------------------------------------------------------------------------------------------- * Expenses are equal to the Fund's annualized expense ratio of 0.85%, 1.52%, 0.37%, 1.10%, and 0.49% 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 181/365 (to reflect the one-half year period). Pioneer Bond Fund | Annual Report | 6/30/19 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 January 1, 2019 through June 30, 2019. --------------------------------------------------------------------------------------------- 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 1/1/19 --------------------------------------------------------------------------------------------- Ending Account $1,020.58 $1,017.26 $1,022.96 $1,019.34 $1,022.36 Value (after expenses) on 6/30/19 --------------------------------------------------------------------------------------------- Expenses Paid $ 4.26 $ 7.60 $ 1.86 $ 5.51 $ 2.46 During Period* --------------------------------------------------------------------------------------------- * Expenses are equal to the Fund's annualized expense ratio of 0.85%, 1.52%, 0.37%, 1.10%, and 0.49% 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 181/365 (to reflect the one-half year period). 18 Pioneer Bond Fund | Annual Report | 6/30/19 Schedule of Investments | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Shares Value ----------------------------------------------------------------------------------------------------------------------------------- UNAFFILIATED ISSUERS -- 100.4% CONVERTIBLE PREFERRED STOCKS -- 0.5% of Net Assets Banks -- 0.5% 9,690(a) Bank of America Corp., 7.25% $ 13,294,680 9,656(a) Wells Fargo & Co., 7.5% 13,172,715 -------------- Total Banks $ 26,467,395 ----------------------------------------------------------------------------------------------------------------------------------- TOTAL CONVERTIBLE PREFERRED STOCKS (Cost $22,381,605) $ 26,467,395 ----------------------------------------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) ----------------------------------------------------------------------------------------------------------------------------------- ASSET BACKED SECURITIES -- 11.7% of Net Assets 689,159(b) 321 Henderson Receivables I LLC, Series 2005-1A, Class A1, 2.624% (1 Month USD LIBOR + 23 bps), 11/15/40 (144A) $ 673,593 500,000 321 Henderson Receivables III LLC, Series 2008-1A, Class B, 8.37%, 1/15/46 (144A) 615,705 1,307,517 ACC Trust, Series 2018-1, Class A, 3.7%, 12/21/20 (144A) 1,309,465 4,300,000 Access Point Funding I LLC, Series 2017-A, Class B, 3.97%, 4/15/29 (144A) 4,338,874 4,000,000 American Credit Acceptance Receivables Trust, Series 2019-2, Class E, 4.29%, 6/12/25 (144A) 4,049,736 2,100,000 Ascentium Equipment Receivables Trust, Series 2017-2A, Class D, 3.56%, 10/10/25 (144A) 2,121,803 1,100,000 Ascentium Equipment Receivables Trust, Series 2018-1A, Class D, 3.99%, 12/11/23 (144A) 1,134,044 1,750,000 Avid Automobile Receivables Trust, Series 2018-1, Class B, 3.85%, 7/15/24 (144A) 1,761,921 800,000 Axis Equipment Finance Receivables IV LLC, Series 2018-1A, Class C, 3.74%, 4/22/24 (144A) 814,169 1,249,999 Axis Equipment Finance Receivables IV LLC, Series 2018-1A, Class D, 3.98%, 4/22/24 (144A) 1,273,400 1,675,000 Axis Equipment Finance Receivables VI LLC, Series 2018-2A, Class C, 4.27%, 1/20/23 (144A) 1,741,118 5,784,000 Axis Equipment Finance Receivables VI LLC, Series 2018-2A, Class D, 4.45%, 6/20/23 (144A) 6,000,481 5,009,064(c) Bayview Koitere Fund Trust, Series 2017-RT4, Class A, 3.5%, 7/28/57 (144A) 5,113,486 1,416,000 BCC Funding XIV LLC, Series 2018-1A, Class B, 3.39%, 8/21/23 (144A) 1,442,622 76,391(b) Bear Stearns Asset Backed Securities Trust, Series 2006-SD2, Class A3, 2.894% (1 Month USD LIBOR + 49 bps), 6/25/36 76,306 944,952 BXG Receivables Note Trust, Series 2015-A, Class A, 2.88%, 5/2/30 (144A) 940,793 5,091,229 Cazenovia Creek Funding II LLC, Series 2018-1A, Class A, 3.561%, 7/15/30 (144A) 5,123,021 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 19 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- ASSET BACKED SECURITIES -- (continued) 1,400,000 CIG Auto Receivables Trust, Series 2017-1A, Class B, 3.81%, 5/15/23 (144A) $ 1,407,398 8,600,000 CIG Auto Receivables Trust, Series 2019-1A, Class B, 3.59%, 8/15/24 (144A) 8,755,270 1,335,177(b) Commonbond Student Loan Trust, Series 2017-BGS, Class A2, 3.054% (1 Month USD LIBOR + 65 bps), 9/25/42 (144A) 1,326,577 4,911,780 Commonbond Student Loan Trust, Series 2018-CGS, Class A1, 3.87%, 2/25/46 (144A) 5,099,556 3,287,034 Conn's Receivables Funding LLC, Series 2019-A, Class A, 3.4%, 10/16/23 (144A) 3,300,432 3,000,000 CoreVest American Finance Trust, Series 2017-1, Class C, 3.756%, 10/15/49 (144A) 3,025,938 1,500,000 Credit Acceptance Auto Loan Trust, Series 2016-2A, Class C, 4.29%, 11/15/24 (144A) 1,502,275 376,305(b) DRB Prime Student Loan Trust, Series 2016-B, Class A1, 4.204% (1 Month USD LIBOR + 180 bps), 6/25/40 (144A) 385,668 3,750,000 Drive Auto Receivables Trust, Series 2018-1, Class C, 3.22%, 3/15/23 3,764,330 4,000,000 Drive Auto Receivables Trust, Series 2019-1, Class C, 3.78%, 4/15/25 4,080,138 118,539(b) Drug Royalty II LP 2, Series 2014-1, Class A1, 5.637% (3 Month USD LIBOR + 285 bps), 7/15/23 (144A) 119,019 4,500,000 Elm Trust, Series 2018-2A, Class A2, 4.605%, 10/20/27 (144A) 4,541,754 1,300,000 Engs Commercial Finance Trust, Series 2016-1A, Class B, 3.45%, 3/22/22 (144A) 1,293,143 1,900,000 Engs Commercial Finance Trust, Series 2016-1A, Class D, 5.22%, 1/22/24 (144A) 1,891,902 2,000,000 Engs Commercial Finance Trust, Series 2018-1A, Class B, 3.8%, 2/22/23 (144A) 2,043,420 1,400,000 Engs Commercial Finance Trust, Series 2018-1A, Class C, 4.05%, 2/22/23 (144A) 1,436,312 1,500,000 Exeter Automobile Receivables Trust, Series 2018-1A, Class C, 3.03%, 1/17/23 (144A) 1,510,954 4,000,000 ExteNet LLC, Series 2019-1A, Class C, 5.219%, 7/26/49 (144A) 4,000,000 2,373,005 FCI Funding LLC, Series 2019-1A, Class A, 3.63%, 2/18/31 (144A) 2,391,614 2,920,622 FCI Funding LLC, Series 2019-1A, Class B, 4.03%, 2/18/31 (144A) 2,943,695 10,615,373(c) Finance of America Structured Securities Trust, Series 2019-A, Class JR2, 0.0%, 3/25/69 11,055,072 3,000,000(c) Finance of America Structured Securities Trust, Series 2019-HB1, Class M2, 3.676%, 4/25/29 (144A) 2,999,997 1,700,000(c) Finance of America Structured Securities Trust, Series 2019-HB1, Class M3, 3.813%, 4/25/29 (144A) 1,699,996 The accompanying notes are an integral part of these financial statements. 20 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- ASSET BACKED SECURITIES -- (continued) 1,140,000 Ford Credit Auto Owner Trust, Series 2018-2, Class A, 3.47%, 1/15/30 (144A) $ 1,194,075 3,750,000 Foundation Finance Trust, Series 2019-1A, Class B, 4.22%, 11/15/34 (144A) 3,748,363 4,200,000 Four Seas LP, Series 2017-1A, Class A2, 5.927%, 8/28/27 (144A) 4,227,563 1,000,000 Foursight Capital Automobile Receivables Trust, Series 2018-1, Class D, 4.19%, 11/15/23 (144A) 1,026,577 1,750,000 Foursight Capital Automobile Receivables Trust, Series 2019-1, Class D, 3.27%, 6/15/25 (144A) 1,755,966 5,080,000 Genesis Sales Finance Master Trust, Series 2019-AA, Class A, 4.68%, 8/20/23 (144A) 5,183,834 6,000,000 GLS Auto Receivables Issuer Trust, Series 2019-1A, Class C, 3.87%, 12/16/24 (144A) 6,144,815 415,000 GLS Auto Receivables Trust, Series 2017-1A, Class B, 2.98%, 12/15/21 (144A) 415,818 18,195(d) GMAT Trust, Series 2013-1A, Class A, 6.967%, 11/25/43 (144A) 18,206 63,985(b) GSRPM Mortgage Loan Trust, Series 2006-2, Class A2, 2.704% (1 Month USD LIBOR + 30 bps), 9/25/36 (144A) 63,977 4,858,288 Hardee's Funding LLC, Series 2018-1A, Class A2II, 4.959%, 6/20/48 (144A) 5,140,651 2,250,000(b) Hertz Fleet Lease Funding LP, Series 2016-1, Class E, 5.912% (1 Month USD LIBOR + 350 bps), 4/10/30 (144A) 2,253,100 1,850,000 Hertz Fleet Lease Funding LP, Series 2018-1, Class C, 3.77%, 5/10/32 (144A) 1,872,748 2,800,000 Hertz Fleet Lease Funding LP, Series 2018-1, Class D, 4.17%, 5/10/32 (144A) 2,836,890 4,344,000 HOA Funding LLC, Series 2014-1A, Class A2, 4.846%, 8/20/44 (144A) 4,347,388 6,117,968(b) Home Partners of America Trust, Series 2018-1, Class A, 3.294% (1 Month USD LIBOR + 90 bps), 7/17/37 (144A) 6,087,569 755,423 Icon Brand Holdings LLC, Series 2012-1A, Class A, 4.229%, 1/25/43 (144A) 561,400 206,522 Icon Brand Holdings LLC, Series 2013-1A, Class A2, 4.352%, 1/25/43 (144A) 151,461 3,650,000(b) Invitation Homes Trust, Series 2018-SFR1, Class C, 3.644% (1 Month USD LIBOR + 125 bps), 3/17/37 (144A) 3,630,701 4,730,000(b) Invitation Homes Trust, Series 2018-SFR2, Class D, 3.844% (1 Month USD LIBOR + 145 bps), 6/17/37 (144A) 4,691,277 6,860,000(b) Invitation Homes Trust, Series 2018-SFR3, Class D, 4.044% (1 Month USD LIBOR + 165 bps), 7/17/37 (144A) 6,848,641 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 21 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- ASSET BACKED SECURITIES -- (continued) 8,960,000(b) Invitation Homes Trust, Series 2018-SFR3, Class E, 4.394% (1 Month USD LIBOR + 200 bps), 7/17/37 (144A) $ 8,974,020 341,470 JG Wentworth XXII LLC, Series 2010-3A, Class A, 3.82%, 12/15/48 (144A) 353,197 3,925,243 JG Wentworth XLI LLC, Series 2018-1A, Class A, 3.74%, 10/17/72 (144A) 4,167,568 6,500,000 JG Wentworth XLIII LLC, Series 2019-1A, Class A, 3.82%, 8/17/71 (144A) 6,936,050 14,500,000 Kabbage Funding LLC, Series 2019-1, Class B, 4.071%, 3/15/24 (144A) 14,680,713 3,651,216 Marlette Funding Trust, Series 2018-3A, Class A, 3.2%, 9/15/28 (144A) 3,661,690 5,950,000 Marlette Funding Trust, Series 2019-2A, Class C, 4.11%, 7/16/29 (144A) 6,044,056 1,750,000 Marlin Receivables LLC, Series 2018-1A, Class C, 3.7%, 6/20/23 (144A) 1,790,941 8,726,000(c) Mill City Mortgage Loan Trust, Series 2016-1, Class B2, 4.015%, 4/25/57 (144A) 8,905,890 13,991,893(c) Mill City Mortgage Loan Trust, Series 2018-2, Class M1, 3.75%, 5/25/58 (144A) 14,446,858 4,997,105(c) Mill City Mortgage Loan Trust, Series 2018-2, Class M3, 3.75%, 5/25/58 (144A) 4,937,034 24,800,000(c) Mill City Mortgage Loan Trust, Series 2018-4, Class A1B, 3.5%, 4/25/66 (144A) 25,138,981 2,645,000(c) Nationstar HECM Loan Trust, Series 2018-3A, Class M3, 4.353%, 11/25/28 (144A) 2,674,312 3,272,332(b) Newtek Small Business Loan Trust, Series 2017-1, Class A, 4.404% (1 Month USD LIBOR + 200 bps), 2/15/43 (144A) 3,270,014 1,677,877(b) NovaStar Mortgage Funding Trust, Series 2005-3, Class M1, 3.079% (1 Month USD LIBOR + 68 bps), 1/25/36 1,675,866 1,775,000 Ocwen Master Advance Receivables Trust, Series 2016-T2, Class BT2, 3.265%, 8/16/49 (144A) 1,774,783 2,673,571 Orange Lake Timeshare Trust, Series 2019-A, Class A, 3.06%, 4/9/38 (144A) 2,711,299 3,888,860 Orange Lake Timeshare Trust, Series 2019-A, Class D, 4.93%, 4/9/38 (144A) 3,946,954 612,077 Oxford Finance Funding LLC, Series 2016-1A, Class A, 3.968%, 6/17/24 (144A) 617,438 3,000,000 Oxford Finance Funding LLC, Series 2019-1A, Class B, 5.438%, 2/15/27 (144A) 3,070,314 3,730,000 Progress Residential Trust, Series 2017-SFR1, Class E, 4.261%, 8/17/34 (144A) 3,828,808 6,180,000 Progress Residential Trust, Series 2017-SFR2, Class E, 4.142%, 12/17/34 (144A) 6,297,830 3,250,000 Progress Residential Trust, Series 2018-SFR2, Class E, 4.656%, 8/17/35 (144A) 3,368,852 The accompanying notes are an integral part of these financial statements. 22 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- ASSET BACKED SECURITIES -- (continued) 5,810,000 Progress Residential Trust, Series 2018-SFR3, Class E, 4.873%, 10/17/35 (144A) $ 6,079,272 8,370,000 Progress Residential Trust, Series 2019-SFR2, Class E, 4.142%, 5/17/36 (144A) 8,587,304 2,000,000 Purchasing Power Funding LLC, Series 2018-A, Class A, 3.34%, 8/15/22 (144A) 2,005,115 2,000,000(c) RMF Buyout Issuance Trust, Series 2019-1, Class M3, 3.011%, 7/25/29 (144A) 1,999,999 1,609,386 SCF Equipment Leasing LLC, Series 2017-2A, Class A, 3.41%, 12/20/23 (144A) 1,625,189 2,250,000 SCF Equipment Leasing LLC, Series 2018-1A, Class C, 4.21%, 4/20/27 (144A) 2,368,058 7,400,000 SCF Equipment Leasing LLC, Series 2019-1A, Class C, 3.92%, 11/20/26 (144A) 7,608,327 3,047,933 Spirit Master Funding LLC, Series 2014-4A, Class A2, 4.629%, 1/20/45 (144A) 3,264,988 14,000,000 SpringCastle Funding Asset-Backed Notes, Series 2019-AA, Class A, 3.2%, 5/27/36 (144A) 14,160,583 1,468,750 STORE Master Funding I LLC, Series 2015-1A, Class A1, 3.75%, 4/20/45 (144A) 1,495,636 3,200,000 Tidewater Auto Receivables Trust, Series 2018-AA, Class C, 3.84%, 11/15/24 (144A) 3,262,086 1,078,000 Tidewater Auto Receivables Trust, Series 2018-AA, Class D, 4.3%, 11/15/24 (144A) 1,102,834 472,237 TLF National Tax Lien Trust, Series 2017-1A, Class B, 3.84%, 12/15/29 (144A) 473,510 885,000(c) Towd Point Mortgage Trust, Series 2015-2, Class 1M1, 3.25%, 11/25/60 (144A) 902,197 12,000,000(c) Towd Point Mortgage Trust, Series 2015-4, Class A2, 3.75%, 4/25/55 (144A) 12,356,933 9,375,000(c) Towd Point Mortgage Trust, Series 2015-5, Class M1, 3.5%, 5/25/55 (144A) 9,623,256 10,011,000(c) Towd Point Mortgage Trust, Series 2016-3, Class M1, 3.5%, 4/25/56 (144A) 10,360,658 9,130,000(c) Towd Point Mortgage Trust, Series 2016-4, Class M1, 3.25%, 7/25/56 (144A) 9,154,421 12,600,000(c) Towd Point Mortgage Trust, Series 2017-2, Class M2, 3.75%, 4/25/57 (144A) 12,947,744 22,338,000(c) Towd Point Mortgage Trust, Series 2017-4, Class A2, 3.0%, 6/25/57 (144A) 22,213,591 20,071,000(c) Towd Point Mortgage Trust, Series 2017-6, Class A2, 3.0%, 10/25/57 (144A) 19,926,113 7,000,000(c) Towd Point Mortgage Trust, Series 2017-6, Class M1, 3.25%, 10/25/57 (144A) 6,966,544 19,865,000(c) Towd Point Mortgage Trust, Series 2018-2, Class A2, 3.5%, 3/25/58 (144A) 20,065,410 3,250,000(c) Towd Point Mortgage Trust, Series 2018-3, Class A2, 3.875%, 5/25/58 (144A) 3,396,250 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 23 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- ASSET BACKED SECURITIES -- (continued) 11,936,344(c) Towd Point Mortgage Trust, Series 2018-4, Class A1, 3.0%, 6/25/58 (144A) $ 12,116,627 13,650,000(c) Towd Point Mortgage Trust, Series 2018-4, Class A2, 3.0%, 6/25/58 (144A) 13,308,062 15,025,000(c) Towd Point Mortgage Trust, Series 2018-5, Class A1B, 3.25%, 7/25/58 (144A) 15,085,333 9,215,859(c) Towd Point Mortgage Trust, Series 2018-SJ1, Class A1, 4.0%, 10/25/58 (144A) 9,313,195 2,550,000(c) Towd Point Mortgage Trust, Series 2018-SJ1, Class A2, 4.25%, 10/25/58 (144A) 2,596,152 3,986,841(c) Towd Point Mortgage Trust, Series 2018-SJ1, Class XA, 5.0%, 10/25/58 (144A) 3,980,884 13,500,000(c) Towd Point Mortgage Trust, Series 2019-1, Class A2, 3.75%, 3/25/58 (144A) 13,643,563 25,435,000(c) Towd Point Mortgage Trust, Series 2019-2, Class A2, 3.75%, 12/25/58 (144A) 25,538,464 7,400,000(c) Towd Point Mortgage Trust, Series 2019-3, Class A2, 4.0%, 2/25/59 (144A) 7,811,242 13,515,000(b) Towd Point Mortgage Trust, Series 2019-HY2, Class A2, 3.804% (1 Month USD LIBOR + 140 bps), 5/25/58 (144A) 13,572,222 6,979,665(c) Towd Point Mortgage Trust, Series 2019-SJ1, Class A1, 3.75%, 11/25/58 (144A) 7,058,431 3,000,000(b) Trafigura Securitisation Finance Plc, Series 2017-1A, Class A1, 3.244% (1 Month USD LIBOR + 85 bps), 12/15/20 (144A) 3,010,162 8,500,000 Tricon American Homes Trust, Series 2017-SFR2, Class B, 3.275%, 1/17/36 (144A) 8,623,252 1,250,000 United Auto Credit Securitization Trust, Series 2019-1, Class D, 3.47%, 8/12/24 (144A) 1,260,405 2,125,000 United Auto Credit Securitization Trust, Series 2019-1, Class E, 4.29%, 8/12/24 (144A) 2,144,411 37,299 United States Small Business Administration, 6.14%, 1/1/22 38,309 163,888 United States Small Business Administration, Series 2005-20B, Class 1, 4.625%, 2/1/25 170,950 146,131 United States Small Business Administration, Series 2005-20E, Class 1, 4.84%, 5/1/25 153,111 221,986 United States Small Business Administration, Series 2008-20D, Class 1, 5.37%, 4/1/28 238,851 239,258 United States Small Business Administration, Series 2008-20H, Class 1, 6.02%, 8/1/28 259,307 148,815 United States Small Business Administration, Series 2008-20J, Class 1, 5.63%, 10/1/28 161,854 127,457 United States Small Business Administration, Series 2008-20L, Class 1, 6.22%, 12/1/28 140,313 56,155 United States Small Business Administration, Series 2009-20A, Class 1, 5.72%, 1/1/29 61,173 The accompanying notes are an integral part of these financial statements. 24 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- ASSET BACKED SECURITIES -- (continued) 137,716 United States Small Business Administration, Series 2009-20I, Class 1, 4.2%, 9/1/29 $ 145,908 2,682,578 Upstart Securitization Trust, Series 2018-2, Class A, 3.33%, 12/22/25 (144A) 2,686,452 2,450,000 US Auto Funding LLC, Series 2019-1A, Class B, 3.99%, 12/15/22 (144A) 2,488,859 559,257 Welk Resorts LLC, Series 2015-AA, Class A, 2.79%, 6/16/31 (144A) 559,236 1,986,230 Welk Resorts LLC, Series 2017-AA, Class B, 3.41%, 6/15/33 (144A) 1,987,179 2,500,000 Welk Resorts LLC, Series 2019-AA, Class C, 3.34%, 6/15/38 (144A) 2,505,015 1,299,045 Westgate Resorts LLC, Series 2016-1A, Class B, 4.5%, 12/20/28 (144A) 1,299,423 1,004,675 Westgate Resorts LLC, Series 2017-1A, Class A, 3.05%, 12/20/30 (144A) 1,005,594 5,747,158 Westgate Resorts LLC, Series 2018-1A, Class C, 4.1%, 12/20/31 (144A) 5,803,671 3,870,000 Westlake Automobile Receivables Trust, Series 2018-3A, Class E, 4.9%, 12/15/23 (144A) 3,984,436 2,500,000 WRG Debt Funding II LLC, Series 2017-1, Class A, 4.458%, 3/15/26 (144A) 2,510,645 ----------------------------------------------------------------------------------------------------------------------------------- TOTAL ASSET BACKED SECURITIES (Cost $636,041,669) $ 651,788,194 ----------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- 22.6% of Net Assets 3,190,000 A10 Term Asset Financing LLC, Series 2017-1A, Class B, 3.15%, 3/15/36 (144A) $ 3,192,603 3,772,936(c) Agate Bay Mortgage Trust, Series 2015-1, Class A13, 3.5%, 1/25/45 (144A) 3,793,393 16,705(b) Alternative Loan Trust, Series 2003-14T1, Class A9, 2.854% (1 Month USD LIBOR + 45 bps), 8/25/18 10,382 2,800,000 American Homes 4 Rent, Series 2014-SFR3, Class C, 4.596%, 12/17/36 (144A) 3,000,950 700,000 American Homes 4 Rent, Series 2014-SFR3, Class D, 5.04%, 12/17/36 (144A) 755,930 1,300,000 American Homes 4 Rent, Series 2015-SFR1, Class C, 4.11%, 4/17/52 (144A) 1,361,167 2,320,000(c) Angel Oak Mortgage Trust I LLC, Series 2019-1, Class M1, 4.5%, 11/25/48 (144A) 2,414,311 6,700,000(c) Angel Oak Mortgage Trust I LLC, Series 2019-2, Class M1, 4.065%, 3/25/49 (144A) 6,905,516 5,200,000(b) Arbor Realty Commercial Real Estate Notes, Ltd., Series 2017-FL1, Class B, 4.894% (1 Month USD LIBOR + 250 bps), 4/15/27 (144A) 5,356,000 405,189 B2R Mortgage Trust, Series 2015-1, Class A1, 2.524%, 5/15/48 (144A) 403,532 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 25 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 3,500,000(c) BAMLL Commercial Mortgage Securities Trust, Series 2016-FR14, Class A, 2.981%, 2/27/48 (144A) $ 3,490,504 7,460,000 BANK, Series 2017-BNK5, Class AS, 3.624%, 6/15/60 7,773,183 9,000,000 BANK, Series 2017-BNK7, Class AS, 3.748%, 9/15/60 9,449,359 4,412,656(d)(e) Bayview Commercial Asset Trust, Series 2007-2A, Class IO, 0.0%, 7/25/37 (144A) -- 6,143,918(c) Bayview Opportunity Master Fund IVb Trust, Series 2017-RT2, Class A, 3.5%, 8/28/57 (144A) 6,278,067 2,815,594(c) Bayview Opportunity Master Fund IVb Trust, Series 2017-SPL4, Class A, 3.5%, 1/28/55 (144A) 2,865,444 663,523(c) Bear Stearns Commercial Mortgage Securities Trust, Series 2005-PWR7, Class B, 5.214%, 2/11/41 661,612 2,839,875(b) Bellemeade Re, Ltd., Series 2017-1, Class M1, 4.104% (1 Month USD LIBOR + 170 bps), 10/25/27 (144A) 2,857,436 6,440,000(b) Bellemeade Re, Ltd., Series 2018-1A, Class M1B, 4.004% (1 Month USD LIBOR + 160 bps), 4/25/28 (144A) 6,463,258 5,430,000(b) Bellemeade Re, Ltd., Series 2018-2A, Class M1B, 3.754% (1 Month USD LIBOR + 135 bps), 8/25/28 (144A) 5,429,995 6,720,000(b) Bellemeade Re, Ltd., Series 2018-3A, Class M1B, 4.254% (1 Month USD LIBOR + 185 bps), 10/25/27 (144A) 6,730,066 5,250,000(b) Bellemeade Re, Ltd., Series 2018-3A, Class M2, 5.154% (1 Month USD LIBOR + 275 bps), 10/25/28 (144A) 5,214,150 4,530,000(b) Bellemeade Re, Ltd., Series 2019-1A, Class M1B, 4.154% (1 Month USD LIBOR + 175 bps), 3/25/29 (144A) 4,563,567 4,060,000(b) Bellemeade Re, Ltd., Series 2019-1A, Class M2, 5.104% (1 Month USD LIBOR + 270 bps), 3/25/29 (144A) 4,065,106 7,000,000 Benchmark Mortgage Trust, Series 2018-B2, Class A4, 3.615%, 2/15/51 7,470,623 4,200,000 Benchmark Mortgage Trust, Series 2018-B5, Class A3, 3.944%, 7/15/51 4,600,433 7,400,000 Benchmark Mortgage Trust, Series 2018-B8, Class A4, 3.963%, 1/15/52 8,119,763 4,700,000(b) BTH-13 Mortgage Backed Securities Trust, Series 2018-13, Class A, 4.94% (1 Month USD LIBOR + 250 bps), 8/18/21 (144A) 4,702,966 4,326,000 Cantor Commercial Real Estate Lending, Series 2019-CF1, Class D, 3.0%, 5/15/52 (144A) 3,901,901 3,945,592(c) Cascade Funding Mortgage Trust, Series 2018-RM2, Class A, 4.0%, 10/25/68 (144A) 4,029,363 3,076,163(c) Cascade Funding Mortgage Trust, Series 2018-RM2, Class C, 4.0%, 10/25/68 (144A) 3,020,954 The accompanying notes are an integral part of these financial statements. 26 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 3,250,000 CCRESG Commercial Mortgage Trust, Series 2016-HEAT, Class A, 3.357%, 4/10/29 (144A) $ 3,277,672 3,675,000 CD Mortgage Trust, Series 2018-CD7, Class A3, 4.013%, 8/15/51 4,047,094 4,000,000 CFCRE Commercial Mortgage Trust, Series 2016-C3, Class A2, 3.597%, 1/10/48 4,217,501 13,734,221(c) Chase Home Lending Mortgage Trust, Series 2019-ATR1, Class A4, 4.0%, 4/25/49 (144A) 13,973,306 147,375(c) CHL Mortgage Pass-Through Trust, Series 2003-56, Class 4A2, 4.492%, 12/25/33 153,216 3,400,000(c) Citigroup Commercial Mortgage Trust, Series 2014-GC19, Class B, 4.805%, 3/10/47 3,668,503 6,000,000(c) Citigroup Commercial Mortgage Trust, Series 2014-GC25, Class B, 4.345%, 10/10/47 6,373,093 3,100,000 Citigroup Commercial Mortgage Trust, Series 2015-GC27, Class A5, 3.137%, 2/10/48 3,208,422 6,052,000(c) Citigroup Commercial Mortgage Trust, Series 2015-GC33, Class B, 4.721%, 9/10/58 6,512,706 4,621,000 Citigroup Commercial Mortgage Trust, Series 2016-P5, Class D, 3.0%, 10/10/49 (144A) 4,085,655 7,700,000 Citigroup Commercial Mortgage Trust, Series 2019-SMRT, Class A, 4.149%, 1/10/24 (144A) 8,251,110 10,285,305(c) Citigroup Mortgage Loan Trust, Series 2018-RP2, Class A1, 3.5%, 2/25/58 (144A) 10,512,120 12,028,620(c) Citigroup Mortgage Loan Trust, Series 2019-RP1, Class A1, 3.5%, 1/25/66 (144A) 12,397,705 8,961,556(c) Citigroup Mortgage Loan Trust, Inc., Series 2018-RP1, Class A1, 3.0%, 9/25/64 (144A) 9,084,530 1,208,288 Colony American Finance, Ltd., Series 2015-1, Class A, 2.896%, 10/15/47 (144A) 1,206,394 2,400,000(d) Colony American Finance, Ltd., Series 2016-1, Class D, 5.972%, 6/15/48 (144A) 2,480,150 2,400,000(d) Colony American Finance, Ltd., Series 2016-2, Class D, 5.028%, 11/15/48 (144A) 2,466,823 2,090,000 COMM Mortgage Trust, Series 2012-CR2, Class AM, 3.791%, 8/15/45 2,155,061 2,933,640 COMM Mortgage Trust, Series 2012-CR3, Class A3, 2.822%, 10/15/45 2,966,422 5,000,000(c) COMM Mortgage Trust, Series 2013-CR11, Class C, 5.286%, 8/10/50 (144A) 5,298,896 1,900,000 COMM Mortgage Trust, Series 2013-LC6, Class A4, 2.941%, 1/10/46 1,937,174 2,500,000(c) COMM Mortgage Trust, Series 2014-CR16, Class C, 5.093%, 4/10/47 2,666,293 7,325,000(c) COMM Mortgage Trust, Series 2014-CR20, Class C, 4.651%, 11/10/47 7,735,290 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 27 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 264,441(b) COMM Mortgage Trust, Series 2014-FL5, Class B, 3.826% (1 Month USD LIBOR + 215 bps), 10/15/31 (144A) $ 264,088 6,360,204 COMM Mortgage Trust, Series 2014-UBS3, Class A3, 3.546%, 6/10/47 6,679,470 4,500,000(c) COMM Mortgage Trust, Series 2014-UBS3, Class C, 4.911%, 6/10/47 4,658,746 4,100,000 COMM Mortgage Trust, Series 2014-UBS4, Class A4, 3.42%, 8/10/47 4,287,408 5,200,000 COMM Mortgage Trust, Series 2015-3BP, Class A, 3.178%, 2/10/35 (144A) 5,402,914 4,000,000(c) COMM Mortgage Trust, Series 2015-CR23, Class CMD, 3.807%, 5/10/48 (144A) 4,004,178 3,104,000(c) COMM Mortgage Trust, Series 2015-CR25, Class B, 4.695%, 8/10/48 3,319,546 6,300,000 COMM Mortgage Trust, Series 2015-CR26, Class A3, 3.359%, 10/10/48 6,582,964 4,500,000(c) COMM Mortgage Trust, Series 2015-DC1, Class B, 4.035%, 2/10/48 4,663,478 15,470,000(b) Connecticut Avenue Securities Trust, Series 2019-R01, Class 2M2, 4.854% (1 Month USD LIBOR + 245 bps), 7/25/31 (144A) 15,655,997 5,580,000(b) Connecticut Avenue Securities Trust, Series 2019-R02, Class 1M2, 4.704% (1 Month USD LIBOR + 230 bps), 8/25/31 (144A) 5,628,062 4,480,000(b) Connecticut Avenue Securities Trust, Series 2019-R03, Class 1M2, 4.554% (1 Month USD LIBOR + 215 bps), 9/25/31 (144A) 4,504,687 8,375,000(b) Credit Suisse Mortgage Capital Certificates, Series 2019-ICE4, Class E, 4.544% (1 Month USD LIBOR + 215 bps), 5/15/36 (144A) 8,403,842 7,120,000(c) CSAIL Commercial Mortgage Trust, Series 2016-C5, Class C, 4.687%, 11/15/48 7,542,773 2,090,000 CSAIL Commercial Mortgage Trust, Series 2016-C6, Class A5, 3.09%, 1/15/49 2,142,297 8,007,391(c) CSMC Trust, Series 2013-6, Class 2A3, 3.5%, 8/25/43 (144A) 8,081,828 4,052,007(c) CSMC Trust, Series 2013-IVR3, Class A1, 2.5%, 5/25/43 (144A) 3,977,052 3,469,606(c) CSMC Trust, Series 2013-IVR3, Class B2, 3.451%, 5/25/43 (144A) 3,532,584 2,604,685(c) CSMC Trust, Series 2013-IVR3, Class B4, 3.451%, 5/25/43 (144A) 2,563,316 2,781,368(c) CSMC Trust, Series 2013-IVR5, Class B4, 3.651%, 10/25/43 (144A) 2,817,486 7,763,787(c) CSMC Trust, Series 2013-TH1, Class A1, 2.13%, 2/25/43 (144A) 7,652,967 The accompanying notes are an integral part of these financial statements. 28 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 20,960,812(c) CSMC Trust, Series 2019-RPL1, Class A1A, 3.65%, 7/25/58 (144A) $ 21,589,125 1,403,887(c) Deephaven Residential Mortgage Trust, Series 2017-3A, Class A1, 2.577%, 10/25/47 (144A) 1,400,445 3,352,347(c) Deephaven Residential Mortgage Trust, Series 2018-1A, Class A1, 2.976%, 12/25/57 (144A) 3,360,913 5,470,000(b) Eagle Re, Ltd., Series 2018-1, Class M1, 4.104% (1 Month USD LIBOR + 170 bps), 11/25/28 (144A) 5,469,995 11,100,000(b) Eagle Re, Ltd., Series 2019-1, Class M1B, 4.204% (1 Month USD LIBOR + 180 bps), 4/25/29 (144A) 11,108,777 4,467,871(c) EverBank Mortgage Loan Trust, Series 2013-2, Class A, 3.0%, 6/25/43 (144A) 4,472,866 9,907,334(b) Fannie Mae Connecticut Avenue Securities, Series 2016-C05, Class 2M2, 6.854% (1 Month USD LIBOR + 445 bps), 1/25/29 10,550,022 2,159,995(b) Fannie Mae Connecticut Avenue Securities, Series 2018-C01, Class 1M1, 3.004% (1 Month USD LIBOR + 60 bps), 7/25/30 2,158,819 13,220,000(b) Fannie Mae Connecticut Avenue Securities, Series 2018-C03, Class 1M2, 4.554% (1 Month USD LIBOR + 215 bps), 10/25/30 13,308,481 855,037(b) Fannie Mae Connecticut Avenue Securities, Series 2018-C04, Class 2M1, 3.154% (1 Month USD LIBOR + 75 bps), 12/25/30 855,469 6,842,238(b) Fannie Mae Connecticut Avenue Securities, Series 2018-C05, Class 1M1, 3.124% (1 Month USD LIBOR + 72 bps), 1/25/31 6,844,628 3,900,000(b) Fannie Mae Connecticut Avenue Securities, Series 2018-C05, Class 1M2, 4.754% (1 Month USD LIBOR + 235 bps), 1/25/31 3,934,650 5,750,000(b) Fannie Mae Connecticut Avenue Securities, Series 2019-R04, Class 2M2, 4.504% (1 Month USD LIBOR + 210 bps), 6/25/39 (144A) 5,765,100 431,601(c) Fannie Mae Grantor Trust, Series 2004-T2, Class 2A, 4.615%, 7/25/43 455,104 14,565(b) Federal Home Loan Mortgage Corp. REMICS, Series 3780, Class FE, 2.794% (1 Month USD LIBOR + 40 bps), 12/15/20 14,594 12,690,933(b)(e) Federal Home Loan Mortgage Corp. REMICS, Series 4091, Class SH, 4.156% (1 Month USD LIBOR + 655 bps), 8/15/42 2,790,772 1,262,465 Federal Home Loan Mortgage Corp. Whole Loan Securities Trust, Series 2017-SC02, Class 2A1, 3.5%, 5/25/47 1,276,535 236,905 Federal National Mortgage Association REMICS, Series 2009-36, Class HX, 4.5%, 6/25/29 245,541 890,267 Federal National Mortgage Association REMICS, Series 2013-128, Class DV, 3.0%, 6/25/23 900,095 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 29 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 2,942,834 Finance of America Structured Securities Trust, Series 2018-A, Class JR2, 2.0%, 12/26/68 $ 3,066,985 13,500,000 Finance of America Structured Securities Trust, Series 2019-JR2, 0.0%, 6/25/26 13,755,234 2,197,000(c) FirstKey Mortgage Trust, Series 2015-1, Class B4, 3.924%, 3/25/45 (144A) 2,150,314 5,404,759(c) Flagstar Mortgage Trust, Series 2018-2, Class A14, 3.5%, 4/25/48 (144A) 5,412,640 4,646,079(c) Flagstar Mortgage Trust, Series 2018-3INV, Class B1, 4.516%, 5/25/48 (144A) 5,103,401 4,812,045(c) Flagstar Mortgage Trust, Series 2018-3INV, Class B3, 4.516%, 5/25/48 (144A) 5,050,335 5,425,396(c) Flagstar Mortgage Trust, Series 2018-5, Class A7, 4.0%, 9/25/48 (144A) 5,495,970 4,230,000(b) Freddie Mac Stacr Trust, Series 2018-HQA2, Class B1, 6.654% (1 Month USD LIBOR + 425 bps), 10/25/48 (144A) 4,366,014 9,880,000(b) Freddie Mac Stacr Trust, Series 2018-HQA2, Class M2, 4.704% (1 Month USD LIBOR + 230 bps), 10/25/48 (144A) 9,923,071 11,470,000(b) Freddie Mac Stacr Trust, Series 2019-DNA2, Class M2, 4.854% (1 Month USD LIBOR + 245 bps), 3/25/49 (144A) 11,630,382 4,350,000(b) Freddie Mac Stacr Trust, Series 2019-HQA1, Class B2, 14.654% (1 Month USD LIBOR + 1,225 bps), 2/25/49 (144A) 5,054,505 3,926,000(b) Freddie Mac Stacr Trust, Series 2019-HQA1, Class M2, 4.754% (1 Month USD LIBOR + 235 bps), 2/25/49 (144A) 3,961,970 3,165,000(b) Freddie Mac Stacr Trust, Series 2019-HQA2, Class B2, 13.654% (1 Month USD LIBOR + 1,125 bps), 4/25/49 (144A) 3,517,044 3,530,000(b) Freddie Mac Stacr Trust, Series 2019-HQA2, Class M2, 4.454% (1 Month USD LIBOR + 205 bps), 4/25/49 (144A) 3,546,451 2,107,424(b) Freddie Mac Structured Agency Credit Risk Debt Notes, Series 2016-DNA4, Class M2, 3.704% (1 Month USD LIBOR + 130 bps), 3/25/29 2,113,134 11,465,925(b) Freddie Mac Structured Agency Credit Risk Debt Notes, Series 2017-DNA2, Class M2, 5.854% (1 Month USD LIBOR + 345 bps), 10/25/29 12,260,113 8,940,000(b) Freddie Mac Structured Agency Credit Risk Debt Notes, Series 2017-DNA3, Class M2, 4.904% (1 Month USD LIBOR + 250 bps), 3/25/30 9,140,532 3,306,928(b) Freddie Mac Structured Agency Credit Risk Debt Notes, Series 2018-HQA1, Class M1, 3.104% (1 Month USD LIBOR + 70 bps), 9/25/30 3,308,238 The accompanying notes are an integral part of these financial statements. 30 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 3,030,406(c) Freddie Mac Structured Agency Credit Risk Debt Notes, Series 2018-SPI3, Class M1, 4.165%, 8/25/48 (144A) $ 3,062,216 890,000(c) FREMF Mortgage Trust, Series 2010-K9, Class B, 5.375%, 9/25/45 (144A) 913,222 902,511(b) FREMF Mortgage Trust, Series 2014-KF05, Class B, 6.431% (1 Month USD LIBOR + 400 bps), 9/25/22 (144A) 921,325 2,653,276(b) FREMF Mortgage Trust, Series 2014-KS02, Class B, 7.431% (1 Month USD LIBOR + 500 bps), 8/25/23 (144A) 2,694,571 3,700,000(c) FREMF Mortgage Trust, Series 2015-K51, Class B, 4.088%, 10/25/48 (144A) 3,866,271 2,623,000(c) FREMF Mortgage Trust, Series 2017-K66, Class B, 4.173%, 7/25/27 (144A) 2,747,869 4,900,000(c) FREMF Mortgage Trust, Series 2019-KJ24, Class B, 7.6%, 10/25/27 (144A) 4,635,909 5,967,087(c) FRESB Mortgage Trust, Series 2018-SB52, Class A7F, 3.39%, 6/25/25 6,263,840 7,465,000(c) FWDSecuritization Trust, Series 2019-INV1, Class A1, 2.81%, 7/25/49 (144A) 7,464,414 2,150,000(c) FWDSecuritization Trust, Series 2019-INV1, Class M1, 3.48%, 7/25/49 (144A) 2,149,371 1,083,622 Government National Mortgage Association, Series 2005-61, Class UZ, 5.25%, 8/16/35 1,138,913 532,800 Government National Mortgage Association, Series 2012-130, Class PA, 3.0%, 4/20/41 537,563 634,073 Government National Mortgage Association, Series 2013-169, Class TE, 3.25%, 4/16/27 650,454 38,522,816(c)(e) Government National Mortgage Association, Series 2017-21, Class IO, 0.795%, 10/16/58 2,728,802 3,660,935 Government National Mortgage Association, Series 2018-20, Class A, 2.5%, 9/16/49 3,624,246 6,500,000 GS Mortgage Securities Trust, Series 2015-GC28, Class A5, 3.396%, 2/10/48 6,803,477 3,815,335(c) GS Mortgage-Backed Securities Corp. Trust, Series 2019-PJ1, Class A1, 4.0%, 8/25/49 (144A) 3,894,771 2,867,198(c) GS Mortgage-Backed Securities Corp. Trust, Series 2019-PJ1, Class B1, 4.329%, 8/25/49 (144A) 2,956,798 3,547,715(c) GS Mortgage-Backed Securities Trust, Series 2014-EB1A, Class B3, 3.118%, 7/25/44 (144A) 3,554,639 2,364,011 GS Mortgage-Backed Securities Trust, Series 2018-RPL1, Class A1A, 3.75%, 10/25/57 (144A) 2,442,222 750,000(b) Home Partners of America Trust, Series 2017-1, Class B, 3.744% (1 Month USD LIBOR + 135 bps), 7/17/34 (144A) 750,761 2,270,000(b) Home Re, Ltd., Series 2018-1, Class M1, 3.83% (1 Month USD LIBOR + 160 bps), 10/25/28 (144A) 2,266,183 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 31 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 7,040,000(b) Home Re, Ltd., Series 2019-1, Class M1, 4.054% (1 Month USD LIBOR + 165 bps), 5/25/29 (144A) $ 7,039,993 8,951,000 ILPT Trust, Series 2019-SURF, Class A, 4.145%, 2/11/41 (144A) 9,938,086 767,435 JP Morgan Chase Commercial Mortgage Securities Trust, Series 2011-C5, Class A3, 4.171%, 8/15/46 791,105 1,900,000(c) JP Morgan Chase Commercial Mortgage Securities Trust, Series 2012-C8, Class B, 3.977%, 10/15/45 (144A) 1,960,848 4,555,234 JP Morgan Chase Commercial Mortgage Securities Trust, Series 2012-LC9, Class A5, 2.84%, 12/15/47 4,632,291 5,925,000(c) JP Morgan Chase Commercial Mortgage Securities Trust, Series 2018-BCON, Class C, 3.881%, 1/5/31 (144A) 6,121,880 6,700,000 JP Morgan Chase Commercial Mortgage Securities Trust, Series 2018-WPT, Class AFX, 4.248%, 7/5/33 (144A) 7,162,639 6,540,396(c) JP Morgan Mortgage Trust, Series 2013-1, Class 2A2, 2.5%, 3/25/43 (144A) 6,520,467 2,329,684(c) JP Morgan Mortgage Trust, Series 2013-1, Class 2A3, 3.0%, 3/25/43 (144A) 2,348,559 70,349(c) JP Morgan Mortgage Trust, Series 2016-3, Class AM, 3.377%, 10/25/46 (144A) 71,491 6,991,549(c) JP Morgan Mortgage Trust, Series 2016-4, Class A13, 3.5%, 10/25/46 (144A) 7,058,273 10,555,000(c) JP Morgan Mortgage Trust, Series 2017-1, Class A6, 3.5%, 1/25/47 (144A) 10,728,661 2,376,919(c) JP Morgan Mortgage Trust, Series 2017-2, Class A4, 3.0%, 5/25/47 (144A) 2,374,495 4,639,907(c) JP Morgan Mortgage Trust, Series 2017-3, Class 1A13, 3.5%, 8/25/47 (144A) 4,689,524 5,625,192(c) JP Morgan Mortgage Trust, Series 2017-4, Class A6, 3.0%, 11/25/48 (144A) 5,664,568 4,161,277(c) JP Morgan Mortgage Trust, Series 2017-5, Class A1A, 3.0%, 10/26/48 (144A) 4,188,975 1,670,928(c) JP Morgan Mortgage Trust, Series 2017-5, Class A2, 3.182%, 10/26/48 (144A) 1,666,926 4,401,269(c) JP Morgan Mortgage Trust, Series 2017-5, Class B1, 3.182%, 10/26/48 (144A) 4,368,301 9,985,043(c) JP Morgan Mortgage Trust, Series 2017-6, Class B1, 3.84%, 12/25/48 (144A) 10,314,084 2,912,449(c) JP Morgan Mortgage Trust, Series 2018-1, Class B1, 3.765%, 6/25/48 (144A) 3,041,450 3,797,804(c) JP Morgan Mortgage Trust, Series 2018-3, Class B1, 3.778%, 9/25/48 (144A) 3,893,896 13,815,000(c) JP Morgan Mortgage Trust, Series 2018-4, Class A17, 3.5%, 10/25/48 (144A) 14,056,609 The accompanying notes are an integral part of these financial statements. 32 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 3,102,524(c) JP Morgan Mortgage Trust, Series 2018-9, Class A5, 4.0%, 2/25/49 (144A) $ 3,156,533 12,482,956(c) JP Morgan Mortgage Trust, Series 2019-1, Class A4, 4.0%, 5/25/49 (144A) 12,700,259 7,852,268(c) JP Morgan Mortgage Trust, Series 2019-2, Class A6, 4.0%, 8/25/49 (144A) 8,041,651 13,200,000(c) JP Morgan Mortgage Trust, Series 2019-5, Class A3, 4.0%, 11/25/49 (144A) 13,505,639 4,500,000(c) JP Morgan Mortgage Trust, Series 2019-5, Class A15, 4.0%, 11/25/49 (144A) 4,578,867 8,073,098(c) JP Morgan Mortgage Trust, Series 2019-LTV1, Class A3, 4.0%, 6/25/49 (144A) 8,230,685 8,687,754(c) JP Morgan Mortgage Trust, Series 2019-LTV1, Class A15, 4.0%, 6/25/49 (144A) 8,909,675 4,191,936(c) JP Morgan Trust, Series 2015-3, Class B3, 3.671%, 5/25/45 (144A) 4,249,665 7,850,000 JPMBB Commercial Mortgage Securities Trust, Series 2015-C32, Class A4, 3.329%, 11/15/48 8,190,166 3,450,000(c) JPMDB Commercial Mortgage Securities Trust, Series 2016-C2, Class B, 3.99%, 6/15/49 3,644,803 6,650,000 JPMDB Commercial Mortgage Securities Trust, Series 2016-C4, Class A3, 3.141%, 12/15/49 6,877,243 2,000,000(c) JPMDB Commercial Mortgage Securities Trust, Series 2016-C4, Class D, 3.22%, 12/15/49 (144A) 1,786,344 7,640,000 JPMDB Commercial Mortgage Securities Trust, Series 2018-C8, Class A4, 4.211%, 6/15/51 8,489,031 45,714,000(c)(e) JPMDB Commercial Mortgage Securities Trust, Series 2018-C8, Class XB, 0.193%, 6/15/51 531,910 1,782,606 La Hipotecaria El Salvadorian Mortgage Trust, Series 2016-1A, Class A, 3.358%, 1/15/46 (144A) 1,838,312 840,450(b) La Hipotecaria Panamanian Mortgage Trust, Series 2010-1GA, Class A, 2.75% (Panamanian Mortgage Reference Rate + 300 bps), 9/8/39 (144A) 842,552 2,678,781(b) La Hipotecaria Panamanian Mortgage Trust, Series 2014-1A, Class A1, 3.508% (Panamanian Mortgage Reference Rate + 224 bps), 11/24/42 (144A) 2,780,492 4,789,746(c) Metlife Securitization Trust, Series 2019-1A, Class A1A, 3.75%, 4/25/58 (144A) 4,975,689 10,000,000(c) Mill City Mortgage Loan Trust, Series 2019-1, Class A1, 3.25%, 10/25/69 (144A) 10,191,660 4,900,241 Morgan Stanley Bank of America Merrill Lynch Trust, Series 2012-C6, Class A4, 2.858%, 11/15/45 4,974,746 3,563,500(c) Morgan Stanley Bank of America Merrill Lynch Trust, Series 2015-C21, Class C, 4.297%, 3/15/48 3,659,732 6,900,000 Morgan Stanley Capital I Trust, Series 2018-MP, Class A, 4.418%, 7/11/40 (144A) 7,723,668 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 33 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 4,857,729(b) New Residential Mortgage Loan Trust, Series 2018-4A, Class A1S, 3.154% (1 Month USD LIBOR + 75 bps), 1/25/48 (144A) $ 4,854,353 3,634,232(c) New Residential Mortgage Loan Trust, Series 2018-5A, Class A1, 4.75%, 12/25/57 (144A) 3,815,005 114,932(c) New Residential Mortgage Loan Trust, Series 2018-RPL1, Class A1, 3.5%, 12/25/57 (144A) 117,498 14,890,831(c) New Residential Mortgage Loan Trust, Series 2019-2A, Class A1, 4.25%, 12/25/57 (144A) 15,471,911 5,538,478(c) NRP Mortgage Trust, Series 2013-1, Class B1, 3.315%, 7/25/43 (144A) 5,600,609 4,259,980(c) NRP Mortgage Trust, Series 2013-1, Class B2, 3.315%, 7/25/43 (144A) 4,284,068 2,457,000(b) Oaktown Re II, Ltd., Series 2018-1A, Class M2, 5.254% (1 Month USD LIBOR + 285 bps), 7/25/28 (144A) 2,478,306 2,553,836(c) OBX Trust, Series 2018-EXP1, Class 1A6, 4.5%, 4/25/48 (144A) 2,602,157 5,148,800(c) OBX Trust, Series 2019-EXP1, Class 1A3, 4.0%, 1/25/59 (144A) 5,233,858 10,200,000(c) OBX Trust, Series 2019-INV1, Class A10, 4.0%, 11/25/48 (144A) 10,562,699 13,250,000(c) OBX Trust, Series 2019-INV2, Class A5, 4.0%, 5/27/49 (144A) 13,652,018 253,214(b) Pepper Residential Securities Trust No. 18, Series 18A, Class A1UA, 3.363% (1 Month USD LIBOR + 95 bps), 3/12/47 (144A) 253,113 11,762,823(c) PMT Loan Trust, Series 2013-J1, Class A1, 3.5%, 9/25/43 (144A) 11,883,198 8,498,040(c) PMT Loan Trust, Series 2013-J1, Class A11, 3.5%, 9/25/43 (144A) 8,620,162 4,800,000 Progress Residential Trust, Series 2017-SFR1, Class B, 3.017%, 8/17/34 (144A) 4,822,887 700,000 Progress Residential Trust, Series 2017-SFR1, Class D, 3.565%, 8/17/34 (144A) 709,444 5,135,000 Progress Residential Trust, Series 2017-SFR2, Class B, 3.196%, 12/17/34 (144A) 5,174,586 4,890,411(b) Radnor Re, Ltd., Series 2018-1, Class M1, 3.804% (1 Month USD LIBOR + 140 bps), 3/25/28 (144A) 4,902,838 11,160,000(b) Radnor Re, Ltd., Series 2019-1, Class M1B, 4.354% (1 Month USD LIBOR + 195 bps), 2/25/29 (144A) 11,238,024 3,437,000(b) Radnor Re, Ltd., Series 2019-1, Class M2, 5.604% (1 Month USD LIBOR + 320 bps), 2/25/29 (144A) 3,471,613 2,924 RALI Trust, Series 2003-QS14, Class A1, 5.0%, 7/25/18 2,854 327,554(b) RESIMAC Premier, Series 2017-1A, Class A1A, 3.362% (1 Month USD LIBOR + 95 bps), 9/11/48 (144A) 327,100 6,716,728 Seasoned Loans Structured Transaction, Series 2019-1, Class A1, 3.5%, 5/25/29 6,986,004 The accompanying notes are an integral part of these financial statements. 34 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 2,475,382(c) Sequoia Mortgage Trust, Series 2012-6, Class A2, 1.808%, 12/25/42 $ 2,445,025 2,697,542(c) Sequoia Mortgage Trust, Series 2012-6, Class B3, 3.73%, 12/25/42 2,731,442 3,535,637(c) Sequoia Mortgage Trust, Series 2013-2, Class A, 1.874%, 2/25/43 3,291,407 6,906,450(c) Sequoia Mortgage Trust, Series 2013-4, Class A1, 2.325%, 4/25/43 6,659,902 7,092,762(c) Sequoia Mortgage Trust, Series 2013-5, Class A1, 2.5%, 5/25/43 (144A) 6,856,408 14,566,139(c) Sequoia Mortgage Trust, Series 2013-5, Class A2, 3.0%, 5/25/43 (144A) 14,527,917 7,175,802(c) Sequoia Mortgage Trust, Series 2013-6, Class A1, 2.5%, 5/25/43 7,047,148 10,850,720(c) Sequoia Mortgage Trust, Series 2013-6, Class A2, 3.0%, 5/25/43 10,854,935 8,069,271(c) Sequoia Mortgage Trust, Series 2013-7, Class A1, 2.5%, 6/25/43 7,714,229 9,948,156(c) Sequoia Mortgage Trust, Series 2013-7, Class A2, 3.0%, 6/25/43 9,926,891 9,974,092(c) Sequoia Mortgage Trust, Series 2013-8, Class A1, 3.0%, 6/25/43 9,990,505 16,171,048(c) Sequoia Mortgage Trust, Series 2013-10, Class A1, 3.5%, 8/25/43 (144A) 16,405,106 2,949,402(c) Sequoia Mortgage Trust, Series 2017-1, Class B2, 3.635%, 2/25/47 (144A) 2,971,590 2,176,718(c) Sequoia Mortgage Trust, Series 2017-CH2, Class A1, 4.0%, 12/25/47 (144A) 2,255,952 10,283,602(c) Sequoia Mortgage Trust, Series 2018-6, Class A22, 4.0%, 7/25/48 (144A) 10,462,357 8,017,714(c) Sequoia Mortgage Trust, Series 2018-8, Class A4, 4.0%, 11/25/48 (144A) 8,162,097 4,031,617(c) Sequoia Mortgage Trust, Series 2018-CH1, Class A1, 4.0%, 2/25/48 (144A) 4,170,077 4,344,853(c) Sequoia Mortgage Trust, Series 2018-CH3, Class A1, 4.5%, 8/25/48 (144A) 4,508,323 3,190,439(c) Sequoia Mortgage Trust, Series 2018-CH4, Class A10, 4.5%, 10/25/48 (144A) 3,277,006 4,621,462(b) STACR Trust, Series 2018-DNA3, Class M1, 3.154% (1 Month USD LIBOR + 75 bps), 9/25/48 (144A) 4,625,493 10,870,000(b) STACR Trust, Series 2018-DNA3, Class M2, 4.504% (1 Month USD LIBOR + 210 bps), 9/25/48 (144A) 10,870,039 11,220,000(b) STACR Trust, Series 2018-HRP2, Class B1, 6.604% (1 Month USD LIBOR + 420 bps), 2/25/47 (144A) 11,536,135 6,450,000(b) STACR Trust, Series 2018-HRP2, Class M3, 4.804% (1 Month USD LIBOR + 240 bps), 2/25/47 (144A) 6,582,976 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 35 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- (continued) 2,950,000(b) Starwood Waypoint Homes Trust, Series 2017-1, Class B, 3.564% (1 Month USD LIBOR + 117 bps), 1/17/35 (144A) $ 2,946,980 4,638,391 Toro Mortgage Funding Trust, Series 2017-RJ1, 4.0%, 4/25/74 4,639,841 7,540,000(c) Towd Point Mortgage Trust, Series 2015-6, Class M1, 3.75%, 4/25/55 (144A) 7,865,410 5,485,000(c) Towd Point Mortgage Trust, Series 2017-1, Class M1, 3.75%, 10/25/56 (144A) 5,670,174 12,015,000(c) Towd Point Mortgage Trust, Series 2017-2, Class A2, 3.25%, 4/25/57 (144A) 12,125,294 10,055,000(c) Towd Point Mortgage Trust, Series 2017-3, Class A2, 3.0%, 7/25/57 (144A) 9,954,334 5,315,616(c) Towd Point Mortgage Trust, Series 2017-5, Class XA, 3.5%, 2/25/57 (144A) 5,290,815 192,845 Vendee Mortgage Trust, Series 2008-1, Class GD, 5.25%, 1/15/32 199,363 326,575 Vendee Mortgage Trust, Series 2010-1, Class DA, 4.25%, 2/15/35 333,434 3,810,000 Wells Fargo Commercial Mortgage Trust, Series 2015-NXS3, Class A4, 3.617%, 9/15/57 4,039,180 8,200,000 Wells Fargo Commercial Mortgage Trust, Series 2016-C32, Class A3, 3.294%, 1/15/59 8,542,310 10,000,000 Wells Fargo Commercial Mortgage Trust, Series 2016-LC24, Class A3, 2.684%, 10/15/49 10,028,208 4,200,000(c) WFRBS Commercial Mortgage Trust, Series 2013-C12, Class D, 4.556%, 3/15/48 (144A) 4,036,582 6,200,000 WFRBS Commercial Mortgage Trust, Series 2013-C16, Class A4, 4.136%, 9/15/46 6,608,892 2,857,677(c) WinWater Mortgage Loan Trust, Series 2014-2, Class B4, 4.101%, 9/20/44 (144A) 2,944,002 ----------------------------------------------------------------------------------------------------------------------------------- TOTAL COLLATERALIZED MORTGAGE OBLIGATIONS (Cost $1,238,811,958) $1,260,022,981 ----------------------------------------------------------------------------------------------------------------------------------- CORPORATE BONDS -- 27.4% of Net Assets Aerospace & Defense -- 0.9% 9,785,000 Boeing Co., 2.7%, 5/1/22 $ 9,925,825 14,425,000 Boeing Co., 3.9%, 5/1/49 15,076,428 13,470,000 Rockwell Collins, Inc., 3.2%, 3/15/24 13,868,943 7,910,000 United Technologies Corp., 4.125%, 11/16/28 8,689,938 -------------- Total Aerospace & Defense $ 47,561,134 ----------------------------------------------------------------------------------------------------------------------------------- Agriculture -- 0.7% 7,795,000 Altria Group, Inc., 5.375%, 1/31/44 $ 8,359,920 12,540,000 Philip Morris International, Inc., 3.25%, 11/10/24 12,986,532 14,708,000 Reynolds American, Inc., 4.45%, 6/12/25 15,596,364 -------------- Total Agriculture $ 36,942,816 ----------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 36 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- Airlines -- 0.1% 6,743,822 Air Canada 2017-1 Class AA Pass Through Trust, 3.3%, 1/15/30 (144A) $ 6,795,925 -------------- Total Airlines $ 6,795,925 ----------------------------------------------------------------------------------------------------------------------------------- Auto Manufacturers -- 0.9% 6,885,000 Ford Motor Credit Co. LLC, 5.584%, 3/18/24 $ 7,390,206 2,300,000 General Motors Financial Co., Inc., 3.7%, 11/24/20 2,329,721 10,710,000 General Motors Financial Co., Inc., 4.0%, 1/15/25 10,870,972 12,300,000 Hyundai Capital Services, Inc., 3.0%, 8/29/22 (144A) 12,328,389 3,590,000 Nissan Motor Acceptance Corp., 2.15%, 7/13/20 (144A) 3,575,145 7,495,000 Nissan Motor Acceptance Corp., 3.15%, 3/15/21 (144A) 7,557,314 7,040,000 Volkswagen Group of America Finance LLC, 4.0%, 11/12/21 (144A) 7,266,235 -------------- Total Auto Manufacturers $ 51,317,982 ----------------------------------------------------------------------------------------------------------------------------------- Banks -- 4.5% 16,040,000(c) AIB Group Plc, 4.263% (3 Month USD LIBOR + 187 bps), 4/10/25 (144A) $ 16,516,515 1,150,000 Bank of America Corp., 4.2%, 8/26/24 1,222,451 10,345,000(b) Bank of New York Mellon Corp., 3.633% (3 Month USD LIBOR + 105 bps), 10/30/23 10,529,706 6,525,000(a)(c) Barclays Plc, 7.75% (5 Year USD Swap Rate + 484 bps) 6,688,125 5,205,000(a)(c) Barclays Plc, 8.0% (5 Year CMT Index + 567 bps) 5,458,744 13,875,000(a)(c) BNP Paribas SA, 6.625% (5 Year USD Swap Rate + 415 bps) (144A) 14,447,344 6,900,000 BPCE SA, 2.25%, 1/27/20 6,893,615 3,860,000 BPCE SA, 4.875%, 4/1/26 (144A) 4,152,189 21,955,000(b) Canadian Imperial Bank of Commerce, 2.891% (3 Month USD LIBOR + 32 bps), 2/2/21 21,988,147 3,435,000 Cooperatieve Rabobank UA, 3.875%, 2/8/22 3,574,884 7,175,000 Cooperatieve Rabobank UA, 3.95%, 11/9/22 7,442,711 11,725,000(a)(c) Credit Suisse Group AG, 7.125% (5 Year USD Swap Rate + 511 bps) 12,443,156 7,300,000 Credit Suisse Group Funding Guernsey, Ltd., 3.8%, 9/15/22 7,567,922 5,337,000 Danske Bank AS, 5.375%, 1/12/24 (144A) 5,768,592 4,700,000(a)(c) Danske Bank AS, 6.125% (7 Year USD Swap Rate + 390 bps) 4,556,086 3,888,000(c) DBS Group Holdings, Ltd., 4.52% (5 Year USD 1100 Run ICE Swap Rate + 159 bps), 12/11/28 (144A) 4,120,134 7,891,000(c) Goldman Sachs Group, Inc., 3.272% (3 Month USD LIBOR + 120 bps), 9/29/25 8,075,615 6,335,000(c) Goldman Sachs Group, Inc., 4.223% (3 Month USD LIBOR + 130 bps), 5/1/29 6,794,340 1,305,000 HSBC Bank Plc, 7.65%, 5/1/25 1,561,360 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 37 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- Banks -- (continued) 2,400,000(b) HSBC Holdings Plc, 3.52% (3 Month USD LIBOR + 100 bps), 5/18/24 $ 2,406,392 5,550,000(a)(c) Intesa Sanpaolo S.p.A., 7.7% (5 Year USD Swap Rate + 546 bps) (144A) 5,452,875 7,378,000 KeyCorp, 5.1%, 3/24/21 7,713,622 8,675,000 Lloyds Banking Group Plc, 4.65%, 3/24/26 9,057,459 5,450,000 Morgan Stanley, 4.1%, 5/22/23 5,737,020 4,500,000 Nordea Bank Abp, 4.25%, 9/21/22 (144A) 4,688,461 8,524,000 Nordea Bank Abp, 4.875%, 5/13/21 (144A) 8,845,834 10,505,000(a)(c) Royal Bank of Scotland Group Plc, 8.625% (5 Year USD Swap Rate + 760 bps) 11,321,764 9,051,000(a)(c) Societe Generale SA, 7.375% (5 Year USD Swap Rate + 624 bps) (144A) 9,515,316 12,575,000 SunTrust Bank, 2.45%, 8/1/22 12,612,742 2,250,000(c) Turkiye Garanti Bankasi AS, 6.125% (5 Year USD Swap Rate + 422 bps), 5/24/27 (144A) 1,900,710 4,900,000 UBS AG, 7.625%, 8/17/22 5,496,379 11,650,000(a)(c) UBS Group Funding Switzerland AG, 7.0% (5 Year USD Swap Rate + 434 bps) (144A) 12,376,028 4,497,000(a)(c) UBS Group Funding Switzerland AG, 7.125% (5 Year USD Swap Rate + 588 bps) 4,721,850 -------------- Total Banks $ 251,648,088 ----------------------------------------------------------------------------------------------------------------------------------- Beverages -- 0.5% 17,710,000 Anheuser-Busch InBev Worldwide, Inc., 5.55%, 1/23/49 $ 21,703,744 7,630,000 Bacardi, Ltd., 5.3%, 5/15/48 (144A) 8,030,467 -------------- Total Beverages $ 29,734,211 ----------------------------------------------------------------------------------------------------------------------------------- Biotechnology -- 0.4% 3,990,000 Baxalta, Inc., 3.6%, 6/23/22 $ 4,094,417 3,550,000 Biogen, Inc., 3.625%, 9/15/22 3,664,243 11,735,000 Biogen, Inc., 5.2%, 9/15/45 13,180,412 -------------- Total Biotechnology $ 20,939,072 ----------------------------------------------------------------------------------------------------------------------------------- Building Materials -- 0.5% 1,882,000 American Woodmark Corp., 4.875%, 3/15/26 (144A) $ 1,858,475 11,000,000 CRH America, Inc., 3.875%, 5/18/25 (144A) 11,505,673 7,680,000 Fortune Brands Home & Security, Inc., 3.0%, 6/15/20 7,705,324 3,250,000 Fortune Brands Home & Security, Inc., 4.0%, 9/21/23 3,420,869 4,385,000 Standard Industries, Inc., 5.5%, 2/15/23 (144A) 4,505,587 -------------- Total Building Materials $ 28,995,928 ----------------------------------------------------------------------------------------------------------------------------------- Chemicals -- 0.4% 1,567,000 CF Industries, Inc., 4.95%, 6/1/43 $ 1,402,465 6,830,000 CF Industries, Inc., 5.375%, 3/15/44 6,405,174 6,365,000 Chemours Co., 7.0%, 5/15/25 6,651,425 The accompanying notes are an integral part of these financial statements. 38 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- Chemicals -- (continued) 4,479,000 Dow Chemical Co., 4.8%, 5/15/49 (144A) $ 4,829,659 2,803,000 NOVA Chemicals Corp., 4.875%, 6/1/24 (144A) 2,901,105 -------------- Total Chemicals $ 22,189,828 ----------------------------------------------------------------------------------------------------------------------------------- Commercial Services -- 0.3% 3,950,000 ERAC USA Finance LLC, 3.3%, 12/1/26 (144A) $ 4,002,874 1,300,000 ERAC USA Finance LLC, 3.8%, 11/1/25 (144A) 1,376,535 2,400,000 Moody's Corp., 3.25%, 6/7/21 2,433,943 2,600,000 President & Fellows of Harvard College, 2.3%, 10/1/23 2,625,034 5,942,000 Verisk Analytics, Inc., 5.5%, 6/15/45 6,970,913 -------------- Total Commercial Services $ 17,409,299 ----------------------------------------------------------------------------------------------------------------------------------- Diversified Financial Services -- 1.0% 800,000(b) AIG Global Funding, 2.8% (3 Month USD LIBOR + 48 bps), 7/2/20 (144A) $ 802,628 3,075,000 Ally Financial, Inc., 3.875%, 5/21/24 3,148,031 2,980,000 Cantor Fitzgerald LP, 7.875%, 10/15/19 (144A) 3,018,350 1,465,000 Capital One Bank USA NA, 8.8%, 7/15/19 1,468,194 4,885,000 Capital One Financial Corp., 3.3%, 10/30/24 5,010,806 9,675,000 Capital One Financial Corp., 3.75%, 4/24/24 10,152,942 5,200,000 Capital One Financial Corp., 4.25%, 4/30/25 5,572,444 4,031,000 GE Capital International Funding Co. Unlimited Co., 2.342%, 11/15/20 4,011,863 2,350,000 GTP Acquisition Partners I LLC, 2.35%, 6/15/20 (144A) 2,342,282 6,200,000 TD Ameritrade Holding Corp., 3.3%, 4/1/27 6,396,940 11,625,000 USAA Capital Corp., 2.45%, 8/1/20 (144A) 11,659,202 4,550,000 Visa, Inc., 2.2%, 12/14/20 4,557,140 -------------- Total Diversified Financial Services $ 58,140,822 ----------------------------------------------------------------------------------------------------------------------------------- Electric -- 1.9% 2,159,000(c) AES Gener SA, 7.125% (5 Year USD Swap Rate + 464 bps), 3/26/79 (144A) $ 2,303,675 8,385,000 Consolidated Edison Co. of New York, Inc., 4.625%, 12/1/54 9,405,085 2,700,000 Dominion Energy, Inc., 2.75%, 1/15/22 2,720,062 4,027,000(d) Dominion Energy, Inc., 3.071%, 8/15/24 4,059,492 925,000 Edison International, 2.4%, 9/15/22 881,066 2,150,000(a)(c) Electricite de France SA, 5.25% (10 Year USD Swap Rate + 371 bps) (144A) 2,193,000 4,170,000(c) Enel S.p.A., 8.75% (5 Year USD Swap Rate + 588 bps), 9/24/73 (144A) 4,805,925 6,365,000 Exelon Corp., 2.85%, 6/15/20 6,385,161 4,655,000 Iberdrola International BV, 6.75%, 7/15/36 6,138,522 2,725,000 Indiana Michigan Power Co., 4.55%, 3/15/46 3,063,977 610,000 Israel Electric Corp., Ltd., 9.375%, 1/28/20 (144A) 633,168 460,957 Kiowa Power Partners LLC, 5.737%, 3/30/21 (144A) 468,876 10,270,000 NextEra Energy Capital Holdings, Inc., 3.55%, 5/1/27 10,721,538 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 39 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- Electric -- (continued) 2,327,000 NRG Energy, Inc., 5.75%, 1/15/28 $ 2,495,707 195,567 OrCal Geothermal, Inc., 6.21%, 12/30/20 (144A) 196,304 11,910,000 PPL Capital Funding, Inc, 3.1%, 5/15/26 11,821,988 1,435,714 San Diego Gas & Electric Co., 1.914%, 2/1/22 1,405,605 9,720,000 Sempra Energy, 3.4%, 2/1/28 9,703,787 2,839,286 Southern California Edison Co., 1.845%, 2/1/22 2,789,430 8,605,000 Southern California Edison Co., 4.875%, 3/1/49 9,675,412 11,475,000 Southwestern Electric Power Co., 3.9%, 4/1/45 11,438,524 -------------- Total Electric $ 103,306,304 ----------------------------------------------------------------------------------------------------------------------------------- Electronics -- 0.6% 8,412,000 Amphenol Corp., 3.125%, 9/15/21 $ 8,535,269 3,065,000 Amphenol Corp., 3.2%, 4/1/24 3,140,957 7,391,000 Amphenol Corp., 4.35%, 6/1/29 7,998,904 5,780,000 Flex, Ltd., 4.75%, 6/15/25 5,992,198 9,510,000 Flex, Ltd., 4.875%, 6/15/29 9,690,334 -------------- Total Electronics $ 35,357,662 ----------------------------------------------------------------------------------------------------------------------------------- Energy-Alternate Sources -- 0.0%+ 416,249 Alta Wind Holdings LLC, 7.0%, 6/30/35 (144A) $ 466,785 -------------- Total Energy-Alternate Sources $ 466,785 ----------------------------------------------------------------------------------------------------------------------------------- Environmental Control -- 0.0%+ 2,678,000 Republic Services, Inc., 2.9%, 7/1/26 $ 2,692,267 -------------- Total Environmental Control $ 2,692,267 ----------------------------------------------------------------------------------------------------------------------------------- Food -- 0.6% 12,410,000 Conagra Brands, Inc., 4.3%, 5/1/24 $ 13,164,931 4,119,000 Mondelez International Holdings Netherlands BV, 2.0%, 10/28/21 (144A) 4,081,116 2,500,000 Smithfield Foods, Inc., 2.65%, 10/3/21 (144A) 2,464,279 7,555,000 Smithfield Foods, Inc., 2.7%, 1/31/20 (144A) 7,539,300 3,430,000(b) Tyson Foods, Inc., 2.972% (3 Month USD LIBOR + 45 bps), 8/21/20 3,429,211 3,075,000(b) Tyson Foods, Inc., 3.07% (3 Month USD LIBOR + 55 bps), 6/2/20 3,078,085 -------------- Total Food $ 33,756,922 ----------------------------------------------------------------------------------------------------------------------------------- Forest Products & Paper -- 0.1% 1,275,000 International Paper Co., 4.8%, 6/15/44 $ 1,308,728 2,575,000 International Paper Co., 6.0%, 11/15/41 3,018,346 -------------- Total Forest Products & Paper $ 4,327,074 ----------------------------------------------------------------------------------------------------------------------------------- Gas -- 0.1% 3,060,000 Boston Gas Co., 3.15%, 8/1/27 (144A) $ 3,108,987 1,931,530 Nakilat, Inc., 6.267%, 12/31/33 (144A) 2,216,817 -------------- Total Gas $ 5,325,804 ----------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 40 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- Healthcare-Products -- 0.4% 4,155,000 Abbott Laboratories, 3.75%, 11/30/26 $ 4,492,371 3,522,000(b) Becton Dickinson & Co., 3.194% (3 Month USD LIBOR + 88 bps), 12/29/20 3,522,521 11,200,000 Thermo Fisher Scientific, Inc., 3.0%, 4/15/23 11,484,985 -------------- Total Healthcare-Products $ 19,499,877 ----------------------------------------------------------------------------------------------------------------------------------- Healthcare-Services -- 0.3% 6,585,000 Anthem, Inc., 3.35%, 12/1/24 $ 6,812,269 4,506,000 Anthem, Inc., 3.65%, 12/1/27 4,684,139 1,140,000 Anthem, Inc., 4.101%, 3/1/28 1,219,547 3,630,000 Humana, Inc., 3.95%, 3/15/27 3,784,650 2,400,000 NYU Hospitals Center, 4.428%, 7/1/42 2,705,146 -------------- Total Healthcare-Services $ 19,205,751 ----------------------------------------------------------------------------------------------------------------------------------- Home Builders -- 0.1% 4,320,000 Meritage Homes Corp., 6.0%, 6/1/25 $ 4,644,000 -------------- Total Home Builders $ 4,644,000 ----------------------------------------------------------------------------------------------------------------------------------- Household Products & Wares -- 0.1% 8,203,000 Church & Dwight Co., Inc., 2.45%, 8/1/22 $ 8,219,870 -------------- Total Household Products & Wares $ 8,219,870 ----------------------------------------------------------------------------------------------------------------------------------- Insurance -- 1.8% 2,335,000 AXA SA, 8.6%, 12/15/30 $ 3,321,537 1,480,000 CNO Financial Group, Inc., 5.25%, 5/30/29 1,602,100 1,850,000 Delphi Financial Group, Inc., 7.875%, 1/31/20 1,902,847 2,960,000(c) Farmers Exchange Capital III, 5.454% (3 Month USD LIBOR + 345 bps), 10/15/54 (144A) 3,196,800 9,610,000(c) Farmers Insurance Exchange, 4.747% (3 Month USD LIBOR + 323 bps), 11/1/57 (144A) 9,239,150 5,045,000 Great-West Lifeco Finance 2018 LP, 4.581%, 5/17/48 (144A) 5,683,384 15,248,000 Liberty Mutual Insurance Co., 7.697%, 10/15/97 (144A) 22,036,849 13,250,000 MassMutual Global Funding II, 2.75%, 6/22/24 (144A) 13,504,658 6,200,000 MassMutual Global Funding II, 2.95%, 1/11/25 (144A) 6,335,293 7,265,000 New York Life Global Funding, 2.875%, 4/10/24 (144A) 7,427,030 7,300,000 New York Life Insurance Co., 4.45%, 5/15/69 (144A) 8,052,008 10,395,000 Protective Life Corp., 4.3%, 9/30/28 (144A) 10,949,423 4,250,000 Protective Life Corp., 7.375%, 10/15/19 4,306,690 1,090,000 Prudential Financial, Inc., 4.5%, 11/16/21 1,145,964 690,000 Teachers Insurance & Annuity Association of America, 6.85%, 12/16/39 (144A) 977,989 1,465,000 Torchmark Corp., 4.55%, 9/15/28 1,600,530 -------------- Total Insurance $ 101,282,252 ----------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 41 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- Internet -- 0.5% 7,170,000 Booking Holdings, Inc., 3.55%, 3/15/28 $ 7,473,147 1,925,000 Booking Holdings, Inc., 3.6%, 6/1/26 2,029,853 7,875,000 Booking Holdings, Inc., 3.65%, 3/15/25 8,323,196 4,125,000 Expedia Group, Inc., 3.8%, 2/15/28 4,198,794 5,900,000 Expedia Group, Inc., 4.5%, 8/15/24 6,276,894 950,000 Expedia Group, Inc., 5.0%, 2/15/26 1,034,774 -------------- Total Internet $ 29,336,658 ----------------------------------------------------------------------------------------------------------------------------------- Iron & Steel -- 0.1% 3,550,000 Commercial Metals Co., 4.875%, 5/15/23 $ 3,576,625 1,525,000 Commercial Metals Co., 5.75%, 4/15/26 1,522,331 -------------- Total Iron & Steel $ 5,098,956 ----------------------------------------------------------------------------------------------------------------------------------- Media -- 0.2% 7,745,000 Comcast Corp., 4.15%, 10/15/28 $ 8,536,155 3,450,000 Videotron, Ltd., 5.375%, 6/15/24 (144A) 3,691,500 -------------- Total Media $ 12,227,655 ----------------------------------------------------------------------------------------------------------------------------------- Mining -- 0.3% 1,325,000 Anglo American Capital Plc, 4.0%, 9/11/27 (144A) $ 1,330,114 1,993,000 Anglo American Capital Plc, 4.5%, 3/15/28 (144A) 2,066,749 2,750,000 Anglo American Capital Plc, 4.75%, 4/10/27 (144A) 2,912,789 6,600,000 Anglo American Capital Plc, 4.875%, 5/14/25 (144A) 7,111,800 3,605,000 Freeport-McMoRan, Inc., 5.45%, 3/15/43 3,298,575 -------------- Total Mining $ 16,720,027 ----------------------------------------------------------------------------------------------------------------------------------- Miscellaneous Manufacturers -- 0.1% 3,485,000 Amsted Industries, Inc., 5.375%, 9/15/24 (144A) $ 3,567,769 1,392,000 General Electric Co., 5.3%, 2/11/21 1,442,196 -------------- Total Miscellaneous Manufacturers $ 5,009,965 ----------------------------------------------------------------------------------------------------------------------------------- Multi-National -- 0.3% 11,165,000 Africa Finance Corp., 4.375%, 4/17/26 (144A) $ 11,522,727 2,230,000 Banque Ouest Africaine de Developpement, 5.0%, 7/27/27 (144A) 2,296,900 4,450,000 Banque Ouest Africaine de Developpement, 5.5%, 5/6/21 (144A) 4,633,563 -------------- Total Multi-National $ 18,453,190 ----------------------------------------------------------------------------------------------------------------------------------- Oil & Gas -- 1.5% 1,480,000 Apache Corp., 4.25%, 1/15/30 $ 1,526,154 13,130,000 Apache Corp., 4.375%, 10/15/28 13,721,056 6,360,000 BP Capital Markets Plc, 3.062%, 3/17/22 6,506,638 5,275,000 CNOOC Nexen Finance 2014 ULC, 4.25%, 4/30/24 5,598,083 14,000,000 EQT Corp., 3.9%, 10/1/27 13,292,051 215,000 Motiva Enterprises LLC, 5.75%, 1/15/20 (144A) 218,069 1,770,000 Newfield Exploration Co., 5.375%, 1/1/26 1,939,514 The accompanying notes are an integral part of these financial statements. 42 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- Oil & Gas -- (continued) 1,400,000 Newfield Exploration Co., 5.625%, 7/1/24 $ 1,547,980 12,720,000 Noble Energy, Inc., 5.25%, 11/15/43 13,706,072 4,750,000 Sinopec Group Overseas Development 2014, Ltd., 4.375%, 4/10/24 (144A) 5,078,840 10,050,000 Sinopec Group Overseas Development 2015, Ltd., 2.5%, 4/28/20 (144A) 10,049,737 8,468,000 Valero Energy Corp., 6.625%, 6/15/37 10,728,254 -------------- Total Oil & Gas $ 83,912,448 ----------------------------------------------------------------------------------------------------------------------------------- Oil & Gas Services -- 0.1% 2,250,000 Halliburton Co., 7.6%, 8/15/96 (144A) $ 3,043,866 -------------- Total Oil & Gas Services $ 3,043,866 ----------------------------------------------------------------------------------------------------------------------------------- Pharmaceuticals -- 1.6% 12,975,000 AbbVie, Inc., 4.875%, 11/14/48 $ 13,656,203 4,900,000 Bayer US Finance II LLC, 4.25%, 12/15/25 (144A) 5,184,582 14,240,000 Bristol-Myers Squibb Co., 2.9%, 7/26/24 (144A) 14,573,504 12,950,000 Cardinal Health, Inc., 3.079%, 6/15/24 13,037,317 6,225,000 Cigna Corp., 4.375%, 10/15/28 (144A) 6,715,937 461,661 CVS Pass-Through Trust, 5.298%, 1/11/27 (144A) 491,100 2,511,654 CVS Pass-Through Trust, 5.773%, 1/10/33 (144A) 2,801,847 1,738,440 CVS Pass-Through Trust, 5.926%, 1/10/34 (144A) 1,975,729 3,156,465 CVS Pass-Through Trust, 6.036%, 12/10/28 3,534,421 4,623,226 CVS Pass-Through Trust, 8.353%, 7/10/31 (144A) 5,810,941 1,391,000 Perrigo Finance Unlimited Co., 3.5%, 3/15/21 1,387,514 4,570,000 Perrigo Finance Unlimited Co., 3.9%, 12/15/24 4,536,864 3,084,000 Shire Acquisitions Investments Ireland, DAC, 3.2%, 9/23/26 3,109,866 7,150,000 Takeda Pharmaceutical Co., Ltd., 4.0%, 11/26/21 (144A) 7,398,104 6,382,000 Teva Pharmaceutical Finance Netherlands III BV, 3.15%, 10/1/26 4,946,050 -------------- Total Pharmaceuticals $ 89,159,979 ----------------------------------------------------------------------------------------------------------------------------------- Pipelines -- 3.4% 9,940,000 Andeavor Logistics LP/Tesoro Logistics Finance Corp., 4.25%, 12/1/27 $ 10,499,740 5,595,000 Cheniere Energy Partners LP, 5.25%, 10/1/25 5,783,831 750,000 DCP Midstream Operating LP, 5.35%, 3/15/20 (144A) 760,313 3,450,000 DCP Midstream Operating LP, 5.375%, 7/15/25 3,635,437 4,025,000 DCP Midstream Operating LP, 5.6%, 4/1/44 3,783,500 3,629,000 Enable Midstream Partners LP, 4.4%, 3/15/27 3,657,564 14,441,000 Enable Midstream Partners LP, 4.95%, 5/15/28 15,138,142 10,550,000 Enbridge, Inc., 3.7%, 7/15/27 10,896,218 1,149,000 Energy Transfer Operating LP, 5.5%, 6/1/27 1,284,384 5,130,000 Energy Transfer Operating LP, 6.0%, 6/15/48 5,855,503 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 43 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- Pipelines -- (continued) 4,207,000 Energy Transfer Operating LP, 6.5%, 2/1/42 $ 4,973,266 510,000 EnLink Midstream LLC, 5.375%, 6/1/29 522,750 8,316,000 EnLink Midstream Partners LP, 5.45%, 6/1/47 7,110,180 1,590,000 EnLink Midstream Partners LP, 5.6%, 4/1/44 1,458,825 3,573,000 Enterprise Products Operating LLC, 2.8%, 2/15/21 3,597,778 10,830,000 Kinder Morgan, Inc., 5.05%, 2/15/46 11,801,481 4,724,000 Midwest Connector Capital Co. LLC, 4.625%, 4/1/29 (144A) 5,062,950 3,875,000 MPLX LP, 4.875%, 12/1/24 4,215,355 3,045,000 MPLX LP, 4.875%, 6/1/25 3,309,373 6,920,000 MPLX LP, 5.5%, 2/15/49 7,859,543 12,125,000 Phillips 66 Partners LP, 3.75%, 3/1/28 12,362,606 10,675,000 Sabine Pass Liquefaction LLC, 5.0%, 3/15/27 11,704,658 6,730,000 Sunoco Logistics Partners Operations LP, 5.35%, 5/15/45 6,998,988 10,876,000 Sunoco Logistics Partners Operations LP, 5.4%, 10/1/47 11,551,449 786,000 Sunoco Logistics Partners Operations LP, 6.1%, 2/15/42 870,357 2,713,000 Targa Resources Partners LP/Targa Resources Partners Finance Corp., 5.0%, 1/15/28 2,719,782 8,870,000 Texas Eastern Transmission LP, 3.5%, 1/15/28 (144A) 9,013,719 17,007,000 Williams Cos., Inc., 5.75%, 6/24/44 19,848,583 2,475,000 Williams Cos., Inc., 7.75%, 6/15/31 3,263,170 -------------- Total Pipelines $ 189,539,445 ----------------------------------------------------------------------------------------------------------------------------------- Real Estate -- 0.2% 10,250,000(a)(c) AT Securities BV, 5.25% (5 Year USD Swap Rate + 355 bps) $ 10,029,625 -------------- Total Real Estate $ 10,029,625 ----------------------------------------------------------------------------------------------------------------------------------- REITs -- 1.5% 2,681,000 Alexandria Real Estate Equities, Inc., 2.75%, 1/15/20 $ 2,682,117 2,768,000 Alexandria Real Estate Equities, Inc., 3.9%, 6/15/23 2,903,367 1,350,000 Alexandria Real Estate Equities, Inc., 3.95%, 1/15/27 1,416,229 3,415,000 Alexandria Real Estate Equities, Inc., 4.6%, 4/1/22 3,600,219 3,450,000 Duke Realty LP, 3.625%, 4/15/23 3,568,749 8,560,000 Duke Realty LP, 3.75%, 12/1/24 8,957,392 9,500,000 Essex Portfolio LP, 3.5%, 4/1/25 9,812,504 1,480,000 Essex Portfolio LP, 3.625%, 5/1/27 1,537,165 6,805,000 Healthcare Trust of America Holdings LP, 3.5%, 8/1/26 6,875,063 4,675,000 Healthcare Trust of America Holdings LP, 3.75%, 7/1/27 4,818,365 2,032,000 Highwoods Realty LP, 3.2%, 6/15/21 2,046,369 3,390,000 Highwoods Realty LP, 3.625%, 1/15/23 3,463,460 7,105,000 Highwoods Realty LP, 4.125%, 3/15/28 7,400,895 1,800,000 SBA Tower Trust, 2.877%, 7/9/21 (144A) 1,803,263 6,975,000 SBA Tower Trust, 3.869%, 10/8/24 (144A) 7,202,287 The accompanying notes are an integral part of these financial statements. 44 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- REITs -- (continued) 1,520,000 UDR, Inc., 2.95%, 9/1/26 $ 1,511,179 6,077,000 UDR, Inc., 4.0%, 10/1/25 6,460,009 5,300,000 UDR, Inc., 4.4%, 1/26/29 5,790,914 -------------- Total REITs $ 81,849,546 ----------------------------------------------------------------------------------------------------------------------------------- Retail -- 0.2% 7,040,000 Alimentation Couche-Tard, Inc., 3.55%, 7/26/27 (144A) $ 7,182,410 3,994,000 AutoZone, Inc., 2.5%, 4/15/21 4,003,223 -------------- Total Retail $ 11,185,633 ----------------------------------------------------------------------------------------------------------------------------------- Semiconductors -- 0.1% 4,470,000 Broadcom, Inc., 3.625%, 10/15/24 (144A) $ 4,492,220 3,485,000 Broadcom, Inc., 4.25%, 4/15/26 (144A) 3,536,841 -------------- Total Semiconductors $ 8,029,061 ----------------------------------------------------------------------------------------------------------------------------------- Software -- 0.2% 5,501,000 Fiserv, Inc., 3.8%, 10/1/23 $ 5,786,449 5,650,000 salesforce.com, Inc., 3.7%, 4/11/28 6,091,469 -------------- Total Software $ 11,877,918 ----------------------------------------------------------------------------------------------------------------------------------- Telecommunications -- 0.2% 5,227,000 CommScope Technologies LLC, 5.0%, 3/15/27 (144A) $ 4,547,490 3,989,000 Level 3 Financing, Inc., 5.375%, 1/15/24 4,078,753 -------------- Total Telecommunications $ 8,626,243 ----------------------------------------------------------------------------------------------------------------------------------- Transportation -- 0.3% 13,715,000 Union Pacific Corp., 3.375%, 2/1/35 $ 13,650,188 -------------- Total Transportation $ 13,650,188 ----------------------------------------------------------------------------------------------------------------------------------- Trucking & Leasing -- 0.3% 6,623,000 Penske Truck Leasing Co. LP/PTL Finance Corp., 2.7%, 3/14/23 (144A) $ 6,620,271 4,825,000 Penske Truck Leasing Co. LP/PTL Finance Corp., 3.375%, 2/1/22 (144A) 4,918,793 4,615,000 Penske Truck Leasing Co. LP/PTL Finance Corp., 4.2%, 4/1/27 (144A) 4,797,107 -------------- Total Trucking & Leasing $ 16,336,171 ----------------------------------------------------------------------------------------------------------------------------------- Water -- 0.1% 3,340,000 Aqua America, Inc., 3.566%, 5/1/29 $ 3,470,901 -------------- Total Water $ 3,470,901 ----------------------------------------------------------------------------------------------------------------------------------- TOTAL CORPORATE BONDS (Cost $1,467,257,093) $1,527,317,148 ----------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 45 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- FOREIGN GOVERNMENT BOND -- 0.2% of Net Assets Mexico -- 0.2% 13,425,000 Mexico Government International Bond, 4.6%, 2/10/48 $ 13,827,884 -------------- Total Mexico $ 13,827,884 ----------------------------------------------------------------------------------------------------------------------------------- TOTAL FOREIGN GOVERNMENT BOND (Cost $12,361,309) $ 13,827,884 ----------------------------------------------------------------------------------------------------------------------------------- INSURANCE-LINKED SECURITIES -- 3.1% of Net Assets(f) Catastrophe Linked Bonds -- 1.0% Earthquakes -- California -- 0.1% 2,700,000(b) Ursa Re, 5.587% (3 Month U.S. Treasury Bill + 350 bps), 5/27/20 (144A) $ 2,672,730 3,000,000(b) Ursa Re, 6.087% (3 Month U.S. Treasury Bill + 400 bps), 12/10/19 (144A) 2,960,700 800,000(b) Ursa Re, 8.087% (3 Month U.S. Treasury Bill + 600 bps), 5/27/20 (144A) 791,760 -------------- $ 6,425,190 ----------------------------------------------------------------------------------------------------------------------------------- Earthquakes -- Chile -- 0.0%+ 1,500,000(b) International Bank for Reconstruction & Development, 4.818% (3 Month USD LIBOR + 250 bps), 2/15/21 (144A) $ 1,486,200 ----------------------------------------------------------------------------------------------------------------------------------- Earthquakes -- Colombia -- 0.0%+ 1,250,000(b) International Bank for Reconstruction & Development, 5.318% (3 Month USD LIBOR + 300 bps), 2/15/21 (144A) $ 1,236,125 ----------------------------------------------------------------------------------------------------------------------------------- Earthquakes -- Mexico -- 0.0%+ 1,050,000(b) International Bank for Reconstruction & Development, 4.818% (3 Month USD LIBOR + 250 bps), 2/14/20 (144A) $ 1,040,760 ----------------------------------------------------------------------------------------------------------------------------------- Earthquakes -- U.S. -- 0.1% 1,150,000(b) Acorn Re, 5.151% (3 Month USD LIBOR + 275 bps), 11/10/21 (144A) $ 1,136,200 700,000(b) Kilimanjaro Re, 5.837% (3 Month U.S. Treasury Bill + 375 bps), 11/25/19 (144A) 694,400 -------------- $ 1,830,600 ----------------------------------------------------------------------------------------------------------------------------------- Health -- U.S. -- 0.1% 2,900,000(b) Vitality Re VII, 4.237% (3 Month U.S. Treasury Bill + 215 bps), 1/7/20 (144A) $ 2,906,960 1,000,000(b) Vitality Re VII, 4.737% (3 Month U.S. Treasury Bill + 265 bps), 1/7/20 (144A) 1,005,600 -------------- $ 3,912,560 ----------------------------------------------------------------------------------------------------------------------------------- Flood -- U.S. -- 0.0%+ 250,000(b) FloodSmart Re, 13.337% (3 Month U.S. Treasury Bill + 1,125 bps), 3/7/22 (144A) $ 249,750 ----------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 46 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- Multiperil -- U.S. -- 0.4% 2,000,000(b) Bowline Re, 6.587% (3 Month U.S. Treasury Bill + 450 bps), 5/23/22 (144A) $ 1,936,000 1,350,000(b) Caelus Re IV, 7.337% (3 Month U.S. Treasury Bill + 525 bps), 3/6/20 (144A) 1,329,750 750,000(b) Caelus Re V, 5.217% (3 Month U.S. Treasury Bill + 313 bps), 6/5/20 (144A) 674,925 1,000,000(b) Caelus Re V, 6.847% (1 Month U.S. Treasury Bill + 476 bps), 6/5/20 (144A) 250,000 2,000,000(b) Kilimanjaro Re, 7.338% (3 Month USD LIBOR + 494 bps), 5/6/22 (144A) 1,930,200 3,000,000(b) Kilimanjaro Re, 8.837% (3 Month U.S. Treasury Bill + 675 bps), 12/6/19 (144A) 2,964,300 1,500,000(b) Kilimanjaro Re, 11.337% (3 Month U.S. Treasury Bill + 925 bps), 12/6/19 (144A) 1,465,500 2,600,000(b) Kilimanjaro II Re, 7.633% (6 Month USD LIBOR + 630 bps), 4/20/21 (144A) 2,568,800 3,500,000(b) Kilimanjaro II Re, 9.823% (6 Month USD LIBOR + 791 bps), 4/20/21 (144A) 3,445,050 1,250,000+(b) Panthera Re, 5.587% (3 Month U.S. Treasury Bill + 350 bps), 3/9/20 (144A) 1,253,375 2,500,000(b) Residential Reinsurance 2016, 6.057% (3 Month U.S. Treasury Bill + 397 bps), 12/6/20 (144A) 2,418,250 1,600,000(b) Sanders Re, 5.271% (6 Month USD LIBOR + 307 bps), 12/6/21 (144A) 1,556,640 1,000,000(b) Skyline Re, 4.587% (3 Month U.S. Treasury Bill + 250 bps), 1/6/20 (144A) 1,000,000 -------------- $ 22,792,790 ----------------------------------------------------------------------------------------------------------------------------------- Multiperil -- U.S. Regional -- 0.1% 2,500,000(b) Long Point Re III, 2.75% (ZERO + 275 bps), 6/1/22 (144A) $ 2,463,750 ----------------------------------------------------------------------------------------------------------------------------------- Multiperil -- Worldwide -- 0.2% 1,300,000(b) Galilei Re, 7.306% (6 Month USD LIBOR + 479 bps), 1/8/20 (144A) $ 1,288,430 1,500,000(b) Galilei Re, 7.326% (6 Month USD LIBOR + 479 bps), 1/8/21 (144A) 1,489,350 1,300,000(b) Galilei Re, 8.116% (6 Month USD LIBOR + 560 bps), 1/8/20 (144A) 1,285,700 1,200,000(b) Galilei Re, 8.136% (6 Month USD LIBOR + 560 bps), 1/8/21 (144A) 1,179,960 1,400,000(b) Galilei Re, 9.296% (6 Month USD LIBOR + 678 bps), 1/8/20 (144A) 1,386,000 1,500,000(b) Galilei Re, 9.316% (6 Month USD LIBOR + 678 bps), 1/8/21 (144A) 1,485,750 -------------- $ 8,115,190 ----------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 47 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- Pandemic -- Worldwide -- 0.0%+ 1,700,000(b) International Bank for Reconstruction & Development, 9.365% (6 Month USD LIBOR + 690 bps), 7/15/20 (144A) $ 1,705,100 ----------------------------------------------------------------------------------------------------------------------------------- Windstorm -- Florida -- 0.0%+ 1,400,000(b) Casablanca Re, 6.127% (6 Month USD LIBOR + 402 bps), 6/4/20 (144A) $ 1,403,640 ----------------------------------------------------------------------------------------------------------------------------------- Windstorm -- Japan -- 0.0%+ 500,000(b) Aozora Re, 4.343% (6 Month USD LIBOR + 229 bps), 4/7/20 (144A) $ 493,000 ----------------------------------------------------------------------------------------------------------------------------------- Windstorm -- Texas -- 0.0%+ 1,700,000(b) Alamo Re, 5.897% (3 Month U.S. Treasury Bill + 381 bps), 6/8/20 (144A) $ 1,684,870 ----------------------------------------------------------------------------------------------------------------------------------- Windstorm -- U.S. Multistate -- 0.0%+ 1,000,000(b) Citrus Re, 2.587% (1 Month U.S. Treasury Bill + 50 bps), 4/9/20 (144A) $ 250,000 -------------- Total Catastrophe Linked Bonds $ 55,089,525 ----------------------------------------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------------------------------------- Face Amount USD ($) ----------------------------------------------------------------------------------------------------------------------------------- Collateralized Reinsurance -- 0.4% Earthquakes -- California -- 0.0%+ 1,600,000+(g)(h) Resilience Re, 10/8/19 $ 1,747,040 ----------------------------------------------------------------------------------------------------------------------------------- Multiperil -- Massachusetts -- 0.1% 5,000,000+(g)(h) Denning Re 2018, 7/15/19 $ 5,041,996 ----------------------------------------------------------------------------------------------------------------------------------- Multiperil -- U.S. -- 0.1% 600,000+(g)(h) Dingle Re 2019, 2/1/20 $ 558,055 2,800,000+(g)(h) Kingsbarns Re 2017, 5/19/20 2,828 2,000,000+(g)(h) Port Royal Re 2019, 5/31/20 1,951,580 1,600,000+(g)(h) Riviera Re 2019, 5/31/20 1,519,977 -------------- $ 4,032,440 ----------------------------------------------------------------------------------------------------------------------------------- Multiperil -- U.S. Regional -- 0.1% 2,500,000+(g)(h) Ailsa Re 2019, 6/30/20 $ 2,510,000 1,000,000+(g)(h) EC0012 Re, 9/15/19 999,000 2,500,000+(g)(h) Ocean View Re 2019, 6/30/20 2,368,851 -------------- $ 5,877,851 ----------------------------------------------------------------------------------------------------------------------------------- Multiperil -- Worldwide -- 0.1% 4,918,415+(h) Kilarney Re 2018, 4/15/20 $ 2,482,816 28,000+(h) Limestone Re 2016-1, 8/31/21 68,631 82,000+(h) Limestone Re 2016-1, 8/31/21 200,990 2,000,000+(h) Resilience Re, 7/26/19 16,000 3,600,000+(h) Resilience Re, 4/6/20 360 The accompanying notes are an integral part of these financial statements. 48 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Face Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- Multiperil -- Worldwide -- (continued) 567,400+(h) Seminole Re 2018, 1/15/20 $ 234,052 142,857+(g)(h) Seminole Re 2019, 1/31/20 124,342 553,333+(h) Walton Health Re 2018, 6/15/20 276,667 -------------- $ 3,403,858 ----------------------------------------------------------------------------------------------------------------------------------- Windstorm -- Florida -- 0.0%+ 1,500,000+(h) Formby Re 2018, 8/31/19 $ 1,543,300 511,212+(g)(h) Formby Re 2018-2, 9/30/19 4,192 -------------- $ 1,547,492 ----------------------------------------------------------------------------------------------------------------------------------- Windstorm -- North Carolina -- 0.0%+ 1,500,000+(g)(h) Lahinch Re 2019, 5/31/20 $ 1,467,000 ----------------------------------------------------------------------------------------------------------------------------------- Windstorm -- U.S. Regional -- 0.0%+ 1,000,000+(g)(h) Oakmont Re 2017, 4/15/20 $ 29,400 2,500,000+(g)(h) Oakmont Re 2019, 4/30/20 2,347,801 250,000+(g)(h) Resilience Re, 6/15/20 121,250 -------------- $ 2,498,451 -------------- Total Collateralized Reinsurance $ 25,616,128 ----------------------------------------------------------------------------------------------------------------------------------- Industry Loss Warranties -- 0.1% Multiperil -- U.S. -- 0.1% 4,257,500+(h) Cypress Re 2018, 7/15/19 $ 310,797 2,300,000+(g)(h) Cypress Re 2019, 1/31/20 2,173,575 -------------- Total Industry Loss Warranties $ 2,484,372 ----------------------------------------------------------------------------------------------------------------------------------- Reinsurance Sidecars -- 1.6% Multiperil -- U.S. -- 0.2% 3,000,000+(g)(h) Carnoustie Re 2015, 7/31/20 $ 9,600 3,600,000+(g)(h) Carnoustie Re 2016, 11/30/20 97,200 4,500,000+(g)(h) Carnoustie Re 2017, 11/30/21 1,143,900 2,000,000+(g)(h) Carnoustie Re 2018, 12/31/21 199,600 1,139,928+(g)(h) Carnoustie Re 2019, 12/31/22 1,160,511 1,300,000+(g)(h) Castle Stuart Re 2018, 12/1/21 1,096,420 2,000,000+(g)(i) Harambee Re 2018, 12/31/21 371,674 5,000,000+(g)(i) Harambee Re 2019, 12/31/22 5,095,000 1,000,000+(g)(h) Prestwick Re 2015-1, 7/31/20 17,000 1,200,007+(g)(h) Sector Re V, Series 7, Class G, 3/1/22 (144A) 860,322 -------------- $ 10,051,227 ----------------------------------------------------------------------------------------------------------------------------------- Multiperil -- Worldwide -- 1.4% 550,000+(g)(h) Alturas Re 2019-1, 3/10/23 $ 575,025 2,800,000+(g)(h) Alturas Re 2019-2, 3/10/22 2,847,880 250,000+(g)(h) Alturas Re 2019-3, 9/12/23 250,000 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 49 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Face Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- Multiperil -- Worldwide -- (continued) 900,000+(g)(h) Arlington Re 2015, 2/1/20 $ 43,740 2,000,000+(g)(h) Bantry Re 2016, 3/30/20 161,200 1,500,000+(g)(h) Bantry Re 2017, 3/31/20 475,650 2,000,000+(g)(h) Bantry Re 2018, 12/31/21 122,800 5,000,000+(g)(h) Bantry Re 2019, 12/31/22 5,114,411 2,000,000+(g)(h) Berwick Re 2017-1, 2/1/20 66,200 10,192,268+(h) Berwick Re 2018-1, 12/31/21 1,682,743 7,846,828+(g)(h) Berwick Re 2019-1, 12/31/22 8,102,109 1,250,000+(g)(i) Blue Lotus Re 2018, 12/31/21 1,339,500 125,000+(g)(h) Eden Re II, 3/22/22 (144A) 297,038 185,850+(g)(h) Eden Re II, 3/22/22 (144A) 394,355 600,000+(g)(h) Eden Re II, 3/22/23 (144A) 636,420 5,906,150+(g)(h) Eden Re II, 3/22/23 (144A) 6,261,110 3,500,000+(g)(h) Gleneagles Re 2016, 11/30/20 109,340 1,000,000+(g)(h) Gleneagles Re 2018, 12/31/21 118,300 886,832+(g)(h) Gleneagles Re 2019, 12/31/22 914,797 2,118,314+(h) Gullane Re 2018, 12/31/21 1,998,841 2,500,000+(g)(h) Limestone Re 2018, 3/1/22 2,688,750 500,000+(g)(h) Limestone Re 2019, 9/9/22 516,100 500,000+(g)(i) Lion Rock Re 2019, 1/31/20 517,950 3,000,000+(g)(i) Lorenz Re 2017, 3/31/20 51,300 5,000,000+(g)(i) Lorenz Re 2018, 7/1/21 3,699,000 420,872+(g)(i) Lorenz Re 2019, 6/30/22 420,872 7,000,000+(g)(h) Merion Re 2018-2, 12/31/21 7,013,300 1,000,000+(g)(i) NCM Re 2019, 12/31/22 1,047,400 3,600,000+(h) Pangaea Re 2015-1, 2/1/20 4,680 4,000,000+(h) Pangaea Re 2015-2, 11/30/19 3,600 4,500,000+(h) Pangaea Re 2016-1, 11/30/20 14,850 3,000,000+(h) Pangaea Re 2016-2, 11/30/20 10,800 3,000,000+(h) Pangaea Re 2017-1, 11/30/21 48,300 3,800,000+(g)(h) Pangaea Re 2018-1, 12/31/21 223,440 6,500,000+(g)(h) Pangaea Re 2018-3, 7/1/22 5,101,850 4,017,011+(g)(h) Pangaea Re 2019-1, 2/1/23 4,099,323 2,100,000+(g)(h) Sector Re V, Series 7, Class A, 12/1/23 (144A) 2,188,718 300,000+(g)(h) Sector Re V, Series 7, Class C, 12/1/22 (144A) 145,900 300,000+(g)(h) Sector Re V, Series 7, Class C, 12/1/22 (144A) 145,900 400,000+(g)(h) Sector Re V, Series 8, Class D, 12/1/23 (144A) 416,899 758+(g)(h) Sector Re V, Series 8, Class F, 3/1/23 (144A) 39,743 2,557+(g)(h) Sector Re V, Series 8, Class G, 3/1/23 (144A) 96,140 1,500,000+(g)(h) Sector Re V, Series 9, Class A, 3/1/24 (144A) 1,536,192 900,000+(g)(h) Sector Re V, Series 9, Class G, 3/1/24 (144A) 912,489 2,000,000+(g)(h) Silverton Re 2017, 9/16/19 (144A) 24,400 3,000,000+(g)(h) St. Andrews Re 2017-1, 2/1/20 203,400 The accompanying notes are an integral part of these financial statements. 50 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Face Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- Multiperil -- Worldwide -- (continued) 1,737,984+(g)(h) St. Andrews Re 2017-4, 6/1/20 $ 171,018 500,000+(g)(i) Thopas Re 2018, 12/31/21 90,550 3,000,000+(g)(i) Thopas Re 2019, 12/31/22 3,132,600 4,000,000+(h) Versutus Re 2017, 11/30/21 30,400 2,000,000+(g)(h) Versutus Re 2018, 12/31/21 4,600 1,734,905+(g)(h) Versutus Re 2019-B, 12/31/21 1,774,461 1,765,095+(g)(h) Versutus Re 2019-A, 12/31/21 1,805,339 1,000,000+(g)(i) Viribus Re 2018, 12/31/21 238,400 3,650,000+(g)(i) Viribus Re 2019, 12/31/22 3,925,575 1,623,326+(h) Woburn Re 2018, 12/31/21 689,914 4,979,452+(g)(h) Woburn Re 2019, 12/31/22 5,167,622 -------------- $ 79,713,234 -------------- Total Reinsurance Sidecars $ 89,764,461 ----------------------------------------------------------------------------------------------------------------------------------- TOTAL INSURANCE-LINKED SECURITIES (Cost $178,914,867) $ 172,954,486 ----------------------------------------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) ----------------------------------------------------------------------------------------------------------------------------------- MUNICIPAL BONDS -- 0.3% of Net Assets(j) Municipal General Obligation -- 0.1% 2,335,000 Virginia Commonwealth Transportation Board, Transportation Capital Projects, 4.0%, 5/15/32 $ 2,541,554 -------------- Total Municipal General Obligation $ 2,541,554 ----------------------------------------------------------------------------------------------------------------------------------- Municipal Higher Education -- 0.2% 525,000 Amherst College, 3.794%, 11/1/42 $ 546,025 7,425,000 Massachusetts Development Finance Agency, Harvard University, Series A, 5.0%, 7/15/40 10,363,518 -------------- Total Municipal Higher Education $ 10,909,543 ----------------------------------------------------------------------------------------------------------------------------------- Municipal Transportation -- 0.0%+ 600,000 Port Authority of New York & New Jersey, Consolidated-174th, 4.458%, 10/1/62 $ 719,070 -------------- Total Municipal Transportation $ 719,070 ----------------------------------------------------------------------------------------------------------------------------------- TOTAL MUNICIPAL BONDS (Cost $13,892,320) $ 14,170,167 ----------------------------------------------------------------------------------------------------------------------------------- SENIOR SECURED FLOATING RATE LOAN INTERESTS -- 1.7% of Net Assets*(b) Automobile -- 0.2% 4,108,813 American Axle & Manufacturing, Inc., Tranche B Term Loan, 4.721% (LIBOR + 225 bps), 4/6/24 $ 4,028,177 1,347,124 Cooper-Standard Automotive, Inc., Additional Term B-1 Loan, 4.402% (LIBOR + 200 bps), 11/2/23 1,296,607 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 51 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- Automobile -- (continued) 1,431,664 CWGS Group LLC (aka Camping World, Inc.), Term Loan, 5.19% (LIBOR + 275 bps), 11/8/23 $ 1,324,289 1,396,667 Goodyear Tire & Rubber Co., Second Lien Term Loan, 4.4% (LIBOR + 200 bps), 3/3/25 1,379,208 729,488 Navistar, Inc., Tranche B Term Loan, 5.91% (LIBOR + 350 bps), 11/6/24 729,792 1,334,117 TI Group Automotive Systems LLC, Initial US Term Loan, 4.902% (LIBOR + 250 bps), 6/30/22 1,324,520 -------------- Total Automobile $ 10,082,593 ----------------------------------------------------------------------------------------------------------------------------------- Beverage, Food & Tobacco -- 0.1% 1,673,075 Darling Ingredients, Inc. (fka Darling International, Inc.), Term B Loan, 4.41% (LIBOR + 200 bps), 12/18/24 $ 1,675,585 3,729,449 JBS USA Lux SA (fka JBS USA LLC), New Term Loan, 4.902% (LIBOR + 250 bps), 5/1/26 3,727,636 -------------- Total Beverage, Food & Tobacco $ 5,403,221 ----------------------------------------------------------------------------------------------------------------------------------- Broadcasting & Entertainment -- 0.0%+ 408,127 UPC Financing Partnership, Facility AR, 4.894% (LIBOR + 250 bps), 1/15/26 $ 408,040 -------------- Total Broadcasting & Entertainment $ 408,040 ----------------------------------------------------------------------------------------------------------------------------------- Buildings & Real Estate -- 0.0%+ 143,237 Builders FirstSource, Inc., Refinancing Term Loan, 5.33% (LIBOR + 300 bps), 2/29/24 $ 142,958 1,592,632 Uniti Group, Inc., Shortfall Term Loan, 7.402% (LIBOR + 500 bps), 10/24/22 1,556,201 -------------- Total Buildings & Real Estate $ 1,699,159 ----------------------------------------------------------------------------------------------------------------------------------- Chemicals -- 0.0%+ 409,195 Allnex (Luxembourg) & Cy SCA (fka AI Chem & Cy SCA), Tranche B-2 Term Loan, 5.771% (LIBOR + 325 bps), 9/13/23 $ 402,034 308,296 Allnex (Luxembourg) & Cy SCA (fka AI Chem & Cy SCA), Tranche B-3 Term Loan, 5.771% (LIBOR + 325 bps), 9/13/23 302,901 -------------- Total Chemicals $ 704,935 ----------------------------------------------------------------------------------------------------------------------------------- Chemicals, Plastics & Rubber -- 0.1% 994,962 Axalta Coating Systems Dutch Holding B BV (Axalta Coating Systems U.S. Holdings, Inc.), Term B-3 Dollar Loan, 4.08% (LIBOR + 175 bps), 6/1/24 $ 985,013 488,750 Berry Global, Inc. (fka Berry Plastics Corp.), Term R Loan, 4.412% (LIBOR + 200 bps), 1/19/24 484,779 235,216 Element Solutions, Inc. (Macdermid, Inc.), Initial Term Loan, 4.652% (LIBOR + 225 bps), 1/30/26 234,873 384,378 Infiltrator Water Technologies LLC, First Lien Term B-2 Loan, 5.33% (LIBOR + 300 bps), 5/27/22 382,936 The accompanying notes are an integral part of these financial statements. 52 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- Chemicals, Plastics & Rubber -- (continued) 514,929 Omnova Solutions, Inc., Term B-2 Loan, 5.652% (LIBOR + 325 bps), 8/25/23 $ 515,253 1,431,110 Tronox Finance LLC, First Lien Initial Dollar Term Loan, 5.374% (LIBOR + 300 bps), 9/23/24 1,418,290 -------------- Total Chemicals, Plastics & Rubber $ 4,021,144 ----------------------------------------------------------------------------------------------------------------------------------- Computers & Electronics -- 0.1% 1,060,366 Energy Acquisition LP (aka Electrical Components International), First Lien Initial Term Loan, 6.58% (LIBOR + 425 bps), 6/26/25 $ 1,033,857 2,135,722 Microchip Technology, Inc., Initial Term Loan, 4.41% (LIBOR + 200 bps), 5/29/25 2,128,771 798,040 ON Semiconductor Corp., 2018 New Replacement Term B-3 Loan, 4.152% (LIBOR + 175 bps), 3/31/23 788,785 -------------- Total Computers & Electronics $ 3,951,413 ----------------------------------------------------------------------------------------------------------------------------------- Diversified & Conglomerate Service -- 0.2% 563,714 Bright Horizons Family Solutions LLC (fka Bright Horizons Family Solutions, Inc.), Term B Loan, 4.158% (LIBOR + 175bps/PRIME + 75 bps), 11/7/23 $ 564,591 1,244,750 Change Healthcare Holdings, Inc. (fka Emdeon, Inc.), Closing Date Term Loan, 5.152% (LIBOR + 275 bps), 3/1/24 1,236,711 637,000 Constellis Holdings LLC, First Lien Term B Loan, 7.583% (LIBOR + 500 bps), 4/21/24 487,305 499,065 Filtration Group Corp., Initial Dollar Term Loan, 5.402% (LIBOR + 300 bps), 3/29/25 498,619 2,328,120 NVA Holdings, Inc., First Lien Term B-3 Loan, 5.152% (LIBOR + 275 bps), 2/2/25 2,327,149 1,075,250 Team Health Holdings, Inc., Initial Term Loan, 5.152% (LIBOR + 275 bps), 2/6/24 947,564 -------------- Total Diversified & Conglomerate Service $ 6,061,939 ----------------------------------------------------------------------------------------------------------------------------------- Electric & Electrical -- 0.0%+ 1,243,687 Dell International LLC (EMC Corp.), Refinancing Term B Loan, 4.41% (LIBOR + 200 bps), 9/7/23 $ 1,238,609 224,359 Micron Technology, Inc., Term Loan, 4.16% (LIBOR + 175 bps), 4/26/22 224,429 460,605 Rackspace Hosting, Inc., First Lien Term B Loan, 5.576% (LIBOR + 300 bps), 11/3/23 425,714 -------------- Total Electric & Electrical $ 1,888,752 ----------------------------------------------------------------------------------------------------------------------------------- Electronics -- 0.2% 167,514 Avast Software BV, 2018 Refinancing Dollar Term Loan, 4.58% (LIBOR + 225 bps), 9/29/23 $ 167,451 1,341,753 Rovi Solutions Corp./Rovi Guides, Inc., Term B Loan, 4.91% (LIBOR + 250 bps), 7/2/21 1,317,434 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 53 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- Electronics -- (continued) 4,948,186 Scientific Games International, Inc., Initial Term B-5 Loan, 5.216% (LIBOR + 275 bps), 8/14/24 $ 4,880,148 4,641,499 Western Digital Corp., U.S. Term B-4 Loan, 4.152% (LIBOR + 175 bps), 4/29/23 4,549,829 -------------- Total Electronics $ 10,914,862 ----------------------------------------------------------------------------------------------------------------------------------- Environmental Services -- 0.0%+ 955,615 GFL Environmental, Inc., Effective Date Incremental Term Loan, 5.402% (LIBOR + 300 bps), 5/30/25 $ 941,041 -------------- Total Environmental Services $ 941,041 ----------------------------------------------------------------------------------------------------------------------------------- Finance -- 0.0%+ 1,318,874 Trans Union LLC, 2017 Replacement Term B-3 Loan, 4.402% (LIBOR + 200 bps), 4/10/23 $ 1,318,756 -------------- Total Finance $ 1,318,756 ----------------------------------------------------------------------------------------------------------------------------------- Financial Services -- 0.1% 2,411,395 RPI Finance Trust, Initial Term B-6 Loan, 4.402% (LIBOR + 200 bps), 3/27/23 $ 2,416,562 -------------- Total Financial Services $ 2,416,562 ----------------------------------------------------------------------------------------------------------------------------------- Healthcare & Pharmaceuticals -- 0.2% 717,895 Alkermes, Inc., 2023 Term Loan, 4.67% (LIBOR + 225 bps), 3/27/23 $ 715,651 491,250 Alphabet Holding Co., Inc. (aka Nature's Bounty), First Lien Initial Term Loan, 5.902% (LIBOR + 350 bps), 9/26/24 464,999 240,994 DaVita, Inc. (fka DaVita HealthCare Partners, Inc.), Tranche B Term Loan, 5.135% (LIBOR + 275 bps), 6/24/21 241,145 4,996,272 Endo Luxembourg Finance Co. I S.a r.l., Initial Term Loan, 6.688% (LIBOR + 425 bps), 4/29/24 4,699,618 398,941 Gentiva Health Services, Inc., First Lien Closing Date Initial Term Loan, 6.188% (LIBOR + 375 bps), 7/2/25 399,679 708,687 Grifols Worldwide Operations, Ltd., Tranche B Term Loan, 4.635% (LIBOR + 225 bps), 1/31/25 707,479 1,409,024 HCA, Inc., Tranche B-11 Term Loan, 4.08% (LIBOR + 175 bps), 3/17/23 1,411,078 719,081 Sterigenics-Nordion Holdings LLC, Incremental Term Loan, 5.402% (LIBOR + 300 bps), 5/15/22 711,591 -------------- Total Healthcare & Pharmaceuticals $ 9,351,240 ----------------------------------------------------------------------------------------------------------------------------------- Healthcare, Education & Childcare -- 0.1% 770,000 Alliance HealthCare Services, Inc., First Lien Initial Term Loan, 6.902% (LIBOR + 450 bps), 10/24/23 $ 743,050 566,162 Bausch Health Cos., Inc. (fka Valeant Pharmaceuticals International, Inc.), Initial Term Loan, 5.412% (LIBOR + 300 bps), 6/2/25 566,516 The accompanying notes are an integral part of these financial statements. 54 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- Healthcare, Education & Childcare -- (continued) 2,194,004 KUEHG Corp. (fka KC MergerSub, Inc.) (aka KinderCare), Term B-3 Loan, 6.08% (LIBOR + 375 bps), 2/21/25 $ 2,190,164 1,044,863 Select Medical Corp., Tranche B Term Loan, 4.85% (LIBOR + 250 bps), 3/6/25 1,043,531 -------------- Total Healthcare, Education & Childcare $ 4,543,261 ----------------------------------------------------------------------------------------------------------------------------------- Home & Office Furnishings -- 0.0%+ 653 Serta Simmons Bedding LLC, First Lien Initial Term Loan, 5.908% (LIBOR + 350 bps), 11/8/23 $ 422 -------------- Total Home & Office Furnishings $ 422 ----------------------------------------------------------------------------------------------------------------------------------- Hotel, Gaming & Leisure -- 0.0%+ 1,670,358 1011778 BC Unlimited Liability Co. (New Red Finance, Inc.) (aka Burger King/Tim Hortons), Term B-3 Loan, 4.652% (LIBOR + 225 bps), 2/16/24 $ 1,661,223 -------------- Total Hotel, Gaming & Leisure $ 1,661,223 ----------------------------------------------------------------------------------------------------------------------------------- Insurance -- 0.1% 3,829,438 Asurion LLC (fka Asurion Corp.), New Term B-7 Loan, 5.402% (LIBOR + 300 bps), 11/3/24 $ 3,825,846 420,807 MPH Acquisition Holdings LLC, Initial Term Loan, 5.08% (LIBOR + 275 bps), 6/7/23 403,361 835,125 USI, Inc. (fka Compass Investors, Inc.), 2017 New Term Loan, 5.33% (LIBOR + 300 bps), 5/16/24 815,813 -------------- Total Insurance $ 5,045,020 ----------------------------------------------------------------------------------------------------------------------------------- Leasing -- 0.1% 941,582 Avolon TLB Borrower 1 (US) LLC, Term B-3 Loan, 4.133% (LIBOR + 175 bps), 1/15/25 $ 941,681 2,715,625 IBC Capital I, Ltd. (aka Goodpack, Ltd.), First Lien Tranche B-1 Term Loan, 6.152% (LIBOR + 375 bps), 9/11/23 2,713,363 -------------- Total Leasing $ 3,655,044 ----------------------------------------------------------------------------------------------------------------------------------- Leisure & Entertainment -- 0.0%+ 550,279 AMC Entertainment Holdings, Inc. (fka AMC Entertainment, Inc.), Term B-1 Loan, 5.23% (LIBOR + 300 bps), 4/22/26 $ 549,978 375,088 Fitness International LLC, Term B Loan, 5.652% (LIBOR + 325 bps), 4/18/25 373,056 1,257,239 Six Flags Theme Parks, Inc., Tranche B Term Loan, 4.41% (LIBOR + 200 bps), 4/17/26 1,259,596 -------------- Total Leisure & Entertainment $ 2,182,630 ----------------------------------------------------------------------------------------------------------------------------------- Machinery -- 0.0%+ 1,159,642 NN, Inc., Tranche B Term Loan, 6.152% (LIBOR + 375 bps), 10/19/22 $ 1,144,663 -------------- Total Machinery $ 1,144,663 ----------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 55 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- Metals & Mining -- 0.0%+ 500,778 BWay Holding Co., Initial Term Loan, 5.854% (LIBOR + 325 bps), 4/3/24 $ 484,659 -------------- Total Metals & Mining $ 484,659 ----------------------------------------------------------------------------------------------------------------------------------- Printing & Publishing -- 0.0%+ 1,274,000 Nielsen Finance LLC (VNU, Inc.), Class B-4 Term Loan, 4.412% (LIBOR + 200 bps), 10/4/23 $ 1,263,307 -------------- Total Printing & Publishing $ 1,263,307 ----------------------------------------------------------------------------------------------------------------------------------- Professional & Business Services -- 0.0%+ 587,534 GW Honos Security Corp. (Garda World Security Corp.), Term B Loan, 6.025% (LIBOR + 350bps/PRIME + 250 bps), 5/24/24 $ 584,376 987,500 Lamar Media Corp., Term B Loan, 4.125% (LIBOR + 175 bps), 3/14/25 989,963 -------------- Total Professional & Business Services $ 1,574,339 ----------------------------------------------------------------------------------------------------------------------------------- Retail -- 0.0%+ 535,000 Staples, Inc., 2019 Refinancing New Term B-2 Loan, 7.101% (LIBOR + 450 bps), 9/12/24 $ 525,972 -------------- Total Retail $ 525,972 ----------------------------------------------------------------------------------------------------------------------------------- Telecommunications -- 0.1% 4,115,949 CenturyLink, Inc., Initial Term B Loan, 5.152% (LIBOR + 275 bps), 1/31/25 $ 4,024,625 895,500 Ciena Corp., Refinancing Term Loan, 4.383% (LIBOR + 200 bps), 9/26/25 896,480 904,891 Go Daddy Operating Co. LLC (GD Finance Co., Inc.), Tranche B-1 Term Loan, 4.402% (LIBOR + 200 bps), 2/15/24 905,941 1,200,000 Level 3 Financing, Inc., Tranche B 2024 Term Loan, 4.652% (LIBOR + 225 bps), 2/22/24 1,191,625 1,270,750 Sprint Communications, Inc., Initial Term Loan, 4.938% (LIBOR + 250 bps), 2/2/24 1,253,807 -------------- Total Telecommunications $ 8,272,478 ----------------------------------------------------------------------------------------------------------------------------------- Utilities -- 0.1% 938,698 Eastern Power LLC (Eastern Covert Midco LLC) (aka TPF II LC LLC), Term Loan, 6.152% (LIBOR + 375 bps), 10/2/23 $ 939,088 1,481,735 Vistra Operations Co. LLC (fka Tex Operations Co. LLC), Initial Term Loan, 4.402% (LIBOR + 200 bps), 8/4/23 1,481,646 -------------- Total Utilities $ 2,420,734 ----------------------------------------------------------------------------------------------------------------------------------- TOTAL SENIOR SECURED FLOATING RATE LOAN INTERESTS (Cost $93,031,879) $ 91,937,409 ----------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 56 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- 32.1% of Net Assets 1,040,449 Fannie Mae, 2.5%, 7/1/30 $ 1,048,325 1,101,042 Fannie Mae, 2.5%, 7/1/30 1,109,881 1,838,124 Fannie Mae, 2.5%, 7/1/30 1,852,866 220,410 Fannie Mae, 2.5%, 12/1/42 219,223 229,747 Fannie Mae, 2.5%, 12/1/42 229,048 213,639 Fannie Mae, 2.5%, 1/1/43 212,989 86,357 Fannie Mae, 2.5%, 2/1/43 86,094 111,880 Fannie Mae, 2.5%, 2/1/43 111,090 2,343,606 Fannie Mae, 2.5%, 2/1/43 2,336,476 326,211 Fannie Mae, 2.5%, 3/1/43 325,219 118,790 Fannie Mae, 2.5%, 4/1/43 118,428 288,088 Fannie Mae, 2.5%, 8/1/43 287,211 226,967 Fannie Mae, 2.5%, 12/1/43 226,277 162,194 Fannie Mae, 2.5%, 3/1/44 161,701 198,806 Fannie Mae, 2.5%, 4/1/45 197,401 305,011 Fannie Mae, 2.5%, 4/1/45 302,856 410,679 Fannie Mae, 2.5%, 4/1/45 407,777 430,367 Fannie Mae, 2.5%, 4/1/45 427,326 496,118 Fannie Mae, 2.5%, 4/1/45 492,612 523,817 Fannie Mae, 2.5%, 4/1/45 520,115 1,177,757 Fannie Mae, 2.5%, 4/1/45 1,169,434 1,369,780 Fannie Mae, 2.5%, 4/1/45 1,360,101 69,821 Fannie Mae, 2.5%, 5/1/45 69,328 75,525 Fannie Mae, 2.5%, 7/1/45 74,991 249,863 Fannie Mae, 2.5%, 8/1/45 248,097 86,664 Fannie Mae, 2.5%, 1/1/46 86,052 2,888,993 Fannie Mae, 3.0%, 9/1/28 2,960,972 2,613,306 Fannie Mae, 3.0%, 10/1/30 2,673,009 1,072,590 Fannie Mae, 3.0%, 4/1/31 1,096,400 15,158,877 Fannie Mae, 3.0%, 8/1/42 15,420,030 3,602,141 Fannie Mae, 3.0%, 9/1/42 3,673,108 1,081,996 Fannie Mae, 3.0%, 12/1/42 1,103,984 2,164,206 Fannie Mae, 3.0%, 2/1/43 2,208,185 589,241 Fannie Mae, 3.0%, 5/1/43 601,215 8,004,047 Fannie Mae, 3.0%, 5/1/43 8,141,969 555,052 Fannie Mae, 3.0%, 7/1/43 564,616 1,372,911 Fannie Mae, 3.0%, 8/1/43 1,396,567 3,868,163 Fannie Mae, 3.0%, 9/1/43 3,934,815 711,324 Fannie Mae, 3.0%, 3/1/45 725,329 5,990,398 Fannie Mae, 3.0%, 6/1/45 6,115,739 623,322 Fannie Mae, 3.0%, 5/1/46 637,146 801,518 Fannie Mae, 3.0%, 5/1/46 817,807 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 57 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 4,394,756 Fannie Mae, 3.0%, 9/1/46 $ 4,452,591 8,090,891 Fannie Mae, 3.0%, 10/1/46 8,196,534 8,196,739 Fannie Mae, 3.0%, 11/1/46 8,303,344 6,970,266 Fannie Mae, 3.0%, 1/1/47 7,124,850 2,566,226 Fannie Mae, 3.0%, 3/1/47 2,599,471 2,230,340 Fannie Mae, 3.5%, 6/1/28 2,309,856 943,916 Fannie Mae, 3.5%, 11/1/40 973,279 481,100 Fannie Mae, 3.5%, 10/1/41 500,231 404,883 Fannie Mae, 3.5%, 6/1/42 420,359 2,492,735 Fannie Mae, 3.5%, 7/1/42 2,587,860 2,637,194 Fannie Mae, 3.5%, 8/1/42 2,738,010 210,020 Fannie Mae, 3.5%, 11/1/42 218,959 433,355 Fannie Mae, 3.5%, 12/1/42 451,793 458,743 Fannie Mae, 3.5%, 12/1/42 478,255 4,468,731 Fannie Mae, 3.5%, 2/1/44 4,637,959 2,340,365 Fannie Mae, 3.5%, 9/1/44 2,424,396 4,992,451 Fannie Mae, 3.5%, 2/1/45 5,204,585 1,481,486 Fannie Mae, 3.5%, 4/1/45 1,535,300 5,647,243 Fannie Mae, 3.5%, 6/1/45 5,839,323 2,192,278 Fannie Mae, 3.5%, 8/1/45 2,261,103 7,034,091 Fannie Mae, 3.5%, 8/1/45 7,365,538 5,305,747 Fannie Mae, 3.5%, 9/1/45 5,455,989 6,412,362 Fannie Mae, 3.5%, 9/1/45 6,613,662 1,323,288 Fannie Mae, 3.5%, 10/1/45 1,368,299 10,723,746 Fannie Mae, 3.5%, 11/1/45 11,229,058 2,186,834 Fannie Mae, 3.5%, 12/1/45 2,253,465 2,332,613 Fannie Mae, 3.5%, 12/1/45 2,403,686 4,128,168 Fannie Mae, 3.5%, 12/1/45 4,257,759 4,758,985 Fannie Mae, 3.5%, 1/1/46 4,907,621 6,360,523 Fannie Mae, 3.5%, 1/1/46 6,560,207 2,650,984 Fannie Mae, 3.5%, 2/1/46 2,733,372 4,332,336 Fannie Mae, 3.5%, 2/1/46 4,467,644 1,754,829 Fannie Mae, 3.5%, 3/1/46 1,809,636 3,738,225 Fannie Mae, 3.5%, 4/1/46 3,854,404 2,375,337 Fannie Mae, 3.5%, 5/1/46 2,472,390 5,316,542 Fannie Mae, 3.5%, 7/1/46 5,473,308 8,111,247 Fannie Mae, 3.5%, 9/1/46 8,354,596 446,478 Fannie Mae, 3.5%, 10/1/46 461,456 983,237 Fannie Mae, 3.5%, 10/1/46 1,012,282 1,113,261 Fannie Mae, 3.5%, 11/1/46 1,146,146 4,183,876 Fannie Mae, 3.5%, 12/1/46 4,307,458 2,079,644 Fannie Mae, 3.5%, 1/1/47 2,141,030 4,244,468 Fannie Mae, 3.5%, 1/1/47 4,369,762 The accompanying notes are an integral part of these financial statements. 58 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 5,884,713 Fannie Mae, 3.5%, 1/1/47 $ 6,123,331 9,770,921 Fannie Mae, 3.5%, 1/1/47 10,098,481 5,390,411 Fannie Mae, 3.5%, 2/1/47 5,549,524 6,753,519 Fannie Mae, 3.5%, 5/1/47 6,952,884 7,607,481 Fannie Mae, 3.5%, 5/1/47 7,832,003 270,254 Fannie Mae, 3.5%, 7/1/47 278,183 2,597,727 Fannie Mae, 3.5%, 7/1/47 2,674,415 7,858,235 Fannie Mae, 3.5%, 7/1/47 8,081,016 10,733,909 Fannie Mae, 3.5%, 7/1/47 11,050,765 1,272,936 Fannie Mae, 3.5%, 8/1/47 1,310,514 17,246,670 Fannie Mae, 3.5%, 8/1/47 17,755,815 2,946,204 Fannie Mae, 3.5%, 11/1/47 3,033,172 6,884,495 Fannie Mae, 3.5%, 12/1/47 7,087,732 11,641,954 Fannie Mae, 3.5%, 12/1/47 11,980,562 14,820,958 Fannie Mae, 3.5%, 12/1/47 15,254,873 3,785,185 Fannie Mae, 3.5%, 1/1/48 3,888,503 2,922,982 Fannie Mae, 3.5%, 2/1/48 3,005,312 805,547 Fannie Mae, 3.771%, 12/1/20 821,302 9,457 Fannie Mae, 4.0%, 9/1/20 9,817 188,874 Fannie Mae, 4.0%, 4/1/25 196,422 208,698 Fannie Mae, 4.0%, 11/1/34 219,803 2,073,191 Fannie Mae, 4.0%, 4/1/39 2,185,678 5,644,571 Fannie Mae, 4.0%, 10/1/40 5,996,654 1,026,593 Fannie Mae, 4.0%, 12/1/40 1,090,024 1,028,158 Fannie Mae, 4.0%, 4/1/41 1,084,344 675,093 Fannie Mae, 4.0%, 5/1/41 711,986 1,323,578 Fannie Mae, 4.0%, 10/1/41 1,395,908 909,869 Fannie Mae, 4.0%, 12/1/41 959,597 326,070 Fannie Mae, 4.0%, 1/1/42 343,892 2,165,515 Fannie Mae, 4.0%, 1/1/42 2,283,887 1,997,393 Fannie Mae, 4.0%, 2/1/42 2,109,038 5,499,721 Fannie Mae, 4.0%, 2/1/42 5,800,303 117,365 Fannie Mae, 4.0%, 4/1/42 123,781 523,274 Fannie Mae, 4.0%, 4/1/42 551,875 2,210,263 Fannie Mae, 4.0%, 4/1/42 2,331,072 4,013,024 Fannie Mae, 4.0%, 5/1/42 4,231,293 91,827 Fannie Mae, 4.0%, 6/1/42 96,846 272,314 Fannie Mae, 4.0%, 6/1/42 283,314 138,000 Fannie Mae, 4.0%, 7/1/42 145,544 6,329,501 Fannie Mae, 4.0%, 8/1/42 6,675,438 1,230,923 Fannie Mae, 4.0%, 10/1/42 1,298,199 3,676,471 Fannie Mae, 4.0%, 8/1/43 3,866,308 4,619,469 Fannie Mae, 4.0%, 9/1/43 4,862,233 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 59 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 2,879,976 Fannie Mae, 4.0%, 11/1/43 $ 3,051,392 105,758 Fannie Mae, 4.0%, 1/1/44 110,994 4,475,133 Fannie Mae, 4.0%, 2/1/44 4,696,376 65,445 Fannie Mae, 4.0%, 6/1/44 68,543 80,319 Fannie Mae, 4.0%, 6/1/44 84,133 239,438 Fannie Mae, 4.0%, 7/1/44 250,697 4,317,470 Fannie Mae, 4.0%, 7/1/44 4,521,131 171,602 Fannie Mae, 4.0%, 8/1/44 179,592 198,612 Fannie Mae, 4.0%, 8/1/44 207,950 1,016,789 Fannie Mae, 4.0%, 8/1/44 1,064,284 3,078,955 Fannie Mae, 4.0%, 8/1/44 3,225,626 34,657 Fannie Mae, 4.0%, 9/1/44 36,287 269,867 Fannie Mae, 4.0%, 9/1/44 282,431 350,351 Fannie Mae, 4.0%, 9/1/44 366,716 1,307,350 Fannie Mae, 4.0%, 10/1/44 1,368,814 83,143 Fannie Mae, 4.0%, 11/1/44 87,002 89,421 Fannie Mae, 4.0%, 11/1/44 93,557 174,366 Fannie Mae, 4.0%, 11/1/44 182,401 4,249,243 Fannie Mae, 4.0%, 11/1/44 4,446,421 32,034 Fannie Mae, 4.0%, 12/1/44 33,506 413,162 Fannie Mae, 4.0%, 12/1/44 432,144 59,278 Fannie Mae, 4.0%, 1/1/45 62,020 182,415 Fannie Mae, 4.0%, 1/1/45 190,879 276,865 Fannie Mae, 4.0%, 1/1/45 289,585 43,502 Fannie Mae, 4.0%, 2/1/45 45,500 150,315 Fannie Mae, 4.0%, 2/1/45 157,471 324,893 Fannie Mae, 4.0%, 2/1/45 340,366 3,435,748 Fannie Mae, 4.0%, 3/1/45 3,593,588 2,350,558 Fannie Mae, 4.0%, 10/1/45 2,461,445 3,493,618 Fannie Mae, 4.0%, 10/1/45 3,654,126 4,039,742 Fannie Mae, 4.0%, 10/1/45 4,225,345 56,344 Fannie Mae, 4.0%, 11/1/45 58,933 2,817,590 Fannie Mae, 4.0%, 11/1/45 2,947,040 4,748,098 Fannie Mae, 4.0%, 12/1/45 4,966,236 1,945,916 Fannie Mae, 4.0%, 1/1/46 2,035,282 5,269,081 Fannie Mae, 4.0%, 2/1/46 5,521,755 1,310,157 Fannie Mae, 4.0%, 4/1/46 1,371,956 4,485,011 Fannie Mae, 4.0%, 6/1/46 4,691,036 4,812,483 Fannie Mae, 4.0%, 7/1/46 5,033,546 6,516,437 Fannie Mae, 4.0%, 7/1/46 6,815,724 3,677,239 Fannie Mae, 4.0%, 8/1/46 3,846,156 4,617,673 Fannie Mae, 4.0%, 8/1/46 4,829,790 1,373,207 Fannie Mae, 4.0%, 11/1/46 1,436,977 The accompanying notes are an integral part of these financial statements. 60 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 11,417,202 Fannie Mae, 4.0%, 1/1/47 $ 11,932,653 2,867,907 Fannie Mae, 4.0%, 4/1/47 2,994,741 2,912,555 Fannie Mae, 4.0%, 4/1/47 3,050,607 4,446,219 Fannie Mae, 4.0%, 4/1/47 4,656,978 516,790 Fannie Mae, 4.0%, 6/1/47 541,287 1,757,490 Fannie Mae, 4.0%, 6/1/47 1,840,799 2,730,116 Fannie Mae, 4.0%, 6/1/47 2,849,525 4,522,175 Fannie Mae, 4.0%, 6/1/47 4,716,614 8,126,414 Fannie Mae, 4.0%, 6/1/47 8,469,166 2,605,226 Fannie Mae, 4.0%, 7/1/47 2,728,720 2,654,986 Fannie Mae, 4.0%, 7/1/47 2,765,879 2,575,907 Fannie Mae, 4.0%, 8/1/47 2,685,606 4,662,629 Fannie Mae, 4.0%, 8/1/47 4,857,376 6,166,649 Fannie Mae, 4.0%, 12/1/47 6,416,020 8,395,806 Fannie Mae, 4.0%, 4/1/48 8,726,560 42,921,000 Fannie Mae, 4.0%, 7/1/49 (TBA) 44,360,362 3,282 Fannie Mae, 4.5%, 11/1/20 3,350 53,383 Fannie Mae, 4.5%, 11/1/20 54,615 155,497 Fannie Mae, 4.5%, 10/1/35 166,745 376,593 Fannie Mae, 4.5%, 8/1/40 404,466 820,128 Fannie Mae, 4.5%, 8/1/40 880,864 1,369,974 Fannie Mae, 4.5%, 11/1/40 1,467,196 517,927 Fannie Mae, 4.5%, 2/1/41 556,268 1,222,648 Fannie Mae, 4.5%, 4/1/41 1,313,121 65,100 Fannie Mae, 4.5%, 5/1/41 69,920 1,768,328 Fannie Mae, 4.5%, 5/1/41 1,899,292 2,294,016 Fannie Mae, 4.5%, 5/1/41 2,463,904 2,908,903 Fannie Mae, 4.5%, 5/1/41 3,139,998 870,601 Fannie Mae, 4.5%, 7/1/41 935,075 1,156,158 Fannie Mae, 4.5%, 7/1/41 1,241,790 3,223,208 Fannie Mae, 4.5%, 1/1/42 3,460,732 4,187,348 Fannie Mae, 4.5%, 1/1/42 4,497,035 422,730 Fannie Mae, 4.5%, 11/1/43 450,511 3,468,772 Fannie Mae, 4.5%, 12/1/43 3,694,150 5,730,732 Fannie Mae, 4.5%, 12/1/43 6,110,349 4,144,615 Fannie Mae, 4.5%, 1/1/44 4,413,892 2,238,947 Fannie Mae, 4.5%, 2/1/44 2,380,955 2,762,362 Fannie Mae, 4.5%, 2/1/44 2,939,539 4,396,750 Fannie Mae, 4.5%, 5/1/46 4,653,403 505,415 Fannie Mae, 4.5%, 1/1/47 532,546 426,992 Fannie Mae, 4.5%, 2/1/47 451,523 3,105,609 Fannie Mae, 4.5%, 2/1/47 3,273,584 4,160,000 Fannie Mae, 4.5%, 7/1/49 (TBA) 4,346,997 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 61 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 3,166 Fannie Mae, 5.0%, 1/1/20 $ 3,239 11,462 Fannie Mae, 5.0%, 1/1/20 11,728 1,573 Fannie Mae, 5.0%, 2/1/20 1,609 32,797 Fannie Mae, 5.0%, 10/1/20 33,557 3,352 Fannie Mae, 5.0%, 2/1/22 3,439 33,044 Fannie Mae, 5.0%, 2/1/22 33,810 36,946 Fannie Mae, 5.0%, 3/1/23 37,803 143,443 Fannie Mae, 5.0%, 5/1/23 149,537 34,808 Fannie Mae, 5.0%, 7/1/34 36,070 145,791 Fannie Mae, 5.0%, 10/1/34 155,847 564,328 Fannie Mae, 5.0%, 2/1/39 616,470 432,747 Fannie Mae, 5.0%, 6/1/40 467,082 488,525 Fannie Mae, 5.0%, 6/1/40 530,765 337,984 Fannie Mae, 5.0%, 7/1/40 367,294 502,849 Fannie Mae, 5.0%, 7/1/40 546,457 773,485 Fannie Mae, 5.0%, 7/1/40 840,549 601,521 Fannie Mae, 5.0%, 8/1/40 653,685 2,237,682 Fannie Mae, 5.0%, 2/1/41 2,431,735 7,794,643 Fannie Mae, 5.0%, 12/1/44 8,463,826 47,890,000 Fannie Mae, 5.0%, 7/1/49 (TBA) 50,622,162 4,893 Fannie Mae, 5.5%, 9/1/19 4,887 14,917 Fannie Mae, 5.5%, 6/1/33 16,465 65,097 Fannie Mae, 5.5%, 7/1/33 71,865 398,175 Fannie Mae, 5.5%, 7/1/34 442,276 197,907 Fannie Mae, 5.5%, 3/1/36 216,212 82,124 Fannie Mae, 5.5%, 5/1/36 89,692 120,713 Fannie Mae, 5.5%, 6/1/36 134,054 43,338 Fannie Mae, 5.72%, 11/1/28 43,923 23,534 Fannie Mae, 5.72%, 6/1/29 23,579 19,591 Fannie Mae, 5.9%, 11/1/27 19,608 67,760 Fannie Mae, 5.9%, 4/1/28 69,319 616 Fannie Mae, 6.0%, 9/1/29 686 2,760 Fannie Mae, 6.0%, 1/1/32 3,114 9,810 Fannie Mae, 6.0%, 2/1/32 10,980 3,903 Fannie Mae, 6.0%, 3/1/32 4,425 2,538 Fannie Mae, 6.0%, 8/1/32 2,875 290 Fannie Mae, 6.0%, 9/1/32 327 33,643 Fannie Mae, 6.0%, 10/1/32 38,122 5,706 Fannie Mae, 6.0%, 2/1/33 6,246 49,242 Fannie Mae, 6.0%, 3/1/33 55,834 54,774 Fannie Mae, 6.0%, 4/1/33 60,341 32,473 Fannie Mae, 6.0%, 7/1/33 35,547 103,183 Fannie Mae, 6.0%, 7/1/33 114,052 The accompanying notes are an integral part of these financial statements. 62 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 23,746 Fannie Mae, 6.0%, 11/1/33 $ 26,898 85,360 Fannie Mae, 6.0%, 8/1/34 96,770 4,371 Fannie Mae, 6.0%, 9/1/34 4,952 17,201 Fannie Mae, 6.0%, 9/1/34 19,538 27,860 Fannie Mae, 6.0%, 9/1/34 31,517 85,288 Fannie Mae, 6.0%, 9/1/34 94,318 8,174 Fannie Mae, 6.0%, 10/1/34 9,264 7,550 Fannie Mae, 6.0%, 11/1/34 8,561 115,280 Fannie Mae, 6.0%, 11/1/34 127,474 2,676 Fannie Mae, 6.0%, 2/1/35 3,031 6,175 Fannie Mae, 6.0%, 2/1/35 7,003 119,117 Fannie Mae, 6.0%, 4/1/35 135,031 18,467 Fannie Mae, 6.0%, 5/1/35 20,279 80,803 Fannie Mae, 6.0%, 10/1/35 88,459 149,191 Fannie Mae, 6.0%, 12/1/35 168,257 14,652 Fannie Mae, 6.0%, 12/1/37 16,576 164,920 Fannie Mae, 6.0%, 6/1/38 186,662 28,880 Fannie Mae, 6.0%, 7/1/38 32,016 5,965 Fannie Mae, 6.5%, 7/1/29 6,616 1,225 Fannie Mae, 6.5%, 1/1/31 1,359 1,690 Fannie Mae, 6.5%, 4/1/31 1,875 3,397 Fannie Mae, 6.5%, 5/1/31 3,768 61,235 Fannie Mae, 6.5%, 6/1/31 67,922 7,845 Fannie Mae, 6.5%, 8/1/31 8,702 2,735 Fannie Mae, 6.5%, 9/1/31 3,034 3,069 Fannie Mae, 6.5%, 9/1/31 3,404 2,460 Fannie Mae, 6.5%, 10/1/31 2,728 112,907 Fannie Mae, 6.5%, 12/1/31 125,236 4,229 Fannie Mae, 6.5%, 2/1/32 4,690 34,567 Fannie Mae, 6.5%, 3/1/32 38,341 76,085 Fannie Mae, 6.5%, 7/1/32 85,775 64,118 Fannie Mae, 6.5%, 10/1/32 71,119 26,654 Fannie Mae, 6.5%, 7/1/34 29,564 76,202 Fannie Mae, 6.5%, 11/1/37 89,316 20,236 Fannie Mae, 6.5%, 11/1/47 21,667 567 Fannie Mae, 7.0%, 12/1/30 587 5,958 Fannie Mae, 7.0%, 12/1/30 6,658 5,110 Fannie Mae, 7.0%, 4/1/31 5,990 6,649 Fannie Mae, 7.0%, 9/1/31 7,760 14,264 Fannie Mae, 7.0%, 12/1/31 14,558 12,755 Fannie Mae, 7.0%, 1/1/32 15,062 2,301,701 Federal Home Loan Mortgage Corp., 3.0%, 8/1/29 2,357,365 2,099,433 Federal Home Loan Mortgage Corp., 3.0%, 10/1/29 2,147,271 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 63 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 890,387 Federal Home Loan Mortgage Corp., 3.0%, 9/1/42 $ 908,481 5,608,323 Federal Home Loan Mortgage Corp., 3.0%, 11/1/42 5,722,111 659,463 Federal Home Loan Mortgage Corp., 3.0%, 2/1/43 673,684 1,692,974 Federal Home Loan Mortgage Corp., 3.0%, 2/1/43 1,729,477 1,852,327 Federal Home Loan Mortgage Corp., 3.0%, 5/1/43 1,889,982 1,380,271 Federal Home Loan Mortgage Corp., 3.0%, 5/1/45 1,404,040 1,133,188 Federal Home Loan Mortgage Corp., 3.0%, 8/1/45 1,150,136 4,409,693 Federal Home Loan Mortgage Corp., 3.0%, 6/1/46 4,499,328 3,651,358 Federal Home Loan Mortgage Corp., 3.0%, 9/1/46 3,701,312 1,215,690 Federal Home Loan Mortgage Corp., 3.0%, 12/1/46 1,240,402 1,886,823 Federal Home Loan Mortgage Corp., 3.0%, 12/1/46 1,910,449 5,386,179 Federal Home Loan Mortgage Corp., 3.0%, 2/1/47 5,457,232 756,517 Federal Home Loan Mortgage Corp., 3.0%, 3/1/47 764,976 355,658 Federal Home Loan Mortgage Corp., 3.0%, 7/1/47 359,278 183,684 Federal Home Loan Mortgage Corp., 3.5%, 3/1/26 189,692 1,334,998 Federal Home Loan Mortgage Corp., 3.5%, 4/1/42 1,386,619 2,376,518 Federal Home Loan Mortgage Corp., 3.5%, 8/1/43 2,468,721 5,765,299 Federal Home Loan Mortgage Corp., 3.5%, 7/1/44 5,982,512 666,085 Federal Home Loan Mortgage Corp., 3.5%, 8/1/44 690,804 493,097 Federal Home Loan Mortgage Corp., 3.5%, 9/1/44 513,790 2,028,603 Federal Home Loan Mortgage Corp., 3.5%, 10/1/44 2,101,594 97,056 Federal Home Loan Mortgage Corp., 3.5%, 11/1/44 100,275 5,327,708 Federal Home Loan Mortgage Corp., 3.5%, 12/1/44 5,510,376 2,584,367 Federal Home Loan Mortgage Corp., 3.5%, 3/1/45 2,667,152 636,832 Federal Home Loan Mortgage Corp., 3.5%, 4/1/45 657,232 6,382,040 Federal Home Loan Mortgage Corp., 3.5%, 6/1/45 6,649,943 166,713 Federal Home Loan Mortgage Corp., 3.5%, 7/1/45 173,910 5,558,540 Federal Home Loan Mortgage Corp., 3.5%, 10/1/45 5,791,883 6,288,300 Federal Home Loan Mortgage Corp., 3.5%, 10/1/45 6,489,752 6,387,316 Federal Home Loan Mortgage Corp., 3.5%, 11/1/45 6,608,684 3,430,230 Federal Home Loan Mortgage Corp., 3.5%, 3/1/46 3,534,082 5,591,429 Federal Home Loan Mortgage Corp., 3.5%, 5/1/46 5,759,571 5,682,042 Federal Home Loan Mortgage Corp., 3.5%, 7/1/46 5,926,428 8,062,910 Federal Home Loan Mortgage Corp., 3.5%, 8/1/46 8,399,803 8,405,986 Federal Home Loan Mortgage Corp., 3.5%, 8/1/46 8,713,773 10,153,333 Federal Home Loan Mortgage Corp., 3.5%, 8/1/46 10,546,923 3,375,275 Federal Home Loan Mortgage Corp., 3.5%, 12/1/46 3,477,655 9,840,383 Federal Home Loan Mortgage Corp., 3.5%, 12/1/46 10,245,989 2,015,832 Federal Home Loan Mortgage Corp., 3.5%, 1/1/47 2,076,632 568,895 Federal Home Loan Mortgage Corp., 3.5%, 6/1/47 588,839 1,899,047 Federal Home Loan Mortgage Corp., 3.5%, 6/1/47 1,956,327 3,660,853 Federal Home Loan Mortgage Corp., 3.5%, 6/1/47 3,771,274 8,612,294 Federal Home Loan Mortgage Corp., 3.5%, 7/1/47 8,872,068 The accompanying notes are an integral part of these financial statements. 64 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 8,290,862 Federal Home Loan Mortgage Corp., 3.5%, 8/1/47 $ 8,540,937 9,996,710 Federal Home Loan Mortgage Corp., 3.5%, 10/1/47 10,293,886 3,312,286 Federal Home Loan Mortgage Corp., 3.5%, 11/1/47 3,410,746 4,497,104 Federal Home Loan Mortgage Corp., 3.5%, 11/1/47 4,632,747 3,143,256 Federal Home Loan Mortgage Corp., 3.5%, 1/1/48 3,232,439 6,521,447 Federal Home Loan Mortgage Corp., 3.5%, 1/1/48 6,712,161 7,841,088 Federal Home Loan Mortgage Corp., 4.0%, 11/1/41 8,377,152 271,769 Federal Home Loan Mortgage Corp., 4.0%, 6/1/42 286,805 93,597 Federal Home Loan Mortgage Corp., 4.0%, 7/1/42 98,775 3,651,515 Federal Home Loan Mortgage Corp., 4.0%, 10/1/42 3,853,248 57,979 Federal Home Loan Mortgage Corp., 4.0%, 11/1/42 61,186 1,368,278 Federal Home Loan Mortgage Corp., 4.0%, 1/1/44 1,438,474 3,869,028 Federal Home Loan Mortgage Corp., 4.0%, 5/1/44 4,055,709 3,607,314 Federal Home Loan Mortgage Corp., 4.0%, 6/1/44 3,780,975 5,222,504 Federal Home Loan Mortgage Corp., 4.0%, 7/1/44 5,473,118 2,079,582 Federal Home Loan Mortgage Corp., 4.0%, 9/1/44 2,178,418 1,419,873 Federal Home Loan Mortgage Corp., 4.0%, 12/1/44 1,486,050 997,932 Federal Home Loan Mortgage Corp., 4.0%, 4/1/45 1,044,439 3,959,457 Federal Home Loan Mortgage Corp., 4.0%, 12/1/45 4,143,957 1,497,711 Federal Home Loan Mortgage Corp., 4.0%, 1/1/46 1,567,500 223,730 Federal Home Loan Mortgage Corp., 4.0%, 5/1/46 231,400 451,722 Federal Home Loan Mortgage Corp., 4.0%, 5/1/46 471,545 3,325,764 Federal Home Loan Mortgage Corp., 4.0%, 6/1/46 3,480,746 4,285,009 Federal Home Loan Mortgage Corp., 4.0%, 7/1/46 4,484,690 3,688,013 Federal Home Loan Mortgage Corp., 4.0%, 8/1/46 3,859,803 55,411 Federal Home Loan Mortgage Corp., 4.0%, 10/1/46 57,311 1,152,122 Federal Home Loan Mortgage Corp., 4.0%, 3/1/47 1,205,255 1,976,427 Federal Home Loan Mortgage Corp., 4.0%, 4/1/47 2,071,421 3,079,705 Federal Home Loan Mortgage Corp., 4.0%, 4/1/47 3,227,728 5,928,150 Federal Home Loan Mortgage Corp., 4.0%, 4/1/47 6,196,678 6,613,648 Federal Home Loan Mortgage Corp., 4.0%, 4/1/47 6,931,511 9,143,458 Federal Home Loan Mortgage Corp., 4.0%, 4/1/47 9,553,894 10,936,333 Federal Home Loan Mortgage Corp., 4.0%, 5/1/47 11,426,665 1,221,968 Federal Home Loan Mortgage Corp., 4.0%, 6/1/47 1,274,817 2,865,386 Federal Home Loan Mortgage Corp., 4.0%, 7/1/47 2,989,316 6,497,072 Federal Home Loan Mortgage Corp., 4.0%, 10/1/47 6,765,761 7,504 Federal Home Loan Mortgage Corp., 4.5%, 3/1/20 7,662 38,078 Federal Home Loan Mortgage Corp., 4.5%, 10/1/20 38,883 2,129,767 Federal Home Loan Mortgage Corp., 4.5%, 11/1/40 2,288,958 1,335,720 Federal Home Loan Mortgage Corp., 4.5%, 3/1/42 1,435,416 3,052,348 Federal Home Loan Mortgage Corp., 4.5%, 3/1/42 3,280,217 117,032 Federal Home Loan Mortgage Corp., 4.5%, 11/1/43 124,813 5,485,383 Federal Home Loan Mortgage Corp., 4.5%, 5/1/47 5,781,080 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 65 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 73,051 Federal Home Loan Mortgage Corp., 5.0%, 10/1/20 $ 74,778 4,315 Federal Home Loan Mortgage Corp., 5.0%, 12/1/21 4,422 8,192 Federal Home Loan Mortgage Corp., 5.0%, 11/1/34 8,967 54,444 Federal Home Loan Mortgage Corp., 5.0%, 6/1/35 57,581 227,832 Federal Home Loan Mortgage Corp., 5.0%, 9/1/38 247,497 221,223 Federal Home Loan Mortgage Corp., 5.0%, 10/1/38 240,328 140,655 Federal Home Loan Mortgage Corp., 5.5%, 9/1/33 156,033 7,943 Federal Home Loan Mortgage Corp., 5.5%, 1/1/34 8,800 5,551 Federal Home Loan Mortgage Corp., 5.5%, 11/1/34 5,920 71,988 Federal Home Loan Mortgage Corp., 5.5%, 11/1/34 80,018 87,841 Federal Home Loan Mortgage Corp., 5.5%, 8/1/35 96,963 18,069 Federal Home Loan Mortgage Corp., 5.5%, 11/1/35 20,053 758,220 Federal Home Loan Mortgage Corp., 5.5%, 6/1/41 842,715 41,828 Federal Home Loan Mortgage Corp., 6.0%, 1/1/33 45,926 52,970 Federal Home Loan Mortgage Corp., 6.0%, 1/1/33 58,317 3,306 Federal Home Loan Mortgage Corp., 6.0%, 2/1/33 3,727 31,818 Federal Home Loan Mortgage Corp., 6.0%, 2/1/33 36,089 10,746 Federal Home Loan Mortgage Corp., 6.0%, 3/1/33 11,770 100,465 Federal Home Loan Mortgage Corp., 6.0%, 3/1/33 113,988 70,473 Federal Home Loan Mortgage Corp., 6.0%, 9/1/33 79,920 11,661 Federal Home Loan Mortgage Corp., 6.0%, 11/1/33 13,225 29,182 Federal Home Loan Mortgage Corp., 6.0%, 11/1/33 32,467 8,241 Federal Home Loan Mortgage Corp., 6.0%, 12/1/33 9,027 110,674 Federal Home Loan Mortgage Corp., 6.0%, 12/1/33 121,497 19,399 Federal Home Loan Mortgage Corp., 6.0%, 1/1/34 22,004 32,943 Federal Home Loan Mortgage Corp., 6.0%, 1/1/34 36,304 119,870 Federal Home Loan Mortgage Corp., 6.0%, 5/1/34 132,601 305,633 Federal Home Loan Mortgage Corp., 6.0%, 5/1/34 346,794 59,608 Federal Home Loan Mortgage Corp., 6.0%, 8/1/34 65,783 14,694 Federal Home Loan Mortgage Corp., 6.0%, 4/1/35 16,095 44,266 Federal Home Loan Mortgage Corp., 6.0%, 6/1/35 48,485 48,379 Federal Home Loan Mortgage Corp., 6.0%, 4/1/36 53,140 7,312 Federal Home Loan Mortgage Corp., 6.0%, 7/1/36 8,297 31,510 Federal Home Loan Mortgage Corp., 6.0%, 7/1/36 34,520 20,329 Federal Home Loan Mortgage Corp., 6.0%, 12/1/36 22,483 46,532 Federal Home Loan Mortgage Corp., 6.0%, 1/1/38 52,807 53,549 Federal Home Loan Mortgage Corp., 6.0%, 7/1/38 59,651 285 Federal Home Loan Mortgage Corp., 6.5%, 11/1/30 316 141 Federal Home Loan Mortgage Corp., 6.5%, 1/1/31 157 316 Federal Home Loan Mortgage Corp., 6.5%, 3/1/31 351 1,160 Federal Home Loan Mortgage Corp., 6.5%, 3/1/31 1,287 4,682 Federal Home Loan Mortgage Corp., 6.5%, 5/1/31 5,196 4,891 Federal Home Loan Mortgage Corp., 6.5%, 5/1/31 5,524 The accompanying notes are an integral part of these financial statements. 66 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 471 Federal Home Loan Mortgage Corp., 6.5%, 8/1/31 $ 533 3,589 Federal Home Loan Mortgage Corp., 6.5%, 8/1/31 3,984 113 Federal Home Loan Mortgage Corp., 6.5%, 6/1/32 125 7,754 Federal Home Loan Mortgage Corp., 6.5%, 7/1/32 8,953 102 Federal Home Loan Mortgage Corp., 6.5%, 1/1/33 113 25,506 Federal Home Loan Mortgage Corp., 6.5%, 10/1/33 29,588 7,400 Federal Home Loan Mortgage Corp., 7.0%, 8/1/22 7,437 39,702 Federal Home Loan Mortgage Corp., 7.0%, 9/1/22 40,960 1,916 Federal Home Loan Mortgage Corp., 7.0%, 11/1/30 2,214 1,367 Federal Home Loan Mortgage Corp., 7.0%, 6/1/31 1,369 72,647 Federal Home Loan Mortgage Corp., 7.0%, 10/1/46 74,838 11,385,000 Government National Mortgage Association, 4.0%, 7/1/49 (TBA) 11,802,154 6,702,382 Government National Mortgage Association I, 3.5%, 11/15/41 6,958,754 5,203,204 Government National Mortgage Association I, 3.5%, 7/15/42 5,420,703 1,212,172 Government National Mortgage Association I, 3.5%, 10/15/42 1,260,939 764,176 Government National Mortgage Association I, 3.5%, 1/15/44 793,424 8,376,518 Government National Mortgage Association I, 3.5%, 1/15/45 8,659,173 2,293,360 Government National Mortgage Association I, 3.5%, 8/15/46 2,370,746 7,314 Government National Mortgage Association I, 4.0%, 5/15/39 7,628 2,981 Government National Mortgage Association I, 4.0%, 6/15/39 3,166 4,870 Government National Mortgage Association I, 4.0%, 8/15/40 5,174 216,925 Government National Mortgage Association I, 4.0%, 8/15/40 226,262 5,173 Government National Mortgage Association I, 4.0%, 9/15/40 5,497 92,830 Government National Mortgage Association I, 4.0%, 9/15/40 96,826 5,029 Government National Mortgage Association I, 4.0%, 10/15/40 5,343 5,869 Government National Mortgage Association I, 4.0%, 11/15/40 6,121 30,739 Government National Mortgage Association I, 4.0%, 11/15/40 32,359 15,368 Government National Mortgage Association I, 4.0%, 1/15/41 16,331 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 67 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 51,092 Government National Mortgage Association I, 4.0%, 1/15/41 $ 54,290 7,569 Government National Mortgage Association I, 4.0%, 2/15/41 8,043 47,012 Government National Mortgage Association I, 4.0%, 6/15/41 49,900 110,684 Government National Mortgage Association I, 4.0%, 7/15/41 117,624 2,108 Government National Mortgage Association I, 4.0%, 9/15/41 2,199 294,312 Government National Mortgage Association I, 4.0%, 9/15/41 312,702 5,300 Government National Mortgage Association I, 4.0%, 10/15/41 5,529 6,100 Government National Mortgage Association I, 4.0%, 10/15/41 6,417 3,072 Government National Mortgage Association I, 4.0%, 11/15/41 3,232 3,131 Government National Mortgage Association I, 4.0%, 11/15/41 3,266 5,002 Government National Mortgage Association I, 4.0%, 12/15/41 5,314 18,006 Government National Mortgage Association I, 4.0%, 2/15/42 19,113 204,932 Government National Mortgage Association I, 4.0%, 2/15/42 213,753 947,066 Government National Mortgage Association I, 4.0%, 8/15/43 1,006,066 18,576 Government National Mortgage Association I, 4.0%, 11/15/43 19,534 8,511 Government National Mortgage Association I, 4.0%, 3/15/44 8,956 135,050 Government National Mortgage Association I, 4.0%, 3/15/44 141,272 536,513 Government National Mortgage Association I, 4.0%, 3/15/44 569,833 3,072,006 Government National Mortgage Association I, 4.0%, 3/15/44 3,263,417 3,291 Government National Mortgage Association I, 4.0%, 4/15/44 3,433 21,091 Government National Mortgage Association I, 4.0%, 4/15/44 22,401 2,127,686 Government National Mortgage Association I, 4.0%, 4/15/44 2,259,816 307,310 Government National Mortgage Association I, 4.0%, 8/15/44 326,465 The accompanying notes are an integral part of these financial statements. 68 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 56,125 Government National Mortgage Association I, 4.0%, 9/15/44 $ 59,623 189,720 Government National Mortgage Association I, 4.0%, 9/15/44 199,701 209,920 Government National Mortgage Association I, 4.0%, 9/15/44 219,878 381,526 Government National Mortgage Association I, 4.0%, 9/15/44 401,469 1,953,366 Government National Mortgage Association I, 4.0%, 9/15/44 2,075,196 75,347 Government National Mortgage Association I, 4.0%, 10/15/44 78,843 348,942 Government National Mortgage Association I, 4.0%, 11/15/44 367,202 1,585,567 Government National Mortgage Association I, 4.0%, 12/15/44 1,668,901 355,626 Government National Mortgage Association I, 4.0%, 1/15/45 377,678 1,102,686 Government National Mortgage Association I, 4.0%, 1/15/45 1,170,612 1,125,039 Government National Mortgage Association I, 4.0%, 1/15/45 1,184,104 1,783,017 Government National Mortgage Association I, 4.0%, 1/15/45 1,876,326 768,701 Government National Mortgage Association I, 4.0%, 2/15/45 808,662 1,293,622 Government National Mortgage Association I, 4.0%, 2/15/45 1,361,357 90,260 Government National Mortgage Association I, 4.0%, 3/15/45 94,145 1,486,313 Government National Mortgage Association I, 4.0%, 3/15/45 1,564,245 2,723,714 Government National Mortgage Association I, 4.0%, 4/15/45 2,893,025 1,372,034 Government National Mortgage Association I, 4.0%, 5/15/45 1,457,393 3,750,987 Government National Mortgage Association I, 4.0%, 6/15/45 3,983,956 576,738 Government National Mortgage Association I, 4.0%, 7/15/45 612,596 542,305 Government National Mortgage Association I, 4.0%, 8/15/45 576,066 138 Government National Mortgage Association I, 4.5%, 8/15/19 138 1,681 Government National Mortgage Association I, 4.5%, 12/15/19 1,700 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 69 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 146,012 Government National Mortgage Association I, 4.5%, 6/15/25 $ 150,451 40,315 Government National Mortgage Association I, 4.5%, 7/15/33 42,918 134,247 Government National Mortgage Association I, 4.5%, 9/15/33 144,181 134,991 Government National Mortgage Association I, 4.5%, 10/15/33 142,272 142,380 Government National Mortgage Association I, 4.5%, 10/15/33 152,061 21,297 Government National Mortgage Association I, 4.5%, 2/15/34 22,548 14,873 Government National Mortgage Association I, 4.5%, 3/15/35 15,680 50,756 Government National Mortgage Association I, 4.5%, 3/15/35 53,521 19,317 Government National Mortgage Association I, 4.5%, 4/15/35 20,368 133,092 Government National Mortgage Association I, 4.5%, 4/15/35 141,927 5,338 Government National Mortgage Association I, 4.5%, 9/15/35 5,627 70,725 Government National Mortgage Association I, 4.5%, 10/15/35 75,306 45,832 Government National Mortgage Association I, 4.5%, 4/15/38 48,304 798,902 Government National Mortgage Association I, 4.5%, 12/15/39 860,160 291,965 Government National Mortgage Association I, 4.5%, 1/15/40 314,788 172,223 Government National Mortgage Association I, 4.5%, 9/15/40 185,633 656,195 Government National Mortgage Association I, 4.5%, 10/15/40 707,218 349,685 Government National Mortgage Association I, 4.5%, 4/15/41 375,707 715,841 Government National Mortgage Association I, 4.5%, 5/15/41 771,165 705,724 Government National Mortgage Association I, 4.5%, 6/15/41 759,990 238,126 Government National Mortgage Association I, 4.5%, 7/15/41 256,532 722,200 Government National Mortgage Association I, 4.5%, 8/15/41 778,014 134 Government National Mortgage Association I, 5.0%, 7/15/19 135 49,985 Government National Mortgage Association I, 5.0%, 7/15/33 54,122 The accompanying notes are an integral part of these financial statements. 70 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 52,723 Government National Mortgage Association I, 5.0%, 9/15/33 $ 57,194 55,463 Government National Mortgage Association I, 5.0%, 4/15/34 60,168 322,848 Government National Mortgage Association I, 5.0%, 4/15/35 350,253 139,713 Government National Mortgage Association I, 5.0%, 7/15/40 153,686 280 Government National Mortgage Association I, 5.5%, 8/15/19 280 1,307 Government National Mortgage Association I, 5.5%, 10/15/19 1,307 6,998 Government National Mortgage Association I, 5.5%, 11/15/19 7,000 43,201 Government National Mortgage Association I, 5.5%, 1/15/29 46,002 9,074 Government National Mortgage Association I, 5.5%, 6/15/33 9,907 46,523 Government National Mortgage Association I, 5.5%, 7/15/33 52,466 47,289 Government National Mortgage Association I, 5.5%, 7/15/33 53,271 13,820 Government National Mortgage Association I, 5.5%, 8/15/33 15,578 22,136 Government National Mortgage Association I, 5.5%, 8/15/33 24,947 115,723 Government National Mortgage Association I, 5.5%, 8/15/33 130,040 38,987 Government National Mortgage Association I, 5.5%, 9/15/33 41,670 40,280 Government National Mortgage Association I, 5.5%, 9/15/33 42,892 31,583 Government National Mortgage Association I, 5.5%, 10/15/33 33,733 42,234 Government National Mortgage Association I, 5.5%, 10/15/33 47,562 234,946 Government National Mortgage Association I, 5.5%, 7/15/34 265,064 21,909 Government National Mortgage Association I, 5.5%, 10/15/34 23,949 279,681 Government National Mortgage Association I, 5.5%, 11/15/34 314,280 96,451 Government National Mortgage Association I, 5.5%, 1/15/35 108,585 17,421 Government National Mortgage Association I, 5.5%, 2/15/35 19,009 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 71 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 35,721 Government National Mortgage Association I, 5.5%, 2/15/35 $ 38,045 28,985 Government National Mortgage Association I, 5.5%, 6/15/35 30,875 325,710 Government National Mortgage Association I, 5.5%, 7/15/35 366,212 31,572 Government National Mortgage Association I, 5.5%, 10/15/35 33,964 108,998 Government National Mortgage Association I, 5.5%, 10/15/35 122,403 27,350 Government National Mortgage Association I, 5.5%, 2/15/37 30,725 5,757 Government National Mortgage Association I, 5.72%, 4/15/29 6,183 986 Government National Mortgage Association I, 6.0%, 9/15/19 984 79,584 Government National Mortgage Association I, 6.0%, 12/15/23 84,683 6,602 Government National Mortgage Association I, 6.0%, 1/15/24 7,221 26,300 Government National Mortgage Association I, 6.0%, 4/15/28 29,507 112,426 Government National Mortgage Association I, 6.0%, 9/15/28 124,391 5,551 Government National Mortgage Association I, 6.0%, 10/15/28 6,116 45,906 Government National Mortgage Association I, 6.0%, 2/15/29 51,557 52,232 Government National Mortgage Association I, 6.0%, 2/15/29 57,766 24,511 Government National Mortgage Association I, 6.0%, 6/15/31 26,811 14,147 Government National Mortgage Association I, 6.0%, 11/15/31 16,048 940 Government National Mortgage Association I, 6.0%, 3/15/32 1,069 4,512 Government National Mortgage Association I, 6.0%, 8/15/32 5,088 51,078 Government National Mortgage Association I, 6.0%, 9/15/32 56,364 83,041 Government National Mortgage Association I, 6.0%, 9/15/32 90,876 116,874 Government National Mortgage Association I, 6.0%, 9/15/32 128,012 5,913 Government National Mortgage Association I, 6.0%, 10/15/32 6,468 The accompanying notes are an integral part of these financial statements. 72 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 22,543 Government National Mortgage Association I, 6.0%, 10/15/32 $ 24,749 5,771 Government National Mortgage Association I, 6.0%, 11/15/32 6,316 6,182 Government National Mortgage Association I, 6.0%, 11/15/32 6,765 7,559 Government National Mortgage Association I, 6.0%, 12/15/32 8,319 8,109 Government National Mortgage Association I, 6.0%, 12/15/32 8,982 49,151 Government National Mortgage Association I, 6.0%, 12/15/32 53,783 107,625 Government National Mortgage Association I, 6.0%, 12/15/32 117,823 148,887 Government National Mortgage Association I, 6.0%, 12/15/32 163,171 158,213 Government National Mortgage Association I, 6.0%, 12/15/32 173,335 262,623 Government National Mortgage Association I, 6.0%, 12/15/32 289,637 18,194 Government National Mortgage Association I, 6.0%, 1/15/33 19,901 31,092 Government National Mortgage Association I, 6.0%, 1/15/33 34,813 106,578 Government National Mortgage Association I, 6.0%, 1/15/33 121,570 19,608 Government National Mortgage Association I, 6.0%, 2/15/33 22,232 63,314 Government National Mortgage Association I, 6.0%, 2/15/33 69,828 67,812 Government National Mortgage Association I, 6.0%, 2/15/33 77,099 85,260 Government National Mortgage Association I, 6.0%, 2/15/33 94,676 27,998 Government National Mortgage Association I, 6.0%, 3/15/33 30,653 39,034 Government National Mortgage Association I, 6.0%, 3/15/33 44,274 70,212 Government National Mortgage Association I, 6.0%, 3/15/33 76,961 68,180 Government National Mortgage Association I, 6.0%, 3/15/33 77,780 75,560 Government National Mortgage Association I, 6.0%, 3/15/33 86,187 93,744 Government National Mortgage Association I, 6.0%, 3/15/33 106,948 158,379 Government National Mortgage Association I, 6.0%, 3/15/33 180,544 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 73 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 268,494 Government National Mortgage Association I, 6.0%, 3/15/33 $ 305,374 13,351 Government National Mortgage Association I, 6.0%, 4/15/33 14,604 15,052 Government National Mortgage Association I, 6.0%, 4/15/33 16,464 31,928 Government National Mortgage Association I, 6.0%, 4/15/33 35,066 16,943 Government National Mortgage Association I, 6.0%, 5/15/33 18,537 100,723 Government National Mortgage Association I, 6.0%, 5/15/33 112,294 7,263 Government National Mortgage Association I, 6.0%, 6/15/33 8,064 12,226 Government National Mortgage Association I, 6.0%, 9/15/33 13,620 13,685 Government National Mortgage Association I, 6.0%, 9/15/33 14,978 39,850 Government National Mortgage Association I, 6.0%, 9/15/33 45,441 35,576 Government National Mortgage Association I, 6.0%, 10/15/33 40,321 89,206 Government National Mortgage Association I, 6.0%, 11/15/33 97,727 161,855 Government National Mortgage Association I, 6.0%, 3/15/34 184,020 37,384 Government National Mortgage Association I, 6.0%, 6/15/34 42,639 27,135 Government National Mortgage Association I, 6.0%, 8/15/34 30,957 42,395 Government National Mortgage Association I, 6.0%, 8/15/34 46,374 20,813 Government National Mortgage Association I, 6.0%, 9/15/34 23,666 35,452 Government National Mortgage Association I, 6.0%, 9/15/34 38,818 98,082 Government National Mortgage Association I, 6.0%, 9/15/34 111,431 43,128 Government National Mortgage Association I, 6.0%, 10/15/34 47,192 45,251 Government National Mortgage Association I, 6.0%, 10/15/34 49,539 94,736 Government National Mortgage Association I, 6.0%, 10/15/34 103,683 87,278 Government National Mortgage Association I, 6.0%, 11/15/34 97,501 560,786 Government National Mortgage Association I, 6.0%, 9/15/35 639,057 The accompanying notes are an integral part of these financial statements. 74 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 149,135 Government National Mortgage Association I, 6.0%, 8/15/36 $ 170,325 101,626 Government National Mortgage Association I, 6.0%, 10/15/36 116,053 32,155 Government National Mortgage Association I, 6.0%, 11/15/37 36,720 30,781 Government National Mortgage Association I, 6.0%, 8/15/38 35,078 12,131 Government National Mortgage Association I, 6.5%, 10/15/24 13,062 2,111 Government National Mortgage Association I, 6.5%, 2/15/28 2,319 5,872 Government National Mortgage Association I, 6.5%, 4/15/28 6,451 31,270 Government National Mortgage Association I, 6.5%, 4/15/28 34,353 6,125 Government National Mortgage Association I, 6.5%, 6/15/28 6,935 5,203 Government National Mortgage Association I, 6.5%, 8/15/28 5,716 2,228 Government National Mortgage Association I, 6.5%, 10/15/28 2,448 12,377 Government National Mortgage Association I, 6.5%, 10/15/28 13,597 19,598 Government National Mortgage Association I, 6.5%, 1/15/29 21,530 886 Government National Mortgage Association I, 6.5%, 2/15/29 973 4,234 Government National Mortgage Association I, 6.5%, 2/15/29 4,652 10,850 Government National Mortgage Association I, 6.5%, 2/15/29 11,934 4,059 Government National Mortgage Association I, 6.5%, 3/15/29 4,459 4,746 Government National Mortgage Association I, 6.5%, 3/15/29 5,214 6,028 Government National Mortgage Association I, 6.5%, 3/15/29 6,622 15,535 Government National Mortgage Association I, 6.5%, 3/15/29 17,067 66,016 Government National Mortgage Association I, 6.5%, 3/15/29 72,526 1,588 Government National Mortgage Association I, 6.5%, 5/15/29 1,745 3,011 Government National Mortgage Association I, 6.5%, 5/15/29 3,308 40,630 Government National Mortgage Association I, 6.5%, 5/15/29 46,167 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 75 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 21,746 Government National Mortgage Association I, 6.5%, 6/15/29 $ 23,891 38,866 Government National Mortgage Association I, 6.5%, 4/15/31 44,644 10,662 Government National Mortgage Association I, 6.5%, 5/15/31 12,270 11,508 Government National Mortgage Association I, 6.5%, 5/15/31 13,369 34,780 Government National Mortgage Association I, 6.5%, 5/15/31 38,210 5,645 Government National Mortgage Association I, 6.5%, 6/15/31 6,223 11,790 Government National Mortgage Association I, 6.5%, 7/15/31 12,953 30,330 Government National Mortgage Association I, 6.5%, 8/15/31 33,320 16,149 Government National Mortgage Association I, 6.5%, 9/15/31 17,741 4,325 Government National Mortgage Association I, 6.5%, 10/15/31 4,751 12,197 Government National Mortgage Association I, 6.5%, 10/15/31 13,399 52,787 Government National Mortgage Association I, 6.5%, 10/15/31 57,992 2,670 Government National Mortgage Association I, 6.5%, 11/15/31 2,933 39,634 Government National Mortgage Association I, 6.5%, 11/15/31 43,542 16,345 Government National Mortgage Association I, 6.5%, 1/15/32 17,957 70,416 Government National Mortgage Association I, 6.5%, 1/15/32 80,108 7,523 Government National Mortgage Association I, 6.5%, 2/15/32 8,326 11,522 Government National Mortgage Association I, 6.5%, 2/15/32 13,060 14,612 Government National Mortgage Association I, 6.5%, 2/15/32 17,064 18,495 Government National Mortgage Association I, 6.5%, 2/15/32 20,319 26,054 Government National Mortgage Association I, 6.5%, 2/15/32 30,288 9,424 Government National Mortgage Association I, 6.5%, 3/15/32 10,353 71,005 Government National Mortgage Association I, 6.5%, 3/15/32 79,213 4,246 Government National Mortgage Association I, 6.5%, 4/15/32 4,664 The accompanying notes are an integral part of these financial statements. 76 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 8,033 Government National Mortgage Association I, 6.5%, 4/15/32 $ 8,925 8,407 Government National Mortgage Association I, 6.5%, 4/15/32 9,247 48,711 Government National Mortgage Association I, 6.5%, 4/15/32 56,209 3,238 Government National Mortgage Association I, 6.5%, 5/15/32 3,557 4,906 Government National Mortgage Association I, 6.5%, 5/15/32 5,389 8,096 Government National Mortgage Association I, 6.5%, 5/15/32 9,340 8,483 Government National Mortgage Association I, 6.5%, 5/15/32 9,378 8,366 Government National Mortgage Association I, 6.5%, 6/15/32 9,191 9,305 Government National Mortgage Association I, 6.5%, 6/15/32 10,223 9,221 Government National Mortgage Association I, 6.5%, 6/15/32 10,260 8,045 Government National Mortgage Association I, 6.5%, 7/15/32 8,839 9,128 Government National Mortgage Association I, 6.5%, 7/15/32 10,028 94,317 Government National Mortgage Association I, 6.5%, 7/15/32 110,411 3,465 Government National Mortgage Association I, 6.5%, 8/15/32 3,823 27,571 Government National Mortgage Association I, 6.5%, 8/15/32 32,275 39,795 Government National Mortgage Association I, 6.5%, 8/15/32 44,311 14,368 Government National Mortgage Association I, 6.5%, 9/15/32 16,458 33,478 Government National Mortgage Association I, 6.5%, 9/15/32 36,780 35,496 Government National Mortgage Association I, 6.5%, 9/15/32 39,572 38,154 Government National Mortgage Association I, 6.5%, 10/15/32 41,916 36,234 Government National Mortgage Association I, 6.5%, 11/15/32 42,253 224,694 Government National Mortgage Association I, 6.5%, 12/15/32 263,430 2,444 Government National Mortgage Association I, 6.5%, 1/15/33 2,818 245,082 Government National Mortgage Association I, 6.5%, 1/15/33 287,058 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 77 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 28,102 Government National Mortgage Association I, 6.5%, 5/15/33 $ 30,925 1,490 Government National Mortgage Association I, 6.5%, 10/15/33 1,649 1,872 Government National Mortgage Association I, 6.5%, 2/15/34 2,057 102,717 Government National Mortgage Association I, 6.5%, 6/15/34 113,662 3,721 Government National Mortgage Association I, 6.5%, 9/15/34 4,088 37,272 Government National Mortgage Association I, 6.5%, 4/15/35 40,948 6,001 Government National Mortgage Association I, 6.5%, 6/15/35 6,593 16,840 Government National Mortgage Association I, 6.5%, 7/15/35 18,500 60,035 Government National Mortgage Association I, 6.5%, 7/15/35 65,955 867 Government National Mortgage Association I, 6.75%, 4/15/26 952 10,955 Government National Mortgage Association I, 7.0%, 8/15/23 11,460 34,087 Government National Mortgage Association I, 7.0%, 9/15/24 36,826 13,240 Government National Mortgage Association I, 7.0%, 7/15/25 14,175 5,184 Government National Mortgage Association I, 7.0%, 11/15/26 5,733 12,889 Government National Mortgage Association I, 7.0%, 6/15/27 14,389 15,072 Government National Mortgage Association I, 7.0%, 1/15/28 16,419 9,589 Government National Mortgage Association I, 7.0%, 2/15/28 10,348 11,054 Government National Mortgage Association I, 7.0%, 3/15/28 11,236 4,501 Government National Mortgage Association I, 7.0%, 4/15/28 4,508 10,902 Government National Mortgage Association I, 7.0%, 7/15/28 12,022 909 Government National Mortgage Association I, 7.0%, 8/15/28 1,017 11,270 Government National Mortgage Association I, 7.0%, 11/15/28 12,975 30,165 Government National Mortgage Association I, 7.0%, 11/15/28 34,369 19,775 Government National Mortgage Association I, 7.0%, 4/15/29 20,260 The accompanying notes are an integral part of these financial statements. 78 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 21,956 Government National Mortgage Association I, 7.0%, 4/15/29 $ 23,610 20,344 Government National Mortgage Association I, 7.0%, 5/15/29 20,666 2,924 Government National Mortgage Association I, 7.0%, 6/15/29 2,929 7,052 Government National Mortgage Association I, 7.0%, 7/15/29 7,840 39,173 Government National Mortgage Association I, 7.0%, 11/15/29 42,999 1,771 Government National Mortgage Association I, 7.0%, 12/15/30 1,797 5,566 Government National Mortgage Association I, 7.0%, 12/15/30 5,766 25,208 Government National Mortgage Association I, 7.0%, 12/15/30 29,270 34,657 Government National Mortgage Association I, 7.0%, 12/15/30 35,049 38,854 Government National Mortgage Association I, 7.0%, 1/15/31 39,203 4,810 Government National Mortgage Association I, 7.0%, 3/15/31 4,892 18,742 Government National Mortgage Association I, 7.0%, 6/15/31 22,061 2,292 Government National Mortgage Association I, 7.0%, 7/15/31 2,685 102,611 Government National Mortgage Association I, 7.0%, 8/15/31 120,697 10,572 Government National Mortgage Association I, 7.0%, 9/15/31 10,993 27,326 Government National Mortgage Association I, 7.0%, 9/15/31 30,375 7,419 Government National Mortgage Association I, 7.0%, 11/15/31 7,706 44,939 Government National Mortgage Association I, 7.0%, 3/15/32 49,871 33,625 Government National Mortgage Association I, 7.0%, 4/15/32 37,221 68,720 Government National Mortgage Association I, 7.0%, 5/15/32 82,024 3,325 Government National Mortgage Association I, 7.5%, 3/15/23 3,441 19,526 Government National Mortgage Association I, 7.5%, 10/15/23 20,667 1,101 Government National Mortgage Association I, 7.5%, 6/15/24 1,115 7,650 Government National Mortgage Association I, 7.5%, 8/15/25 7,721 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 79 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 3,372 Government National Mortgage Association I, 7.5%, 9/15/25 $ 3,623 3,141 Government National Mortgage Association I, 7.5%, 12/15/25 3,192 8,786 Government National Mortgage Association I, 7.5%, 2/15/27 9,530 22,151 Government National Mortgage Association I, 7.5%, 3/15/27 25,180 33,010 Government National Mortgage Association I, 7.5%, 10/15/27 36,476 13,576 Government National Mortgage Association I, 7.5%, 6/15/29 15,001 2,439 Government National Mortgage Association I, 7.5%, 8/15/29 2,467 7,331 Government National Mortgage Association I, 7.5%, 8/15/29 7,397 14,620 Government National Mortgage Association I, 7.5%, 9/15/29 14,649 2,015 Government National Mortgage Association I, 7.5%, 10/15/29 2,034 5,220 Government National Mortgage Association I, 7.5%, 10/15/29 5,369 13,031 Government National Mortgage Association I, 7.5%, 2/15/31 13,147 14,408 Government National Mortgage Association I, 7.5%, 2/15/31 14,775 6,474 Government National Mortgage Association I, 7.5%, 3/15/31 6,628 39,910 Government National Mortgage Association I, 7.5%, 12/15/31 41,401 1,989 Government National Mortgage Association I, 7.75%, 2/15/30 2,011 114 Government National Mortgage Association I, 8.25%, 5/15/20 114 838 Government National Mortgage Association I, 8.5%, 8/15/21 840 51 Government National Mortgage Association I, 9.0%, 12/15/19 51 57 Government National Mortgage Association I, 9.0%, 9/15/21 58 1,147 Government National Mortgage Association I, 9.0%, 6/15/22 1,161 524,742 Government National Mortgage Association II, 3.5%, 3/20/45 542,280 493,423 Government National Mortgage Association II, 3.5%, 4/20/45 510,609 The accompanying notes are an integral part of these financial statements. 80 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 767,960 Government National Mortgage Association II, 3.5%, 4/20/45 $ 793,178 1,084,928 Government National Mortgage Association II, 3.5%, 4/20/45 1,122,316 1,401,838 Government National Mortgage Association II, 3.5%, 3/20/46 1,452,721 5,935,931 Government National Mortgage Association II, 4.0%, 7/20/44 6,258,963 161,046 Government National Mortgage Association II, 4.0%, 9/20/44 169,816 1,389,564 Government National Mortgage Association II, 4.0%, 10/20/44 1,459,732 5,384,522 Government National Mortgage Association II, 4.0%, 10/20/46 5,649,244 1,923,848 Government National Mortgage Association II, 4.0%, 2/20/48 2,028,507 1,953,478 Government National Mortgage Association II, 4.0%, 4/20/48 2,060,187 49,965 Government National Mortgage Association II, 4.5%, 12/20/34 52,545 188,358 Government National Mortgage Association II, 4.5%, 1/20/35 197,566 31,548 Government National Mortgage Association II, 4.5%, 3/20/35 33,151 938,677 Government National Mortgage Association II, 4.5%, 9/20/41 1,001,495 4,911,835 Government National Mortgage Association II, 4.5%, 9/20/44 5,129,005 1,367,522 Government National Mortgage Association II, 4.5%, 10/20/44 1,450,754 2,831,962 Government National Mortgage Association II, 4.5%, 11/20/44 3,003,914 6,906,837 Government National Mortgage Association II, 4.5%, 2/20/48 7,257,630 1,150 Government National Mortgage Association II, 5.0%, 1/20/20 1,177 1,690 Government National Mortgage Association II, 5.5%, 10/20/19 1,689 137,565 Government National Mortgage Association II, 5.5%, 3/20/34 150,561 117,029 Government National Mortgage Association II, 5.5%, 4/20/34 128,057 87,609 Government National Mortgage Association II, 5.5%, 10/20/37 93,198 65,001 Government National Mortgage Association II, 5.75%, 6/20/33 69,460 22,233 Government National Mortgage Association II, 5.9%, 1/20/28 23,928 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 81 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 53,624 Government National Mortgage Association II, 5.9%, 7/20/28 $ 57,302 12,996 Government National Mortgage Association II, 6.0%, 10/20/31 14,739 64,188 Government National Mortgage Association II, 6.0%, 1/20/33 73,628 69,783 Government National Mortgage Association II, 6.0%, 10/20/33 79,993 39,790 Government National Mortgage Association II, 6.0%, 6/20/34 45,623 44,018 Government National Mortgage Association II, 6.45%, 7/20/32 47,356 76,954 Government National Mortgage Association II, 6.45%, 1/20/33 82,788 12,449 Government National Mortgage Association II, 6.5%, 1/20/24 12,981 28,919 Government National Mortgage Association II, 6.5%, 8/20/28 32,762 1,353 Government National Mortgage Association II, 6.5%, 2/20/29 1,548 544 Government National Mortgage Association II, 6.5%, 3/20/29 620 16,507 Government National Mortgage Association II, 6.5%, 4/20/29 18,783 9,156 Government National Mortgage Association II, 6.5%, 4/20/31 10,638 6,347 Government National Mortgage Association II, 6.5%, 6/20/31 7,380 29,597 Government National Mortgage Association II, 6.5%, 10/20/32 34,677 42,098 Government National Mortgage Association II, 6.5%, 3/20/34 49,790 4,596 Government National Mortgage Association II, 7.0%, 5/20/26 5,036 12,421 Government National Mortgage Association II, 7.0%, 8/20/27 14,083 14,077 Government National Mortgage Association II, 7.0%, 6/20/28 16,104 46,189 Government National Mortgage Association II, 7.0%, 11/20/28 52,922 48,743 Government National Mortgage Association II, 7.0%, 1/20/29 55,985 4,721 Government National Mortgage Association II, 7.0%, 2/20/29 5,414 1,369 Government National Mortgage Association II, 7.0%, 12/20/30 1,583 7,082 Government National Mortgage Association II, 7.0%, 1/20/31 8,314 The accompanying notes are an integral part of these financial statements. 82 Pioneer Bond Fund | Annual Report | 6/30/19 ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 3,575 Government National Mortgage Association II, 7.0%, 3/20/31 $ 4,200 19,794 Government National Mortgage Association II, 7.0%, 7/20/31 23,313 7,691 Government National Mortgage Association II, 7.0%, 11/20/31 9,094 8,076 Government National Mortgage Association II, 7.5%, 5/20/30 9,430 2,513 Government National Mortgage Association II, 7.5%, 6/20/30 2,937 5,876 Government National Mortgage Association II, 7.5%, 7/20/30 6,724 8,359 Government National Mortgage Association II, 7.5%, 8/20/30 9,974 4,250 Government National Mortgage Association II, 7.5%, 12/20/30 5,083 14 Government National Mortgage Association II, 8.0%, 5/20/25 15 1,372 Government National Mortgage Association II, 9.0%, 3/20/22 1,376 186 Government National Mortgage Association II, 9.0%, 4/20/22 186 1,811 Government National Mortgage Association II, 9.0%, 11/20/24 1,816 480,857 Tennessee Valley Authority, 4.929%, 1/15/21 496,617 25,000,000(k) U.S. Treasury Bills, 7/2/19 24,998,653 65,000,000(k) U.S. Treasury Bills, 7/9/19 64,972,050 20,000,000(k) U.S. Treasury Bills, 7/16/19 19,982,927 100,000,000(k) U.S. Treasury Bills, 7/23/19 99,873,795 51,545,000 U.S. Treasury Bonds, 3.0%, 2/15/49 56,610,907 14,000,000 U.S. Treasury Bonds, 3.125%, 5/15/48 15,709,531 29,957,222 U.S. Treasury Inflation Indexed Bonds, 0.75%, 2/15/45 29,632,795 63,904,804 U.S. Treasury Inflation Indexed Bonds, 0.875%, 2/15/47 65,108,752 75,738,365 U.S. Treasury Inflation Indexed Bonds, 1.0%, 2/15/46 79,351,714 64,121,063 U.S. Treasury Inflation Indexed Bonds, 1.0%, 2/15/48 67,451,797 51,985,149 U.S. Treasury Inflation Indexed Bonds, 1.0%, 2/15/49 54,984,410 18,575,000 U.S. Treasury Notes, 2.25%, 4/30/24 18,996,565 15,488,000 U.S. Treasury Notes, 2.625%, 2/15/29 16,332,580 12,430,000 U.S. Treasury Notes, 2.875%, 5/15/28 13,347,198 ----------------------------------------------------------------------------------------------------------------------------------- TOTAL U.S. GOVERNMENT AND AGENCY OBLIGATIONS (Cost $1,766,605,827) $1,785,996,247 ----------------------------------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 83 Schedule of Investments | 6/30/19 (continued) ----------------------------------------------------------------------------------------------------------------------------------- Principal Amount USD ($) Value ----------------------------------------------------------------------------------------------------------------------------------- TEMPORARY CASH INVESTMENTS -- 0.8% of Net Assets REPURCHASE AGREEMENTS -- 0.8% 14,400,000 $14,400,000 RBC Capital Markets LLC, 2.48%, dated 6/28/19 plus accrued interest on 7/1/19 collateralized by the following: $7,012,124 Federal National Mortgage Association, 3.0% -- 4.0%, 11/1/32 -- 11/1/48 $7,674,667 Freddie Mac Giant, 3.5% -- 4.5%, 2/1/44 -- 3/1/49 $4,245 Government National Mortgage Association, 4.0%, 10/15/47 $ 14,400,000 16,230,000 $16,230,000 ScotiaBank, 2.45%, dated 6/28/19 plus accrued interest on 7/1/19 collateralized by the following: $158,130 Federal National Mortgage Association, 2.5% -- 6.4%, 2/1/21 -- 5/1/48 $16,388,309 Freddie Mac Giant, 3.0% -- 4.5%, 11/1/48 -- 6/1/49 $11,548 U.S. Treasury Notes, 2.0%, 5/31/24 16,230,000 8,670,000 $8,670,000 TD Securities USA LLC, 2.49%, dated 6/28/19 plus accrued interest on 7/1/19 collateralized by $8,843,457 U.S. Treasury Notes, 2.6%, 6/15/21 8,670,000 7,580,000 $7,580,000 TD Securities USA LLC, 2.51%, dated 6/28/19 plus accrued interest on 7/1/19 collateralized by $7,731,601 Freddie Mac Giant, 4.0%, 10/1/48 7,580,000 -------------- $ 46,880,000 ----------------------------------------------------------------------------------------------------------------------------------- TOTAL TEMPORARY CASH INVESTMENTS (Cost $46,880,000) $ 46,880,000 ----------------------------------------------------------------------------------------------------------------------------------- TOTAL INVESTMENTS IN UNAFFILIATED ISSUERS -- 100.4% (Cost $5,476,178,527) $5,591,361,911 ----------------------------------------------------------------------------------------------------------------------------------- OTHER ASSETS AND LIABILITIES -- (0.4)% $ (22,999,642) ----------------------------------------------------------------------------------------------------------------------------------- NET ASSETS -- 100.0% $5,568,362,269 =================================================================================================================================== 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. ZERO Zero Constant Index. The accompanying notes are an integral part of these financial statements. 84 Pioneer Bond Fund | Annual Report | 6/30/19 (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 June 30, 2019, the value of these securities amounted to $2,045,107,678, or 36.7% of net assets. (TBA) "To Be Announced" Securities. + 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 June 30, 2019. + Security 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 June 30, 2019. (c) The interest rate is subject to change periodically. The interest rate and/or reference index and spread is shown at June 30, 2019. (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 June 30, 2019. (e) Security represents the interest-only portion payments on a pool of underlying mortgages or mortgage-backed securities. (f) Securities are restricted as to resale. (g) Non-income producing security. (h) Issued as participation notes. (i) Issued as preference shares. (j) Consists of Revenue Bonds unless otherwise indicated. (k) Security issued with a zero coupon. Income is recognized through accretion of discount. FUTURES CONTRACTS FIXED INCOME INTEREST RATE FUTURES CONTRACTS ---------------------------------------------------------------------------------------- Number of Contracts Expiration Notional Unrealized Long Description Date Amount Market Value Appreciation ---------------------------------------------------------------------------------------- 1,062 U.S. 2 Year 9/30/19 $227,078,922 $228,520,829 $1,441,907 Note (CBT) 3,394 U.S. 5 Year 9/30/19 396,912,391 401,022,313 4,109,922 Note (CBT) 263 U.S. Ultra 9/19/19 45,612,008 46,698,938 1,086,930 Bond (CBT) ---------------------------------------------------------------------------------------- $669,603,321 $676,242,080 $6,638,759 ======================================================================================== The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 85 Schedule of Investments | 6/30/19 (continued) --------------------------------------------------------------------------------------- Number of Contracts Expiration Notional Unrealized Short Description Date Amount Market Value (Depreciation) --------------------------------------------------------------------------------------- 1,457 U.S. 10 Year 9/19/19 $183,725,953 $186,450,469 $(2,724,516) Note (CBT) 1,178 U.S. 10 Year 9/19/19 159,711,031 162,711,250 (3,000,219) Ultra 342 U.S. Long 9/19/19 52,102,860 53,213,063 (1,110,203) Bond (CBT) --------------------------------------------------------------------------------------- $395,539,844 $402,374,782 $(6,834,938) --------------------------------------------------------------------------------------- TOTAL FUTURES CONTRACTS $274,063,477 $273,867,298 $ (196,179) ======================================================================================= SWAP CONTRACTS 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) $102,350 $ 89,213 Bank NA Property Group LP 2,851,000 JPMorgan Chase Simon Receive 1.00% 6/20/22 (8,072) 71,993 63,921 Bank NA Property Group LP ---------------------------------------------------------------------------------------------------------------------- TOTAL OVER THE COUNTER (OTC) CREDIT DEFAULT SWAP CONTRACTS -- SELL PROTECTION $(21,209) $174,343 $153,134 ---------------------------------------------------------------------------------------------------------------------- TOTAL SWAP CONTRACTS $(21,209) $174,343 $153,134 ====================================================================================================================== (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 year ended June 30, 2019, were as follows: --------------------------------------------------------------------------------------------------------- Purchases Sales --------------------------------------------------------------------------------------------------------- Long-Term U.S. Government Securities $ 501,191,019 $ 491,715,593 Other Long-Term Securities $2,250,249,529 $2,074,656,817 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 Fund's 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 year ended June 30, 2019, the Fund engaged in sales of $8,233,202 which resulted in a net realized gain/(loss) of $(6,345). During the year ended June 30, 2019, the Fund did not engage in purchases pursuant to these procedures. The accompanying notes are an integral part of these financial statements. 86 Pioneer Bond Fund | Annual Report | 6/30/19 At June 30, 2019, the net unrealized appreciation on investments based on cost for federal tax purposes of $5,485,996,749 was as follows: Aggregate gross unrealized appreciation for all investments in which there is an excess of value over tax cost $144,316,207 Aggregate gross unrealized depreciation for all investments in which there is an excess of tax cost over value (38,994,090) ------------ Net unrealized appreciation $105,322,117 ============ 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. Pioneer Bond Fund | Annual Report | 6/30/19 87 Schedule of Investments | 6/30/19 (continued) The following is a summary of the inputs used as of June 30, 2019, in valuing the Fund's investments: ---------------------------------------------------------------------------------------------------------------- Level 1 Level 2 Level 3 Total ---------------------------------------------------------------------------------------------------------------- Convertible Preferred Stocks $26,467,395 $ -- $ -- $ 26,467,395 Asset Backed Securities -- 651,788,194 -- 651,788,194 Collateralized Mortgage Obligations -- 1,260,022,981 -- 1,260,022,981 Corporate Bonds -- 1,527,317,148 -- 1,527,317,148 Foreign Government Bond -- 13,827,884 -- 13,827,884 Insurance-Linked Securities Catastrophe Linked Bonds Multiperil - U.S. -- 21,539,415 1,253,375 22,792,790 Collateralized Reinsurance Earthquakes - California -- -- 1,747,040 1,747,040 Multiperil - Massachusetts -- -- 5,041,996 5,041,996 Multiperil - U.S. -- -- 4,032,440 4,032,440 Multiperil - U.S. Regional -- -- 5,877,851 5,877,851 Multiperil - Worldwide -- -- 3,403,858 3,403,858 Windstorm - Florida -- -- 1,547,492 1,547,492 Windstorm - North Carolina -- -- 1,467,000 1,467,000 Windstorm - U.S. Regional -- -- 2,498,451 2,498,451 Industry Loss Warranties Multiperil - U.S. -- -- 2,484,372 2,484,372 Reinsurance Sidecars Multiperil - U.S. -- -- 10,051,227 10,051,227 Multiperil - Worldwide -- -- 79,713,234 79,713,234 All Other Insurance-Linked Securities -- 32,296,735 -- 32,296,735 Municipal Bonds -- 14,170,167 -- 14,170,167 Senior Secured Floating Rate Loan Interests -- 91,937,409 -- 91,937,409 U.S. Government and Agency Obligations -- 1,785,996,247 -- 1,785,996,247 Repurchase Agreements -- 46,880,000 -- 46,880,000 ---------------------------------------------------------------------------------------------------------------- Total Investments in Securities $26,467,395 $5,445,776,180 $119,118,336 $5,591,361,911 ---------------------------------------------------------------------------------------------------------------- Other Financial Instruments Net unrealized depreciation on futures contracts $ (196,179) $ -- $ -- $ (196,179) Swap contracts, at value -- 153,134 -- 153,134 ---------------------------------------------------------------------------------------------------------------- Total Other Financial Instruments $ (196,179) $ 153,134 $ -- $ (43,045) ================================================================================================================ The accompanying notes are an integral part of these financial statements. 88 Pioneer Bond Fund | Annual Report | 6/30/19 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) (876,968) Changed in unrealized appreciation (depreciation)(2) (4,100,464) Accrued discounts/premiums (57,162) Purchases 87,193,409 Sales (70,684,957) Transfers in to Level 3* -- Transfers out of Level 3* -- ------------------------------------------------------------------------------------- Balance as of 6/30/19 $119,118,336 ===================================================================================== (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 values. For the year ended June 30, 2019, 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 June 30, 2019: $(4,096,733) ----------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 89 Statement of Assets and Liabilities | 6/30/19 ASSETS: Investments in unaffiliated issuers, at value (cost $5,476,178,527) $5,591,361,911 Cash 83,654,309 Futures collateral 1,741,389 Swap contracts, at value (net premiums received $(21,209)) 153,134 Receivables -- Investment securities sold 21,474,397 Fund shares sold 13,896,986 Dividends 175,631 Interest 26,440,735 Other assets 75,091 -------------------------------------------------------------------------------------------------- Total assets $5,738,973,583 ================================================================================================== LIABILITIES: Payables -- Investment securities purchased $ 154,261,292 Fund shares repurchased 10,443,886 Distributions 2,986,562 Trustees' fees 7,146 Due to broker for futures 470,187 Variation margin for futures contracts 130,390 Net unrealized depreciation on futures contracts 196,179 Due to affiliates 292,417 Accrued expenses 1,823,255 -------------------------------------------------------------------------------------------------- Total liabilities $ 170,611,314 ================================================================================================== NET ASSETS: Paid-in capital $5,491,067,466 Distributable earnings 77,294,803 -------------------------------------------------------------------------------------------------- Net assets $5,568,362,269 ================================================================================================== NET ASSET VALUE PER SHARE: No par value (unlimited number of shares authorized) Class A (based on $979,874,009/100,096,841 shares) $ 9.79 Class C (based on $62,446,858/6,447,897 shares) $ 9.68 Class K (based on $1,273,821,407/130,185,478 shares) $ 9.78 Class R (based on $198,457,330/20,088,403 shares) $ 9.88 Class Y (based on $3,053,762,665/314,821,780 shares) $ 9.70 MAXIMUM OFFERING PRICE PER SHARE: Class A (based on $9.79 net asset value per share/100%-4.50% maximum sales charge) $ 10.25 ================================================================================================== The accompanying notes are an integral part of these financial statements. 90 Pioneer Bond Fund | Annual Report | 6/30/19 Statement of Operations For the Year Ended 6/30/19 INVESTMENT INCOME: Interest from unaffiliated issuers $185,073,998 Dividends from unaffiliated issuers 6,251,082 --------------------------------------------------------------------------------------------------------- Total investment income $191,325,080 ========================================================================================================= EXPENSES: Management fees $ 15,997,027 Administrative expense 1,380,221 Transfer agent fees Class A 2,444,875 Class C 83,330 Class K 6,907 Class R 475,421 Class Y 3,147,968 Distribution fees Class A 2,509,049 Class C 661,529 Class R 930,110 Shareowner communications expense 262,900 Custodian fees 235,504 Registration fees 233,556 Professional fees 321,927 Printing expense 83,705 Pricing expense 250,313 Trustees' fees 245,411 Insurance expense 64,747 Miscellaneous 106,246 --------------------------------------------------------------------------------------------------------- Total expenses $ 29,440,746 Less fees waived and expenses reimbursed by the Adviser (291,088) --------------------------------------------------------------------------------------------------------- Net expenses $ 29,149,658 --------------------------------------------------------------------------------------------------------- Net investment income $162,175,422 --------------------------------------------------------------------------------------------------------- REALIZED AND UNREALIZED GAIN (LOSS) ON INVESTMENTS: Net realized gain (loss) on: Investments in unaffiliated issuers $ (3,413,982) Futures contracts (13,842,373) Swap contracts 3,509,578 $(13,746,777) --------------------------------------------------------------------------------------------------------- Change in net unrealized appreciation (depreciation) on: Investments in unaffiliated issuers $210,908,601 Futures contracts 2,125,503 Swap contracts (40,995) Unfunded loan commitments (1,444) $212,991,665 --------------------------------------------------------------------------------------------------------- Net realized and unrealized gain (loss) on investments $199,244,888 --------------------------------------------------------------------------------------------------------- Net increase in net assets resulting from operations $361,420,310 ========================================================================================================= The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 91 Statements of Changes in Net Assets ------------------------------------------------------------------------------------------------------------------ Year Ended Year Ended 6/30/19 6/30/18 ------------------------------------------------------------------------------------------------------------------ FROM OPERATIONS: Net investment income (loss) $ 162,175,422 $ 143,173,744 Net realized gain (loss) on investments (13,746,777) 10,923,996 Change in net unrealized appreciation (depreciation) on investments 212,991,665 (140,359,697) ------------------------------------------------------------------------------------------------------------------ Net increase in net assets resulting from operations $ 361,420,310 $ 13,738,043 ------------------------------------------------------------------------------------------------------------------ DISTRIBUTIONS TO SHAREOWNERS: Class A ($0.30 and $0.28 per share, respectively) $ (31,768,715) $ (32,824,981)* Class C ($0.23 and $0.20 per share, respectively) (1,624,633) (1,902,820)* Class K ($0.34 and $0.31 per share, respectively) (38,746,201) (27,240,137)* Class R ($0.28 and $0.25 per share, respectively) (5,436,508) (4,692,437)* Class Y ($0.33 and $0.30 per share, respectively) (96,979,642) (84,440,366)* ------------------------------------------------------------------------------------------------------------------ Total distributions to shareowners $ (174,555,699) $ (151,100,741) ------------------------------------------------------------------------------------------------------------------ FROM FUND SHARE TRANSACTIONS: Net proceeds from sales of shares $ 2,280,096,185 $ 1,964,162,519 Reinvestment of distributions 140,968,997 119,480,660 Cost of shares repurchased (2,027,763,106) (1,674,666,408) ------------------------------------------------------------------------------------------------------------------ Net increase in net assets resulting from Fund share transactions $ 393,302,076 $ 408,976,771 ------------------------------------------------------------------------------------------------------------------ Net increase in net assets $ 580,166,687 $ 271,614,073 NET ASSETS:** Beginning of year $ 4,988,195,582 $ 4,716,581,509 ------------------------------------------------------------------------------------------------------------------ End of year $ 5,568,362,269 $ 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. 92 Pioneer Bond Fund | Annual Report | 6/30/19 -------------------------------------------------------------------------------------------------------------- Year Ended Year Ended Year Ended Year Ended 6/30/19 6/30/19 6/30/18 6/30/18 Shares Amount Shares Amount -------------------------------------------------------------------------------------------------------------- Class A Shares sold 26,995,582 $ 255,919,620 32,509,729 $ 313,658,795 Reinvestment of distributions 2,394,810 22,690,254 2,370,359 22,839,925 Less shares repurchased (43,647,656) (412,375,791) (39,650,187) (381,172,700) -------------------------------------------------------------------------------------------------------------- Net decrease (14,257,264) $ (133,765,917) (4,770,099) $ (44,673,980) ============================================================================================================== Class C Shares sold 1,620,055 $ 15,140,871 1,175,621 $ 11,253,310 Reinvestment of distributions 129,683 1,215,362 152,545 1,453,906 Less shares repurchased (3,785,268) (35,370,201) (2,897,968) (27,587,924) -------------------------------------------------------------------------------------------------------------- Net decrease (2,035,530) $ (19,013,968) (1,569,802) $ (14,880,708) ============================================================================================================== Class K Shares sold 80,341,266 $ 760,556,110 45,145,368 $ 434,364,284 Reinvestment of distributions 3,212,139 30,464,825 2,183,632 20,998,540 Less shares repurchased (52,786,664) (497,673,237) (22,716,260) (217,864,913) -------------------------------------------------------------------------------------------------------------- Net increase 30,766,741 $ 293,347,698 24,612,740 $ 237,497,911 ============================================================================================================== Class R Shares sold 4,802,537 $ 45,936,991 6,423,616 $ 62,506,249 Reinvestment of distributions 525,321 5,026,777 411,975 4,003,314 Less shares repurchased (4,077,850) (38,900,021) (6,238,265) (60,823,043) -------------------------------------------------------------------------------------------------------------- Net increase 1,250,008 $ 12,063,747 597,326 $ 5,686,520 ============================================================================================================== Class Y Shares sold 128,196,595 $ 1,202,542,593 119,625,124 $1,142,379,881 Reinvestment of distributions 8,677,520 81,571,779 7,353,829 70,184,975 Less shares repurchased (111,303,616) (1,043,443,856) (103,621,965) (987,217,828) -------------------------------------------------------------------------------------------------------------- Net increase (decrease) 25,570,499 $ 240,670,516 23,356,988 $ 225,347,028 ============================================================================================================== The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 93 Financial Highlights ------------------------------------------------------------------------------------------------------------------------------------ Year Year Year Year Year Ended Ended Ended Ended Ended 6/30/19 6/30/18 6/30/17 6/30/16* 6/30/15* ------------------------------------------------------------------------------------------------------------------------------------ Class A Net asset value, beginning of period $ 9.45 $ 9.71 $ 9.76 $ 9.68 $ 9.88 ------------------------------------------------------------------------------------------------------------------------------------ Increase (decrease) from investment operations: Net investment income (loss) $ 0.27(a) $ 0.26(a) $ 0.25(a) $ 0.25(a) $ 0.27 Net realized and unrealized gain (loss) on investments 0.37 (0.24) (0.01) 0.12 (0.14) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) from investment operations $ 0.64 $ 0.02 $ 0.24 $ 0.37 $ 0.13 ------------------------------------------------------------------------------------------------------------------------------------ Distributions to shareowners: Net investment income $ (0.30) $ (0.28) $ (0.29) $ (0.27) $ (0.29) Net realized gain -- -- -- (0.02) (0.04) ------------------------------------------------------------------------------------------------------------------------------------ Total distributions $ (0.30) $ (0.28) $ (0.29) $ (0.29) $ (0.33) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) in net asset value $ 0.34 $ (0.26) $ (0.05) $ 0.08 $ (0.20) ------------------------------------------------------------------------------------------------------------------------------------ Net asset value, end of period $ 9.79 $ 9.45 $ 9.71 $ 9.76 $ 9.68 ==================================================================================================================================== Total return (b) 6.93% 0.14% 2.48% 3.93% 1.32% Ratio of net expenses to average net assets 0.85% 0.85% 0.85% 0.85% 0.85% Ratio of net investment income (loss) to average net assets 2.88% 2.71% 2.60% 2.58% 2.68% Portfolio turnover rate 52% 45% 44% 43% 81% Net assets, end of period (in thousands) $979,874 $1,081,121 $1,156,940 $1,177,941 $1,044,659 Ratios with no waiver of fees and assumption of expenses by the Adviser and no reduction for fees paid indirectly: Total expenses to average net assets 0.87% 0.96% 0.99% 0.98% 0.93% Net investment income (loss) to average net assets 2.86% 2.60% 2.46% 2.45% 2.60% ==================================================================================================================================== * 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. The accompanying notes are an integral part of these financial statements. 94 Pioneer Bond Fund | Annual Report | 6/30/19 ------------------------------------------------------------------------------------------------------------------------------------ Year Year Year Year Year Ended Ended Ended Ended Ended 6/30/19 6/30/18 6/30/17 6/30/16* 6/30/15* ------------------------------------------------------------------------------------------------------------------------------------ Class C Net asset value, beginning of period $ 9.35 $ 9.60 $ 9.66 $ 9.57 $ 9.77 ------------------------------------------------------------------------------------------------------------------------------------ Increase (decrease) from investment operations: Net investment income (loss) $ 0.21(a) $ 0.19(a) $ 0.18(a) $ 0.17(a) $ 0.19 Net realized and unrealized gain (loss) on investments 0.35 (0.24) (0.03) 0.14 (0.14) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) from investment operations $ 0.56 $ (0.05) $ 0.15 $ 0.31 $ 0.05 ------------------------------------------------------------------------------------------------------------------------------------ Distributions to shareowners: Net investment income $ (0.23) $ (0.20) $ (0.21) $ (0.20) $ (0.21) Net realized gain -- -- -- (0.02) (0.04) ------------------------------------------------------------------------------------------------------------------------------------ Total distributions $ (0.23) $ (0.20) $ (0.21) $ (0.22) $ (0.25) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) in net asset value $ 0.33 $ (0.25) $ (0.06) $ 0.09 $ (0.20) ------------------------------------------------------------------------------------------------------------------------------------ Net asset value, end of period $ 9.68 $ 9.35 $ 9.60 $ 9.66 $ 9.57 ==================================================================================================================================== Total return (b) 6.10% (0.52)% 1.62% 3.28% 0.49% Ratio of net expenses to average net assets 1.52% 1.60% 1.59% 1.60% 1.63% Ratio of net investment income (loss) to average net assets 2.21% 1.96% 1.84% 1.84% 1.89% Portfolio turnover rate 52% 45% 44% 43% 81% Net assets, end of period (in thousands) $62,447 $79,308 $96,547 $134,299 $114,222 ==================================================================================================================================== * 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. The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 95 Financial Highlights (continued) ------------------------------------------------------------------------------------------------------------------------------------ Year Year Year Year Year Ended Ended Ended Ended Ended 6/30/19 6/30/18 6/30/17 6/30/16* 6/30/15* ------------------------------------------------------------------------------------------------------------------------------------ Class K Net asset value, beginning of period $ 9.45 $ 9.71 $ 9.76 $ 9.68 $ 9.87 ------------------------------------------------------------------------------------------------------------------------------------ Increase (decrease) from investment operations: Net investment income (loss) $ 0.32(a) $ 0.30(a) $ 0.29(a) $ 0.29(a) $ 0.30 Net realized and unrealized gain (loss) on investments 0.35 (0.25) (0.01) 0.12 (0.13) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) from investment operations $ 0.67 $ 0.05 $ 0.28 $ 0.41 $ 0.17 ------------------------------------------------------------------------------------------------------------------------------------ Distributions to shareowners: Net investment income $ (0.34) $ (0.31) $ (0.33) $ (0.31) $ (0.32) Net realized gain -- -- -- (0.02) (0.04) ------------------------------------------------------------------------------------------------------------------------------------ Total distributions $ (0.34) $ (0.31) $ (0.33) $ (0.33) $ (0.36) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) in net asset value $ 0.33 $ (0.26) $ (0.05) $ 0.08 $ (0.19) ------------------------------------------------------------------------------------------------------------------------------------ Net asset value, end of period $ 9.78 $ 9.45 $ 9.71 $ 9.76 $ 9.68 ==================================================================================================================================== Total return (b) 7.28% 0.54% 2.87% 4.32% 1.80% Ratio of net expenses to average net assets 0.37% 0.46% 0.47% 0.47% 0.47% Ratio of net investment income (loss) to average net assets 3.37% 3.11% 3.01% 2.98% 3.03% Portfolio turnover rate 52% 45% 44% 43% 81% Net assets, end of period (in thousands) $1,273,821 $939,272 $726,063 $340,096 $179,135 ==================================================================================================================================== * 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. The accompanying notes are an integral part of these financial statements. 96 Pioneer Bond Fund | Annual Report | 6/30/19 ------------------------------------------------------------------------------------------------------------------------------------ Year Year Year Year Year Ended Ended Ended Ended Ended 6/30/19 6/30/18 6/30/17 6/30/16* 6/30/15* ------------------------------------------------------------------------------------------------------------------------------------ Class R Net asset value, beginning of period $ 9.54 $ 9.80 $ 9.85 $ 9.77 $ 9.97 ------------------------------------------------------------------------------------------------------------------------------------ Increase (decrease) from investment operations: Net investment income (loss) $ 0.25(a) $ 0.24(a) $ 0.23(a) $ 0.23(a) $ 0.25 Net realized and unrealized gain (loss) on investments 0.37 (0.25) (0.01) 0.12 (0.15) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) from investment operations $ 0.62 $ (0.01) $ 0.22 $ 0.35 $ 0.10 ------------------------------------------------------------------------------------------------------------------------------------ Distributions to shareowners: Net investment income $ (0.28) $ (0.25) $ (0.27) $ (0.25) $ (0.26) Net realized gain -- -- -- (0.02) (0.04) ------------------------------------------------------------------------------------------------------------------------------------ Total distributions $ (0.28) $ (0.25) $ (0.27) $ (0.27) $ (0.30) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) in net asset value $ 0.34 $ (0.26) $ (0.05) $ 0.08 $ (0.20) ------------------------------------------------------------------------------------------------------------------------------------ Net asset value, end of period $ 9.88 $ 9.54 $ 9.80 $ 9.85 $ 9.77 ==================================================================================================================================== Total return (b) 6.62% (0.08)% 2.23% 3.66% 1.06% Ratio of net expenses to average net assets 1.10% 1.10% 1.10% 1.10% 1.10% Ratio of net investment income (loss) to average net assets 2.64% 2.46% 2.35% 2.33% 2.43% Portfolio turnover rate 52% 45% 44% 43% 81% Net assets, end of period (in thousands) $198,457 $179,729 $178,770 $156,110 $116,815 Ratios with no waiver of fees and assumption of expenses by the Adviser and no reduction for fees paid indirectly: Total expenses to average net assets 1.12% 1.21% 1.24% 1.21% 1.21% Net investment income (loss) to average net assets 2.62% 2.35% 2.21% 2.22% 2.32% ==================================================================================================================================== * 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. The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Annual Report | 6/30/19 97 Financial Highlights (continued) ------------------------------------------------------------------------------------------------------------------------------------ Year Year Year Year Year Ended Ended Ended Ended Ended 6/30/19 6/30/18 6/30/17 6/30/16* 6/30/15* ------------------------------------------------------------------------------------------------------------------------------------ Class Y Net asset value, beginning of period $ 9.36 $ 9.62 $ 9.67 $ 9.59 $ 9.79 ------------------------------------------------------------------------------------------------------------------------------------ Increase (decrease) from investment operations: Net investment income (loss) $ 0.31(a) $ 0.28(a) $ 0.28(a) $ 0.27(a) $ 0.30 Net realized and unrealized gain (loss) on investments 0.36 (0.24) (0.02) 0.12 (0.15) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) from investment operations $ 0.67 $ 0.04 $ 0.26 $ 0.39 $ 0.15 ------------------------------------------------------------------------------------------------------------------------------------ Distributions to shareowners: Net investment income $ (0.33) $ (0.30) $ (0.31) $ (0.29) $ (0.31) Net realized gain -- -- -- (0.02) (0.04) ------------------------------------------------------------------------------------------------------------------------------------ Total distributions $ (0.33) $ (0.30) $ (0.31) $ (0.31) $ (0.35) ------------------------------------------------------------------------------------------------------------------------------------ Net increase (decrease) in net asset value $ 0.34 $ (0.26) $ (0.05) $ 0.08 $ (0.20) ------------------------------------------------------------------------------------------------------------------------------------ Net asset value, end of period $ 9.70 $ 9.36 $ 9.62 $ 9.67 $ 9.59 ==================================================================================================================================== Total return (b) 7.30% 0.40% 2.76% 4.22% 1.59% Ratio of net expenses to average net assets 0.49% 0.58% 0.58% 0.58% 0.58% Ratio of net investment income (loss) to average net assets 3.26% 2.98% 2.87% 2.85% 2.95% Portfolio turnover rate 52% 45% 44% 43% 81% Net assets, end of period (in thousands) $3,053,763 $2,708,766 $2,558,262 $2,136,681 $1,644,161 Ratios with no waiver of fees and assumption of expenses by the Adviser and no reduction for fees paid indirectly: Total expenses to average net assets 0.49% 0.58% 0.59% 0.59% 0.58% Net investment income (loss) to average net assets 3.26% 2.98% 2.86% 2.84% 2.95% ==================================================================================================================================== * 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. The accompanying notes are an integral part of these financial statements. 98 Pioneer Bond Fund | Annual Report | 6/30/19 Notes to Financial Statements | 6/30/19 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 five classes of shares designated as Class A, Class C, Class K, Class R and Class Y shares. 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 Pioneer Bond Fund | Annual Report | 6/30/19 99 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 100 Pioneer Bond Fund | Annual Report | 6/30/19 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. 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. Repurchase agreements are valued at par. Cash may include overnight time deposits at approved financial institutions. 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 June 30, 2019, no securities were valued using fair value methods (other to than securities valued using prices supplied by independent pricing services, broker-dealers or using a third party insurance industry pricing model). Pioneer Bond Fund | Annual Report | 6/30/19 101 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, asset-backed securities and corporate bonds 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, 2019, 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 102 Pioneer Bond Fund | Annual Report | 6/30/19 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. At June 30, 2019, the Fund was permitted to carry forward indefinitely $4,364,357 of short-term losses and $32,138,057 of long-term losses under the Regulated Investment Company Modernization Act of 2010 without limitation. The tax character of distributions paid during the years ended June 30, 2019 and June 30, 2018, were as follows: -------------------------------------------------------------------------- 2019 2018 -------------------------------------------------------------------------- Distributions paid from: Ordinary income $174,555,699 $151,100,741 -------------------------------------------------------------------------- Total $174,555,699 $151,100,741 ========================================================================== The following shows the components of distributable earnings on a federal income tax basis at June 30, 2019: -------------------------------------------------------------------------- 2019 -------------------------------------------------------------------------- Distributable earnings: Undistributed ordinary income $ 11,461,661 Capital Loss Carryforward (36,502,414) Current year dividends payable (2,986,562) Net unrealized depreciation 105,322,118 -------------------------------------------------------------------------- Total $ 77,294,803 ========================================================================== The difference between book basis and tax basis unrealized depreciation is attributable to the tax deferral of losses on wash sales, adjustments relating to catastrophe bonds, swaps, the tax treatment of premium and amortization and the mark to market of futures contracts. D. Fund Shares The Fund records sales and repurchases of its shares as of trade date. The Distributor earned $36,259 in underwriting commissions on the sale of Class A shares during the year ended June 30, 2019. 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. Pioneer Bond Fund | Annual Report | 6/30/19 103 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. 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. 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. 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. 104 Pioneer Bond Fund | Annual Report | 6/30/19 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 shareowner 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 ILS. The Fund could lose a portion or all of the principal it has invested in an ILS, and the right to additional interest or dividend payments with respect to the security, upon the occurrence of one or more trigger events, as defined within the terms of an 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 Pioneer Bond Fund | Annual Report | 6/30/19 105 trigger event will occur, and accordingly, ILS carry significant risk. The Fund is entitled to receive principal, and interest and/or dividend 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 event-linked bonds. ILS also 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 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 106 Pioneer Bond Fund | Annual Report | 6/30/19 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. Open repurchase agreements as of June 30, 2019 are disclosed in the Fund's Schedule of Investments. 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 June 30, 2019, 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 futures contracts open during the year ended June 30, 2019, was $197,240,467. Open futures contracts outstanding at June 30, 2019, are listed in the Schedule of Investments. Pioneer Bond Fund | Annual Report | 6/30/19 107 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 instrument received by the Fund, together with the periodic payments received, may be less than the amount the Fund pays to the protection buyer, 108 Pioneer Bond Fund | Annual Report | 6/30/19 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 average market value of credit default swap contracts open during the year ended June 30, 2019, was $(1,725,245). Open credit default swap contracts at June 30, 2019, 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 year ended June 30, 2019, the effective management fee (excluding waivers and/or assumption of expenses) was equivalent to 0.31% 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) to the extent required to reduce Fund expenses to 0.85%, 1.10% and 0.58% of the average daily net assets attributable to Class A, Class R and Class Y shares, respectively. Fees waived and expenses reimbursed during the year ended June 30, 2019 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. Pioneer Bond Fund | Annual Report | 6/30/19 109 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 $236,683 in management fees, administrative costs and certain other reimbursements payable to the Adviser at June 30, 2019. 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 year ended June 30, 2019, such out-of-pocket expenses by class of shares were as follows: -------------------------------------------------------------------------------- Shareowner Communications -------------------------------------------------------------------------------- Class A $ 89,292 Class C 11,989 Class K 18,291 Class R 393 Class Y 142,935 -------------------------------------------------------------------------------- Total $262,900 ================================================================================ 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 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 $55,734 in distribution fees payable to the Distributor at June 30, 2019. 110 Pioneer Bond Fund | Annual Report | 6/30/19 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 Class A and Class C 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 year ended June 30, 2019, CDSCs in the amount of $9,378 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. Effective August 1, 2018 the Fund participates in a credit facility in the amount of $250 million. Under such facility, depending on the type of loan, interest on borrowings is payable at the London Interbank Offered Rate ("LIBOR") plus 0.90% 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 a credit facility. The commitment fee is allocated among participating Funds based on an allocation schedule set forth in the credit agreement. For the year ended June 30, 2019, the Fund had no borrowings under the credit facility. Pioneer Bond Fund | Annual Report | 6/30/19 111 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 set-off 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. 112 Pioneer Bond Fund | Annual Report | 6/30/19 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 chart shows gross assets and liabilities of the Fund as of June 30, 2019. --------------------------------------------------------------------------------------------------------- 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 $174,343 $ -- $ -- $ -- $174,343 --------------------------------------------------------------------------------------------------------- Total $174,343 $ -- $ -- $ -- $174,343 ========================================================================================================= (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. 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. 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. Pioneer Bond Fund | Annual Report | 6/30/19 113 The fair value of open derivative instruments (not considered to be hedging instruments for accounting disclosure purposes) by risk exposure at June 30, 2019 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 $ -- $153,134 $ -- $ -- $ -- -------------------------------------------------------------------------------- Total Value $ -- $153,134 $ -- $ -- $ -- ================================================================================ Liabilities: Net unrealized depreciation on futures contracts $(196,179) $ -- $ -- $ -- $ -- -------------------------------------------------------------------------------- Total Value $(196,179) $ -- $ -- $ -- $ -- ================================================================================ The effect of derivative instruments (not considered to be hedging instruments for accounting disclosure purposes) on the Statement of Operations by risk exposure at June 30, 2019 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 $(13,842,373) $ -- $ -- $ -- $ -- Swap contracts -- 3,509,578 -- -- -- -------------------------------------------------------------------------------------------- Total Value $(13,842,373) $3,509,578 $ -- $ -- $ -- ============================================================================================ Change in net unrealized appreciation (depreciation) on: Futures contracts $ 2,125,503 $ -- $ -- $ -- $ -- Swap contracts -- (40,995) -- -- -- -------------------------------------------------------------------------------------------- Total Value $ 2,125,503 $ (40,995) $ -- $ -- $ -- ============================================================================================ 114 Pioneer Bond Fund | Annual Report | 6/30/19 Report of Independent Registered Public Accounting Firm To the Board of Trustees and the Shareholders of Pioneer Bond Fund: -------------------------------------------------------------------------------- Opinion on the Financial Statements We have audited the accompanying statement of assets and liabilities of Pioneer Bond Fund (the "Fund"), including the schedule of investments, as of June 30, 2019, and the related statement of operations for the year then ended, the statements changes in net assets for each of the two years in the period then ended and the financial highlights for each of the three years in the period then ended (collectively referred to as the "financial statements"). The financial highlights for the periods ended June 30, 2015 and June 30, 2016 were audited by another independent registered public accounting firm whose report, dated August 25, 2016, expressed an unqualified opinion on those financial highlights. In our opinion, the financial statements present fairly, in all material respects, the financial position of Pioneer Bond Fund at June 30, 2019, the results of its operations for the year then ended, the changes in its net assets for each of the two years in the period then ended, and the financial highlights for each of the three years in the period then ended, in conformity with U.S. generally accepted accounting principles. Basis for Opinion These financial statements are the responsibility of the Fund's management. Our responsibility is to express an opinion on the Fund's financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) ("PCAOB") and are required to be independent with respect to the Fund in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB. We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Fund is not required to have, nor were we engaged to perform, an audit of the Fund's internal control over financial reporting. As part of our audits, we are required to obtain an understanding of internal control over financial reporting, but not for the purpose of expressing an opinion on the effectiveness of the Fund's internal control over financial reporting. Accordingly, we express no such opinion. Pioneer Bond Fund | Annual Report | 6/30/19 115 Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our procedures included confirmation of securities owned as of June 30, 2019, by correspondence with the custodian and brokers. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion. /s/ Ernst & Young LLP We have served as the Fund's auditor since 2017. Boston, Massachusetts August 27, 2019 116 Pioneer Bond Fund | Annual Report | 6/30/19 ADDITIONAL INFORMATION (unaudited) Qualified interest income is exempt from nonresident alien (NRA) tax withholding. The percentage of the Fund's ordinary income distributions derived from qualified interest income was 82.86%. Pioneer Bond Fund | Annual Report | 6/30/19 117 Trustees, Officers and Service Providers Investment Adviser and Administrator Amundi Pioneer Asset Management, Inc. Custodian and Sub-Administrator Brown Brothers Harriman & Co. Independent Registered Public Accounting Firm Ernst & Young LLP Principal Underwriter Amundi Pioneer Distributor, Inc. Legal Counsel Morgan, Lewis & Bockius LLP 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/us. This information is also available on the Securities and Exchange Commission's web site at www.sec.gov. Trustees and Officers The Fund's Trustees and officers are listed below, together with their principal occupations and other directorships they have held during at least the past five years. Trustees who are interested persons of the Fund within the meaning of the 1940 Act are referred to as Interested Trustees. Trustees who are not interested persons of the Fund are referred to as Independent Trustees. Each of the Trustees, except for Ms. Durnin, serves as a Trustee of each of the 43 U.S. registered investment portfolios for which Amundi Pioneer serves as investment adviser (the "Pioneer Funds"). Ms. Durnin serves as a Trustee of 38 Pioneer Funds. The address for all Trustees and all officers of the Fund is 60 State Street, Boston, Massachusetts 02109. The Statement of Additional Information of the Fund includes additional information about the Trustees and is available, without charge, upon request, by calling 1-800-225-6292. 118 Pioneer Bond Fund | Annual Report | 6/30/19 Independent Trustees Name, Age and Position Term of Office and Other Directorships Held With the Fund Length of Service Principal Occupation Held by Trustee ------------------------------------------------------------------------------------------------------------------------------------ Thomas J. Perna (68) Trustee since 2006. Private investor (2004 - Director, Broadridge Financial Solutions, Chairman of the Board Serves until a successor 2008 and 2013 - present); Inc. (investor communications and and Trustee trustee is elected or earlier Chairman (2008 - 2013) and securities processing provider for financial retirement or removal. Chief Executive Officer services industry) (2009 - present); (2008 - 2012), Quadriserv, Director, Quadriserv, Inc. (2005 - 2013); Inc. (technology products for and Commissioner, New Jersey State Civil securities lending industry); Service Commission (2011 - 2015) and Senior Executive Vice President, The Bank of New York (financial and securities services) (1986 - 2004) ------------------------------------------------------------------------------------------------------------------------------------ David R. Bock (75) Trustee since 2005. Managing Partner, Federal Director of New York Mortgage Trust Trustee Serves until a successor City Capital Advisors (publicly-traded mortgage REIT) trustee is elected or earlier (corporate advisory services (2004 - 2009, 2012 - present); Director retirement or removal. company) (1997 - 2004 and of The Swiss Helvetia Fund, Inc. 2008 - present); Interim (closed-end fund) (2010 - 2017); Chief Executive Officer, Director of Oxford Analytica, Inc. Oxford Analytica, Inc. (2008 - 2015); and Director of Enterprise (privately held research and Community Investment, Inc. (privately-held consulting company) (2010); affordable housing finance company) Executive Vice President and (1985 - 2010) Chief Financial Officer, I-trax, Inc. (publicly traded health care services company) (2004 - 2007); and Executive Vice President and Chief Financial Officer, Pedestal Inc. (internet-based mortgage trading company) (2000 - 2002); Private Consultant (1995 - 1997); Managing Director, Lehman Brothers (1992 - 1995); and Executive, The World Bank (1979 - 1992) ------------------------------------------------------------------------------------------------------------------------------------ Diane Durnin (62) Trustee since 2019. Managing Director - Head of None Trustee Serves until a successor Product Strategy and trustee is elected or earlier Development, BNY Mellon retirement or removal. Investment Management (2012-2018); Vice Chairman - The Dreyfus Corporation (2005 - 2018): Executive Vice President Head of Product, BNY Mellon Investment Management (2007 - 2012); Executive Director- Product Strategy, Mellon Asset Management (2005 - 2007); Executive Vice President Head of Products, Marketing and Client Service, Dreyfus Corporation (2000 - 2005); and Senior Vice President - Strategic Product and Business Development, Dreyfus Corporation (1994 - 2000) ------------------------------------------------------------------------------------------------------------------------------------ Benjamin M. Friedman (74) Trustee since 2008. William Joseph Maier Trustee, Mellon Institutional Funds Trustee Serves until a successor Professor of Political Investment Trust and Mellon Institutional trustee is elected or earlier Economy, Harvard University Funds Master Portfolio (oversaw 17 retirement or removal. (1972 - present) portfolios in fund complex) (1989 - 2008) ------------------------------------------------------------------------------------------------------------------------------------ Pioneer Bond Fund | Annual Report | 6/30/19 119 Independent Trustees (continued) Name, Age and Position Term of Office and Other Directorships Held With the Fund Length of Service Principal Occupation Held by Trustee ------------------------------------------------------------------------------------------------------------------------------------ Margaret B.W. Graham (72) Trustee since 1996. Founding Director, None Trustee Serves until a successor Vice-President and Corporate trustee is elected or earlier Secretary, The Winthrop retirement or removal. Group, Inc. (consulting firm) (1982 - present); Desautels Faculty of Management, McGill University (1999 - 2017); and Manager of Research Operations and Organizational Learning, Xerox PARC, Xerox's advance research center (1990-1994) ------------------------------------------------------------------------------------------------------------------------------------ Lorraine H. Monchak (62) Trustee since 2017. Chief Investment Officer, None Trustee (Advisory Trustee from 1199 SEIU Funds (healthcare 2014 - 2017) Serves workers union pension funds) until a successor trustee (2001 - present); Vice is elected or earlier President - International retirement or removal. Investments Group, American International Group, Inc. (insurance company) (1993 - 2001); Vice President - Corporate Finance and Treasury Group, Citibank, N.A. (1980 - 1986 and 1990 - 1993); Vice President - Asset/Liability Management Group, Federal Farm Funding Corporation (government- sponsored issuer of debt securities) (1988 - 1990); Mortgage Strategies Group, Shearson Lehman Hutton, Inc. (investment bank) (1987 - 1988); and Mortgage Strategies Group, Drexel Burnham Lambert, Ltd. (investment bank) (1986 - 1987) ------------------------------------------------------------------------------------------------------------------------------------ Marguerite A. Piret (71) Trustee since 1996. President and Chief Executive Director of New America High Income Trustee Serves until a successor Officer, Metric Financial Fund, Inc. (closed-end investment trustee is elected or earlier Inc. (formerly known as company) (2004 - present); and Member, retirement or removal. NewburyPiret Company) Board of Governors, Investment Company (investment banking firm) Institute (2000 - 2006) (1981 - present) ------------------------------------------------------------------------------------------------------------------------------------ Fred J. Ricciardi (72) Trustee since 2014. Consultant (investment None Trustee Serves until a successor company services) (2012 - trustee is elected or earlier present); Executive Vice retirement or removal. President, BNY Mellon (financial and investment company services) (1969 - 2012); Director, BNY International Financing Corp. (financial services) (2002 - 2012); Director, Mellon Overseas Investment Corp. (financial services) (2009 - 2012); Director, Financial Models (technology) (2005 - 2007); Director, BNY Hamilton Funds, Ireland (offshore investment companies) (2004 - 2007); Chairman/Director, AIB/BNY Securities Services, Ltd., Ireland (financial services) (1999 - 2006); and Chairman, BNY Alternative Investment Services, Inc. (financial services) (2005 - 2007) ------------------------------------------------------------------------------------------------------------------------------------ 120 Pioneer Bond Fund | Annual Report | 6/30/19 Interested Trustees Name, Age and Position Term of Office and Other Directorships Held With the Fund Length of Service Principal Occupation Held by Trustee ------------------------------------------------------------------------------------------------------------------------------------ Lisa M. Jones (57)* Trustee since 2017. Director, CEO and President None Trustee, President and Serves until a successor of Amundi Pioneer Asset Chief Executive Officer trustee is elected or earlier Management USA, Inc. retirement or removal (since September 2014); Director, CEO and President of Amundi Pioneer Asset Management, Inc. (since September 2014); Director, CEO and President of Amundi Pioneer Distributor, Inc. (since September 2014); Director, CEO and President of Amundi Pioneer Institutional Asset Management, Inc. (since September 2014); Chair, Amundi Pioneer Asset Management USA, Inc., Amundi Pioneer Distributor, Inc. and Amundi Pioneer Institutional Asset Management, Inc. (September 2014 - 2018); Managing Director, Morgan Stanley Investment Management (2010 - 2013); Director of Institutional Business, CEO of International, Eaton Vance Management (2005 - 2010); and Director of Amundi USA, Inc. (since 2017) ------------------------------------------------------------------------------------------------------------------------------------ Kenneth J. Taubes (61)* Trustee since 2014. Director and Executive Vice None Trustee Serves until a successor President (since 2008) and trustee is elected or earlier Chief Investment Officer, retirement or removal U.S. (since 2010) of Amundi Pioneer Asset Management USA, Inc.; Director and Executive Vice President and Chief Investment Officer, U.S. of Amundi Pioneer (since 2008); Executive Vice President and Chief Investment Officer, U.S. of Amundi Pioneer Institutional Asset Management, Inc. (since 2009); Portfolio Manager of Amundi Pioneer (since 1999); and Director of Amundi USA, Inc. (since 2017) ------------------------------------------------------------------------------------------------------------------------------------ * Ms. Jones and Mr. Taubes are Interested Trustees because they are officers or directors of the Fund's investment adviser and certain of its affiliates. Pioneer Bond Fund | Annual Report | 6/30/19 121 Fund Officers Name, Age and Position Term of Office and Other Directorships Held With the Fund Length of Service Principal Occupation Held by Officer ------------------------------------------------------------------------------------------------------------------------------------ Christopher J. Kelley (54) Since 2010. Serves Vice President and Associate None Secretary and Chief at the discretion of General Counsel of Amundi Legal Officer the Board Pioneer since January 2008; Secretary and Chief Legal Officer of all of the Pioneer Funds since June 2010; Assistant Secretary of all of the Pioneer Funds from September 2003 to May 2010; and Vice President and Senior Counsel of Amundi Pioneer from July 2002 to December 2007 ------------------------------------------------------------------------------------------------------------------------------------ Carol B. Hannigan (58) Since 2010. Serves Fund Governance Director of None Assistant Secretary at the discretion of Amundi Pioneer since December the Board 2006 and Assistant Secretary of all the Pioneer Funds since June 2010; Manager - Fund Governance of Amundi Pioneer from December 2003 to November 2006; and Senior Paralegal of Amundi Pioneer from January 2000 to November 2003 ------------------------------------------------------------------------------------------------------------------------------------ Thomas Reyes (56) Since 2010. Serves Senior Counsel of Amundi None Assistant Secretary at the discretion of Pioneer since May 2013 and the Board Assistant Secretary of all the Pioneer Funds since June 2010; and Counsel of Amundi Pioneer from June 2007 to May 2013 ------------------------------------------------------------------------------------------------------------------------------------ Mark E. Bradley (59) Since 2008. Serves Vice President - Fund None Treasurer and Chief at the discretion of Treasury of Amundi Pioneer; Financial and Accounting the Board Treasurer of all of the Officer Pioneer Funds since March 2008; Deputy Treasurer of Amundi Pioneer from March 2004 to February 2008; and Assistant Treasurer of all of the Pioneer Funds from March 2004 to February 2008 ------------------------------------------------------------------------------------------------------------------------------------ Luis I. Presutti (54) Since 2000. Serves Director - Fund Treasury of None Assistant Treasurer at the discretion of Amundi Pioneer; and Assistant the Board Treasurer of all of the Pioneer Funds ------------------------------------------------------------------------------------------------------------------------------------ 122 Pioneer Bond Fund | Annual Report | 6/30/19 Name, Age and Position Term of Office and Other Directorships Held With the Fund Length of Service Principal Occupation Held by Officer ------------------------------------------------------------------------------------------------------------------------------------ Gary Sullivan (61) Since 2002. Serves Senior Manager - Fund None Assistant Treasurer at the discretion of Treasury of Amundi Pioneer; the Board and Assistant Treasurer of all of the Pioneer Funds ------------------------------------------------------------------------------------------------------------------------------------ David F. Johnson (39) Since 2009. Serves Senior Manager - Fund None Assistant Treasurer at the discretion of Treasury of Amundi Pioneer the Board since November 2008; Assistant Treasurer of all of the Pioneer Funds since January 2009; and Client Service Manager - Institutional Investor Services at State Street Bank from March 2003 to March 2007 ------------------------------------------------------------------------------------------------------------------------------------ John Malone (48) Since 2018. Serves Managing Director, Chief None Chief Compliance Officer at the discretion of Compliance Officer of Amundi the Board Pioneer Asset Management; Amundi Pioneer Institutional Asset Management, Inc.; and the Pioneer Funds since September 2018; and Chief Compliance Officer of Amundi Pioneer Distributor, Inc. since January 2014. ------------------------------------------------------------------------------------------------------------------------------------ Kelly O'Donnell (48) Since 2006. Serves Vice President - Amundi None Anti-Money Laundering at the discretion of Pioneer Asset Management; and Officer the Board Anti-Money Laundering Officer of all the Pioneer Funds since 2006 ------------------------------------------------------------------------------------------------------------------------------------ Pioneer Bond Fund | Annual Report | 6/30/19 123 This page is for your notes. 124 Pioneer Bond Fund | Annual Report | 6/30/19 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/us This report must be preceded or accompanied by a prospectus. The Fund files a complete schedule of portfolio holdings with the Securities and Exchange Commission for the first and third quarters of each fiscal year as an exhibit to its reports on Form N-PORT. Shareholders may view the filed Form N-PORT 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/us 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 19398-13-0819 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. Pioneer Bond Fund: The audit fees for the Fund were $60,000 payable to Ernst & Young LLP for the year ended June 30, 2019 and $60,000 payable for the year ended June 30, 2018. (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. Pioneer Bond Fund: Audit-Related Fees There were no audit-related services in 2019 or 2018. (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. Pioneer Bond Fund: The tax fees for the Fund were $17,197 payable to Ernst & Young LLP for the year ended June 30, 2019 and $17,197 for the year ended June 30, 2018. (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. Pioneer Bond Fund: Other Fees There were no other fees in 2019 or 2018. (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. Non-Audit Services Beginning with non-audit service contracts entered into on or after May 6, 2003, the effective date of the new SEC pre-approval rules, the Fund's audit committee is required to pre-approve services to affiliates defined by SEC rules to the extent that the services are determined to have a direct impact on the operations or financial reporting of the Fund. For the years ended June 30, 2019 and 2018, there were no services provided to an affiliate that required the Fund's audit committee pre-approval. (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. The aggregate non-audit fees for the Fund were $17,197 payable to Ernst & Young LLP for the year ended June 30, 2019 and $17,197 for the year ended June 30, 2018. (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 August 29, 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 August 29, 2019 By (Signature and Title)* /s/ Mark E. Bradley Mark E. Bradley, Treasurer & Chief Accounting & Financial Officer Date August 29, 2019 * Print the name and title of each signing officer under his or her signature.