OMB APPROVAL OMB Number: 3235-0570 Expires: January 31, 2017 Estimated average burden hours per response.....20.6 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM N-CSR CERTIFIED SHAREHOLDER REPORT OF REGISTERED MANAGEMENT INVESTMENT COMPANIES 		Investment Company Act file number 811-02864 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, Pioneer Investment Management, Inc., 60 State Street, Boston, MA 02109 (Name and address of agent for service) Registrant's telephone number, including area code: (617) 742-7825 Date of fiscal year end: June 30 Date of reporting period: July 1, 2015 through December 31, 2015 Form N-CSR is to be used by management investment companies to file reports with the Commission not later than 10 days after the transmission to stockholders of any report that is required to be transmitted to stockholders under Rule 30e-1 under the Investment Company Act of 1940 (17 CFR 270.30e-1). The Commission may use the information provided on Form N-CSR in its regulatory, disclosure review, inspection, and policymaking roles. A registrant is required to disclose the information specified by Form N-CSR, and the Commission will make this information public. A registrant is not required to respond to the collection of information contained in Form N-CSR unless the Form displays a currently valid Office of Management and Budget ("OMB") control number. Please direct comments concerning the accuracy of the information collection burden estimate and any suggestions for reducing the burden to Secretary, Securities and Exchange Commission, 450 Fifth Street, NW, Washington, DC 20549-0609. The OMB has reviewed this collection of information under the clearance requirements of 44 U.S.C. ss. 3507. ITEM 1. REPORTS TO STOCKHOLDERS. Pioneer Bond Fund -------------------------------------------------------------------------------- Semiannual Report | December 31, 2015 -------------------------------------------------------------------------------- Ticker Symbols: Class A PIOBX Class C PCYBX Class K PBFKX Class R PBFRX Class Y PICYX [LOGO] PIONEER Investments(R) visit us: us.pioneerinvestments.com Table of Contents President's Letter 2 Portfolio Management Discussion 4 Portfolio Summary 9 Prices and Distributions 10 Performance Update 11 Comparing Ongoing Fund Expenses 16 Schedule of Investments 18 Financial Statements 78 Notes to Financial Statements 87 Approval of Investment Advisory Agreement 101 Trustees, Officers and Service Providers 106 Pioneer Bond Fund | Semiannual Report | 12/31/15 1 President's Letter Dear Shareowner, Over the past several years, many investors experienced positive returns across most major asset classes. However, 2015 was a tale of two markets, with favorable market conditions in the first half of the year, followed by an abrupt slowdown and increased volatility beginning in August. The global markets were challenged by significant economic cross-currents in different geographic regions and industrial sectors. While the U.S. economy gradually improved, growth slowed in China. Emerging markets struggled following a decline in commodity prices, especially oil. While lower energy prices are good for the consumer, there were ripple effects throughout the global economy. Against this backdrop, the Standard & Poor's 500 Index rose by just 1.4% in 2015, international equity markets were essentially flat, and emerging market equities fell sharply. Across U.S. fixed-income sectors, U.S. government and investment-grade corporate bonds were fairly flat for the year, while high-yield bonds, as measured by the Bank of America Merrill Lynch Master II High Yield Index, posted a -4.9% total return. Entering 2016, we see the U.S. economy growing modestly, against an overall global economic backdrop that remains fragile and points towards structurally lower growth. As always in a Presidential election year, political rhetoric has the potential to impact U.S. sectors such as health care in 2016. Economies around the world in both developed and emerging markets are experiencing deep structural change. Geopolitical instability on many fronts, the rising risk of policy mistakes, and market liquidity issues all increase the possibility of sharp swings in asset values. In this environment, financial markets remain vulnerable to unusual levels of volatility. While divergences among regions and industries is an important theme, we are generally optimistic about the outlook for the U.S. economy, which we expect will see continued, positive growth led by a strengthened consumer. Throughout Pioneer's history, we have believed in the importance of active management. In periods of market volatility, we believe that the value of active management is even more compelling. Our experienced and tenured investment teams focus on identifying value across global markets using proprietary research, careful risk management, and a long-term perspective. Our ongoing goal is to produce compelling returns consistent with the stated objectives of our investment products, and with our shareowners' expectations. We believe our shareowners can benefit from the experience and tenure of our investment teams as well as the insights generated from our extensive research process. 2 Pioneer Bond Fund | Semiannual Report | 12/31/15 As always, and particularly during times of market uncertainty, we encourage you to work with your financial advisor to develop an overall investment plan that addresses both your short- and long-term goals, and to implement such a plan in a disciplined manner. We greatly appreciate the trust you have placed in us and look forward to continuing to serve you in the future. Sincerely, /s/ Lisa M. Jones Lisa M. Jones President and CEO Pioneer Investment Management USA Inc. December 31, 2015 Any information in this shareowner report regarding market or economic trends or the factors influencing the Fund's historical or future performance are statements of opinion as of the date of this report. Past performance is no guarantee of future results. Pioneer Bond Fund | Semiannual Report | 12/31/15 3 Portfolio Management Discussion | 12/31/15 The domestic bond market generated low returns during the second half of 2015, as growing concerns about credit-sensitive markets and rising interest rates limited potential investment opportunities. In the following interview, Kenneth J. Taubes and Charles Melchreit review the factors that affected the performance of Pioneer Bond Fund during the six-month period ended December 31, 2015. Mr. Taubes, Executive Vice President, Chief Investment Officer, U.S., and a portfolio manager at Pioneer Investments, is responsible for the daily management of the Portfolio, along with Mr. Melchreit, Director of Investment- Grade Management, a senior vice president, and a portfolio manager at Pioneer. Q How did the Fund perform during the six-month period ended December 31, 2015? A Pioneer Bond Fund's Class A shares returned -0.11% at net asset value during the six-month period ended December 31, 2015, while the Fund's benchmark, the Barclays Aggregate Bond Index (the Barclays Index), returned 0.65%. During the same period, the average return of the 48 mutual funds in Lipper's Corporate Debt, A-rated Underlying Funds Category was 0.01%, and the average return of the 1,086 mutual funds in Morningstar's Intermediate-Term Bond Funds Category was -0.26%. Q How would you describe the investment environment in the fixed-income market during the six-month period ended December 31, 2015? A The backdrop for investing in bonds became increasingly challenging as the period progressed. Although the U.S. economy appeared to be growing steadily, rising market interest rates and heightened investor worries about slowing economic growth trends outside the United States limited total returns in the domestic fixed-income market. Market conditions were relatively benign in the first half of the year, prior to the start of the six-month period, as credit-sensitive debt performed well and market interest rates declined, leading to price gains by Treasuries and other high-quality debt securities. Global oil prices, which had declined precipitously in the final few months of 2014, appeared to strengthen early in 2015, lending support to corporate bond prices, especially prices of domestic high-yield corporates, which included many securities issued by energy companies. At the same time, solid job gains and a strengthening housing market suggested domestic economic growth was improving. 4 Pioneer Bond Fund | Semiannual Report | 12/31/15 Late in the second quarter, however, right around the beginning of the period, oil prices started falling again at the same time investors were growing concerned about global economic growth trends, as fundamentals outside of the U.S. appeared to be weakening. Among the mounting issues threatening global growth were a debt crisis in Greece, which led to renewed anxieties about the European economy, especially in the banking system, and new evidence pointing to slowing growth in China's economy. Those anxieties were exacerbated by speculation that weakness in foreign markets might lead to less demand for American-manufactured goods, especially as the U.S. dollar gained strength -- a strong U.S. dollar makes U.S.-made products more expensive overseas. Counter-balancing all the negative factors was a very strong U.S. automotive industry, which generated record production and sales. One of two major developments resulting from the multitude of headline worries during the six-month period was that the U.S. Federal Reserve (Fed) chose to delay its plans to begin tightening monetary policy by raising short-term rates, as a rate hike once widely anticipated to take effect in September did not occur until December. A second consequence was the deterioration of credit-market conditions, especially in the energy and basic materials sectors. Credit spreads widened, which resulted in weak performance by lower-quality bonds, notably high-yield corporates. (Credit spreads are commonly defined as the differences in yield between Treasuries and other types of fixed-income securities with similar maturities.) Over the six-month period ended December 31, 2015, market interest rates rose across the yield curve, with the largest increases at the shorter end as the curve flattened. (The yield curve reflects the differences in yields between shorter- and longer-maturity bonds.) The upward movement in interest rates exerted downward pressure on bond prices, including the prices of Treasuries and other higher-quality debt. During the six-month period, the yields on the two-year Treasury rose by 41 basis points (0.41%), while the yields on 10-year Treasuries gained 8 basis points (0.08%), and the yields on 30-year Treasuries rose by 0.11%, or 11 basis points. High-yield corporates posted negative returns for the full six-month period, with energy sector bonds performing especially poorly. Emerging markets debt also struggled, with the sovereign bonds of many emerging markets nations declining sharply. U.S. Treasuries posted slightly negative results over the period as interest rates rose. Finally, the U.S. dollar continued to strengthen against most all foreign currencies. Pioneer Bond Fund | Semiannual Report | 12/31/15 5 Q What were the principal factors affecting the Fund's performance relative to the benchmark Barclays Index during the six-month period ended December 31, 2015? A The Fund's performance slightly lagged that of the Barclays Index during the period. The main factor holding back relative results was an overweight portfolio position in industrials bonds, including high-yield corporates. Security selection, particularly in the energy industry, also detracted from relative returns. In addition, after the yield curve had steepened very early in the year, prior to the beginning of the period, we had purchased some floating-rate Treasury Inflation Protected Securities (TIPS) to add to the Fund's overall duration. (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.) However, nominal Treasuries outperformed TIPS during the six-month period, and so the Fund's TIPS position did not help performance as much as would have comparable purchases of nominal Treasuries. Despite the fact that we added duration to the portfolio, the Fund still had a short-duration position relative to the Barclays Index, and that tended to help relative returns as interest rates climbed during the period. Overall sector positioning also had a positive impact on the Fund's benchmark-relative performance, especially the portfolio's non-benchmark positions in insurance-linked securities and non-government-agency mortgage obligations. Finally, portfolio allocations to securities issued by financial companies, and to municipal bonds, contributed positively to the Fund's relative results during the period; municipals were one of the best- performing asset classes within fixed income over the six months, returning 3.80%. At the end of the period, on December 31, 2015, the effective duration of the Fund's investments was 4.59 years, and the top-three allocations in the Fund's portfolio were to U.S. government securities (31% of assets), U.S. corporate bonds (28%), and collateralized mortgage obligations, or CMOs (17%). 6 Pioneer Bond Fund | Semiannual Report | 12/31/15 Q What factors affected the Fund's distributions to shareholders during the six-month period ended December 31, 2015? A As interest rates crept up during the period, the Fund was able to earn additional current income; that, in turn, resulted in increased distributions to shareholders. Q Did the Fund invest in any derivative securities during the six-month period ended December 31, 2015? If so, did the investments have any notable effect on the Fund's benchmark-relative performance? A Yes, we invested in some Treasury futures, which had a positive influence on relative performance by helping to shorten the Fund's duration. We also invested in some credit default swaps as a proxy for corporate bonds. The swaps did not have a material effect on the Fund's results. Q What is your investment outlook? A We believe fixed-income markets will continue to be volatile and challenging for investors in 2016. We anticipate that the Fed will follow through on its decision to tighten monetary policy further in 2016. The U.S. dollar also is likely to remain strong relative to other currencies. If the domestic economy continues to expand at a moderate pace, investors are likely to focus on growth, which could lead to a rally in credit-sensitive debt, including corporate bonds. We anticipate that, in spite of global pressures, the U.S. economy should still expand this year, perhaps with gross domestic product growth in the 2.25% - 2.50% range. If, however, domestic economic growth tapers off, we could see a more difficult period for credit markets, and the Fed may be more likely to slow down the pace of its rate hikes. We think it is likely that the fixed-income market will continue to feature yields that are relatively low by historic standards, and that total returns will remain modest. In this environment, we may look for opportunities to add higher-yielding debt to the Fund's portfolio, although we plan to remain cautious in a low-return market. While economic fundamentals in the United States appear to be good, we anticipate that the capital markets will be more volatile, especially in the early months of the year. Pioneer Bond Fund | Semiannual Report | 12/31/15 7 Please refer to the Schedule of Investments on pages 18-77 for a full listing of Fund securities. 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 fail- ure 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 Pioneer Investments for a prospectus or summary prospectus containing this information. Read it carefully. Any information in this shareholder report regarding market or economic trends or the factors influencing the Fund's historical or future performance are statements of opinion as of the date of this report. Past performance is no guarantee of future results. 8 Pioneer Bond Fund | Semiannual Report | 12/31/15 Portfolio Summary | 12/31/15 Portfolio Diversification* -------------------------------------------------------------------------------- (As a percentage of total investment portfolio) [THE FOLLOWING DATA WAS REPRESENTED AS A PIE CHART IN THE PRINTED MATERIAL] U.S. Government Securities 31.3% U.S. Corporate Bonds 28.3% Collateralized Mortgage Obligations 17.0% International Corporate Bonds 11.8% Asset Backed Securities 4.8% Senior Secured Loans 2.5% Municipal Bonds 2.3% Temporary Cash Investments 1.4% U.S. Preferred Stocks 0.3% Convertible Preferred Stocks 0.2% Foreign Government Bond 0.1% * Includes investments in insurance linked securities totaling 4.4% of total investment portfolio. 10 Largest Holdings -------------------------------------------------------------------------------- (As a percentage of total long-term holdings)* 1. U.S. Treasury Inflation Indexed Bonds, 0.125%, 7/15/24 3.62% -------------------------------------------------------------------------------- 2. U.S. Treasury Inflation Indexed Bonds, 0.75%, 2/15/45 1.61 -------------------------------------------------------------------------------- 3. U.S. Treasury Note, Floating Rate Note, 7/31/17 1.46 -------------------------------------------------------------------------------- 4. Fannie Mae, 3.5%, 1/13/16 1.02 -------------------------------------------------------------------------------- 5. Fannie Mae, 4.0%, 1/13/16 1.02 -------------------------------------------------------------------------------- 6. Government National Mortgage Association I, 3.5%, 1/21/16 0.98 -------------------------------------------------------------------------------- 7. Fannie Mae, 5.0%, 2/1/45 0.64 -------------------------------------------------------------------------------- 8. Fannie Mae, 3.0%, 8/1/42 0.64 -------------------------------------------------------------------------------- 9. Government National Mortgage Association I, 3.5%, 1/15/45 0.57 -------------------------------------------------------------------------------- 10. U.S. Treasury Note Floating Rate Note, 10/31/17 0.51 -------------------------------------------------------------------------------- * This list excludes temporary cash investments and derivative instruments. The Fund is actively managed, and current holdings may be different. The holdings listed should not be considered recommendations to buy or sell any security listed. Pioneer Bond Fund | Semiannual Report | 12/31/15 9 Prices and Distributions | 12/31/15 Net Asset Value per Share -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- Class 12/31/15 6/30/15 -------------------------------------------------------------------------------- A $9.51 $9.68 -------------------------------------------------------------------------------- C $9.40 $9.57 -------------------------------------------------------------------------------- K $9.51 $9.68 -------------------------------------------------------------------------------- R $9.60 $9.77 -------------------------------------------------------------------------------- Y $9.42 $9.59 -------------------------------------------------------------------------------- Distributions per Share: 7/1/15-12/31/15 -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- Net Investment Short-Term Long-Term Class Income Capital Gains Capital Gains -------------------------------------------------------------------------------- A $0.1384 $-- $0.0211 -------------------------------------------------------------------------------- C $0.1015 $-- $0.0211 -------------------------------------------------------------------------------- K $0.1568 $-- $0.0211 -------------------------------------------------------------------------------- R $0.1274 $-- $0.0211 -------------------------------------------------------------------------------- Y $0.1504 $-- $0.0211 -------------------------------------------------------------------------------- Index Definition -------------------------------------------------------------------------------- The Barclays 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 11-15. 10 Pioneer Bond Fund | Semiannual Report | 12/31/15 Performance Update | 12/31/15 Class A Shares Investment Returns -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $10,000 investment made in Class A shares of Pioneer Bond Fund at public offering price during the periods shown, compared to that of the Barclays Aggregate Bond Index. Average Annual Total Returns (As of December 31, 2015) -------------------------------------------------------------------------------- Net Public Barclays Asset Offering Aggregate Value Price Bond Period (NAV) (POP) Index -------------------------------------------------------------------------------- 10 Years 5.10% 4.62% 4.51 5 Years 3.97 3.02 3.25 1 Year -0.01 -4.49 0.55 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated November 1, 2015) -------------------------------------------------------------------------------- Gross Net -------------------------------------------------------------------------------- 0.93% 0.85% -------------------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment Pioneer Bond Barclays Aggregate Fund Bond Index 12/05 $ 9,550 $10,000 12/06 $ 9,892 $10,433 12/07 $10,494 $11,160 12/08 $10,037 $11,745 12/09 $11,813 $12,442 12/10 $12,928 $13,255 12/11 $13,585 $14,295 12/12 $14,761 $14,897 12/13 $14,832 $14,596 12/14 $15,711 $15,467 12/15 $15,709 $15,552 Call 1-800-225-6292 or visit us.pioneerinvestments.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. NAV results represent the percent change in net asset value per share. Returns would have been lower had sales charges been reflected. POP returns reflect deduction of maximum 4.50% sales charge. All results are historical and assume the reinvestment of dividends and capital gains. Other share classes are available for which performance and expenses will differ. Performance results reflect any applicable expense waivers in effect during the periods shown. Without such waivers Fund performance would be lower. Waivers may not be in effect for all funds. Certain fee waivers are contractual through a specified period. Otherwise, fee waivers can be rescinded at any time. See the prospectus and financial statements for more information. The net expense ratio reflects the contractual expense limitation currently in effect through November 1, 2017, for Class A shares. There can be no assurance that Pioneer will extend the expense limitation beyond such time. Please see the prospectus and financial statements for more information. The performance table and graph do not reflect the deduction of fees and taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. Pioneer Bond Fund | Semiannual Report | 12/31/15 11 Performance Update | 12/31/15 Class C Shares Investment Returns -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $10,000 investment made in Class C shares of Pioneer Bond Fund during the periods shown, compared to that of the Barclays Aggregate Bond Index. Average Annual Total Returns (As of December 31, 2015) -------------------------------------------------------------------------------- Barclays Aggregate If If Bond Period Held Redeemed Index -------------------------------------------------------------------------------- 10 Years 4.18% 4.18% 4.51% 5 Years 3.09 3.09 3.25 1 Year -0.80 -0.80 0.55 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated November 1, 2015) -------------------------------------------------------------------------------- Gross -------------------------------------------------------------------------------- 1.63% -------------------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment Pioneer Bond Barclays Aggregate Fund Bond Index 12/05 $10,000 $10,000 12/06 $10,257 $10,433 12/07 $10,802 $11,160 12/08 $10,236 $11,745 12/09 $11,939 $12,442 12/10 $12,941 $13,255 12/11 $13,482 $14,295 12/12 $14,517 $14,897 12/13 $14,456 $14,596 12/14 $15,188 $15,467 12/15 $15,067 $15,552 Call 1-800-225-6292 or visit us.pioneerinvestments.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. Class C shares held for less than one year are also subject to a 1% contingent deferred sales charge (CDSC). If 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. Returns would have been lower had sales charges been reflected. All results are historical and assume the reinvestment of dividends and capital gains. Other share classes are available for which performance and expenses will differ. Performance results reflect any applicable expense waivers in effect during the periods shown. Without such waivers Fund performance would be lower. Waivers may not be in effect for all funds. Certain fee waivers are contractual through a specified period. Otherwise, fee waivers can be rescinded at any time. See the prospectus and financial statements for more information. The performance table and graph do not reflect the deduction of fees and taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. 12 Pioneer Bond Fund | Semiannual Report | 12/31/15 Performance Update | 12/31/15 Class K Shares Investment Returns -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $10,000 investment made in Class K shares of Pioneer Bond Fund during the periods shown, compared to that of the Barclays Aggregate Bond Index. Average Annual Total Returns (As of December 31, 2015) -------------------------------------------------------------------------------- Net Barclays Asset Aggregate Value Bond Period (NAV) Index -------------------------------------------------------------------------------- 10 Years 5.21% 4.51% 5 Years 4.18 3.25 1 Year 0.48 0.55 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated November 1, 2015) -------------------------------------------------------------------------------- Gross -------------------------------------------------------------------------------- 0.47% -------------------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment Pioneer Bond Barclays Aggregate Fund Bond Index 12/05 $10,000 $10,000 12/06 $10,355 $10,433 12/07 $10,986 $11,160 12/08 $10,507 $11,745 12/09 $12,366 $12,442 12/10 $13,534 $13,255 12/11 $14,221 $14,295 12/12 $15,438 $14,897 12/13 $15,576 $14,596 12/14 $16,532 $15,467 12/15 $16,610 $15,552 Call 1-800-225-6292 or visit us.pioneerinvestments.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. The performance shown for Class K shares for the period prior to the commencement of operations of Class K shares on December 20, 2012, is the net asset value performance of the Fund's Class A shares, which has not been restated to reflect any differences in expenses, including Rule 12b-1 fees applicable to Class A shares. Since fees for Class A shares generally are higher than those of Class K shares, the performance of Class K shares prior to their inception would have been higher than the performance shown. 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. Pioneer Bond Fund | Semiannual Report | 12/31/15 13 Performance Update | 12/31/15 Class R Shares Investment Returns -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $10,000 investment made in Class R shares of Pioneer Bond Fund during the periods shown, compared to that of the Barclays Aggregate Bond Index. Average Annual Total Returns (As of December 31, 2015) -------------------------------------------------------------------------------- Net Barclays Asset Aggregate Value Bond Period (NAV) Index -------------------------------------------------------------------------------- 10 Years 4.75% 4.51% 5 Years 3.61 3.25 1 Year -0.24 0.55 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated November 1, 2015) -------------------------------------------------------------------------------- Gross Net -------------------------------------------------------------------------------- 1.21% 1.10% -------------------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment Pioneer Bond Barclays Aggregate Fund Bond Index 12/05 $10,000 $10,000 12/06 $10,330 $10,433 12/07 $10,947 $11,160 12/08 $10,414 $11,745 12/09 $12,216 $12,442 12/10 $13,326 $13,255 12/11 $13,950 $14,295 12/12 $15,077 $14,897 12/13 $15,094 $14,596 12/14 $15,947 $15,467 12/15 $15,909 $15,552 Call 1-800-225-6292 or visit us.pioneerinvestments.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. Class R shares are not subject to sales charges and are available for limited groups of eligible investors, including institutional investors. All results are historical and assume the reinvestment of dividends and capital gains. Other share classes are available for which performance and expenses will differ. Performance results reflect any applicable expense waivers in effect during the periods shown. Without such waivers Fund performance would be lower. Waivers may not be in effect for all funds. Certain fee waivers are contractual through a specified period. Otherwise, fee waivers can be rescinded at any time. See the prospectus and financial statements for more information. The net expense ratio reflects the contractual expense limitation currently in effect through November 1, 2017, for Class R shares. There can be no assurance that Pioneer will extend the expense limitation beyond such time. Please see the prospectus and financial statements for more information. The performance table and graph do not reflect the deduction of fees and taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. 14 Pioneer Bond Fund | Semiannual Report | 12/31/15 Performance Update | 12/31/15 Class Y Shares Investment Returns -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $5 million investment made in Class Y shares of Pioneer Bond Fund during the periods shown, compared to that of the Barclays Aggregate Bond Index. Average Annual Total Returns (As of December 31, 2015) -------------------------------------------------------------------------------- Net Barclays Asset Aggregate Value Bond Period (NAV) Index -------------------------------------------------------------------------------- 10 Years 5.38% 4.51% 5 Years 4.20 3.25 1 Year 0.24 0.55 -------------------------------------------------------------------------------- Expense Ratio (Per prospectus dated November 1, 2015) -------------------------------------------------------------------------------- Gross -------------------------------------------------------------------------------- 0.58% -------------------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $5 Million Investment Pioneer Bond Barclays Aggregate Fund Bond Index 12/05 $5,000,000 $5,000,000 12/06 $5,199,263 $5,216,670 12/07 $5,536,696 $5,580,101 12/08 $5,312,135 $5,872,493 12/09 $6,265,780 $6,220,781 12/10 $6,876,903 $6,627,708 12/11 $7,244,136 $7,147,432 12/12 $7,883,601 $7,448,709 12/13 $7,935,440 $7,297,949 12/14 $8,426,940 $7,733,349 12/15 $8,447,525 $7,775,875 Call 1-800-225-6292 or visit us.pioneerinvestments.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. Class Y shares are not subject to sales charges and are available for limited groups of eligible investors, including institutional investors. All results are historical and assume the reinvestment of dividends and capital gains. Other share classes are available for which performance and expenses will differ. Performance results reflect any applicable expense waivers in effect during the periods shown. Without such waivers Fund performance would be lower. Waivers may not be in effect for all funds. Certain fee waivers are contractual through a specified period. Otherwise, fee waivers can be rescinded at any time. See the prospectus and financial statements for more information. The performance table and graph do not reflect the deduction of fees and taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. Pioneer Bond Fund | Semiannual Report | 12/31/15 15 Comparing Ongoing Fund Expenses As a shareowner in the Fund, you incur two types of costs: (1) ongoing costs, including management fees, distribution and/or service (12b-1) fees, and other Fund expenses; and (2) transaction costs, including sales charges (loads) on purchase payments. This example is intended to help you understand your ongoing expenses (in dollars) of investing in the Fund and to compare these costs with the ongoing costs of investing in other mutual funds. The example is based on an investment of $1,000 at the beginning of the Fund's latest six-month period and held throughout the six months. Using the Tables -------------------------------------------------------------------------------- Actual Expenses The first table below provides information about actual account values and actual expenses. You may use the information in this table, together with the amount you invested, to estimate the expenses that you paid over the period as follows: (1) Divide your account value by $1,000 Example: an $8,600 account value (divided by) $1,000 = 8.6 (2) Multiply the result in (1) above by the corresponding share class's number in the third row under the heading entitled "Expenses Paid During Period" to estimate the expenses you paid on your account during this period. Expenses Paid on a $1,000 Investment in Pioneer Bond Fund Based on actual returns from July 1, 2015 through December 31, 2015. -------------------------------------------------------------------------------- Share Class A C K R Y -------------------------------------------------------------------------------- Beginning $1,000.00 $1,000.00 $1,000.00 $1,000.00 $1,000.00 Account Value on 7/1/15 -------------------------------------------------------------------------------- Ending Account $ 998.90 $ 995.00 $1,000.80 $ 997.70 $1,000.10 Value (after expenses) on 12/31/15 -------------------------------------------------------------------------------- Expenses Paid $ 4.27 $ 7.97 $ 2.36 $ 5.52 $ 2.92 During Period* -------------------------------------------------------------------------------- * Expenses are equal to the Fund's annualized net expense ratio of 0.85%, 1.59%, 0.47%, 1.10%, and 0.58% for Class A, Class C, Class K, Class R, and Class Y shares, respectively, multiplied by the average account value over the period, multiplied by 184/365 (to reflect the one-half year period). 16 Pioneer Bond Fund | Semiannual Report | 12/31/15 Hypothetical Example for Comparison Purposes The table below provides information about hypothetical account values and hypothetical expenses based on the Fund's actual expense ratio and an assumed rate of return of 5% per year before expenses, which is not the Fund's actual return. The hypothetical account values and expenses may not be used to estimate the actual ending account balance or expenses you paid for the period. You may use this information to compare the ongoing costs of investing in the Fund and other funds. To do so, compare this 5% hypothetical example with the 5% hypothetical examples that appear in the shareholder reports of the other funds. Please note that the expenses shown in the tables are meant to highlight your ongoing costs only and do not reflect any transaction costs, such as sales charges (loads) that are charged at the time of the transaction. Therefore, the table below is useful in comparing ongoing costs only and will not help you determine the relative total costs of owning different funds. In addition, if these transaction costs were included, your costs would have been higher. Expenses Paid on a $1,000 Investment in Pioneer Bond Fund Based on a hypothetical 5% per year return before expenses, reflecting the period from July 1, 2015 through December 31, 2015. -------------------------------------------------------------------------------- Share Class A C K R Y -------------------------------------------------------------------------------- Beginning $1,000.00 $1,000.00 $1,000.00 $1,000.00 $1,000.00 Account Value on 7/1/15 -------------------------------------------------------------------------------- Ending Account $1,020.86 $1,017.14 $1,022.77 $1,019.61 $1,022.22 Value (after expenses) on 12/31/15 -------------------------------------------------------------------------------- Expenses Paid $ 4.32 $ 8.06 $ 2.39 $ 5.58 $ 2.95 During Period* -------------------------------------------------------------------------------- * Expenses are equal to the Fund's annualized net expense ratio of 0.85%, 1.59%, 0.47%, 1.10%, and 0.58% for Class A, Class C, Class K, Class R, and Class Y shares, respectively, multiplied by the average account value over the period, multiplied by 184/365 (to reflect the one-half year period). Pioneer Bond Fund | Semiannual Report | 12/31/15 17 Schedule of Investments | 12/31/15 (unaudited) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- PREFERRED STOCKS -- 0.3% BANKS -- 0.2% Diversified Banks -- 0.2% 30,353 6.69 Citigroup Capital XIII, Floating Rate Note, 10/30/40 $ 788,874 171,525 7.12 Citigroup, Inc., Floating Rate Note (Perpetual) 4,804,415 ----------------- $ 5,593,289 ----------------- Total Banks $ 5,593,289 ---------------------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 0.1% Asset Management & Custody Banks -- 0.0%+ 54,200 5.90 State Street Corp., Floating Rate Note, 12/31/73 $ 1,500,256 ---------------------------------------------------------------------------------------------------------- Investment Banking & Brokerage -- 0.1% 110,230 6.38 Morgan Stanley, Floating Rate Note (Perpetual) $ 2,925,504 ----------------- Total Diversified Financials $ 4,425,760 ---------------------------------------------------------------------------------------------------------- TOTAL PREFERRED STOCKS (Cost $9,219,536) $ 10,019,049 ---------------------------------------------------------------------------------------------------------- CONVERTIBLE PREFERRED STOCK -- 0.2% BANKS -- 0.2% Diversified Banks -- 0.2% 5,610 Wells Fargo & Co., 7.5% (Perpetual) $ 6,524,346 ---------------------------------------------------------------------------------------------------------- TOTAL CONVERTIBLE PREFERRED STOCK (Cost $5,839,986) $ 6,524,346 ---------------------------------------------------------------------------------------------------------- ASSET BACKED SECURITIES -- 4.8% CONSUMER SERVICES -- 0.2% Hotels, Resorts & Cruise Lines -- 0.2% 638,876 Westgate Resorts 2012-A LLC, 2.25%, 8/20/25 (144A) $ 638,454 870,468 Westgate Resorts 2012-A LLC, 3.75%, 8/20/25 (144A) 869,329 2,316,505 Westgate Resorts 2014-1 LLC, 2.15%, 12/20/26 (144A) 2,275,503 2,257,681 Westgate Resorts 2015-1 LLC, 2.75%, 5/20/27 (144A) 2,233,676 95,144 Westgate Resorts LLC, 2.5%, 3/20/25 (144A) 95,130 ----------------- $ 6,112,092 ----------------- Total Consumer Services $ 6,112,092 ---------------------------------------------------------------------------------------------------------- FOOD & STAPLES RETAILING -- 0.1% Food Retail -- 0.1% 3,762,135 CKE Restaurant Holdings, Inc., 4.474%, 3/20/43 (144A) $ 3,740,629 ----------------- Total Food & Staples Retailing $ 3,740,629 ---------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 18 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- HEALTH CARE EQUIPMENT & SERVICES -- 0.1% Health Care Distributors -- 0.1% 1,600,000 OneMain Financial Issuance Trust 2015-1, 3.19%, 3/18/26 (144A) $ 1,590,080 ----------------- Total Health Care Equipment & Services $ 1,590,080 ---------------------------------------------------------------------------------------------------------- BANKS -- 3.6% Thrifts & Mortgage Finance -- 3.6% 1,611,951 Access Point Funding I 2015-A LLC, 2.61%, 4/15/20 (144A) $ 1,609,936 24,903 6.21 ACE Securities Corp., Manufactured Housing Trust Series 2003-MH1, Floating Rate Note, 8/15/30 (144A) 24,861 2,200,000 1.68 American Homes 4 Rent 2014-SFR1, Floating Rate Note, 6/17/31 2,143,218 2,800,000 American Homes 4 Rent 2014-SFR3 Trust, 4.596%, 12/18/36 (144A) 2,719,164 700,000 American Homes 4 Rent 2014-SFR3 Trust, 5.04%, 12/18/36 (144A) 692,241 1,300,000 American Homes 4 Rent 2015-SFR1, 4.11%, 4/18/52 (144A) 1,212,684 2,600,000 Applebee's Funding LLC/ IHOP Funding LLC, 4.277%, 9/5/44 (144A) 2,632,874 2,200,000 Ascentium Equipment Receivables 2015-1 LLC, 3.24%, 1/10/22 (144A) 2,201,659 699,990 Axis Equipment Finance Receivables III LLC, 3.41%, 4/20/20 (144A) 697,267 1,075,984 B2R Mortgage Trust 2015-1, 2.524%, 5/15/48 (144A) 1,052,382 266,274 0.92 Bayview Financial Mortgage Pass-Through Trust 2005-C, Floating Rate Note, 6/28/44 264,451 1,335,132 Bayview Financial Mortgage Pass-Through Trust 2006-A, 5.865%, 2/28/41 (Step) 1,398,794 622,696 0.87 Bayview Financial Mortgage Pass-Through Trust Series 2005-B, Floating Rate Note, 4/28/39 618,948 1,650,000 BCC Funding Corp., X, 3.622%, 11/20/20 (144A) 1,647,162 1,195,858 0.92 Bear Stearns Asset Backed Securities I Trust 2005-FR1, Floating Rate Note, 6/25/35 1,186,545 734,498 0.91 Bear Stearns Asset Backed Securities Trust 2006-SD2, Floating Rate Note, 6/25/36 719,823 2,444,169 BXG Receivables Note Trust 2015-A, 2.88%, 5/2/30 (144A) 2,422,363 3,000,000 Capital Automotive Real Estate Investment Trust, 3.66%, 10/17/44 (144A) 3,014,199 7,006 0.82 Carrington Mortgage Loan Trust Series 2005-NC4, Floating Rate Note, 9/25/35 6,998 400,000 1.39 Chesapeake Funding LLC, Floating Rate Note, 3/4/26 399,888 1,400,000 CIT Equipment Collateral 2014-VT1, 2.65%, 2/20/20 (144A) 1,406,080 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 19 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 831,292 1.17 Citigroup Mortgage Loan Trust, Inc., Floating Rate Note, 5/25/35 (144A) $ 827,364 4,990,918 Colony American Finance 2015-1, Ltd., 2.896%, 10/17/47 (144A) 4,911,287 1,800,000 2.18 Colony American Homes 2014-1, Floating Rate Note, 5/19/31 (144A) 1,747,017 1,262,048 Consumer Credit Origination Loan Trust 2015-1, 2.82%, 3/15/21 (144A) 1,261,856 1,935,480 4.75 Countrywide Asset-Backed Certificates, Floating Rate Note, 12/25/35 1,974,020 774,985 0.52 Credit-Based Asset Servicing and Securitization LLC, Floating Rate Note, 7/25/36 768,377 524,355 1.47 CWABS Asset-Backed Certificates Trust 2004-7, Floating Rate Note, 12/25/34 522,606 4,962,500 DB Master Finance LLC 2015-1, 3.98%, 2/21/45 (144A) 4,947,307 1,004,633 3.17 Drug Royalty II LP 2, Floating Rate Note, 7/15/23 (144A) 1,016,496 719,625 GMAT 2013-1 Trust, 3.9669%, 8/25/53 (Step) 727,034 425,088 1.17 GSAMP Trust 2005-HE1, Floating Rate Note, 12/25/34 418,383 1,222,823 1.77 GSRPM Mortgage Loan Trust 2003-2, Floating Rate Note, 6/25/33 1,179,275 584,752 0.72 GSRPM Mortgage Loan Trust 2006-2, Floating Rate Note, 9/25/36 (144A) 557,969 2,973,750 HOA Funding LLC, 4.846%, 8/22/44 (144A) 2,703,232 265,499 0.80 Home Equity Asset Trust 2005-7, Floating Rate Note, 1/25/36 264,676 1,269,306 0.79 Home Equity Mortgage Loan Asset-Backed Trust Series INABS 2005-C, Floating Rate Note, 10/25/35 1,256,443 854,322 1.60 HSBC Home Equity Loan Trust USA 2007-3, Floating Rate Note, 11/20/36 851,587 1,451,293 Icon Brand Holdings LLC, 4.229%, 1/26/43 (144A) 1,340,096 329,518 Icon Brand Holdings LLC, 4.352%, 1/25/43 (144A) 331,017 1,700,000 1.53 Invitation Homes 2014-SFR3 Trust, Floating Rate Note, 12/18/31 (144A) 1,668,607 190,237 Irwin Home Equity Loan Trust 2005-1, 5.82%, 6/25/35 (Step) 188,586 2,965,893 0.66 Irwin Home Equity Loan Trust 2005-1, Floating Rate Note, 6/25/25 2,779,003 528,492 1.92 Irwin Whole Loan Home Equity Trust 2003-C, Floating Rate Note, 6/25/28 522,076 550,000 Leaf Receivables Funding 10 LLC, 2.74%, 3/15/21 (144A) 539,244 881,386 Leaf Receivables Funding 8 LLC, 1.92%, 9/15/20 (144A) 881,580 226,420 Lehman ABS Manufactured Housing Contract Trust 2001-B, 3.01%, 5/15/41 227,402 The accompanying notes are an integral part of these financial statements. 20 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 229,137 Lehman ABS Manufactured Housing Contract Trust 2001-B, 5.873%, 5/15/41 $ 240,522 949,015 Nations Equipment Finance Funding II LLC, 3.276%, 1/22/19 (144A) 947,098 192,918 0.57 Nationstar Home Equity Loan Trust 2007-A, Floating Rate Note, 3/25/37 189,377 908,073 1.12 New Century Home Equity Loan Trust 2005-1, Floating Rate Note, 3/25/35 901,333 1,050,000 NextGear Floorplan Master Owner Trust, 1.92%, 10/15/19 (144A) 1,040,851 1,000,000 NextGear Floorplan Master Owner Trust, 2.61%, 10/15/19 (144A) 983,241 430,000 2.07 NovaStar Mortgage Funding Trust Series 2004-4, Floating Rate Note, 3/25/35 424,392 493,061 5.91 Origen Manufactured Housing Contract Trust 2004-A, Floating Rate Note, 1/15/35 513,495 319,578 5.46 Origen Manufactured Housing Contract Trust 2004-B, Floating Rate Note, 11/15/35 323,584 1,600,000 Oxford Finance Funding Trust 2014-1, 3.475%, 12/15/22 (144A) 1,591,904 1,000,000 1.18 PFS Financing Corp., Floating Rate Note, 10/15/19 (144A) 988,346 3,200,000 Progreso Receivables Funding III LLC, 3.625%, 1/30/25 (144A) 3,193,546 2,000,000 Progreso Receivables Funding LLC, 3.0%, 7/8/20 (144A) 1,977,067 180,000 2.58 Progress Residential 2014-SFR1 Trust, Floating Rate Note, 10/17/31 (144A) 176,034 2,700,000 2.73 Progress Residential 2015-SFR1 Trust, Floating Rate Note, 2/20/32 (144A) 2,649,636 736,500 0.67 RAAC Series 2006-RP2 Trust, Floating Rate Note, 2/25/37 (144A) 727,689 3,360,000 2.38 Silver Bay Realty 2014-1 Trust, Floating Rate Note, 9/18/31 (144A) 3,263,986 786,404 Skopos Auto Receivables Trust 2015-1, 3.1%, 12/15/23 (144A) 782,888 1,557,036 SpringCastle America Funding LLC, 2.7%, 5/25/23 (144A) 1,553,596 1,200,000 Springleaf Funding Trust 2014-A, 2.41%, 12/15/22 (144A) 1,196,591 1,395,333 Store Master Funding I LLC, 3.75%, 4/20/45 (144A) 1,384,332 286,723 Store Master Funding LLC, 4.16%, 3/20/43 (144A) 293,526 1,994,577 Store Master Funding LLC, 5.77%, 8/20/42 (144A) 2,089,678 862,048 0.62 Structured Asset Investment Loan Trust 2006-1, Floating Rate Note, 1/25/36 845,109 1,233,446 0.64 Structured Asset Securities Corp., Mortgage Loan Trust 2006-GEL4, Floating Rate Note, 10/25/36 (144A) 1,224,246 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 21 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 54,519 Structured Asset Securities Corp., 4.77%, 10/25/34 (Step) $ 56,480 1,209,153 Sunset Mortgage Loan Co., 2014-NPL2 LLC, 3.721%, 11/16/44 (Step) (144A) 1,203,107 454,764 SVO 2012-A VOI Mortgage LLC, 2.0%, 9/20/29 (144A) 448,176 771,441 1.36 Terwin Mortgage Trust Series TMTS 2003-8HE, Floating Rate Note, 12/25/34 751,315 282,362 Terwin Mortgage Trust Series TMTS 2005-12ALT, 4.94159%, 7/25/36 (Step) 285,001 2,358,271 Terwin Mortgage Trust Series TMTS 2005-16HE, 4.29956%, 9/25/36 (Step) 2,425,553 800,000 2.58 Trafigura Securitisation Finance Plc 2014-1, Floating Rate Note, 4/16/18 (144A) 796,976 2,140,000 United Auto Credit Securitization Trust 2015-1, 2.92%, 6/17/19 (144A) 2,123,916 2,985,777 US Residential Opportunity Fund III Trust 2015-1, 3.7213%, 1/29/35 (144A) 2,966,378 1,596,818 VOLT XXXI LLC, 3.375%, 2/25/55 (Step) (144A) 1,574,485 3,425,235 VOLT XXXIII LLC, 3.5%, 3/25/55 (Step) (144A) 3,365,374 2,642,056 VOLT XXXVI LLC, 3.625%, 7/25/45 (Step) (144A) 2,604,510 3,237,069 VOLT XXXVII LLC, 3.625%, 7/25/45 (Step) (144A) 3,200,071 1,689,073 Welk Resorts 2015-A LLC, 2.79%, 6/16/31 (144A) 1,662,929 1,000,000 Westlake Automobile Receivables Trust 2015-3, 3.05%, 5/17/21 (144A) 992,867 4,118,073 3.50 WinWater Mortgage Loan Trust 2015-5, Floating Rate Note, 8/20/45 (144A) 4,114,857 ----------------- $ 120,558,139 ----------------- Total Banks $ 120,558,139 ---------------------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 0.8% Other Diversified Financial Services -- 0.3% 500,000 American Credit Acceptance Receivables Trust 2014-1, 5.2%, 4/12/21 (144A) $ 504,612 499,944 AXIS Equipment Finance Receivables II LLC, 4.94%, 7/20/18 (144A) 508,613 371,032 CNH Equipment Trust 2013-A, 0.69%, 6/15/18 370,843 745,741 Diamond Resorts Owner Trust 2015-1, 3.17%, 7/20/27 (144A) 737,784 630,641 Mid-State Capital Trust 2010-1, 5.25%, 12/15/45 (144A) 658,215 803,835 Sierra Timeshare 2012-2 Receivables Funding LLC, 2.38%, 3/20/29 (144A) 803,983 158,959 Sierra Timeshare 2012-3 Receivables Funding LLC, 1.87%, 8/20/29 (144A) 158,060 3,300,000 Spirit Master Funding LLC, 4.6291%, 1/20/45 (144A) 3,362,712 The accompanying notes are an integral part of these financial statements. 22 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Other Diversified Financial Services -- (continued) 267,436 Spirit Master Funding LLC, 5.74%, 3/20/42 (144A) $ 285,034 875,000 Spirit Master Funding VII LLC, 3.8868%, 12/21/43 (144A) 892,344 ----------------- $ 8,282,200 ---------------------------------------------------------------------------------------------------------- Specialized Finance -- 0.3% 5,500,000 Domino's Pizza Master Issuer LLC, 3.484%, 10/25/45 (144A) $ 5,390,000 2,476,174 Domino's Pizza Master Issuer LLC, 5.216%, 1/27/42 (144A) 2,547,071 2,920,000 Hercules Capital Funding Trust 2014-1, 3.524%, 4/16/21 (144A) 2,908,138 617,956 JG Wentworth XXII LLC, 3.82%, 12/15/48 (144A) 633,218 ----------------- $ 11,478,427 ---------------------------------------------------------------------------------------------------------- Consumer Finance -- 0.1% 51,007 California Republic Auto Receivables Trust 2012-1, 1.18%, 8/15/17 (144A) $ 50,999 4,440 First Investors Auto Owner Trust 2012-2, 1.47%, 5/15/18 (144A) 4,441 1,200,000 First Investors Auto Owner Trust 2013-1, 2.02%, 1/15/19 (144A) 1,193,513 2,100,000 First Investors Auto Owner Trust 2014-3, 2.97%, 11/16/20 (144A) 2,090,367 510,000 First Investors Auto Owner Trust 2015-1, 3.59%, 1/18/22 (144A) 501,015 17,623 Santander Drive Auto Receivables Trust 2012-1, 3.78%, 11/15/17 17,637 637,599 Santander Drive Auto Receivables Trust 2012-5, 2.7%, 8/15/18 640,820 ----------------- $ 4,498,792 ---------------------------------------------------------------------------------------------------------- Asset Management & Custody Banks -- 0.1% 492,637 Horizon Funding Trust 2013-1, 3.0%, 5/15/18 (144A) $ 497,255 1,195,544 Newstar Commercial Lease Funding 2015-1 LLC, 3.27%, 4/15/19 (144A) 1,190,026 ----------------- $ 1,687,281 ---------------------------------------------------------------------------------------------------------- Investment Banking & Brokerage -- 0.0%+ 1,600,000 2.02 Chesapeake Funding LLC, Floating Rate Note, 2/7/27 (144A) $ 1,602,948 ----------------- Total Diversified Financials $ 27,549,648 ---------------------------------------------------------------------------------------------------------- TOTAL ASSET BACKED SECURITIES (Cost $160,690,560) $ 159,550,588 ---------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 23 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- 17.0% BANKS -- 16.2% Thrifts & Mortgage Finance -- 16.2% 342,857 A10 Securitization 2013-1 LLC, 2.4%, 11/17/25 (144A) $ 342,931 1,772,845 A10 Term Asset Financing 2013-2 LLC, 2.62%, 11/15/27 (144A) 1,776,464 7,587,680 3.50 Agate Bay Mortgage Trust 2015-1, Floating Rate Note, 1/25/45 (144A) 7,577,012 5,635,826 3.50 Agate Bay Mortgage Trust 2015-2, Floating Rate Note, 3/25/45 (144A) 5,732,914 4,740,311 3.50 Agate Bay Mortgage Trust 2015-5, Floating Rate Note, 7/25/45 (144A) 4,769,563 327,882 0.87 Alternative Loan Trust 2003-14T1, Floating Rate Note, 8/25/18 285,502 1,396,382 Alternative Loan Trust 2003-21T1, 5.75%, 12/25/33 1,422,198 5,000,000 2.08 Arbor Realty Collateralized Loan Obligation 2015-FL1, Ltd., Floating Rate Note, 3/15/25 (144A) 5,000,000 2,580,000 2.53 BAMLL Commercial Mortgage Securities Trust 2014-FL1, Floating Rate Note, 12/17/31 (144A) 2,567,463 1,600,000 2.15 BAMLL Commercial Mortgage Securities Trust 2014-INLD, Floating Rate Note, 12/17/29 (144A) 1,595,922 4,200,000 1.91 BAMLL Commercial Mortgage Securities Trust 2015-ASHF, Floating Rate Note, 1/18/28 (144A) 4,194,834 5,250,000 2.47 BAMLL Re-REMIC Trust 2014-FRR7, Floating Rate Note, 10/26/44 (144A) 5,160,900 534,737 Banc of America Alternative Loan Trust 2003-2, 5.75%, 4/25/33 553,735 964,394 Banc of America Alternative Loan Trust 2004-6, 5.0%, 7/25/19 987,876 549,724 Banc of America Funding 2003-3 Trust, 5.5%, 10/25/33 569,641 997,603 2.75 Banc of America Mortgage 2003-F Trust, Floating Rate Note, 7/25/33 1,002,391 635,009 Banc of America Mortgage Trust 2004-11, 5.75%, 1/25/35 648,844 780,382 Banc of America Mortgage Trust 2004-9, 5.5%, 11/25/34 793,929 831,898 0.98 Bear Stearns ALT-A Trust 2005-1, Floating Rate Note, 1/25/35 809,425 2,798,043 2.73 Bear Stearns ARM Trust 2003-6, Floating Rate Note, 8/25/33 2,774,635 1,000,000 5.21 Bear Stearns Commercial Mortgage Securities Trust 2005-PWR7, Floating Rate Note, 2/11/41 998,745 836,517 5.62 Bear Stearns Commercial Mortgage Securities Trust 2006-TOP22, Floating Rate Note, 4/12/38 836,846 1,460,957 1.10 Bella Vista Mortgage Trust 2004-1, Floating Rate Note, 11/20/34 1,300,248 The accompanying notes are an integral part of these financial statements. 24 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 2,210,000 2.28 BLCP Hotel Trust, Floating Rate Note, 8/15/29 (144A) $ 2,167,714 2,460,000 2.18 Carefree Portfolio Trust 2014-CARE, Floating Rate Note, 11/15/29 (144A) 2,473,827 4,000,000 2.83 CDGJ Commercial Mortgage Trust 2014-BXCH, Floating Rate Note, 12/15/27 (144A) 3,952,334 430,734 2.86 CHL Mortgage Pass-Through Trust 2003-56, Floating Rate Note, 12/25/33 434,174 5,000,000 Citigroup Commercial Mortgage Trust 2014-GC25 REMICS, 3.371%, 10/11/47 5,090,426 4,178,749 3.75 Citigroup Mortgage Loan Trust 2015-PS1, Floating Rate Note, 9/25/42 (144A) 4,245,609 2,729,220 2.29 Citigroup Mortgage Loan Trust, Inc., REMICS, Floating Rate Note, 8/25/34 2,705,617 977,319 Citigroup Mortgage Loan Trust, Inc., 5.5%, 9/25/34 1,050,704 1,000,000 4.65 City Center Trust 2011-CCHP, Floating Rate Note, 7/17/28 (144A) 1,004,926 2,677,338 Colony Multifamily Mortgage Trust 2014-1, 2.5432%, 4/22/50 (144A) 2,647,506 450,000 COMM 2012-CCRE2 Mortgage Trust REMICS, 3.791%, 8/17/45 464,099 850,000 COMM 2012-CCRE2 Mortgage Trust, 3.147%, 8/15/45 857,893 915,000 COMM 2012-CCRE4 Mortgage Trust, 2.436%, 10/17/45 910,610 4,000,000 COMM 2012-LC4 Mortgage Trust, 4.063%, 12/12/44 4,200,046 4,200,000 5.34 COMM 2013-CCRE11 Mortgage Trust, Floating Rate Note, 8/12/50 (144A) 4,370,099 1,900,000 COMM 2013-LC6 Mortgage Trust, 2.941%, 1/12/46 1,889,699 3,800,000 2.48 COMM 2014-FL5 Mortgage Trust, Floating Rate Note, 10/17/31 (144A) 3,809,096 4,150,000 2.08 COMM 2014-SAVA Mortgage Trust, Floating Rate Note, 6/15/34 (144A) 4,136,946 1,750,000 3.81 COMM 2015-CCRE23 Mortgage Trust, Floating Rate Note, 5/12/48 (144A) 1,770,862 5,204,000 4.70 COMM 2015-CCRE25 Mortgage Trust, Floating Rate Note, 8/12/48 5,361,801 3,850,000 Commercial Mortgage Pass Through Certificates, 2.822%, 10/17/45 3,806,269 2,354,452 Credit Suisse Commercial Mortgage Trust Series 2007-C1, 5.361%, 2/15/40 2,418,572 160,549 Credit Suisse First Boston Mortgage Securities Corp., 5.5%, 6/25/33 162,681 2,700,000 2.58 CSMC 2015-TWNI Trust, Floating Rate Note, 3/15/28 (144A) 2,675,939 7,381,207 1.55 CSMC Trust 2013-IVR2, Floating Rate Note, 4/27/43 (144A) 6,918,961 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 25 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 2,892,834 3.00 CSMC Trust 2013-IVR4, Floating Rate Note, 7/27/43 (144A) $ 2,894,539 2,094,285 3.00 CSMC Trust 2013-IVR4, Floating Rate Note, 7/27/43 (144A) 2,091,018 5,006,393 3.00 CSMC Trust 2014-WIN1, Floating Rate Note, 9/25/44 (144A) 5,019,690 8,254,780 CSMC Trust 2015-2, 3.0%, 2/25/45 8,293,442 4,782,550 CSMC Trust 2015-2, 3.5%, 2/25/45 (144A) 4,846,172 1,900,000 5.58 DBUBS 2011-LC3 Mortgage Trust, Floating Rate Note, 8/12/44 (144A) 2,116,685 1,895,000 1.50 Del Coronado Trust 2013-DEL, Floating Rate Note, 3/16/26 (144A) 1,893,638 4,012,912 3.50 EverBank Mortgage Loan Trust REMICS, Floating Rate Note, 4/25/43 (144A) 4,000,299 4,630,000 3.38 GAHR Commercial Mortgage Trust 2015-NRF, Floating Rate Note, 12/15/34 (144A) 4,519,024 747,310 Global Mortgage Securitization, Ltd., 5.25%, 4/25/32 722,979 1,799,294 0.69 Global Mortgage Securitization, Ltd., Floating Rate Note, 4/25/32 1,723,653 2,800,000 GS Mortgage Securities Corp., Trust 2012-SHOP, 2.933%, 6/6/31 (144A) 2,836,554 1,250,000 GS Mortgage Securities Corp. II, 3.377%, 5/10/45 1,279,144 1,000,000 GS Mortgage Securities Corp. II, 3.682%, 2/10/46 (144A) 987,335 755,003 GS Mortgage Securities Corp. II, 5.56%, 11/10/39 753,704 876,715 2.86 GSR Mortgage Loan Trust 2005-AR1, Floating Rate Note, 1/25/35 882,355 5,849,000 2.07 Homestar Mortgage Acceptance Corp., Floating Rate Note, 1/25/35 5,694,168 2,100,000 2.03 Hyatt Hotel Portfolio Trust 2015-HYT, Floating Rate Note, 11/15/29 (144A) 2,107,977 494,498 1.22 Impac CMB Trust Series 2004-6, Floating Rate Note, 10/25/34 471,356 234,981 0.57 Impac Secured Assets Trust 2006-2, Floating Rate Note, 8/25/36 229,625 923,989 0.62 Impac Secured Assets Trust 2006-5, Floating Rate Note, 12/25/36 868,698 4,260,234 JP Morgan Chase Commercial Mortgage Securities Corp., 2.84%, 12/17/47 4,198,769 4,800,000 5.56 JP Morgan Chase Commercial Mortgage Securities Trust 2006-LDP6, Floating Rate Note, 4/15/43 4,817,550 382,804 0.49 JP Morgan Chase Commercial Mortgage Securities Trust 2006-LDP9, Floating Rate Note, 5/15/47 380,016 1,600,000 JP Morgan Chase Commercial Mortgage Securities Trust 2010-C2, 3.6159%, 11/15/43 (144A) 1,635,420 1,350,000 JP Morgan Chase Commercial Mortgage Securities Trust 2011-C5, 4.1712%, 8/17/46 1,437,606 The accompanying notes are an integral part of these financial statements. 26 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 1,200,000 3.98 JP Morgan Chase Commercial Mortgage Securities Trust 2012-C8, Floating Rate Note, 10/17/45 (144A) $ 1,215,430 5,000,000 JP Morgan Chase Commercial Mortgage Securities Trust 2014-C20 REMICS, 3.8046%, 7/17/47 5,149,011 4,600,000 2.28 JP Morgan Chase Commercial Mortgage Securities Trust 2014-CBM, Floating Rate Note, 10/15/29 (144A) 4,552,466 2,200,000 2.53 JP Morgan Chase Commercial Mortgage Securities Trust 2014-FL4 REMICS, Floating Rate Note, 12/16/30 (144A) 2,194,681 900,000 2.43 JP Morgan Chase Commercial Mortgage Securities Trust 2014-FL5 REMICS, Floating Rate Note, 7/15/31 (144A) 891,927 1,260,000 1.68 JP Morgan Chase Commercial Mortgage Securities Trust 2014-FL5, Floating Rate Note, 7/15/31 (144A) 1,254,897 4,600,000 2.58 JP Morgan Chase Commercial Mortgage Securities Trust 2015-COSMO, Floating Rate Note, 1/15/32 (144A) 4,563,694 4,000,000 3.08 JP Morgan Chase Commercial Mortgage Securities Trust 2015-SGP, Floating Rate Note, 7/15/36 (144A) 3,993,245 186,976 2.62 JP Morgan Mortgage Trust 2003-A1, Floating Rate Note, 10/25/33 186,032 1,316,610 2.65 JP Morgan Mortgage Trust 2004-A1, Floating Rate Note, 2/25/34 1,341,692 493,255 2.57 JP Morgan Mortgage Trust 2004-A1, Floating Rate Note, 2/25/34 499,785 596,258 JP Morgan Mortgage Trust 2004-S1, 5.0%, 9/25/34 615,124 2,309,471 3.00 JP Morgan Mortgage Trust 2013-1, Floating Rate Note, 3/25/43 (144A) 2,347,846 5,550,115 3.00 JP Morgan Mortgage Trust 2013-1, Floating Rate Note, 3/25/43 (144A) 5,426,903 7,051,363 2.50 JP Morgan Mortgage Trust 2013-1, Floating Rate Note, 3/25/43 (144A) 6,986,709 1,777,955 3.53 JP Morgan Mortgage Trust 2013-1, Floating Rate Note, 3/25/43 (144A) 1,760,221 1,359,818 3.50 JP Morgan Mortgage Trust 2013-2, Floating Rate Note, 5/25/43 (144A) 1,368,531 1,379,336 3.50 JP Morgan Mortgage Trust 2014-1 REMICS, Floating Rate Note, 1/25/44 (144A) 1,394,673 7,751,679 3.00 JP Morgan Mortgage Trust 2014-2, Floating Rate Note, 6/25/29 (144A) 7,830,405 6,968,961 3.42 JP Morgan Mortgage Trust 2014-2, Floating Rate Note, 6/25/29 (144A) 7,108,609 1,408,468 3.43 JP Morgan Mortgage Trust 2014-2, Floating Rate Note, 6/25/29 (144A) 1,368,829 4,927,602 3.00 JP Morgan Mortgage Trust 2014-5, Floating Rate Note, 10/25/29 (144A) 4,993,045 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 27 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 2,361,304 3.04 JP Morgan Mortgage Trust 2014-5, Floating Rate Note, 10/25/29 (144A) $ 2,330,260 5,822,727 4.08 JP Morgan Mortgage Trust 2014-OAK4, Floating Rate Note, 9/25/44 (144A) 6,031,124 8,999,940 3.50 JP Morgan Mortgage Trust 2015-4, Floating Rate Note, 6/26/45 (144A) 9,130,814 7,014,007 0.92 JP Morgan Seasoned Mortgage Trust 2014-1, Floating Rate Note, 5/25/33 (144A) 6,692,195 6,021,710 3.00 JP Morgan Trust 2015-3 REMICS, Floating Rate Note, 5/25/45 (144A) 6,017,338 3,298,913 3.74 JP Morgan Trust 2015-3 REMICS, Floating Rate Note, 5/25/45 (144A) 3,227,935 4,902,841 3.50 JP Morgan Trust 2015-6, Floating Rate Note, 10/25/45 (144A) 4,897,518 438,445 2.50 La Hipotecaria Panamanian Mortgage Trust 2010-1, Floating Rate Note, 9/8/39 (144A) 453,133 3,801,808 3.26 La Hipotecaria Panamanian Mortgage Trust 2014-1, Floating Rate Note, 11/24/42 (144A) 3,887,349 105,686 LB-UBS Commercial Mortgage Trust 2004-C1, 4.568%, 1/15/31 106,042 173,711 1.17 Lehman Brothers Small Balance Commercial Mortgage Trust 2007-3 Class 1A4, Floating Rate Note, 10/25/37 (144A) 172,948 3,690,000 3.47 LSTAR Commercial Mortgage Trust 2015-3, Floating Rate Note, 4/22/48 (144A) 3,581,145 2,317,335 2.24 LSTAR Securities Investment Trust 2015-3, Floating Rate Note, 3/1/20 (144A) 2,283,961 5,169,477 2.19 LSTAR Securities Investment Trust 2015-4, Floating Rate Note, 4/1/20 (144A) 5,095,166 1,945,457 2.19 LSTAR Securities Investment Trust 2015-5, Floating Rate Note, 4/1/20 (144A) 1,917,324 690,154 0.77 Mellon Residential Funding Corp. Mortgage Pass-Through Trust Series 2000-TBC3, Floating Rate Note, 12/15/30 658,187 1,477,606 0.78 Merrill Lynch Mortgage Investors Trust Series MLCC 2004-G, Floating Rate Note, 1/25/30 1,390,988 3,000,000 3.00 Mill City Mortgage Trust 2015-2, Floating Rate Note, 9/25/57 (144A) 3,011,490 3,899,736 Morgan Stanley Capital I Trust 2007-HQ13, 5.569%, 12/15/44 4,058,096 2,385,000 1.04 Morgan Stanley Mortgage Loan Trust 2005-6AR, Floating Rate Note, 11/25/35 2,028,500 3,838,352 3.75 New Residential Mortgage Loan Trust 2014-2, Floating Rate Note, 5/26/54 (144A) 3,897,783 2,868,701 3.75 New Residential Mortgage Loan Trust 2014-3, Floating Rate Note, 11/25/54 (144A) 2,914,752 9,844,461 3.75 New Residential Mortgage Loan Trust 2015-1, Floating Rate Note, 5/28/52 (144A) 9,835,828 The accompanying notes are an integral part of these financial statements. 28 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 6,253,508 3.32 NRP Mortgage Trust 2013-1, Floating Rate Note, 7/25/43 $ 6,158,816 4,122,117 3.32 NRP Mortgage Trust 2013-1, Floating Rate Note, 7/25/43 (144A) 4,018,451 4,748,881 3.25 NRP Mortgage Trust 2013-1, Floating Rate Note, 7/25/43 (144A) 4,658,623 4,866,034 3.25 NRP Mortgage Trust 2013-1, Floating Rate Note, 7/25/43 (144A) 4,860,221 5,784,060 0.81 Opteum Mortgage Acceptance Corp Trust 2005-4, Floating Rate Note, 11/25/35 5,343,818 433,628 ORES 2014-LV3 LLC, 3.0%, 3/27/24 (144A) 432,934 292,598 RAAC Series 2004-SP2 Trust, 6.0%, 1/25/32 297,593 856,181 0.77 RALI Series 2003-QS13 Trust, Floating Rate Note, 7/25/33 792,322 259,139 RALI Series 2003-QS14 Trust, 5.0%, 7/25/18 262,079 693,521 RALI Series 2004-QS3 Trust, 5.0%, 3/25/19 695,118 2,854,792 1.94 RESI Finance LP 2003-CB1, Floating Rate Note, 7/9/35 2,698,478 2,919,922 RREF 2015-LT7 LLC, 3.0%, 12/25/32 (144A) 2,918,103 5,031,915 1.81 Sequoia Mortgage Trust 2012-6, Floating Rate Note, 12/26/42 4,607,548 6,975,666 3.58 Sequoia Mortgage Trust 2013-10, Floating Rate Note, 8/25/43 (144A) 6,888,662 4,301,266 1.87 Sequoia Mortgage Trust 2013-2, Floating Rate Note, 2/25/43 3,928,435 7,480,661 3.53 Sequoia Mortgage Trust 2013-3, Floating Rate Note, 3/25/43 7,492,523 7,527,716 2.33 Sequoia Mortgage Trust 2013-4 REMICS, Floating Rate Note, 4/27/43 7,013,297 283,692 1.55 Sequoia Mortgage Trust 2013-4, Floating Rate Note, 4/27/43 274,587 6,233,115 3.50 Sequoia Mortgage Trust 2013-4, Floating Rate Note, 4/27/43 6,205,206 2,960,268 2.50 Sequoia Mortgage Trust 2013-5 REMICS, Floating Rate Note, 5/25/43 (144A) 2,787,856 2,644,528 3.00 Sequoia Mortgage Trust 2013-5 REMICS, Floating Rate Note, 5/25/43 (144A) 2,583,373 7,221,373 2.50 Sequoia Mortgage Trust 2013-6, Floating Rate Note, 5/26/43 6,918,133 11,239,235 2.50 Sequoia Mortgage Trust 2013-7, Floating Rate Note, 6/25/43 10,567,106 3,817,677 3.00 Sequoia Mortgage Trust 2013-7, Floating Rate Note, 6/25/43 3,730,586 636,786 2.25 Sequoia Mortgage Trust 2013-8, Floating Rate Note, 6/25/43 611,962 714,286 3.00 Sequoia Mortgage Trust 2013-8, Floating Rate Note, 6/25/43 691,518 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 29 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 6,316,706 3.55 Sequoia Mortgage Trust 2013-8, Floating Rate Note, 6/25/43 $ 6,333,981 1,690,986 Sequoia Mortgage Trust 2013-9, 3.5%, 7/27/43 (144A) 1,698,120 6,449,946 3.00 Sequoia Mortgage Trust 2015-1, Floating Rate Note, 1/25/45 (144A) 6,280,435 9,146,593 3.50 Sequoia Mortgage Trust 2015-2, Floating Rate Note, 5/25/45 (144A) 9,116,583 4,975,000 3.00 Sequoia Mortgage Trust 2015-4, Floating Rate Note, 11/25/30 (144A) 5,024,748 44,839 3.00 Sequoia Mortgage Trust, Floating Rate Note, 9/25/42 43,662 750,000 3.79 Springleaf Mortgage Loan Trust 2013-1, Floating Rate Note, 6/25/58 (144A) 751,889 1,317,280 2.10 Springleaf Mortgage Loan Trust 2013-1, Floating Rate Note, 6/25/58 (144A) 1,315,986 597,273 2.47 Structured Adjustable Rate Mortgage Loan Trust, Floating Rate Note, 1/25/35 590,403 452,883 2.54 Structured Adjustable Rate Mortgage Loan Trust, Floating Rate Note, 11/25/34 447,818 1,938,942 0.94 Structured Asset Mortgage Investments Trust 2003-AR2, Floating Rate Note, 12/19/33 1,862,907 3,502,782 Structured Asset Securities Corp., Trust 2005-17, 5.5%, 10/25/35 3,603,727 555,650 2.59 Structured Asset Securities Corp., Mortgage Certificates Series 2003-31A, Floating Rate Note, 10/25/33 551,264 604,951 0.52 Structured Asset Securities Corp., Trust 2005-14, Floating Rate Note, 7/25/35 510,804 648,368 2.25 Thornburg Mortgage Securities Trust 2003-3, Floating Rate Note, 6/25/43 640,853 4,470,000 TimberStar Trust I REMICS, 5.668%, 10/15/36 (144A) 4,584,533 1,435,000 TimberStar Trust I, 5.7467%, 10/15/36 (144A) 1,467,216 6,663,479 Towd Point Mortgage Trust 2015-1, 2.75%, 11/25/60 (144A) 6,585,587 5,100,000 UBS Commercial Mortgage Trust 2012-C1, 3.4%, 5/12/45 5,193,346 1,769,106 2.42 Velocity Commercial Capital Loan Trust 2014-1, Floating Rate Note, 9/25/44 (144A) 1,751,415 3,356,821 2.83 Velocity Commercial Capital Loan Trust 2015-1, Floating Rate Note, 6/25/45 (144A) 3,373,606 433,123 VFC 2015-3 LLC, 2.75%, 12/20/31 (144A) 432,635 1,907,693 VOLT XXX LLC, 3.625%, 10/25/57 (Step) (144A) 1,901,465 1,753,994 WaMu Mortgage Pass-Through Certificates Series 2003-S10, 4.5%, 10/25/18 1,764,315 1,489,040 Wells Fargo Commercial Mortgage Trust 2010-C1, 3.349%, 11/18/43 (144A) 1,527,903 1,927,000 Wells Fargo Commercial Mortgage Trust 2012-LC5 REMICS, 3.539%, 10/17/45 1,958,978 The accompanying notes are an integral part of these financial statements. 30 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- (continued) 4,500,000 Wells Fargo Commercial Mortgage Trust 2014-LC16 REMICS, 3.477%, 8/17/50 $ 4,602,401 5,300,000 2.18 Wells Fargo Commercial Mortgage Trust 2014-TISH REMICS, Floating Rate Note, 2/16/27 (144A) 5,193,590 2,500,094 2.95 Wells Fargo Credit Risk Transfer Securities Trust 2015, Floating Rate Note, 11/25/25 (144A) 2,501,144 350,000 5.39 WF-RBS Commercial Mortgage Trust 2011-C2, Floating Rate Note, 2/15/44 (144A) 371,055 1,323,000 5.65 WF-RBS Commercial Mortgage Trust 2011-C2, Floating Rate Note, 2/15/44 (144A) 1,389,702 4,800,000 WFRBS Commercial Mortgage Trust 2013-C16, 4.136%, 9/17/46 5,093,984 6,893,205 3.50 WinWater Mortgage Loan Trust 2015-3 REMICS, Floating Rate Note, 3/20/45 (144A) 6,918,841 7,994,790 3.50 WinWater Mortgage Loan Trust 2015-4, Floating Rate Note, 6/20/45 (144A) 7,980,552 ----------------- $ 539,396,271 ----------------- Total Banks $ 539,396,271 ---------------------------------------------------------------------------------------------------------- GOVERNMENT -- 0.8% 1,250,000 4.30 Federal Home Loan Mortgage Corp., Floating Rate Note, 9/26/44 (144A) $ 1,272,222 2,380 Federal National Mortgage Association REMICS, 10.3%, 4/25/19 2,572 542,848 Federal National Mortgage Association REMICS, 4.5%, 6/25/29 580,133 2,311,340 Freddie Mac Whole Loan Securities Trust 2015-SC01, 3.5%, 5/25/45 2,335,320 850,000 5.44 FREMF Mortgage Trust 2010-K7, Floating Rate Note, 5/25/29 (144A) 922,968 600,000 5.42 FREMF Mortgage Trust 2010-K8, Floating Rate Note, 9/25/43 (144A) 647,764 890,000 5.20 FREMF Mortgage Trust 2010-K9 REMICS, Floating Rate Note, 9/25/45 (144A) 960,298 5,380,000 4.93 FREMF Mortgage Trust 2011-K702, Floating Rate Note, 4/25/44 (144A) 5,596,009 1,250,000 4.88 FREMF Mortgage Trust 2011-K703, Floating Rate Note, 7/25/44 (144A) 1,303,949 900,000 3.30 FREMF Mortgage Trust 2013-K502, Floating Rate Note, 3/27/45 (144A) 906,889 3,000,000 3.27 FREMF Mortgage Trust 2013-K713, Floating Rate Note, 4/25/46 (144A) 2,982,634 2,401,000 3.08 FREMF Mortgage Trust 2014-K503, Floating Rate Note, 10/25/47 (144A) 2,381,205 1,897,326 4.24 FREMF Mortgage Trust 2014-KF05 REMICS, Floating Rate Note, 9/25/21 (144A) 1,898,578 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 31 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Government -- (continued) 650,000 3.40 FREMF Mortgage Trust Class B, Floating Rate Note, 11/25/46 (144A) $ 654,346 2,010,000 3.95 FREMF Mortgage Trust Class B, Floating Rate Note, 6/25/47 (144A) 2,050,803 1,333,333 Government National Mortgage Association, 3.0%, 4/20/41 1,370,777 773,221 Government National Mortgage Association, 5.25%, 8/16/35 853,729 ----------------- $ 26,720,196 ----------------- Total Government $ 26,720,196 ---------------------------------------------------------------------------------------------------------- TOTAL COLLATERALIZED MORTGAGE OBLIGATIONS (Cost $570,178,801) $ 566,116,467 ---------------------------------------------------------------------------------------------------------- CORPORATE BONDS -- 39.8% ENERGY -- 4.6% Oil & Gas Drilling -- 0.4% 4,725,000 Ensco Plc, 4.5%, 10/1/24 $ 3,252,553 1,025,000 Pride International, Inc., 6.875%, 8/15/20 951,717 6,185,000 Rowan Companies, Inc., 4.75%, 1/15/24 4,398,265 5,505,000 Rowan Companies, Inc., 5.85%, 1/15/44 3,321,970 ----------------- $ 11,924,505 ---------------------------------------------------------------------------------------------------------- Oil & Gas Equipment & Services -- 0.2% 2,250,000 Halliburton Co., 7.6%, 8/15/96 (144A) $ 2,787,394 675,000 Weatherford International, Ltd., Bermuda, 5.95%, 4/15/42 474,188 2,815,000 Weatherford International, Ltd., Bermuda, 9.625%, 3/1/19 2,741,106 ----------------- $ 6,002,688 ---------------------------------------------------------------------------------------------------------- Integrated Oil & Gas -- 0.6% 4,175,000 BP Capital Markets Plc, 3.062%, 3/17/22 $ 4,091,012 5,350,000 ConocoPhillips Co., 3.35%, 11/15/24 4,892,661 1,000,000 Rosneft Finance SA, 7.875%, 3/13/18 (144A) 1,063,984 10,050,000 Sinopec Group Overseas Development 2015, Ltd., 2.5%, 4/28/20 (144A) 9,886,698 ----------------- $ 19,934,355 ---------------------------------------------------------------------------------------------------------- Oil & Gas Exploration & Production -- 0.3% 1,500,000 Approach Resources, Inc., 7.0%, 6/15/21 $ 532,500 1,096,000 Canadian Natural Resources, Ltd., 6.5%, 2/15/37 1,021,045 1,010,000 EP Energy LLC, 9.375%, 5/1/20 643,875 901,000 Marathon Oil Corp., 5.9%, 3/15/18 911,206 2,360,000 Newfield Exploration Co., 5.375%, 1/1/26 1,952,900 1,400,000 Newfield Exploration Co., 5.625%, 7/1/24 1,193,500 345,396 Ras Laffan Liquefied Natural Gas Co., Ltd., III, 5.832%, 9/30/16 (144A) 352,290 The accompanying notes are an integral part of these financial statements. 32 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Oil & Gas Exploration & Production -- (continued) 4,150,000 WPX Energy, Inc., 7.5%, 8/1/20 $ 3,361,500 ----------------- $ 9,968,816 ---------------------------------------------------------------------------------------------------------- Oil & Gas Refining & Marketing -- 0.4% 4,198,000 EnLink Midstream Partners LP, 4.4%, 4/1/24 $ 3,323,968 3,800,000 Motiva Enterprises LLC, 6.85%, 1/15/40 (144A) 3,898,409 2,825,000 Valero Energy Corp., 6.625%, 6/15/37 2,840,309 2,890,000 Valero Energy Corp., 9.375%, 3/15/19 3,414,333 ----------------- $ 13,477,019 ---------------------------------------------------------------------------------------------------------- Oil & Gas Storage & Transportation -- 2.4% 5,550,000 Boardwalk Pipelines LP, 4.95%, 12/15/24 $ 4,825,892 5,425,000 Buckeye Partners LP, 4.15%, 7/1/23 4,648,129 2,900,000 DCP Midstream LLC, 9.75%, 3/15/19 (144A) 2,952,922 3,340,000 5.85 DCP Midstream LLC, Floating Rate Note, 5/21/43 (144A) 2,555,100 9,250,000 Enbridge Energy Partners LP, 7.375%, 10/15/45 8,862,212 3,825,000 Enterprise Products Operating LLC, 3.7%, 2/15/26 3,431,033 5,310,000 Enterprise Products Operating LLC, 3.9%, 2/15/24 4,954,272 4,675,000 Kinder Morgan Energy Partners LP, 4.25%, 9/1/24 3,976,728 7,100,000 Kinder Morgan, Inc. Delaware, 5.05%, 2/15/46 5,265,445 7,335,000 Kinder Morgan, Inc. Delaware, 5.55%, 6/1/45 5,725,921 5,325,000 Plains All American Pipeline LP, 4.65%, 10/15/25 4,648,464 5,300,000 Plains All American Pipeline LP, 4.9%, 2/15/45 3,811,654 3,500,000 Sabine Pass LNG LP, 6.5%, 11/1/20 3,395,000 2,475,000 Spectra Energy Capital LLC, 6.2%, 4/15/18 2,619,590 1,500,000 Spectra Energy Capital LLC, 6.75%, 7/15/18 1,612,944 2,200,000 Sunoco Logistics Partners Operations LP, 6.1%, 2/15/42 1,757,041 16,525,000 The Williams Companies, Inc., 5.75%, 6/24/44 9,811,818 2,475,000 The Williams Companies, Inc., 7.75%, 6/15/31 1,752,812 4,425,000 TransCanada PipeLines, Ltd., 1.875%, 1/12/18 4,407,526 ----------------- $ 81,014,503 ---------------------------------------------------------------------------------------------------------- Other Diversified Financial Services -- 0.3% 5,275,000 CNOOC Nexen Finance 2014 ULC, 4.25%, 4/30/24 $ 5,316,799 4,750,000 Sinopec Group Overseas Development 2014, Ltd., 4.375%, 4/10/24 (144A) 4,907,429 ----------------- $ 10,224,228 ----------------- Total Energy $ 152,546,114 ---------------------------------------------------------------------------------------------------------- MATERIALS -- 2.1% Commodity Chemicals -- 0.1% 2,625,000 Methanex Corp., 4.25%, 12/1/24 $ 2,327,320 40,000 NOVA Chemicals Corp., 5.0%, 5/1/25 (144A) 38,600 ----------------- $ 2,365,920 ---------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 33 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Diversified Chemicals -- 0.2% 4,845,000 CF Industries, Inc., 5.15%, 3/15/34 $ 4,262,214 980,000 Eastman Chemical Co., 4.8%, 9/1/42 899,761 1,130,000 WR Grace & Co-Conn, 5.125%, 10/1/21 (144A) 1,141,300 ----------------- $ 6,303,275 ---------------------------------------------------------------------------------------------------------- Fertilizers & Agricultural Chemicals -- 0.4% 2,800,000 Agrium, Inc., 4.125%, 3/15/35 $ 2,381,814 7,600,000 Agrium, Inc., 5.25%, 1/15/45 7,084,370 2,675,000 Monsanto Co., 3.375%, 7/15/24 2,550,350 ----------------- $ 12,016,534 ---------------------------------------------------------------------------------------------------------- Specialty Chemicals -- 0.1% 3,025,000 The Valspar Corp., 3.3%, 2/1/25 $ 2,880,556 ---------------------------------------------------------------------------------------------------------- Construction Materials -- 0.4% 3,328,000 CEMEX Espana SA, 9.875%, 4/30/19 (144A) $ 3,519,360 10,600,000 CRH America, Inc., 3.875%, 5/18/25 (144A) 10,526,065 475,000 Holcim US Finance S.a.r.l. & Cie SCS, 6.0%, 12/30/19 (144A) 526,836 ----------------- $ 14,572,261 ---------------------------------------------------------------------------------------------------------- Metal & Glass Containers -- 0.2% 2,275,000 Ball Corp., 4.0%, 11/15/23 $ 2,169,781 4,000,000 Ball Corp., 5.25%, 7/1/25 4,090,000 ----------------- $ 6,259,781 ---------------------------------------------------------------------------------------------------------- Paper Packaging -- 0.3% 6,975,000 International Paper Co., 3.65%, 6/15/24 $ 6,821,913 1,025,000 International Paper Co., 3.8%, 1/15/26 1,009,876 2,400,000 International Paper Co., 6.0%, 11/15/41 2,516,947 ----------------- $ 10,348,736 ---------------------------------------------------------------------------------------------------------- Diversified Metals & Mining -- 0.1% 1,850,000 Freeport-McMoRan, Inc., 3.875%, 3/15/23 $ 1,054,500 1,650,000 Freeport-McMoRan, Inc., 4.55%, 11/14/24 944,625 4,000,000 Gold Fields Orogen Holdings BVI, Ltd., 4.875%, 10/7/20 (144A) 2,980,000 ----------------- $ 4,979,125 ---------------------------------------------------------------------------------------------------------- Steel -- 0.2% 3,550,000 Commercial Metals Co., 4.875%, 5/15/23 $ 2,946,500 1,175,000 Glencore Funding LLC, 4.125%, 5/30/23 (144A) 866,574 3,135,000 Worthington Industries, Inc., 4.55%, 4/15/26 3,097,095 ----------------- $ 6,910,169 ---------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 34 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Paper Products -- 0.1% 1,285,000 Clearwater Paper Corp., 4.5%, 2/1/23 $ 1,207,900 3,930,000 Resolute Forest Products, Inc., 5.875%, 5/15/23 2,859,075 ----------------- $ 4,066,975 ----------------- Total Materials $ 70,703,332 ---------------------------------------------------------------------------------------------------------- CAPITAL GOODS -- 1.7% Aerospace & Defense -- 0.4% 2,600,000 DigitalGlobe, Inc., 5.25%, 2/1/21 (144A) $ 2,184,000 1,915,000 Lockheed Martin Corp., 3.1%, 1/15/23 1,913,734 10,250,000 United Technologies Corp., 1.778%, 5/4/18 (Step) 10,146,526 ----------------- $ 14,244,260 ---------------------------------------------------------------------------------------------------------- Building Products -- 0.7% 7,225,000 Fortune Brands Home & Security, Inc., 3.0%, 6/15/20 $ 7,185,573 1,050,000 Masco Corp., 4.45%, 4/1/25 1,029,000 825,000 Masco Corp., 5.95%, 3/15/22 891,000 4,260,000 Masco Corp., 7.125%, 3/15/20 4,920,300 5,150,000 Owens Corning, 4.2%, 12/1/24 5,012,238 3,600,000 5.75 Stanley Black & Decker, Inc., Floating Rate Note, 12/15/53 3,780,000 ----------------- $ 22,818,111 ---------------------------------------------------------------------------------------------------------- Industrial Conglomerates -- 0.1% 2,950,000 Tyco Electronics Group SA, 6.55%, 10/1/17 $ 3,179,168 ---------------------------------------------------------------------------------------------------------- Construction & Farm Machinery & Heavy Trucks -- 0.1% 3,727,000 Cummins, Inc., 5.65%, 3/1/98 $ 3,891,122 ---------------------------------------------------------------------------------------------------------- Industrial Machinery -- 0.0%+ 604,000 Valmont Industries, Inc., 6.625%, 4/20/20 $ 669,204 ---------------------------------------------------------------------------------------------------------- Trading Companies & Distributors -- 0.4% 2,800,000 Aircastle, Ltd., 6.75%, 4/15/17 $ 2,920,764 2,260,000 GATX Corp., 5.2%, 3/15/44 2,157,104 5,660,000 GATX Corp., 6.0%, 2/15/18 6,064,588 ----------------- $ 11,142,456 ----------------- Total Capital Goods $ 55,944,321 ---------------------------------------------------------------------------------------------------------- COMMERCIAL SERVICES & SUPPLIES -- 0.1% Research & Consulting Services -- 0.1% 4,740,000 Verisk Analytics, Inc., 5.5%, 6/15/45 $ 4,525,581 ----------------- Total Commercial Services & Supplies $ 4,525,581 ---------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 35 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- TRANSPORTATION -- 1.7% Airlines -- 0.7% 4,523,057 Air Canada 2013-1 Class A Pass Through Trust, 4.125%, 11/15/26 (144A) $ 4,517,403 4,025,000 Air Canada 2015-1 Class A Pass Through Trust, 3.6%, 9/15/28 (144A) 3,894,188 4,300,000 American Airlines 2015-2 Class AA Pass Through Trust, 3.6%, 9/22/27 4,343,000 2,575,000 American Airlines 2015-2 Class B Pass Through Trust, 4.4%, 9/22/25 2,555,688 4,370,000 Southwest Airlines Co., 2.65%, 11/5/20 4,347,787 2,350,000 Southwest Airlines Co., 2.75%, 11/6/19 2,368,217 1,356,928 US Airways 2013-1 Class A Pass Through Trust, 3.95%, 5/15/27 1,367,105 ----------------- $ 23,393,388 ---------------------------------------------------------------------------------------------------------- Railroads -- 0.5% 12,160,000 Burlington Northern Santa Fe LLC, 4.15%, 4/1/45 $ 11,020,936 6,650,000 TTX Co., 3.6%, 1/15/25 (144A) 6,590,782 ----------------- $ 17,611,718 ---------------------------------------------------------------------------------------------------------- Trucking -- 0.3% 529,000 Asciano Finance, Ltd., 4.625%, 9/23/20 (144A) $ 533,965 1,400,000 Penske Truck Leasing Co., LP, 3.3%, 4/1/21 (144A) 1,380,260 8,850,000 Penske Truck Leasing Co., LP, 3.375%, 2/1/22 (144A) 8,593,235 ----------------- $ 10,507,460 ---------------------------------------------------------------------------------------------------------- Highways & Railtracks -- 0.2% 1,300,000 ERAC USA Finance LLC, 3.8%, 11/1/25 (144A) $ 1,286,396 4,600,000 ERAC USA Finance LLC, 4.5%, 2/15/45 (144A) 4,277,577 ----------------- $ 5,563,973 ----------------- Total Transportation $ 57,076,539 ---------------------------------------------------------------------------------------------------------- AUTOMOBILES & COMPONENTS -- 0.5% Automobile Manufacturers -- 0.5% 4,975,000 Ford Motor Credit Co., LLC, 2.24%, 6/15/18 $ 4,929,767 6,425,000 Ford Motor Credit Co., LLC, 3.219%, 1/9/22 6,288,482 5,000,000 Toyota Motor Credit Corp., 2.125%, 7/18/19 5,008,960 ----------------- $ 16,227,209 ----------------- Total Automobiles & Components $ 16,227,209 ---------------------------------------------------------------------------------------------------------- CONSUMER DURABLES & APPAREL -- 0.0%+ Home Furnishings -- 0.0%+ 800,000 Mohawk Industries, Inc., 3.85%, 2/1/23 $ 809,989 ----------------- Total Consumer Durables & Apparel $ 809,989 ---------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 36 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- CONSUMER SERVICES -- 0.4% Casinos & Gaming -- 0.2% 1,010,000 GLP Capital LP, 4.375%, 11/1/18 $ 999,900 3,550,000 MGM Resorts International, 6.0%, 3/15/23 3,523,375 ----------------- $ 4,523,275 ---------------------------------------------------------------------------------------------------------- Education Services -- 0.2% 2,600,000 President and Fellows of Harvard College, 2.3%, 10/1/23 $ 2,457,122 3,550,000 Tufts University, 5.017%, 4/15/12 3,652,535 ----------------- $ 6,109,657 ---------------------------------------------------------------------------------------------------------- Specialized Consumer Services -- 0.0%+ 1,300,000 Sotheby's, 5.25%, 10/1/22 (144A) $ 1,183,000 ----------------- Total Consumer Services $ 11,815,932 ---------------------------------------------------------------------------------------------------------- MEDIA -- 1.0% Broadcasting -- 0.2% 6,200,000 DIRECTV Holdings LLC, 3.8%, 3/15/22 $ 6,239,203 ---------------------------------------------------------------------------------------------------------- Cable & Satellite -- 0.6% 7,645,000 CCO Safari II LLC, 6.384%, 10/23/35 (144A) $ 7,723,980 9,690,000 DIRECTV Holdings LLC, 3.95%, 1/15/25 9,552,499 1,900,000 Intelsat Jackson Holdings SA, 7.25%, 4/1/19 1,743,250 ----------------- $ 19,019,729 ---------------------------------------------------------------------------------------------------------- Movies & Entertainment -- 0.2% 8,300,000 Time Warner, Inc., 4.7%, 1/15/21 $ 8,932,958 ----------------- Total Media $ 34,191,890 ---------------------------------------------------------------------------------------------------------- RETAILING -- 1.0% Catalog Retail -- 0.2% 7,300,000 QVC, Inc., 4.45%, 2/15/25 $ 6,770,261 ---------------------------------------------------------------------------------------------------------- Internet Retail -- 0.5% 5,900,000 Expedia, Inc., 4.5%, 8/15/24 $ 5,694,385 3,800,000 Expedia, Inc., 5.95%, 8/15/20 4,146,233 7,375,000 The Priceline Group, Inc., 3.65%, 3/15/25 7,177,807 ----------------- $ 17,018,425 ---------------------------------------------------------------------------------------------------------- Home Improvement Retail -- 0.1% 4,520,000 The Home Depot, Inc., 2.625%, 6/1/22 $ 4,515,277 ---------------------------------------------------------------------------------------------------------- Automotive Retail -- 0.1% 2,575,000 AutoZone, Inc., 2.5%, 4/15/21 $ 2,512,600 ---------------------------------------------------------------------------------------------------------- Homefurnishing Retail -- 0.1% 2,000,000 Bed Bath & Beyond, Inc., 3.749%, 8/1/24 $ 1,950,788 ----------------- Total Retailing $ 32,767,351 ---------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 37 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- FOOD & STAPLES RETAILING -- 0.3% Drug Retail -- 0.1% 650,000 CVS Health Corp., 2.25%, 8/12/19 $ 649,145 627,001 CVS Pass-Through Trust, 5.298%, 1/11/27 (144A) 675,041 1,353,348 CVS Pass-Through Trust, 5.773%, 1/10/33 (144A) 1,456,626 ----------------- $ 2,780,812 ---------------------------------------------------------------------------------------------------------- Food Retail -- 0.2% 7,472,000 The Kroger Co., 2.95%, 11/1/21 $ 7,395,651 ----------------- Total Food & Staples Retailing $ 10,176,463 ---------------------------------------------------------------------------------------------------------- FOOD, BEVERAGE & TOBACCO -- 0.4% Distillers & Vintners -- 0.0%+ 630,000 Constellation Brands, Inc., 3.75%, 5/1/21 $ 631,575 ---------------------------------------------------------------------------------------------------------- Agricultural Products -- 0.2% 5,175,000 Viterra, Inc., 5.95%, 8/1/20 (144A) $ 4,398,750 ---------------------------------------------------------------------------------------------------------- Packaged Foods & Meats -- 0.2% 4,200,000 Grupo Bimbo SAB de CV, 3.875%, 6/27/24 (144A) $ 4,081,930 3,240,000 Kraft Foods Group, Inc., 3.5%, 6/6/22 3,275,465 ----------------- $ 7,357,395 ---------------------------------------------------------------------------------------------------------- Tobacco -- 0.0%+ 1,050,000 Reynolds American, Inc., 3.75%, 5/20/23 $ 1,047,591 ----------------- Total Food, Beverage & Tobacco $ 13,435,311 ---------------------------------------------------------------------------------------------------------- HEALTH CARE EQUIPMENT & SERVICES -- 0.7% Health Care Equipment -- 0.5% 10,525,000 Becton Dickinson and Co., 3.734%, 12/15/24 $ 10,614,736 7,300,000 Medtronic, Inc., 4.625%, 3/15/45 7,529,614 ----------------- $ 18,144,350 ---------------------------------------------------------------------------------------------------------- Health Care Supplies -- 0.0%+ 1,600,000 Fresenius US Finance II, Inc., 4.5%, 1/15/23 (144A) $ 1,616,000 ---------------------------------------------------------------------------------------------------------- Health Care Services -- 0.1% 2,600,000 Catholic Health Initiatives, 4.35%, 11/1/42 $ 2,431,803 ---------------------------------------------------------------------------------------------------------- Health Care Facilities -- 0.1% 2,400,000 NYU Hospitals Center, 4.428%, 7/1/42 $ 2,281,030 ----------------- Total Health Care Equipment & Services $ 24,473,183 ---------------------------------------------------------------------------------------------------------- PHARMACEUTICALS, BIOTECHNOLOGY & LIFE SCIENCES -- 0.9% Biotechnology -- 0.8% 11,025,000 Baxalta, Inc., 3.6%, 6/23/22 (144A) $ 11,022,056 3,550,000 Biogen, Inc., 3.625%, 9/15/22 3,589,320 The accompanying notes are an integral part of these financial statements. 38 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Biotechnology -- (continued) 4,275,000 Biogen, Inc., 4.05%, 9/15/25 $ 4,294,400 7,550,000 Gilead Sciences, Inc., 4.5%, 2/1/45 7,385,138 ----------------- $ 26,290,914 ---------------------------------------------------------------------------------------------------------- Pharmaceuticals -- 0.1% 520,000 Endo, Ltd., 6.0%, 2/1/25 (144A) $ 512,200 3,150,000 Johnson & Johnson, 4.375%, 12/5/33 3,474,390 ----------------- $ 3,986,590 ---------------------------------------------------------------------------------------------------------- Life Sciences Tools & Services -- 0.0%+ 894,000 Agilent Technologies, Inc., 6.5%, 11/1/17 $ 954,230 ----------------- Total Pharmaceuticals, Biotechnology & Life Sciences $ 31,231,734 ---------------------------------------------------------------------------------------------------------- BANKS -- 6.4% Diversified Banks -- 5.5% 5,215,000 Australia & New Zealand Banking Group, Ltd., 4.5%, 3/19/24 (144A) $ 5,233,524 4,600,000 9.00 Banco Bilbao Vizcaya Argentaria SA, Floating Rate Note (Perpetual) 4,924,953 1,150,000 Bank of America Corp., 4.2%, 8/26/24 1,141,005 3,950,000 6.10 Bank of America Corp., Floating Rate Note (Perpetual) 4,004,312 6,975,000 6.50 Bank of America Corp., Floating Rate Note, 10/23/49 7,349,906 2,200,000 6.25 Bank of America Corp., Floating Rate Note, 9/29/49 2,205,500 3,515,000 Barclays Bank Plc, 6.05%, 12/4/17 (144A) 3,749,331 5,250,000 Barclays Plc, 3.65%, 3/16/25 5,045,381 2,400,000 BBVA Bancomer SA Texas, 4.375%, 4/10/24 (144A) 2,370,000 3,815,000 BBVA Bancomer SA Texas, 6.5%, 3/10/21 (144A) 4,043,900 7,800,000 BNP Paribas SA, 4.375%, 9/28/25 (144A) 7,638,712 2,925,000 5.88 Citigroup, Inc., Floating Rate Note (Perpetual) 2,903,062 2,850,000 5.90 Citigroup, Inc., Floating Rate Note (Perpetual) 2,800,125 2,295,000 5.95 Citigroup, Inc., Floating Rate Note (Perpetual) 2,245,658 3,435,000 Cooperatieve Rabobank UA, 3.875%, 2/8/22 3,625,244 6,425,000 Cooperatieve Rabobank UA, 3.95%, 11/9/22 6,503,539 11,575,000 6.62 Credit Agricole SA, Floating Rate Note (Perpetual) (144A) 11,378,225 4,825,000 7.88 Credit Agricole SA, Floating Rate Note (Perpetual) (144A) 4,933,562 11,200,000 Credit Suisse Group Funding Guernsey, Ltd., 3.8%, 9/15/22 (144A) 11,191,163 7,475,000 Export-Import Bank of Korea, 2.25%, 1/21/20 7,360,266 5,425,000 First Tennessee Bank NA, 2.95%, 12/1/19 5,383,732 1,305,000 HSBC Bank Plc, 7.65%, 5/1/25 1,655,546 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 39 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Diversified Banks -- (continued) 3,940,000 HSBC Holdings Plc, 4.25%, 3/14/24 $ 3,954,286 11,836,000 6.50 ING Groep NV, Floating Rate Note, 12/29/49 11,562,292 1,400,000 Intesa Sanpaolo S.p.A., 6.5%, 2/24/21 (144A) 1,588,009 8,125,000 7.70 Intesa Sanpaolo S.p.A., Floating Rate Note (Perpetual) (144A) 8,277,344 5,125,000 Macquarie Bank, Ltd., 4.875%, 6/10/25 (144A) 5,058,150 840,000 Macquarie Bank, Ltd., 6.625%, 4/7/21 (144A) 941,036 4,500,000 Nordea Bank AB, 4.25%, 9/21/22 (144A) 4,609,665 5,600,000 6.12 Nordea Bank AB, Floating Rate Note (Perpetual) (144A) 5,468,120 6,325,000 7.50 Royal Bank of Scotland Group Plc, Floating Rate Note (Perpetual) 6,585,906 526,316 3.26 SBP DPR Finance Co., Floating Rate Note, 3/15/17 (144A) 525,994 2,600,000 4.50 Scotiabank Peru SAA, Floating Rate Note, 12/13/27 (144A) 2,496,000 2,200,000 Standard Chartered Bank, 6.4%, 9/26/17 (144A) 2,338,728 4,800,000 Standard Chartered Plc, 3.95%, 1/11/23 (144A) 4,617,590 1,800,000 Sumitomo Mitsui Banking Corp., 1.75%, 1/16/18 1,793,144 11,675,000 The Bank of Tokyo-Mitsubishi UFJ, Ltd., 2.3%, 3/5/20 (144A) 11,508,258 3,400,000 5.88 Wells Fargo & Co., Floating Rate Note (Perpetual) 3,578,500 ----------------- $ 182,589,668 ---------------------------------------------------------------------------------------------------------- Regional Banks -- 0.8% 1,190,000 CoBank ACB, 7.875%, 4/16/18 (144A) $ 1,332,123 7,000,000 Credit Suisse AG New York NY, 1.75%, 1/29/18 6,980,337 3,350,000 HSBC Bank USA NA New York NY, 6.0%, 8/9/17 3,563,539 7,378,000 KeyCorp, 5.1%, 3/24/21 8,063,763 1,435,000 PNC Bank NA, 6.0%, 12/7/17 1,536,427 1,025,000 SunTrust Banks, Inc., 3.5%, 1/20/17 1,042,692 890,000 6.75 The PNC Financial Services Group, Inc., Floating Rate Note (Perpetual) 946,738 3,540,000 Wells Fargo Bank NA, 6.0%, 11/15/17 3,817,982 ----------------- $ 27,283,601 ---------------------------------------------------------------------------------------------------------- Thrifts & Mortgage Finance -- 0.1% 2,300,000 Astoria Financial Corp., 5.0%, 6/19/17 $ 2,378,906 ----------------- Total Banks $ 212,252,175 ---------------------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 4.6% Other Diversified Financial Services -- 0.6% 5,930,000 Carlyle Holdings II Finance LLC, 5.625%, 3/30/43 (144A) $ 6,298,472 1,392,000 General Electric Capital Corp., 5.3%, 2/11/21 1,569,647 1,857,079 Grain Spectrum Funding II LLC, 3.29%, 10/10/19 (144A) 1,853,364 The accompanying notes are an integral part of these financial statements. 40 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Other Diversified Financial Services -- (continued) 9,100,000 6.75 JPMorgan Chase & Co., Floating Rate Note, 8/29/49 $ 9,919,000 1,250,000 0.00 Tiers Trust, Floating Rate Note, 10/15/97 (144A) (d) 1,150,830 ----------------- $ 20,791,313 ---------------------------------------------------------------------------------------------------------- Specialized Finance -- 0.9% 3,725,000 Aviation Capital Group Corp., 6.75%, 4/6/21 (144A) $ 4,172,000 3,200,000 BM&FBovespa SA - Bolsa de Valores Mercadorias e Futuros, 5.5%, 7/16/20 (144A) 3,144,000 2,980,000 Cantor Fitzgerald LP, 7.875%, 10/15/19 (144A) 3,270,583 2,000,000 National Rural Utilities Cooperative Finance Corp., 5.45%, 2/1/18 2,152,498 5,480,000 Nationstar Mortgage LLC, 6.5%, 6/1/22 4,740,200 11,625,000 USAA Capital Corp., 2.45%, 8/1/20 (144A) 11,620,803 ----------------- $ 29,100,084 ---------------------------------------------------------------------------------------------------------- Consumer Finance -- 1.2% 1,500,000 Ally Financial, Inc., 3.6%, 5/21/18 $ 1,500,000 800,000 Ally Financial, Inc., 4.625%, 3/30/25 790,000 5,050,000 Ally Financial, Inc., 5.125%, 9/30/24 5,169,938 1,125,000 Ally Financial, Inc., 5.75%, 11/20/25 1,139,062 7,695,000 American Honda Finance Corp., 1.2%, 7/14/17 7,661,042 1,465,000 Capital One Bank USA NA, 8.8%, 7/15/19 1,745,241 6,650,000 Capital One Financial Corp., 3.75%, 4/24/24 6,693,045 2,300,000 General Motors Financial Co., Inc., 3.7%, 11/24/20 2,306,222 6,525,000 General Motors Financial Co., Inc., 4.0%, 1/15/25 6,190,639 2,245,000 Hyundai Capital America, 1.45%, 2/6/17 (144A) 2,234,523 3,125,000 Hyundai Capital America, 2.0%, 3/19/18 (144A) 3,087,859 ----------------- $ 38,517,571 ---------------------------------------------------------------------------------------------------------- Asset Management & Custody Banks -- 0.9% 2,525,000 Affiliated Managers Group, Inc., 4.25%, 2/15/24 $ 2,550,578 1,725,000 Blackstone Holdings Finance Co., LLC, 5.0%, 6/15/44 (144A) 1,761,196 6,925,000 Blackstone Holdings Finance Co., LLC, 6.25%, 8/15/42 (144A) 8,182,435 733,000 Eaton Vance Corp., 6.5%, 10/2/17 782,702 5,025,000 KKR Group Finance Co., II LLC, 5.5%, 2/1/43 (144A) 5,238,844 2,400,000 Legg Mason, Inc., 3.95%, 7/15/24 2,360,714 4,290,000 Legg Mason, Inc., 5.625%, 1/15/44 4,261,287 4,250,000 Neuberger Berman Group LLC, 4.875%, 4/15/45 (144A) 3,583,506 1,250,000 4.50 The Bank of New York Mellon Corp., Floating Rate Note (Perpetual) 1,143,750 ----------------- $ 29,865,012 ---------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 41 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Investment Banking & Brokerage -- 0.7% 1,650,000 KKR Group Finance Co., III LLC, 5.125%, 6/1/44 (144A) $ 1,615,932 2,730,000 Macquarie Group, Ltd., 6.0%, 1/14/20 (144A) 3,013,068 5,100,000 Morgan Stanley, 4.1%, 5/22/23 5,152,025 300,000 Morgan Stanley, 4.875%, 11/1/22 318,376 2,900,000 5.55 Morgan Stanley, Floating Rate Note (Perpetual) 2,900,000 643,000 North American Development Bank, 2.3%, 10/10/18 647,431 6,025,000 TD Ameritrade Holding Corp., 3.625%, 4/1/25 6,097,095 4,400,000 UBS AG, 7.625%, 8/17/22 5,016,000 ----------------- $ 24,759,927 ---------------------------------------------------------------------------------------------------------- Diversified Capital Markets -- 0.3% 4,031,000 GE Capital International Funding Co., 2.342%, 11/15/20 (144A) $ 3,997,381 6,900,000 2.01 ICBCIL Finance Co., Ltd., Floating Rate Note, 11/13/18 (144A) 6,894,349 ----------------- $ 10,891,730 ----------------- Total Diversified Financials $ 153,925,637 ---------------------------------------------------------------------------------------------------------- INSURANCE -- 6.2% Insurance Brokers -- 0.1% 5,000,000 Brown & Brown, Inc., 4.2%, 9/15/24 $ 4,937,275 ---------------------------------------------------------------------------------------------------------- Life & Health Insurance -- 0.9% 7,000,000 Aflac, Inc., 3.625%, 11/15/24 $ 7,124,026 4,250,000 Protective Life Corp., 7.375%, 10/15/19 4,916,370 1,090,000 Prudential Financial, Inc., 4.5%, 11/16/21 1,176,943 1,500,000 5.62 Prudential Financial, Inc., Floating Rate Note, 6/15/43 1,533,750 2,140,000 8.88 Prudential Financial, Inc., Floating Rate Note, 6/15/68 2,407,500 1,800,000 5.88 Prudential Financial, Inc., Floating Rate Note, 9/15/42 1,871,100 6,830,000 Teachers Insurance & Annuity Association of America, 6.85%, 12/16/39 (144A) 8,444,469 ----------------- $ 27,474,158 ---------------------------------------------------------------------------------------------------------- Multi-line Insurance -- 0.5% 5,985,000 AIG, 3.875%, 1/15/35 $ 5,278,962 2,335,000 AXA SA, 8.6%, 12/15/30 3,137,654 5,325,000 Liberty Mutual Insurance Co., 7.697% (Perpetual) (144A) 6,572,679 2,650,000 Loews Corp., 5.25%, 3/15/16 2,671,892 ----------------- $ 17,661,187 ---------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 42 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Property & Casualty Insurance -- 0.3% 1,850,000 Delphi Financial Group, Inc., 7.875%, 1/31/20 $ 2,150,723 945,000 OneBeacon US Holdings, Inc., 4.6%, 11/9/22 949,823 1,300,000 The Allstate Corp., 5.95%, 4/1/36 1,567,398 5,455,000 6.50 The Allstate Corp., Floating Rate Note, 5/15/57 6,000,500 ----------------- $ 10,668,444 ---------------------------------------------------------------------------------------------------------- Reinsurance -- 4.5% 1,500,000 3.66 Acorn Re, Ltd., Floating Rate Note, 7/17/18 (Cat Bond) (144A) $ 1,511,550 2,750,000 6.12 Alamo Re, Ltd., Floating Rate Note, 6/7/18 (Cat Bond) (144A) 2,816,275 937,930 Altair Re, Variable Rate Notes, 6/30/16 (e)(g) 65,655 974,064 Altair Re, Variable Rate Notes, 6/30/17 (e)(g) 1,155,435 900,000 Arlington Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 8/31/16 (e)(g) 979,920 500,000 3.52 Atlas IX Capital DAC, Floating Rate Note, 1/17/19 (Cat Bond) (144A) 509,050 250,000 8.33 Atlas Reinsurance VII, Ltd., Floating Rate Note, 1/7/16 (Cat Bond) (144A) 249,850 800,000 Berwick Segregated Account (Kane SAC Ltd.), Variable Rate Note, 1/22/16 (e)(g) 933,200 1,200,000 Berwick Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 1/1/18 (e)(g) 1,200,000 3,050,000 4.56 Blue Danube II, Ltd., Floating Rate Note, 5/23/18 (Cat Bond) (144A) 3,041,765 1,250,000 5.25 Caelus Re, Ltd., Floating Rate Note, 3/7/16 (Cat Bond) (144A) 1,249,500 1,850,000 6.99 Caelus Re, Ltd., Floating Rate Note, 4/7/17 (Cat Bond) (144A) 1,891,995 600,000 Carnoustie Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 11/30/20 (e)(g) 600,000 3,000,000 Carnoustie Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 2/19/16 (e)(g) 3,490,500 250,000 4.47 Citrus Re, Ltd., Floating Rate Note, 4/18/17 (Cat Bond) (144A) 249,225 550,000 4.29 Citrus Re, Ltd., Floating Rate Note, 4/24/17 (Cat Bond) (144A) 550,000 1,200,000 Clarendon Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 6/15/16 (e)(g) 1,199,520 250,000 9.23 East Lane Re V, Ltd., Floating Rate Note, 3/16/16 (Cat Bond) (144A) 252,900 925,000 Eden Re II, Ltd., Variable Rate Notes, 4/23/19 (144A) (e)(g) 925,000 2,500,000 Eden Re II, Ltd., Variable Rate Notes, 4/19/18 (144A) (e)(g) 2,662,500 7,550,000 10.22 Everglades Re, Ltd., Floating Rate Note, 3/28/16 (Cat Bond) (144A) 7,670,045 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 43 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Reinsurance -- (continued) 3,654,000 Exeter Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 1/7/16 (e)(g) $ 4,000,034 1,000,000 Fairfield Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 2/2/16 (e)(g) 1,000,000 1,200,000 7.41 Galileo Re, Ltd., Floating Rate Note, 1/9/17 (Cat Bond) (144A) 1,208,400 2,800,000 2.20 Golden State Re II, Ltd., Floating Rate Note, 1/8/19 (Cat Bond) (144A) 2,779,840 3,700,000 Gullane Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 1/22/17 (e)(g) 4,210,970 1,009,200 Hereford Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 1/7/16 (e)(g) 1,200,040 1,150,000 4.08 Ibis Re II, Ltd., Floating Rate Note, 6/28/16 (Cat Bond) (144A) 1,157,360 1,000,000 4.56 Ibis Re II, Ltd., Floating Rate Note, 6/28/16 (Cat Bond) (144A) 1,008,800 1,700,000 3.74 Kilimanjaro Re, Ltd., Floating Rate Note, 11/25/19 (Cat Bond) (144A) 1,684,190 3,000,000 6.75 Kilimanjaro Re, Ltd., Floating Rate Note, 12/6/19 (Cat Bond) (144A) 3,004,500 1,500,000 9.25 Kilimanjaro Re, Ltd., Floating Rate Note, 12/6/19 (Cat Bond) (144A) 1,505,850 3,700,000 4.74 Kilimanjaro Re, Ltd., Floating Rate Note, 4/30/18 (Cat Bond) (144A) 3,677,430 350,000 4.49 Kilimanjaro Re, Ltd., Floating Rate Note, 4/30/18 (Cat Bond) (144A) 345,380 500,000 Lahinch Re, Variable Rate Notes, 6/15/16 (e)(g) 505,150 250,000 9.76 Loma Reinsurance, Ltd. Bermuda, Floating Rate Note, 1/8/18 (Cat Bond) (144A) 256,800 5,950,000 4.30 Longpoint Re, Ltd. III, Floating Rate Note, 5/18/16 (Cat Bond) (144A) 5,977,370 4,000,000 3.75 Longpoint Re, Ltd. III, Floating Rate Note, 5/23/18 (Cat Bond) (144A) 4,040,400 1,300,000 Lorenz Re, Ltd., Variable Rate Notes, 3/31/18 (e)(g) 1,449,240 1,000,000 2.00 Merna Re V, Ltd., Floating Rate Note, 4/7/17 (Cat Bond) (144A) 997,800 1,956,533 Muirfield Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 1/12/16 (e)(g) 2,199,926 1,000,000 8.73 Mythen Re, Ltd., Series 2012-2 Class A, Floating Rate Note, 1/5/17 (Cat Bond) (144A) 1,028,100 1,100,000 7.24 Northshore Re, Ltd., Floating Rate Note, 7/5/16 (Cat Bond) (144A) 1,113,420 900,000 Pangaea Re Series 2016-1 Principal-at-Risk Notes, 11/30/20 (e)(g) 900,000 3,600,000 Pangaea Re, Series 2015-1, Principal at Risk Notes, 2/1/19 (e)(g) 4,187,160 4,000,000 Pangaea Re, Series 2015-2, Principal at Risk Notes, 11/30/19 (e)(g) 4,238,400 The accompanying notes are an integral part of these financial statements. 44 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Reinsurance -- (continued) 2,000,000 Pangaea Re, Variable Rate Notes, 7/1/18 (e)(g) $ 36,000 3,200,000 4.77 PennUnion Re, Ltd., Floating Rate Note, 12/7/18 (Cat Bond) (144A) 3,186,560 1,000,000 Prestwick Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 7/1/16 (e)(g) 1,116,300 2,000,000 6.39 Queen Street XI RE Dac, Floating Rate Note, 6/7/19 (Cat Bond) (144A) 1,998,600 1,650,000 8.76 Queen Street VII Re, Ltd., Floating Rate Note, 4/8/16 (Cat Bond) (144A) 1,657,590 1,650,000 6.00 Residential Reinsurance 2012, Ltd., Floating Rate Note, 12/6/16 (Cat Bond) (144A) 1,671,615 2,800,000 4.75 Residential Reinsurance 2012, Ltd., Floating Rate Note, 12/6/16 (Cat Bond) (144A) 2,816,520 800,000 8.25 Residential Reinsurance 2012, Ltd., Floating Rate Note, 6/6/16 (Cat Bond) (144A) 814,720 275,000 10.27 Residential Reinsurance 2012, Ltd., Floating Rate Note, 6/6/16 (Cat Bond) (144A) 282,425 250,000 9.52 Residential Reinsurance 2013, Ltd., Floating Rate Note, 6/6/17 (Cat Bond) (144A) 262,925 2,550,000 2.99 Sanders Re, Ltd., Floating Rate Note, 5/25/18 (Cat Bond) (144A) 2,490,330 1,250,000 4.00 Sanders Re, Ltd., Floating Rate Note, 5/5/17 (Cat Bond) (144A) 1,246,375 1,200,000 3.49 Sanders Re, Ltd., Floating Rate Note, 5/5/17 (Cat Bond) (144A) 1,190,040 2,000,000 4.05 Sanders Re, Ltd., Floating Rate Note, 6/7/17 (Cat Bond) (144A) 1,994,800 3,000,000 Sector Re V, Ltd., Variable Rate Notes, 3/1/20 (144A) (e)(g) 3,362,700 400,000 Sector Re V, Ltd., Variable Rate Notes, 3/1/20 (144A) (e) (g) 479,920 1,100,000 Sector Re V, Ltd., Variable Rate Notes, 12/1/20 (144A) (e)(g) 1,105,170 250,000 Silverton Re, Ltd., Variable Rate Notes, 9/16/16 (144A) (e)(g) 2,350 1,000,000 Silverton Re, Ltd., Variable Rate Notes, 9/18/17 (144A) (e)(g) 1,290,000 1,700,000 Silverton Re, Ltd., Variable Rate Notes, 9/18/18 (144A) (e)(g) 1,700,000 700,000 St Andrews Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 2/1/18 (e)(g) 700,000 1,300,000 St. Andrews Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 1/22/16 (e)(g) 1,463,410 7,300,000 8.66 Tar Heel Re, Ltd., Floating Rate Note, 5/9/16 (Cat Bond) (144A) 7,452,570 2,018,867 Troon Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 1/12/16 (e)(g) 2,199,959 1,012,000 Turnberry Segregated Account (Kane SAC Ltd.), Variable Rate Notes, 1/15/16 (e)(g) 1,030,924 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 45 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Reinsurance -- (continued) 1,500,000 5.00 Ursa Re, Ltd., Floating Rate Note, 9/21/18 (Cat Bond) (144A) $ 1,496,850 1,125,000 Versutus 2016 Class A-1, Variable Rate Notes, 11/30/20 (e)(g) 1,125,000 2,500,000 Versutus Ltd., Series 2015-A, Variable Rate Notes, 12/31/2017 (e)(g) 2,920,000 8,850,000 0.00 Vita Capital V, Ltd., Floating Rate Note, 1/15/17 (Cat Bond) (144A) 8,920,800 1,500,000 2.86 Vita Capital V, Ltd., Floating Rate Note, 1/15/17 (Cat Bond) (144A) 1,509,750 500,000 2.75 Vitality Re IV, Ltd., Floating Rate Note, 1/9/17 (Cat Bond) (144A) 502,700 1,750,000 1.75 Vitality Re V, Ltd., Floating Rate Note, 1/7/19 (Cat Bond) (144A) 1,728,475 1,400,000 5.88 Wilton Re Finance LLC, Floating Rate Note, 3/30/33 (144A) 1,468,866 ----------------- $ 148,104,689 ----------------- Total Insurance $ 208,845,753 ---------------------------------------------------------------------------------------------------------- REAL ESTATE -- 1.4% Diversified REIT -- 0.7% 4,225,000 Brixmor Operating Partnership LP, 3.85%, 2/1/25 $ 4,104,938 1,175,000 Brixmor Operating Partnership LP, 3.875%, 8/15/22 1,169,602 1,475,000 DCT Industrial Operating Partnership LP, 4.5%, 10/15/23 1,476,080 2,175,000 Duke Realty LP, 3.625%, 4/15/23 2,125,121 5,300,000 Duke Realty LP, 3.75%, 12/1/24 5,154,875 9,125,000 Essex Portfolio LP, 3.5%, 4/1/25 8,778,432 ----------------- $ 22,809,048 ---------------------------------------------------------------------------------------------------------- Office REIT -- 0.3% 75,000 Alexandria Real Estate Equities, Inc., 2.75%, 1/15/20 $ 73,732 1,093,000 Alexandria Real Estate Equities, Inc., 3.9%, 6/15/23 1,079,495 2,670,000 Alexandria Real Estate Equities, Inc., 4.6%, 4/1/22 2,769,975 2,032,000 Highwoods Realty LP, 3.2%, 6/15/21 1,976,835 2,100,000 Highwoods Realty LP, 3.625%, 1/15/23 2,034,526 2,550,000 Piedmont Operating Partnership LP, 3.4%, 6/1/23 2,391,074 ----------------- $ 10,325,637 ---------------------------------------------------------------------------------------------------------- Healthcare REIT -- 0.2% 3,750,000 Healthcare Realty Trust, Inc., 3.875%, 5/1/25 $ 3,627,022 3,945,000 Omega Healthcare Investors, Inc., 4.95%, 4/1/24 3,984,162 ----------------- $ 7,611,184 ---------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 46 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Specialized REIT -- 0.2% 2,700,000 CubeSmart LP, 4.0%, 11/15/25 $ 2,679,237 730,000 CubeSmart LP, 4.8%, 7/15/22 777,360 1,675,000 DuPont Fabros Technology LP, 5.875%, 9/15/21 1,742,000 1,875,000 Equinix, Inc., 5.75%, 1/1/25 1,917,188 ----------------- $ 7,115,785 ----------------- Total Real Estate $ 47,861,654 ---------------------------------------------------------------------------------------------------------- SOFTWARE & SERVICES -- 1.0% Data Processing & Outsourced Services -- 0.4% 3,750,000 Automatic Data Processing, Inc., 2.25%, 9/15/20 $ 3,764,201 3,000,000 Cardtronics, Inc., 5.125%, 8/1/22 2,895,000 4,550,000 Visa, Inc., 2.2%, 12/14/20 4,541,532 ----------------- $ 11,200,733 ---------------------------------------------------------------------------------------------------------- Application Software -- 0.3% 8,100,000 Adobe Systems, Inc., 3.25%, 2/1/25 $ 7,905,446 2,875,000 Igloo Holdings Corp., 8.25%, 12/15/17 (8.25% Cash, 9.00% PIK) (144A) (PIK) 2,875,000 ----------------- $ 10,780,446 ---------------------------------------------------------------------------------------------------------- Systems Software -- 0.3% 10,600,000 Oracle Corp., 2.5%, 5/15/22 $ 10,404,038 ---------------------------------------------------------------------------------------------------------- Home Entertainment Software -- 0.0%+ 650,000 Activision Blizzard, Inc., 6.125%, 9/15/23 (144A) $ 689,000 ----------------- Total Software & Services $ 33,074,217 ---------------------------------------------------------------------------------------------------------- TECHNOLOGY HARDWARE & EQUIPMENT -- 0.5% Communications Equipment -- 0.1% 2,860,000 Brocade Communications Systems, Inc., 4.625%, 1/15/23 $ 2,717,000 ---------------------------------------------------------------------------------------------------------- Computer Hardware Storage & Peripherals -- 0.2% 4,600,000 NCR Corp., 4.625%, 2/15/21 $ 4,381,500 1,425,000 NCR Corp., 6.375%, 12/15/23 1,403,625 ----------------- $ 5,785,125 ---------------------------------------------------------------------------------------------------------- Electronic Components -- 0.1% 3,675,000 Amphenol Corp., 3.125%, 9/15/21 $ 3,633,715 ---------------------------------------------------------------------------------------------------------- Electronic Manufacturing Services -- 0.1% 2,750,000 Flextronics International, Ltd., 4.75%, 6/15/25 (144A) $ 2,677,812 ----------------- Total Technology Hardware & Equipment $ 14,813,652 ---------------------------------------------------------------------------------------------------------- SEMICONDUCTORS & SEMICONDUCTOR EQUIPMENT -- 0.4% Semiconductor Equipment -- 0.1% 2,500,000 Entegris, Inc., 6.0%, 4/1/22 (144A) $ 2,531,250 ---------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 47 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Semiconductors -- 0.3% 11,075,000 Intel Corp., 4.8%, 10/1/41 $ 11,545,433 ----------------- Total Semiconductors & Semiconductor Equipment $ 14,076,683 ---------------------------------------------------------------------------------------------------------- TELECOMMUNICATION SERVICES -- 1.4% Integrated Telecommunication Services -- 0.9% 2,250,000 AT&T, Inc., 4.75%, 5/15/46 $ 2,060,091 130,000 Frontier Communications Corp., 10.5%, 9/15/22 (144A) 129,512 4,300,000 Frontier Communications Corp., 7.125%, 1/15/23 3,708,750 130,000 Frontier Communications Corp., 8.875%, 9/15/20 (144A) 131,625 4,800,000 GTP Acquisition Partners I LLC, 2.35%, 6/15/45 (144A) 4,654,752 763,103 GTP Cellular Sites LLC, 3.721%, 3/15/17 (144A) 765,270 2,750,000 Telefonica Emisiones SAU, 6.221%, 7/3/17 2,922,590 1,500,000 Unison Ground Lease Funding LLC, 2.981%, 3/16/43 (144A) 1,491,790 1,938,000 Verizon Communications, Inc., 5.012%, 8/21/54 1,774,415 5,100,000 Verizon Communications, Inc., 5.15%, 9/15/23 5,606,563 7,254,000 Verizon Communications, Inc., 6.55%, 9/15/43 8,612,021 ----------------- $ 31,857,379 ---------------------------------------------------------------------------------------------------------- Wireless Telecommunication Services -- 0.5% 1,675,000 Altice Financing SA, 7.875%, 12/15/19 (144A) $ 1,742,000 3,015,000 Crown Castle Towers LLC, 4.883%, 8/15/20 (144A) 3,223,100 1,625,000 Crown Castle Towers LLC, 6.113%, 1/15/20 (144A) 1,772,314 6,975,000 SBA Tower Trust, 3.869%, 10/15/49 (144A) 6,891,671 1,500,000 Sprint Corp., 7.125%, 6/15/24 1,081,875 1,500,000 Sprint Corp., 7.25%, 9/15/21 1,132,050 ----------------- $ 15,843,010 ----------------- Total Telecommunication Services $ 47,700,389 ---------------------------------------------------------------------------------------------------------- UTILITIES -- 2.5% Electric Utilities -- 1.7% 980,000 Commonwealth Edison Co., 6.15%, 9/15/17 $ 1,052,122 514,347 Crockett Cogeneration LP, 5.869%, 3/30/25 (144A) 533,392 4,250,000 Electricite de France SA, 6.0%, 1/22/14 (144A) 4,158,540 2,150,000 5.25 Electricite de France SA, Floating Rate Note (Perpetual) (144A) 2,021,000 2,825,000 Empresa Electrica Angamos SA, 4.875%, 5/25/29 (144A) 2,520,146 3,365,000 Enel Finance International NV, 5.125%, 10/7/19 (144A) 3,635,724 2,320,000 8.13 Enel S.p.A., Floating Rate Note, 9/24/73 (144A) 2,641,900 4,250,000 Exelon Corp., 2.85%, 6/15/20 4,226,765 The accompanying notes are an integral part of these financial statements. 48 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Electric Utilities -- (continued) 586,325 FPL Energy American Wind LLC, 6.639%, 6/20/23 (144A) $ 589,764 69,922 FPL Energy Wind Funding LLC, 6.876%, 6/27/17 (144A) 68,523 4,475,000 Iberdrola International BV, 6.75%, 7/15/36 5,484,193 1,925,000 Israel Electric Corp., Ltd., 7.25%, 1/15/19 (144A) 2,133,501 610,000 Israel Electric Corp., Ltd., 9.375%, 1/28/20 (144A) 743,285 910,000 Nevada Power Co., 6.5%, 8/1/18 1,009,905 454,331 Orcal Geothermal, Inc., 6.21%, 12/30/20 (144A) 465,689 2,690,000 Public Service Co. of New Mexico, 7.95%, 5/15/18 3,010,255 5,757,143 Southern California Edison Co., 1.845%, 2/1/22 5,703,889 2,200,000 6.25 Southern California Edison Co., Floating Rate Note (Perpetual) 2,423,850 10,800,000 Southwestern Electric Power Co., 3.9%, 4/1/45 9,456,761 4,556,000 Talen Energy Supply LLC, 6.5%, 6/1/25 (144A) 3,006,960 ----------------- $ 54,886,164 ---------------------------------------------------------------------------------------------------------- Gas Utilities -- 0.1% 2,125,000 DCP Midstream Operating LP, 5.6%, 4/1/44 $ 1,290,559 2,146,148 Nakilat, Inc., 6.267%, 12/31/33 (144A) 2,361,836 ----------------- $ 3,652,395 ---------------------------------------------------------------------------------------------------------- Multi-Utilities -- 0.4% 5,475,000 Consolidated Edison Co. of New York, Inc., 4.625%, 12/1/54 $ 5,387,132 5,055,000 New York State Electric & Gas Corp., 6.15%, 12/15/17 (144A) 5,385,188 214,387 Ormat Funding Corp., 8.25%, 12/30/20 214,387 2,925,000 San Diego Gas & Electric Co., 1.914%, 2/1/22 2,873,722 ----------------- $ 13,860,429 ---------------------------------------------------------------------------------------------------------- Independent Power Producers & Energy Traders -- 0.3% 532,140 Alta Wind Holdings LLC, 7.0%, 6/30/35 (144A) $ 570,054 4,300,000 Colbun SA, 4.5%, 7/10/24 (144A) 4,194,061 1,427,668 Kiowa Power Partners LLC, 5.737%, 3/30/21 (144A) 1,506,190 2,000,000 NRG Energy, Inc., 8.25%, 9/1/20 1,940,000 2,161,541 Panoche Energy Center LLC, 6.885%, 7/31/29 (144A) 2,485,731 ----------------- $ 10,696,036 ----------------- Total Utilities $ 83,095,024 ---------------------------------------------------------------------------------------------------------- TOTAL CORPORATE BONDS (Cost $1,362,825,677) $ 1,331,570,133 ---------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 49 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- 31.1% 1,822,631 Fannie Mae, 2.5%, 7/1/30 $ 1,839,676 1,834,344 Fannie Mae, 2.5%, 7/1/30 1,850,966 3,058,472 Fannie Mae, 2.5%, 7/1/30 3,087,068 3,900,000 Fannie Mae, 3.0%, 1/19/16 (TBA) 4,017,558 1,804,917 Fannie Mae, 3.0%, 12/1/42 1,814,702 2,958,388 Fannie Mae, 3.0%, 7/1/30 3,050,168 867,688 Fannie Mae, 3.0%, 7/1/43 869,535 20,720,268 Fannie Mae, 3.0%, 8/1/42 20,798,407 5,401,343 Fannie Mae, 3.0%, 9/1/28 5,584,126 6,163,461 Fannie Mae, 3.0%, 9/1/42 6,185,584 5,794,345 Fannie Mae, 3.0%, 9/1/43 5,806,003 32,475,000 Fannie Mae, 3.5%, 1/13/16 (TBA) 33,505,211 292,100 Fannie Mae, 3.5%, 11/1/42 302,579 15,216,591 Fannie Mae, 3.5%, 11/1/45 15,809,948 1,725,932 Fannie Mae, 3.5%, 12/1/26 1,810,725 735,481 Fannie Mae, 3.5%, 12/1/42 761,877 757,244 Fannie Mae, 3.5%, 12/1/42 784,414 3,270,396 Fannie Mae, 3.5%, 2/1/29 3,427,663 14,411,376 Fannie Mae, 3.5%, 2/1/44 14,879,531 9,809,068 Fannie Mae, 3.5%, 4/1/45 10,127,716 3,905,456 Fannie Mae, 3.5%, 6/1/28 4,095,836 4,561,601 Fannie Mae, 3.5%, 9/1/44 4,709,785 2,975,795 Fannie Mae, 3.5%, 9/1/45 3,072,728 634,446 Fannie Mae, 4.0%, 1/1/42 673,071 724,942 Fannie Mae, 4.0%, 1/1/42 769,105 190,195 Fannie Mae, 4.0%, 1/1/44 201,347 151,634 Fannie Mae, 4.0%, 1/1/45 160,510 410,348 Fannie Mae, 4.0%, 1/1/45 434,437 720,512 Fannie Mae, 4.0%, 1/1/45 762,695 31,650,000 Fannie Mae, 4.0%, 1/13/16 (TBA) 33,491,141 152,692 Fannie Mae, 4.0%, 11/1/44 161,694 198,548 Fannie Mae, 4.0%, 11/1/44 210,171 450,114 Fannie Mae, 4.0%, 11/1/44 476,548 3,331,880 Fannie Mae, 4.0%, 11/1/44 3,527,994 9,732,161 Fannie Mae, 4.0%, 11/1/44 10,301,856 1,058,164 Fannie Mae, 4.0%, 12/1/40 1,132,940 1,967,997 Fannie Mae, 4.0%, 12/1/41 2,087,831 41,931 Fannie Mae, 4.0%, 12/1/42 44,490 5,976,229 Fannie Mae, 4.0%, 12/1/43 6,354,812 87,291 Fannie Mae, 4.0%, 12/1/44 92,416 423,909 Fannie Mae, 4.0%, 12/1/44 448,811 782,333 Fannie Mae, 4.0%, 12/1/44 828,260 The accompanying notes are an integral part of these financial statements. 50 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 9,803,089 Fannie Mae, 4.0%, 2/1/42 $ 10,400,366 9,784,327 Fannie Mae, 4.0%, 2/1/44 10,358,735 70,019 Fannie Mae, 4.0%, 2/1/45 74,138 359,261 Fannie Mae, 4.0%, 2/1/45 380,353 715,533 Fannie Mae, 4.0%, 2/1/45 757,419 1,665,608 Fannie Mae, 4.0%, 3/1/42 1,770,286 1,557,897 Fannie Mae, 4.0%, 4/1/39 1,649,092 1,069,422 Fannie Mae, 4.0%, 4/1/41 1,138,594 566,892 Fannie Mae, 4.0%, 4/1/42 601,270 838,212 Fannie Mae, 4.0%, 4/1/42 889,227 1,207,570 Fannie Mae, 4.0%, 5/1/41 1,281,056 2,580,635 Fannie Mae, 4.0%, 5/1/44 2,731,699 845,247 Fannie Mae, 4.0%, 6/1/42 895,176 168,777 Fannie Mae, 4.0%, 6/1/44 178,657 224,034 Fannie Mae, 4.0%, 6/1/44 237,148 20,218 Fannie Mae, 4.0%, 7/1/18 21,077 334,166 Fannie Mae, 4.0%, 7/1/42 354,566 5,152,583 Fannie Mae, 4.0%, 7/1/42 5,485,721 559,314 Fannie Mae, 4.0%, 7/1/44 592,055 8,618,685 Fannie Mae, 4.0%, 7/1/44 9,123,201 12,469,383 Fannie Mae, 4.0%, 8/1/42 13,236,982 384,230 Fannie Mae, 4.0%, 8/1/44 407,376 450,484 Fannie Mae, 4.0%, 8/1/44 476,855 2,423,148 Fannie Mae, 4.0%, 8/1/44 2,568,396 7,263,236 Fannie Mae, 4.0%, 8/1/44 7,695,968 74,735 Fannie Mae, 4.0%, 9/1/44 79,110 629,812 Fannie Mae, 4.0%, 9/1/44 666,680 750,995 Fannie Mae, 4.0%, 9/1/44 794,957 11,124,503 Fannie Mae, 4.0%, 9/1/44 11,823,524 6,588,061 Fannie Mae, 4.5%, 1/1/42 7,127,643 8,535,399 Fannie Mae, 4.5%, 1/1/42 9,233,489 10,196,919 Fannie Mae, 4.5%, 1/1/44 11,012,951 255,363 Fannie Mae, 4.5%, 10/1/35 276,844 282,903 Fannie Mae, 4.5%, 10/1/35 305,543 318,551 Fannie Mae, 4.5%, 11/1/20 331,212 2,415,367 Fannie Mae, 4.5%, 11/1/40 2,614,138 348,387 Fannie Mae, 4.5%, 11/1/43 379,555 702,513 Fannie Mae, 4.5%, 11/1/43 768,521 1,060,858 Fannie Mae, 4.5%, 12/1/41 1,147,725 10,655,652 Fannie Mae, 4.5%, 12/1/43 11,508,395 13,379,079 Fannie Mae, 4.5%, 12/1/43 14,499,954 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 51 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 1,071,991 Fannie Mae, 4.5%, 2/1/41 $ 1,160,281 395,846 Fannie Mae, 4.5%, 2/1/44 428,393 2,502,533 Fannie Mae, 4.5%, 4/1/41 2,708,213 136,773 Fannie Mae, 4.5%, 5/1/41 147,992 3,308,243 Fannie Mae, 4.5%, 5/1/41 3,579,183 4,652,324 Fannie Mae, 4.5%, 5/1/41 5,033,807 306,413 Fannie Mae, 4.5%, 7/1/41 333,263 1,658,426 Fannie Mae, 4.5%, 7/1/41 1,792,922 2,234,420 Fannie Mae, 4.5%, 7/1/41 2,418,195 796,969 Fannie Mae, 4.5%, 8/1/40 862,544 1,257,994 Fannie Mae, 4.5%, 8/1/40 1,361,373 212,704 Fannie Mae, 5.0%, 1/1/20 220,278 337,479 Fannie Mae, 5.0%, 10/1/20 358,393 43,216 Fannie Mae, 5.0%, 2/1/20 45,133 16,305 Fannie Mae, 5.0%, 2/1/22 17,502 253,434 Fannie Mae, 5.0%, 2/1/22 270,915 4,841,750 Fannie Mae, 5.0%, 2/1/41 5,344,893 19,062,836 Fannie Mae, 5.0%, 2/1/45 21,060,213 428,824 Fannie Mae, 5.0%, 5/1/23 460,996 920,283 Fannie Mae, 5.0%, 6/1/40 1,019,213 992,982 Fannie Mae, 5.0%, 6/1/40 1,095,091 754,766 Fannie Mae, 5.0%, 7/1/40 832,566 1,110,136 Fannie Mae, 5.0%, 7/1/40 1,224,877 1,445,585 Fannie Mae, 5.0%, 7/1/40 1,593,706 101,528 Fannie Mae, 5.5%, 12/1/17 104,237 388,424 Fannie Mae, 5.5%, 3/1/36 436,639 188,493 Fannie Mae, 5.5%, 5/1/36 209,869 33,720 Fannie Mae, 5.5%, 6/1/33 37,905 271,784 Fannie Mae, 5.5%, 6/1/36 303,734 119,713 Fannie Mae, 5.5%, 7/1/33 134,592 844,748 Fannie Mae, 5.5%, 7/1/34 952,108 189,044 Fannie Mae, 5.5%, 9/1/19 196,579 4,615 Fannie Mae, 6.0%, 1/1/32 5,270 70,003 Fannie Mae, 6.0%, 10/1/32 79,934 18,608 Fannie Mae, 6.0%, 10/1/34 21,079 171,835 Fannie Mae, 6.0%, 10/1/35 193,980 35,792 Fannie Mae, 6.0%, 11/1/33 40,812 15,129 Fannie Mae, 6.0%, 11/1/34 17,206 365,046 Fannie Mae, 6.0%, 12/1/35 412,353 25,401 Fannie Mae, 6.0%, 2/1/32 28,955 17,304 Fannie Mae, 6.0%, 2/1/33 19,565 5,612 Fannie Mae, 6.0%, 2/1/35 6,383 The accompanying notes are an integral part of these financial statements. 52 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 13,394 Fannie Mae, 6.0%, 2/1/35 $ 15,202 7,714 Fannie Mae, 6.0%, 3/1/32 8,809 98,673 Fannie Mae, 6.0%, 3/1/33 112,671 98,205 Fannie Mae, 6.0%, 4/1/33 111,402 246,542 Fannie Mae, 6.0%, 4/1/35 280,945 58,916 Fannie Mae, 6.0%, 5/1/35 66,485 2,378 Fannie Mae, 6.0%, 6/1/16 2,395 347,938 Fannie Mae, 6.0%, 6/1/38 396,798 197,500 Fannie Mae, 6.0%, 7/1/33 225,075 457,202 Fannie Mae, 6.0%, 7/1/33 519,788 62,694 Fannie Mae, 6.0%, 7/1/38 70,948 4,952 Fannie Mae, 6.0%, 8/1/32 5,653 175,374 Fannie Mae, 6.0%, 8/1/34 199,923 1,285 Fannie Mae, 6.0%, 9/1/29 1,466 565 Fannie Mae, 6.0%, 9/1/32 643 13,030 Fannie Mae, 6.0%, 9/1/34 14,805 35,815 Fannie Mae, 6.0%, 9/1/34 40,714 60,037 Fannie Mae, 6.0%, 9/1/34 68,305 96,513 Fannie Mae, 6.0%, 9/1/34 108,912 3,037 Fannie Mae, 6.5%, 1/1/31 3,471 11,242 Fannie Mae, 6.5%, 10/1/31 12,847 74,143 Fannie Mae, 6.5%, 10/1/32 84,734 177,890 Fannie Mae, 6.5%, 11/1/37 203,301 134,330 Fannie Mae, 6.5%, 12/1/31 153,519 4,916 Fannie Mae, 6.5%, 2/1/32 5,618 77,961 Fannie Mae, 6.5%, 3/1/32 89,098 2,854 Fannie Mae, 6.5%, 4/1/31 3,262 6,588 Fannie Mae, 6.5%, 5/1/31 7,529 74,653 Fannie Mae, 6.5%, 6/1/31 85,317 8,749 Fannie Mae, 6.5%, 7/1/29 9,999 30,159 Fannie Mae, 6.5%, 7/1/34 34,467 9,155 Fannie Mae, 6.5%, 8/1/31 10,462 5,397 Fannie Mae, 6.5%, 9/1/31 6,168 8,334 Fannie Mae, 6.5%, 9/1/31 9,524 21,046 Fannie Mae, 7.0%, 1/1/32 24,014 755 Fannie Mae, 7.0%, 12/1/30 802 7,378 Fannie Mae, 7.0%, 12/1/30 8,261 25,673 Fannie Mae, 7.0%, 12/1/31 27,366 9,952 Fannie Mae, 7.0%, 4/1/31 11,946 13,771 Fannie Mae, 7.0%, 9/1/31 15,328 162 Fannie Mae, 8.0%, 5/1/31 161 449,519 Federal Home Loan Mortgage Corp., 2.5%, 1/1/30 454,287 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 53 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 260,354 Federal Home Loan Mortgage Corp., 2.5%, 4/1/30 $ 263,119 4,312,214 Federal Home Loan Mortgage Corp., 3.0%, 10/1/29 4,448,309 4,154,346 Federal Home Loan Mortgage Corp., 3.0%, 8/1/29 4,292,981 1,707,287 Federal Home Loan Mortgage Corp., 3.5%, 11/1/28 1,796,519 185,002 Federal Home Loan Mortgage Corp., 3.5%, 11/1/44 190,599 9,984,861 Federal Home Loan Mortgage Corp., 3.5%, 11/1/45 10,299,031 9,359,478 Federal Home Loan Mortgage Corp., 3.5%, 12/1/44 9,642,379 4,731,874 Federal Home Loan Mortgage Corp., 3.5%, 3/1/45 4,874,900 2,318,388 Federal Home Loan Mortgage Corp., 3.5%, 4/1/42 2,390,189 255,797 Federal Home Loan Mortgage Corp., 3.5%, 7/1/45 264,250 3,792,887 Federal Home Loan Mortgage Corp., 3.5%, 8/1/43 3,908,633 807,330 Federal Home Loan Mortgage Corp., 3.5%, 9/1/44 833,622 2,829,029 Federal Home Loan Mortgage Corp., 4.0%, 1/1/44 2,991,335 13,992,804 Federal Home Loan Mortgage Corp., 4.0%, 11/1/41 14,959,671 168,620 Federal Home Loan Mortgage Corp., 4.0%, 11/1/42 178,513 2,532,941 Federal Home Loan Mortgage Corp., 4.0%, 12/1/44 2,679,636 593,436 Federal Home Loan Mortgage Corp., 4.0%, 2/1/44 629,682 2,306,730 Federal Home Loan Mortgage Corp., 4.0%, 4/1/45 2,439,179 8,611,832 Federal Home Loan Mortgage Corp., 4.0%, 5/1/44 9,107,739 7,944,647 Federal Home Loan Mortgage Corp., 4.0%, 6/1/44 8,398,749 183,289 Federal Home Loan Mortgage Corp., 4.0%, 7/1/42 194,118 1,012,092 Federal Home Loan Mortgage Corp., 4.0%, 7/1/44 1,073,624 1,339,863 Federal Home Loan Mortgage Corp., 4.0%, 7/1/44 1,421,406 1,394,153 Federal Home Loan Mortgage Corp., 4.0%, 7/1/44 1,478,928 11,203,056 Federal Home Loan Mortgage Corp., 4.0%, 7/1/44 11,844,713 4,555,812 Federal Home Loan Mortgage Corp., 4.0%, 9/1/44 4,816,818 10,487,080 Federal Home Loan Mortgage Corp., 4.0%, 9/1/44 11,125,333 308,395 Federal Home Loan Mortgage Corp., 4.5%, 10/1/20 320,981 4,518,294 Federal Home Loan Mortgage Corp., 4.5%, 11/1/40 4,873,815 299,826 Federal Home Loan Mortgage Corp., 4.5%, 11/1/43 322,882 134,356 Federal Home Loan Mortgage Corp., 4.5%, 3/1/20 139,147 2,690,991 Federal Home Loan Mortgage Corp., 4.5%, 3/1/42 2,902,604 6,831,214 Federal Home Loan Mortgage Corp., 4.5%, 3/1/42 7,367,731 869,959 Federal Home Loan Mortgage Corp., 5.0%, 10/1/20 918,441 412,025 Federal Home Loan Mortgage Corp., 5.0%, 10/1/38 449,675 18,117 Federal Home Loan Mortgage Corp., 5.0%, 11/1/34 19,991 24,643 Federal Home Loan Mortgage Corp., 5.0%, 12/1/21 26,459 351,477 Federal Home Loan Mortgage Corp., 5.0%, 6/1/35 384,783 437,369 Federal Home Loan Mortgage Corp., 5.0%, 9/1/38 477,469 29,592 Federal Home Loan Mortgage Corp., 5.5%, 11/1/34 32,886 143,200 Federal Home Loan Mortgage Corp., 5.5%, 11/1/34 159,391 46,018 Federal Home Loan Mortgage Corp., 5.5%, 11/1/35 51,031 The accompanying notes are an integral part of these financial statements. 54 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 166,816 Federal Home Loan Mortgage Corp., 5.5%, 12/1/18 $ 172,530 1,762,364 Federal Home Loan Mortgage Corp., 5.5%, 6/1/41 1,959,526 195,306 Federal Home Loan Mortgage Corp., 5.5%, 8/1/35 215,806 295,638 Federal Home Loan Mortgage Corp., 5.5%, 9/1/33 328,801 61,284 Federal Home Loan Mortgage Corp., 6.0%, 1/1/33 68,841 37,346 Federal Home Loan Mortgage Corp., 6.0%, 1/1/34 41,955 38,374 Federal Home Loan Mortgage Corp., 6.0%, 1/1/34 43,854 21,960 Federal Home Loan Mortgage Corp., 6.0%, 11/1/33 25,097 9,337 Federal Home Loan Mortgage Corp., 6.0%, 12/1/33 10,494 120,392 Federal Home Loan Mortgage Corp., 6.0%, 12/1/33 135,319 125,789 Federal Home Loan Mortgage Corp., 6.0%, 12/1/33 141,331 47,974 Federal Home Loan Mortgage Corp., 6.0%, 12/1/36 54,353 4,906 Federal Home Loan Mortgage Corp., 6.0%, 2/1/33 5,603 68,995 Federal Home Loan Mortgage Corp., 6.0%, 2/1/33 78,718 38,600 Federal Home Loan Mortgage Corp., 6.0%, 3/1/33 43,362 209,419 Federal Home Loan Mortgage Corp., 6.0%, 3/1/33 239,066 13,766 Federal Home Loan Mortgage Corp., 6.0%, 4/1/33 15,464 57,697 Federal Home Loan Mortgage Corp., 6.0%, 4/1/35 65,548 292,779 Federal Home Loan Mortgage Corp., 6.0%, 4/1/36 328,853 32,464 Federal Home Loan Mortgage Corp., 6.0%, 5/1/17 33,073 200,238 Federal Home Loan Mortgage Corp., 6.0%, 5/1/34 228,220 610,806 Federal Home Loan Mortgage Corp., 6.0%, 5/1/34 698,040 112,604 Federal Home Loan Mortgage Corp., 6.0%, 6/1/35 126,534 125,564 Federal Home Loan Mortgage Corp., 6.0%, 6/1/35 140,942 166,576 Federal Home Loan Mortgage Corp., 6.0%, 8/1/34 190,163 143,339 Federal Home Loan Mortgage Corp., 6.0%, 9/1/33 163,668 168 Federal Home Loan Mortgage Corp., 6.5%, 1/1/31 191 354 Federal Home Loan Mortgage Corp., 6.5%, 1/1/33 403 43,986 Federal Home Loan Mortgage Corp., 6.5%, 10/1/33 52,184 354 Federal Home Loan Mortgage Corp., 6.5%, 11/1/30 403 49,117 Federal Home Loan Mortgage Corp., 6.5%, 11/1/33 55,938 3,576 Federal Home Loan Mortgage Corp., 6.5%, 2/1/33 4,073 507 Federal Home Loan Mortgage Corp., 6.5%, 3/1/31 577 6,874 Federal Home Loan Mortgage Corp., 6.5%, 3/1/31 7,828 3,662 Federal Home Loan Mortgage Corp., 6.5%, 4/1/34 4,170 5,488 Federal Home Loan Mortgage Corp., 6.5%, 5/1/31 6,250 240 Federal Home Loan Mortgage Corp., 6.5%, 6/1/32 274 14,433 Federal Home Loan Mortgage Corp., 6.5%, 7/1/32 16,917 931 Federal Home Loan Mortgage Corp., 6.5%, 8/1/31 1,077 4,237 Federal Home Loan Mortgage Corp., 6.5%, 8/1/31 4,825 3,147 Federal Home Loan Mortgage Corp., 7.0%, 11/1/30 3,690 77,833 Federal Home Loan Mortgage Corp., 7.0%, 8/1/22 84,036 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 55 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 204,177 Federal Home Loan Mortgage Corp., 7.0%, 9/1/22 $ 220,481 4,753,766 Federal National Mortgage Association, 4.0%, 10/1/45 5,034,185 421,105 Federal National Mortgage Association, 4.0%, 11/1/34 450,605 1,152,220 Federal National Mortgage Association, 5.0%, 8/1/40 1,267,278 18,062,267 Government National Mortgage Association I, 3.5%, 1/15/45 18,808,789 30,710,000 Government National Mortgage Association I, 3.5%, 1/21/16 (TBA) 31,949,766 11,147,817 Government National Mortgage Association I, 3.5%, 7/15/42 11,609,777 34,419 Government National Mortgage Association I, 4.0%, 1/15/41 36,541 121,744 Government National Mortgage Association I, 4.0%, 1/15/41 129,230 3,068,956 Government National Mortgage Association I, 4.0%, 1/15/45 3,257,271 3,494,107 Government National Mortgage Association I, 4.0%, 1/15/45 3,708,128 4,304,815 Government National Mortgage Association I, 4.0%, 1/15/45 4,568,963 10,490 Government National Mortgage Association I, 4.0%, 10/15/40 11,137 6,342 Government National Mortgage Association I, 4.0%, 10/15/41 6,731 8,861 Government National Mortgage Association I, 4.0%, 10/15/41 9,406 9,318 Government National Mortgage Association I, 4.0%, 10/15/41 9,893 258,151 Government National Mortgage Association I, 4.0%, 10/15/44 273,977 12,200 Government National Mortgage Association I, 4.0%, 11/15/40 12,957 57,663 Government National Mortgage Association I, 4.0%, 11/15/40 61,211 6,732 Government National Mortgage Association I, 4.0%, 11/15/41 7,147 6,949 Government National Mortgage Association I, 4.0%, 11/15/41 7,374 30,925 Government National Mortgage Association I, 4.0%, 11/15/43 33,031 1,100,507 Government National Mortgage Association I, 4.0%, 11/15/44 1,168,032 9,812 Government National Mortgage Association I, 4.0%, 12/15/41 10,414 The accompanying notes are an integral part of these financial statements. 56 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 3,908,447 Government National Mortgage Association I, 4.0%, 12/15/44 $ 4,148,267 15,039 Government National Mortgage Association I, 4.0%, 2/15/41 15,981 50,189 Government National Mortgage Association I, 4.0%, 2/15/42 53,260 490,777 Government National Mortgage Association I, 4.0%, 2/15/42 521,057 3,773,443 Government National Mortgage Association I, 4.0%, 2/15/45 4,007,494 4,372,069 Government National Mortgage Association I, 4.0%, 2/15/45 4,639,993 24,379 Government National Mortgage Association I, 4.0%, 3/15/44 26,011 753,480 Government National Mortgage Association I, 4.0%, 3/15/44 799,683 1,608,590 Government National Mortgage Association I, 4.0%, 3/15/44 1,707,310 6,718,751 Government National Mortgage Association I, 4.0%, 3/15/44 7,130,980 444,529 Government National Mortgage Association I, 4.0%, 3/15/45 471,807 4,333,768 Government National Mortgage Association I, 4.0%, 3/15/45 4,599,695 15,148 Government National Mortgage Association I, 4.0%, 4/15/44 16,080 62,835 Government National Mortgage Association I, 4.0%, 4/15/44 66,701 4,468,667 Government National Mortgage Association I, 4.0%, 4/15/44 4,742,311 13,265 Government National Mortgage Association I, 4.0%, 5/15/39 14,083 4,478,417 Government National Mortgage Association I, 4.0%, 5/15/45 4,762,204 7,751 Government National Mortgage Association I, 4.0%, 6/15/39 8,226 101,487 Government National Mortgage Association I, 4.0%, 6/15/41 107,752 11,925 Government National Mortgage Association I, 4.0%, 8/15/40 12,658 2,191,935 Government National Mortgage Association I, 4.0%, 8/15/43 2,326,408 757,949 Government National Mortgage Association I, 4.0%, 8/15/44 805,640 10,531 Government National Mortgage Association I, 4.0%, 9/15/40 11,181 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 57 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 7,823 Government National Mortgage Association I, 4.0%, 9/15/41 $ 8,302 729,168 Government National Mortgage Association I, 4.0%, 9/15/41 773,800 152,834 Government National Mortgage Association I, 4.0%, 9/15/44 162,452 461,498 Government National Mortgage Association I, 4.0%, 9/15/44 489,870 640,924 Government National Mortgage Association I, 4.0%, 9/15/44 680,249 795,658 Government National Mortgage Association I, 4.0%, 9/15/44 844,436 4,653,237 Government National Mortgage Association I, 4.0%, 9/15/44 4,938,747 561,996 Government National Mortgage Association I, 4.5%, 1/15/40 614,556 222,783 Government National Mortgage Association I, 4.5%, 10/15/33 242,275 279,840 Government National Mortgage Association I, 4.5%, 10/15/33 302,110 165,144 Government National Mortgage Association I, 4.5%, 10/15/35 178,849 1,740,935 Government National Mortgage Association I, 4.5%, 12/15/39 1,884,754 45,714 Government National Mortgage Association I, 4.5%, 2/15/34 49,704 16,929 Government National Mortgage Association I, 4.5%, 3/15/35 18,248 79,529 Government National Mortgage Association I, 4.5%, 3/15/35 85,723 21,923 Government National Mortgage Association I, 4.5%, 4/15/35 23,648 236,830 Government National Mortgage Association I, 4.5%, 4/15/35 256,711 119,024 Government National Mortgage Association I, 4.5%, 4/15/38 128,303 1,233,808 Government National Mortgage Association I, 4.5%, 4/15/41 1,331,398 1,605,814 Government National Mortgage Association I, 4.5%, 5/15/41 1,733,514 1,353,323 Government National Mortgage Association I, 4.5%, 6/15/41 1,461,113 100,612 Government National Mortgage Association I, 4.5%, 7/15/33 109,171 515,245 Government National Mortgage Association I, 4.5%, 7/15/41 556,350 The accompanying notes are an integral part of these financial statements. 58 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 1,722,272 Government National Mortgage Association I, 4.5%, 8/15/41 $ 1,857,073 251,453 Government National Mortgage Association I, 4.5%, 9/15/33 274,648 25,822 Government National Mortgage Association I, 4.5%, 9/15/35 27,956 373,042 Government National Mortgage Association I, 4.5%, 9/15/40 406,994 92,078 Government National Mortgage Association I, 5.0%, 10/15/18 96,705 125,758 Government National Mortgage Association I, 5.0%, 4/15/34 140,191 518,690 Government National Mortgage Association I, 5.0%, 4/15/35 581,338 1,076 Government National Mortgage Association I, 5.0%, 7/15/19 1,135 91,490 Government National Mortgage Association I, 5.0%, 7/15/19 96,686 116,204 Government National Mortgage Association I, 5.0%, 7/15/33 127,335 118,247 Government National Mortgage Association I, 5.0%, 9/15/33 131,884 152,808 Government National Mortgage Association I, 5.5%, 1/15/35 172,027 26,748 Government National Mortgage Association I, 5.5%, 10/15/17 27,339 84,976 Government National Mortgage Association I, 5.5%, 10/15/17 87,016 87,449 Government National Mortgage Association I, 5.5%, 10/15/33 99,445 121,969 Government National Mortgage Association I, 5.5%, 10/15/35 137,409 215,156 Government National Mortgage Association I, 5.5%, 10/15/35 242,222 38,946 Government National Mortgage Association I, 5.5%, 11/15/18 40,232 252,435 Government National Mortgage Association I, 5.5%, 11/15/19 264,284 536,776 Government National Mortgage Association I, 5.5%, 11/15/34 604,290 25,317 Government National Mortgage Association I, 5.5%, 12/15/18 26,193 76,810 Government National Mortgage Association I, 5.5%, 2/15/18 78,829 109,821 Government National Mortgage Association I, 5.5%, 2/15/18 112,457 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 59 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 43,341 Government National Mortgage Association I, 5.5%, 2/15/35 $ 49,123 58,094 Government National Mortgage Association I, 5.5%, 2/15/35 64,634 55,422 Government National Mortgage Association I, 5.5%, 2/15/37 62,165 1,614 Government National Mortgage Association I, 5.5%, 4/15/19 1,675 16,340 Government National Mortgage Association I, 5.5%, 6/15/33 18,592 132,103 Government National Mortgage Association I, 5.5%, 6/15/35 146,977 89,328 Government National Mortgage Association I, 5.5%, 7/15/33 101,502 96,846 Government National Mortgage Association I, 5.5%, 7/15/33 110,157 446,759 Government National Mortgage Association I, 5.5%, 7/15/34 507,583 614,470 Government National Mortgage Association I, 5.5%, 7/15/35 713,670 138,125 Government National Mortgage Association I, 5.5%, 8/15/19 143,952 144,561 Government National Mortgage Association I, 5.5%, 8/15/19 149,959 25,132 Government National Mortgage Association I, 5.5%, 8/15/33 28,596 25,876 Government National Mortgage Association I, 5.5%, 8/15/33 29,375 41,947 Government National Mortgage Association I, 5.5%, 8/15/33 47,682 145,658 Government National Mortgage Association I, 5.5%, 9/15/19 151,814 182,264 Government National Mortgage Association I, 5.5%, 9/15/33 205,732 3,602 Government National Mortgage Association I, 6.0%, 1/15/17 3,654 17,567 Government National Mortgage Association I, 6.0%, 1/15/19 18,116 46,638 Government National Mortgage Association I, 6.0%, 1/15/33 52,332 140,112 Government National Mortgage Association I, 6.0%, 1/15/33 161,763 42,441 Government National Mortgage Association I, 6.0%, 10/15/32 48,937 54,937 Government National Mortgage Association I, 6.0%, 10/15/33 63,444 The accompanying notes are an integral part of these financial statements. 60 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 278,747 Government National Mortgage Association I, 6.0%, 10/15/34 $ 315,927 129,400 Government National Mortgage Association I, 6.0%, 10/15/36 149,086 37,485 Government National Mortgage Association I, 6.0%, 11/15/31 43,049 147,429 Government National Mortgage Association I, 6.0%, 11/15/34 166,162 164,721 Government National Mortgage Association I, 6.0%, 12/15/32 186,729 120,134 Government National Mortgage Association I, 6.0%, 2/15/29 138,645 41,318 Government National Mortgage Association I, 6.0%, 2/15/33 47,722 12,228 Government National Mortgage Association I, 6.0%, 3/15/17 12,417 16,551 Government National Mortgage Association I, 6.0%, 3/15/17 16,721 2,359 Government National Mortgage Association I, 6.0%, 3/15/32 2,722 111,723 Government National Mortgage Association I, 6.0%, 3/15/33 128,964 131,590 Government National Mortgage Association I, 6.0%, 3/15/33 150,635 142,395 Government National Mortgage Association I, 6.0%, 3/15/33 164,314 187,217 Government National Mortgage Association I, 6.0%, 3/15/33 216,195 315,539 Government National Mortgage Association I, 6.0%, 3/15/33 364,320 421,172 Government National Mortgage Association I, 6.0%, 3/15/33 493,545 3,588 Government National Mortgage Association I, 6.0%, 4/15/18 3,596 24,023 Government National Mortgage Association I, 6.0%, 4/15/33 27,344 39,096 Government National Mortgage Association I, 6.0%, 4/15/33 44,027 49,695 Government National Mortgage Association I, 6.0%, 4/15/33 56,104 8,703 Government National Mortgage Association I, 6.0%, 5/15/17 8,765 22,428 Government National Mortgage Association I, 6.0%, 5/15/17 22,853 158,486 Government National Mortgage Association I, 6.0%, 5/15/33 182,330 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 61 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 2,298 Government National Mortgage Association I, 6.0%, 6/15/17 $ 2,314 13,154 Government National Mortgage Association I, 6.0%, 6/15/33 15,196 8,690 Government National Mortgage Association I, 6.0%, 8/15/32 10,028 323,786 Government National Mortgage Association I, 6.0%, 8/15/36 371,567 88,523 Government National Mortgage Association I, 6.0%, 9/15/19 92,306 244,122 Government National Mortgage Association I, 6.0%, 9/15/28 281,743 96,500 Government National Mortgage Association I, 6.0%, 9/15/32 108,259 18,130 Government National Mortgage Association I, 6.0%, 9/15/33 20,598 62,426 Government National Mortgage Association I, 6.0%, 9/15/33 72,025 68,043 Government National Mortgage Association I, 6.0%, 9/15/34 76,795 201,309 Government National Mortgage Association I, 6.0%, 9/15/34 232,571 882,251 Government National Mortgage Association I, 6.0%, 9/15/35 1,018,717 25,139 Government National Mortgage Association I, 6.5%, 1/15/29 28,762 93,879 Government National Mortgage Association I, 6.5%, 1/15/32 107,410 4,521 Government National Mortgage Association I, 6.5%, 1/15/33 5,278 446,169 Government National Mortgage Association I, 6.5%, 1/15/33 524,617 15,459 Government National Mortgage Association I, 6.5%, 1/15/34 17,687 685 Government National Mortgage Association I, 6.5%, 1/15/35 784 7,848 Government National Mortgage Association I, 6.5%, 10/15/31 8,979 34,105 Government National Mortgage Association I, 6.5%, 10/15/31 39,021 104,314 Government National Mortgage Association I, 6.5%, 10/15/31 119,349 107,750 Government National Mortgage Association I, 6.5%, 10/15/32 123,281 2,112 Government National Mortgage Association I, 6.5%, 10/15/33 2,416 The accompanying notes are an integral part of these financial statements. 62 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 5,350 Government National Mortgage Association I, 6.5%, 11/15/31 $ 6,121 67,729 Government National Mortgage Association I, 6.5%, 11/15/32 80,172 426,232 Government National Mortgage Association I, 6.5%, 12/15/32 500,977 1,430 Government National Mortgage Association I, 6.5%, 2/15/29 1,637 9,546 Government National Mortgage Association I, 6.5%, 2/15/29 10,922 31,123 Government National Mortgage Association I, 6.5%, 2/15/32 36,139 47,959 Government National Mortgage Association I, 6.5%, 2/15/34 54,872 9,881 Government National Mortgage Association I, 6.5%, 3/15/29 11,306 81,477 Government National Mortgage Association I, 6.5%, 3/15/29 93,220 12,172 Government National Mortgage Association I, 6.5%, 3/15/31 13,927 16,655 Government National Mortgage Association I, 6.5%, 3/15/32 19,056 79,485 Government National Mortgage Association I, 6.5%, 4/15/31 90,942 9,857 Government National Mortgage Association I, 6.5%, 4/15/32 11,277 41,986 Government National Mortgage Association I, 6.5%, 4/15/35 48,038 4,634 Government National Mortgage Association I, 6.5%, 5/15/29 5,302 78,809 Government National Mortgage Association I, 6.5%, 5/15/29 90,715 20,401 Government National Mortgage Association I, 6.5%, 5/15/31 23,773 23,456 Government National Mortgage Association I, 6.5%, 5/15/31 27,375 12,080 Government National Mortgage Association I, 6.5%, 5/15/32 13,822 32,401 Government National Mortgage Association I, 6.5%, 5/15/33 37,071 15,574 Government National Mortgage Association I, 6.5%, 6/15/32 17,819 162,022 Government National Mortgage Association I, 6.5%, 6/15/34 185,375 6,718 Government National Mortgage Association I, 6.5%, 6/15/35 7,686 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 63 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 31,644 Government National Mortgage Association I, 6.5%, 7/15/32 $ 36,205 154,271 Government National Mortgage Association I, 6.5%, 7/15/32 181,688 52,562 Government National Mortgage Association I, 6.5%, 7/15/35 60,138 66,342 Government National Mortgage Association I, 6.5%, 7/15/35 75,904 63,121 Government National Mortgage Association I, 6.5%, 8/15/31 72,219 3,969 Government National Mortgage Association I, 6.5%, 8/15/32 4,541 25,006 Government National Mortgage Association I, 6.5%, 8/15/32 28,610 4,157 Government National Mortgage Association I, 6.5%, 9/15/34 4,756 7,158 Government National Mortgage Association I, 7.0%, 10/15/31 7,418 19,197 Government National Mortgage Association I, 7.0%, 11/15/28 22,294 57,499 Government National Mortgage Association I, 7.0%, 11/15/28 68,091 4,296 Government National Mortgage Association I, 7.0%, 12/15/30 4,560 11,187 Government National Mortgage Association I, 7.0%, 12/15/30 12,414 17,476 Government National Mortgage Association I, 7.0%, 3/15/31 19,543 24,223 Government National Mortgage Association I, 7.0%, 4/15/29 25,189 89,829 Government National Mortgage Association I, 7.0%, 5/15/32 109,767 34,906 Government National Mortgage Association I, 7.0%, 6/15/31 40,950 4,135 Government National Mortgage Association I, 7.0%, 7/15/31 4,933 1,551 Government National Mortgage Association I, 7.0%, 8/15/28 1,740 171,455 Government National Mortgage Association I, 7.0%, 8/15/31 207,399 13,725 Government National Mortgage Association I, 7.0%, 9/15/31 14,612 6,310 Government National Mortgage Association I, 7.5%, 10/15/29 6,649 46,201 Government National Mortgage Association I, 7.5%, 12/15/31 48,916 The accompanying notes are an integral part of these financial statements. 64 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 1,829 Government National Mortgage Association I, 7.5%, 2/15/26 $ 1,913 15,120 Government National Mortgage Association I, 7.5%, 2/15/31 15,378 18,207 Government National Mortgage Association I, 7.5%, 8/15/29 19,308 2,346 Government National Mortgage Association I, 7.75%, 2/15/30 2,398 1,272,076 Government National Mortgage Association II, 3.5%, 3/20/45 1,328,667 564,723 Government National Mortgage Association II, 3.5%, 4/20/45 589,624 1,503,356 Government National Mortgage Association II, 3.5%, 4/20/45 1,572,041 6,009,585 Government National Mortgage Association II, 3.5%, 8/20/45 6,273,956 3,286,415 Government National Mortgage Association II, 4.0%, 10/20/44 3,492,067 14,041,149 Government National Mortgage Association II, 4.0%, 7/20/44 14,943,798 389,932 Government National Mortgage Association II, 4.0%, 9/20/44 414,511 339,247 Government National Mortgage Association II, 4.5%, 1/20/35 367,387 127,980 Government National Mortgage Association II, 4.5%, 12/20/34 138,789 60,957 Government National Mortgage Association II, 4.5%, 3/20/35 66,004 2,038,016 Government National Mortgage Association II, 4.5%, 9/20/41 2,220,039 293,217 Government National Mortgage Association II, 5.5%, 10/20/19 306,203 258,274 Government National Mortgage Association II, 5.5%, 3/20/34 288,157 228,755 Government National Mortgage Association II, 5.5%, 4/20/34 255,199 2,526 Government National Mortgage Association II, 6.5%, 2/20/29 2,925 1,073 Government National Mortgage Association II, 6.5%, 3/20/29 1,228 33,098 Government National Mortgage Association II, 6.5%, 4/20/29 38,053 84,263 Government National Mortgage Association II, 7.0%, 1/20/29 100,083 79,270 Government National Mortgage Association II, 7.0%, 11/20/28 93,738 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 65 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- U.S. GOVERNMENT AND AGENCY OBLIGATIONS -- (continued) 2,395 Government National Mortgage Association II, 7.0%, 12/20/30 $ 2,891 18,862 Government National Mortgage Association, 6.5%, 3/15/29 21,580 16,800,000 U.S. Treasury Bills, 7/21/16 (c) 16,752,674 6,865,000 U.S. Treasury Bonds, 4.375%, 11/15/39 8,631,934 3,700,000 U.S. Treasury Bonds, 4.375%, 5/15/40 4,655,640 124,785,557 U.S. Treasury Inflation Indexed Bonds, 0.125%, 7/15/24 118,511,578 60,423,848 U.S. Treasury Inflation Indexed Bonds, 0.75%, 2/15/45 52,696,182 16,800,000 0.43 U.S. Treasury Note, Floating Rate Note, 10/31/17 16,784,678 16,395,000 0.33 U.S. Treasury Note, Floating Rate Note, 4/30/17 16,380,556 48,000,000 0.33 U.S. Treasury Note, Floating Rate Note, 7/31/17 47,922,432 4,400,000 U.S. Treasury Notes, 2.0%, 2/15/25 4,301,172 4,250,000 U.S. Treasury Notes, 2.125%, 5/15/25 4,194,550 ----------------- $ 1,038,192,208 ---------------------------------------------------------------------------------------------------------- TOTAL U.S. GOVERNMENT AND AGENCY OBLIGATIONS (Cost $1,037,954,585) $ 1,038,192,208 ---------------------------------------------------------------------------------------------------------- FOREIGN GOVERNMENT BOND -- 0.1% 4,550,000 Africa Finance Corp., 4.375%, 4/29/20 (144A) $ 4,562,649 ---------------------------------------------------------------------------------------------------------- TOTAL FOREIGN GOVERNMENT BOND (Cost $4,511,144) $ 4,562,649 ---------------------------------------------------------------------------------------------------------- MUNICIPAL BONDS -- 2.3% (f) Municipal Airport -- 0.0%+ 1,000,000 Indianapolis Airport Authority, 5.1%, 1/15/17 $ 1,042,150 ---------------------------------------------------------------------------------------------------------- Municipal Development -- 0.5% 2,925,000 California Statewide Communities Development Authority, 6.0%, 8/15/42 $ 3,480,340 2,350,000 Louisiana Local Government Environmental Facilities & Community Development Authority, 6.5%, 11/1/35 2,783,598 4,500,000 New Jersey Economic Development Authority, 2/15/18 (c) 4,227,660 2,560,000 Parish of St. John the Baptist Louisiana, 5.125%, 6/1/37 2,594,867 2,310,000 Selma Industrial Development Board, 5.8%, 5/1/34 2,583,850 ----------------- $ 15,670,315 ---------------------------------------------------------------------------------------------------------- Municipal Education -- 0.0%+ 525,000 Amherst College, 3.794%, 11/1/42 $ 498,875 ---------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 66 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Municipal General -- 0.5% 4,075,000 JobsOhio Beverage System, 3.985%, 1/1/29 $ 4,241,504 1,035,000 JobsOhio Beverage System, 4.532%, 1/1/35 1,095,289 2,750,000 New Jersey Transportation Trust Fund Authority, Transportation System-Series A, 5.5%, 6/15/41 2,978,332 1,050,000 Texas Municipal Gas Acquisition & Supply Corp. III, 5.0%, 12/15/30 1,156,690 2,100,000 Texas Municipal Gas Acquisition & Supply Corp. III, 5.0%, 12/15/31 2,306,535 2,200,000 Virginia Commonwealth Transportation Board, 4.0%, 5/15/31 2,402,620 2,210,000 Virginia Commonwealth Transportation Board, 4.0%, 5/15/32 2,401,496 ----------------- $ 16,582,466 ---------------------------------------------------------------------------------------------------------- Municipal Higher Education -- 0.6% 1,025,000 Baylor University, 4.313%, 3/1/42 $ 1,032,667 1,425,000 Massachusetts Health & Educational Facilities Authority, Massachusetts Institute of Technology -Series K, 5.5%, 7/1/32 1,977,758 1,100,000 Massachusetts Institute of Technology, 5.6%, 7/1/11 1,345,640 3,100,000 New Jersey Educational Facilities Authority, Princeton University Series D, 4.0%, 7/1/45 3,343,970 800,000 Permanent University Fund, 5.0%, 7/1/30 972,720 3,095,000 President and Fellows of Harvard College, 6.3%, 10/1/37 3,135,600 1,900,000 The George Washington University, 1.827%, 9/15/17 1,894,437 525,000 The University of Texas System, 5.0%, 8/15/43 606,480 2,600,000 University of California, 3.38%, 5/15/28 2,637,076 3,100,000 University of Virginia, Green Bond Series A, 5.0%, 4/1/45 3,652,265 ----------------- $ 20,598,613 ---------------------------------------------------------------------------------------------------------- Municipal Medical -- 0.1% 325,000 Massachusetts Development Finance Agency, 5.25%, 4/1/37 $ 376,197 550,000 Massachusetts Development Finance Agency, Broad Institute -Series A, 5.375%, 4/1/41 631,125 1,765,000 Ohio Higher Educational Facility Commission, 5.0%, 1/1/42 1,961,656 ----------------- $ 2,968,978 ---------------------------------------------------------------------------------------------------------- Municipal Pollution -- 0.1% 3,965,000 Port Freeport Texas, 5.95%, 5/15/33 $ 4,353,491 ---------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 67 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Municipal School District -- 0.1% 2,700,000 Frisco Independent School District, 4.0%, 8/15/40 (h) $ 2,878,443 1,700,000 Frisco Independent School District, 4.0%, 8/15/45 (h) 1,801,286 ----------------- $ 4,679,729 ---------------------------------------------------------------------------------------------------------- Municipal Transportation -- 0.1% 600,000 Port Authority of New York & New Jersey, 4.458%, 10/1/62 $ 571,296 1,000,000 Texas Transportation Commission State Highway Fund, 5.0%, 4/1/33 1,182,020 ----------------- $ 1,753,316 ---------------------------------------------------------------------------------------------------------- Municipal Obligation -- 0.3% 3,000,000 State of Texas, 4.0%, 10/1/44 (h) $ 3,167,700 1,600,000 State of Washington, 5.0%, 7/1/30 (h) 1,922,736 1,620,000 Washington Suburban Sanitary Commission, 4.0%, 6/1/43 (h) 1,721,072 1,565,000 Washington Suburban Sanitary Commission, 4.0%, 6/1/44 (h) 1,661,451 ----------------- $ 8,472,959 ---------------------------------------------------------------------------------------------------------- TOTAL MUNICIPAL BONDS (Cost $71,610,997) $ 76,620,892 ---------------------------------------------------------------------------------------------------------- SENIOR FLOATING RATE LOAN INTERESTS -- 2.5%** ENERGY -- 0.0%+ Integrated Oil & Gas -- 0.0%+ 269,232 4.50 Glenn Pool Oil & Gas Trust, Term Loan, 5/2/16 $ 268,559 ----------------- Total Energy $ 268,559 ---------------------------------------------------------------------------------------------------------- MATERIALS -- 0.2% Commodity Chemicals -- 0.0%+ 760,962 4.50 Tronox Pigments Holland BV, New Term Loan, 3/19/20 $ 678,683 ---------------------------------------------------------------------------------------------------------- Diversified Chemicals -- 0.0%+ 193,149 4.25 OXEA Sarl, Tranche B-2 Term Loan (First Lien), 1/15/20 $ 186,630 ---------------------------------------------------------------------------------------------------------- Specialty Chemicals -- 0.1% 154,286 3.50 Chemtura Corp., New Term Loan, 8/29/16 $ 154,157 252,086 3.32 Huntsman International LLC 2015, Extended Term B Dollar Loan, 4/19/19 249,145 906,873 5.50 MacDermid, Inc., Tranche B Term Loan (First Lien), 6/7/20 879,856 475,000 4.25 OMNOVA Solutions, Inc., Term B-1 Loan, 5/31/18 468,766 237,546 2.75 WR Grace & Co-Conn, Term Loan, 1/23/21 236,061 The accompanying notes are an integral part of these financial statements. 68 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Specialty Chemicals -- (continued) 660,089 2.75 WR Grace & Co-Conn, U.S. Term Loan, 1/23/21 $ 655,963 ----------------- $ 2,643,948 ---------------------------------------------------------------------------------------------------------- Construction Materials -- 0.1% 1,011,286 4.25 CeramTec Service GmbH, Initial Dollar Term B-1 Loan, 8/30/20 $ 1,005,387 ---------------------------------------------------------------------------------------------------------- Metal & Glass Containers -- 0.0%+ 197,000 5.50 BWay Intermediate, Initial Term Loan, 8/14/20 $ 190,762 ---------------------------------------------------------------------------------------------------------- Aluminum -- 0.0%+ 696,500 4.00 Novelis, Inc., Initial Term Loan, 5/28/22 $ 666,681 ---------------------------------------------------------------------------------------------------------- Diversified Metals & Mining -- 0.0%+ 414,883 4.25 Fortescue Metals Group, Ltd., Bank Loan, 6/30/19 $ 311,450 ----------------- Total Materials $ 5,683,541 ---------------------------------------------------------------------------------------------------------- CAPITAL GOODS -- 0.2% Aerospace & Defense -- 0.1% 2,556,756 4.75 DigitalGlobe, Inc., Term Loan, 1/25/20 $ 2,514,795 425,419 6.25 DynCorp International, Inc., Term Loan, 7/7/16 409,466 591,352 7.00 TASC, Inc., First Lien Term Loan, 2/28/17 593,071 ----------------- $ 3,517,332 ---------------------------------------------------------------------------------------------------------- Building Products -- 0.1% 1,369,026 3.50 Nortek, Inc., Incremental Loan, 10/30/20 $ 1,345,068 ---------------------------------------------------------------------------------------------------------- Industrial Conglomerates -- 0.0%+ 105,355 4.25 CeramTec Acquisition Corp., Initial Dollar Term B-2 Loan, 8/30/20 $ 104,741 307,740 4.25 CeramTec GmbH, Dollar Term B-3 Loan, 8/30/20 305,945 ----------------- $ 410,686 ---------------------------------------------------------------------------------------------------------- Trading Companies & Distributors -- 0.0%+ 590,405 3.75 WESCO Distribution, Inc., Tranche B-1 Loan, 12/12/19 $ 588,929 ----------------- Total Capital Goods $ 5,862,015 ---------------------------------------------------------------------------------------------------------- COMMERCIAL SERVICES & SUPPLIES -- 0.0%+ Security & Alarm Services -- 0.0%+ 201,723 4.00 Garda World Security Corp., Term B Delayed Draw Loan, 11/8/20 $ 193,339 788,554 4.00 Garda World Security Corp., Term B Loan, 11/1/20 755,780 ----------------- $ 949,119 ----------------- Total Commercial Services & Supplies $ 949,119 ---------------------------------------------------------------------------------------------------------- TRANSPORTATION -- 0.0%+ Airlines -- 0.0%+ 798,000 3.25 Delta Air Lines, Inc., Term Loan, 8/24/22 $ 798,250 ---------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 69 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Marine -- 0.0%+ 653,165 5.25 Navios Maritime Partners LP, Term Loan, 6/27/18 $ 640,102 ----------------- Total Transportation $ 1,438,352 ---------------------------------------------------------------------------------------------------------- AUTOMOBILES & COMPONENTS -- 0.3% Auto Parts & Equipment -- 0.1% 1,125,688 3.50 Allison Transmission, Inc., Term B-3 Loan, 8/23/19 $ 1,121,265 1,728,070 4.00 Cooper Standard Intermediate Holdco 2 LLC, Term Loan, 3/28/21 1,705,749 531,005 4.50 TI Group Automotive Systems LLC, Initial US Term Loan, 6/25/22 520,385 ----------------- $ 3,347,399 ---------------------------------------------------------------------------------------------------------- Tires & Rubber -- 0.1% 2,095,000 3.75 The Goodyear Tire & Rubber Co., Term Loan (Second Lien), 3/27/19 $ 2,099,347 ---------------------------------------------------------------------------------------------------------- Automobile Manufacturers -- 0.1% 3,738,825 3.50 Chrysler Group LLC, Term Loan B, 5/24/17 $ 3,732,189 ----------------- Total Automobiles & Components $ 9,178,935 ---------------------------------------------------------------------------------------------------------- CONSUMER DURABLES & APPAREL -- 0.0%+ Apparel, Accessories & Luxury Goods -- 0.0%+ 496,250 3.25 Hanesbrands, Inc., New Term B Loan, 4/15/22 $ 498,731 306,034 3.25 PVH Corp., Tranche B Term Loan, 12/19/19 307,839 ----------------- $ 806,570 ----------------- Total Consumer Durables & Apparel $ 806,570 ---------------------------------------------------------------------------------------------------------- CONSUMER SERVICES -- 0.1% Casinos & Gaming -- 0.1% 288,511 3.75 Pinnacle Entertainment, Inc., Tranche B-2 Term Loan, 8/13/20 $ 288,082 4,306,500 6.00 Scientific Games, Initial Term B-2, 10/1/21 3,945,831 ----------------- $ 4,233,913 ---------------------------------------------------------------------------------------------------------- Restaurants -- 0.0%+ 362,475 3.75 1011778 BC ULC, Term B-2 Loan, 12/12/21 $ 360,776 ----------------- Total Consumer Services $ 4,594,689 ---------------------------------------------------------------------------------------------------------- MEDIA -- 0.3% Advertising -- 0.0%+ 1,054,201 6.75 Affinion Group, Inc., Tranche B Term Loan, 4/30/18 $ 976,454 ---------------------------------------------------------------------------------------------------------- Broadcasting -- 0.1% 2,242,029 4.00 Univision Communications, Inc., Replacement First-Lien Term Loan, 3/1/20 $ 2,199,525 ---------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 70 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Cable & Satellite -- 0.1% 1,681,875 3.00 Charter Communications Operating LLC, Term F Loan, 1/1/21 $ 1,652,792 146,464 4.50 WideOpenWest Finance LLC, Replacement Term B Loan, 4/1/19 141,484 ----------------- $ 1,794,276 ---------------------------------------------------------------------------------------------------------- Movies & Entertainment -- 0.0%+ 230,629 3.75 Cinedigm Digital Funding 1 LLC, Term Loan, 2/28/18 $ 230,052 1,392,938 3.50 Live Nation Entertainment, Inc., Term B-1 Loan, 8/17/20 1,391,777 ----------------- $ 1,621,829 ----------------- Total Media $ 6,592,084 ---------------------------------------------------------------------------------------------------------- RETAILING -- 0.1% General Merchandise Stores -- 0.0%+ 665,000 3.50 Dollar Tree, Inc., Term B-1 Loan, 3/9/22 $ 664,050 ---------------------------------------------------------------------------------------------------------- Specialty Stores -- 0.1% 1,925,000 3.50 Staples, Inc., Initial Loan, 4/24/21 $ 1,907,074 ----------------- Total Retailing $ 2,571,124 ---------------------------------------------------------------------------------------------------------- FOOD, BEVERAGE & TOBACCO -- 0.0%+ Agricultural Products -- 0.0%+ 1,233,038 3.25 Darling International, Inc., Term B USD Loan, 12/19/20 $ 1,208,377 ---------------------------------------------------------------------------------------------------------- Packaged Foods & Meats -- 0.0%+ 20,755 3.00 Pinnacle Foods Finance LLC, New Term Loan G, 4/29/20 $ 20,459 ----------------- Total Food, Beverage & Tobacco $ 1,228,836 ---------------------------------------------------------------------------------------------------------- HOUSEHOLD & PERSONAL PRODUCTS -- 0.1% Personal Products -- 0.1% 1,415,164 4.75 Federal-Mogul Corp., Tranche C Term, 4/15/21 $ 1,251,713 828,016 3.50 NBTY, Inc., Term B-2 Loan, 10/1/17 810,680 972,098 4.00 Revlon Consumer Products Corp., Acquisition Term Loan, 8/19/19 969,365 ----------------- $ 3,031,758 ----------------- Total Household & Personal Products $ 3,031,758 ---------------------------------------------------------------------------------------------------------- HEALTH CARE EQUIPMENT & SERVICES -- 0.3% Health Care Equipment -- 0.1% 1,978,551 4.50 Kinetic Concepts, Inc., Term DTL-E1 loan, 5/4/18 $ 1,907,654 ---------------------------------------------------------------------------------------------------------- Health Care Supplies -- 0.0%+ 1,909,924 5.00 Immucor, Inc., Term B-2 Loan, 8/19/18 $ 1,819,203 ---------------------------------------------------------------------------------------------------------- Health Care Services -- 0.0%+ 184,686 6.50 Ardent Legacy Acquisitions, Inc. (Ardent Mergeco LLC) Term Loan, 7/31/21 $ 183,763 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 71 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Health Care Services -- (continued) 249,873 3.50 DaVita HealthCare Partners, Inc., Tranche B Loan (First Lien), 6/19/21 $ 249,122 ----------------- $ 432,885 ---------------------------------------------------------------------------------------------------------- Health Care Facilities -- 0.2% 589,688 3.66 CHS, Incremental 2018 Term F Loans, 12/31/18 $ 582,211 1,114,278 3.36 CHS, Incremental 2019 Term G Loan, 12/31/19 1,087,988 2,050,243 4.00 CHS, Incremental 2021 Term H Loan, 1/27/21 2,017,568 731,072 3.36 HCA, Inc., Tranche B-4 Term Loan, 5/1/18 731,174 1,753,257 3.17 HCA, Inc., Tranche B-5 Term Loan, 3/31/17 1,753,136 ----------------- $ 6,172,077 ---------------------------------------------------------------------------------------------------------- Health Care Technology -- 0.0%+ 449,239 3.50 IMS Health, Inc., Term B Dollar Loan, 3/17/21 $ 437,259 ----------------- Total Health Care Equipment & Services $ 10,769,078 ---------------------------------------------------------------------------------------------------------- PHARMACEUTICALS, BIOTECHNOLOGY & LIFE SCIENCES -- 0.2% Biotechnology -- 0.0%+ 742,327 3.50 Alkermes, Inc., 2019 Term Loan, 9/25/19 $ 740,008 ---------------------------------------------------------------------------------------------------------- Pharmaceuticals -- 0.1% 383,175 3.42 Grifols Worldwide Operations USA, Inc., U.S. Tranche B Term Loam, 4/1/21 $ 380,110 1,640,289 3.50 RPI Finance Trust, Term B-4 Term Loan, 11/9/20 1,634,479 532,996 3.75 Valeant Pharmaceuticals International, Inc., Series C-2 Tranche B Term Loan, 12/11/19 514,508 992,500 4.00 Valeant Pharmaceuticals, Series F-1, 3/11/22 958,797 ----------------- $ 3,487,894 ---------------------------------------------------------------------------------------------------------- Life Sciences Tools & Services -- 0.1% 1,628,854 4.25 Catalent Pharma Solutions, Dollar Term Loan, 5/20/21 $ 1,617,995 ----------------- Total Pharmaceuticals, Biotechnology & Life Sciences $ 5,845,897 ---------------------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 0.1% Specialized Finance -- 0.1% 1,484,887 3.50 Trans Union LLC 2015, Term B-2 Loan, 4/9/21 $ 1,445,166 ----------------- Total Diversified Financials $ 1,445,166 ---------------------------------------------------------------------------------------------------------- INSURANCE -- 0.2% Insurance Brokers -- 0.2% 1,155,382 4.50 National Financial Partners Corp., Tranche B Term Loan (First Lien), 7/1/20 $ 1,114,943 6,146,019 4.25 USI Insurance Services LLC, Term B Loan, 12/30/19 5,940,515 ----------------- $ 7,055,458 ----------------- Total Insurance $ 7,055,458 ---------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 72 Pioneer Bond Fund | Semiannual Report | 12/31/15 ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- SOFTWARE & SERVICES -- 0.0%+ Systems Software -- 0.0%+ 603,900 5.75 AVG Technologies N.V., Term Loan, 10/15/20 $ 601,635 ---------------------------------------------------------------------------------------------------------- Home Entertainment Software -- 0.0%+ 1,146,608 3.25 Activision Blizzard, Inc., Term Loan, 7/26/20 $ 1,147,324 ----------------- Total Software & Services $ 1,748,959 ---------------------------------------------------------------------------------------------------------- TECHNOLOGY HARDWARE & EQUIPMENT -- 0.0%+ Communications Equipment -- 0.0%+ 248,023 3.31 Commscope, Inc., Tranche 4 Term Loan, 1/14/18 $ 247,403 ----------------- Total Technology Hardware & Equipment $ 247,403 ---------------------------------------------------------------------------------------------------------- SEMICONDUCTORS & SEMICONDUCTOR EQUIPMENT -- 0.1% Semiconductor Equipment -- 0.1% 1,160,357 2.86 Sensata Technologies B.V. (Sensata Technologies Finance Co., LLC) Sixth Amendment Term Loan, 10/14/21 $ 1,141,791 ---------------------------------------------------------------------------------------------------------- Semiconductors -- 0.0%+ 325,000 4.25 Avago Technologies Cayman, Ltd., (Avago Technologies Holdings Luxembourg S.a r.l.) Term Loan, 11/13/22 $ 321,524 322,619 3.75 Avago Technologies Ltd., Tranche B Term Loan (First Lien), 4/16/21 322,418 350,189 3.25 Microsemi Corp., Term Loan (First Lien), 3/14/21 349,751 350,189 5.25 Microsemi Corp., Term Loan (2014), 12/17/22 344,761 ----------------- $ 1,338,454 ----------------- Total Semiconductors & Semiconductor Equipment $ 2,480,245 ---------------------------------------------------------------------------------------------------------- TELECOMMUNICATION SERVICES -- 0.2% Integrated Telecommunication Services -- 0.1% 1,911,013 4.00 Cincinnati Bell, Inc., Tranche B Term Loan, 9/10/20 $ 1,851,293 1,205,888 4.00 GCI Holdings, Inc., New Term B Loan, 2/2/22 1,208,149 ----------------- $ 3,059,442 ---------------------------------------------------------------------------------------------------------- Wireless Telecommunication Services -- 0.1% 1,484,848 3.00 Crown Castle International Corp., Tranche B-2 Term Loan (First Lien), 1/31/21 $ 1,475,568 333,333 4.00 Syniverse Holdings, Inc., Initial Term Loan, 4/23/19 247,500 666,667 4.00 Syniverse Holdings, Inc., Tranche B Term Loan, 4/23/19 495,000 ----------------- $ 2,218,068 ----------------- Total Telecommunication Services $ 5,277,510 ---------------------------------------------------------------------------------------------------------- UTILITIES -- 0.1% Electric Utilities -- 0.0%+ 1,285,660 3.75 Texas Competitive Electric Holdings Co., LLC, DIP Delayed Draw Term Loan (2014), 5/5/16 $ 1,279,232 ---------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 73 Schedule of Investments | 12/31/15 (unaudited) (continued) ---------------------------------------------------------------------------------------------------------- Principal Floating Amount ($) Rate (b) Value ---------------------------------------------------------------------------------------------------------- Independent Power Producers & Energy Traders -- 0.1% 1,013,391 4.00 Dynegy, Inc., Tranche B-2 Term Loan, 4/23/20 $ 982,356 1,309,009 2.75 NRG Energy, Inc., Term Loan (2013), 7/1/18 1,278,330 722,016 3.75 NSG Holdings LLC, New Term Loan, 12/11/19 711,822 ----------------- $ 2,972,508 ----------------- Total Utilities $ 4,251,740 ---------------------------------------------------------------------------------------------------------- TOTAL SENIOR FLOATING RATE LOAN INTERESTS (Cost $82,493,442) $ 81,327,038 ---------------------------------------------------------------------------------------------------------- TEMPORARY CASH INVESTMENTS -- 1.4% Commercial Paper -- 0.3% 8,370,000 Prudential Funding LLC, Commercial Paper, 1/4/16 (c) $ 8,369,766 ---------------------------------------------------------------------------------------------------------- Repurchase Agreements -- 1.1% 5,375,000 $5,375,000 Bank of Nova Scotia, 0.33%, dated 12/31/15 plus accrued interest on 1/4/16 collateralized by the following: $2,850 Federal Home Loan Mortgage Corp, 2.179% - 3.166%, 6/1/42 - 9/1/44 $2,257,755 Federal National Mortgage Association (ARM), 1.793% - 3.341%, 2/1/25 - 4/1/44 $3,222,097 Federal National Mortgage Association, 2.5%-5.0%, 12/1/23-8/1/45 $ 5,375,000 30,930,000 $30,930,000 RBC Capital Markets LLC, 0.30%, dated 12/31/15 plus accrued interest on 1/4/16 collateralized by the following: $4,327,067 Federal Home Loan Mortgage Corp, 2.202% - 2.68%, 5/1/36 - 5/1/45 $20,545,672 Federal National Mortgage Association (ARM), 0% - 4.866%, 9/1/33 - 12/1/45 $6,675,862 Federal National Mortgage Association, 2.5%-4.0%, 12/1/32-12/1/45 30,930,000 1,690,000 $1,690,000 TD Securities USA LLC, 0.31%, dated 12/31/15 plus accrued interest on 1/4/16 collateralized by $1,723,801 Freddie Mac Giant, 4.0%, 7/1/45 1,690,000 ----------------- $ 37,995,000 ---------------------------------------------------------------------------------------------------------- TOTAL TEMPORARY CASH INVESTMENTS (Cost $46,364,791) $ 46,364,766 ---------------------------------------------------------------------------------------------------------- TOTAL INVESTMENT IN SECURITIES -- 99.5% (Cost $3,351,689,519) (a) $ 3,320,848,136 ---------------------------------------------------------------------------------------------------------- OTHER ASSETS & LIABILITIES -- 0.5% $ 17,485,462 ---------------------------------------------------------------------------------------------------------- TOTAL NET ASSETS -- 100.0% $ 3,338,333,598 ========================================================================================================== The accompanying notes are an integral part of these financial statements. 74 Pioneer Bond Fund | Semiannual Report | 12/31/15 REIT Real Estate Investment Trust. + Rounds to less than 0.01%. (PIK) Represents a pay-in kind security. (Perpetual) Security with no stated maturity date. (Cat Bond) Catastrophe or event linked bond. At December 31, 2015 the value of these securities amounted to $91,001,440 or 2.7% of total net assets. See Notes to Financial Statements -- 1F. REMICS Real Estate Mortgage Investment Conduits. ARM Adjustable Rate Mortgage. (Step) Bond issued with an initial coupon rate which converts to a higher rate at a later date. (TBA) "To Be Announced" Securities. (144A) Security is exempt from registration under Rule 144A of the Securities Act of 1933. Such securities may be resold normally to qualified institutional buyers in a transaction exempt from registration. At December 31, 2015, the value of these securities amounted to $79,033,486 or 29.3% of total net assets. ** Senior floating rate loan interests in which the Fund invests generally pay interest at rates that are periodically redetermined by reference to a base lending rate plus a premium. These base lending rates are generally (i) the lending rate offered by one or more major European banks, such as LIBOR (London InterBank Offered Rate), (ii) the prime rate offered by one or more major U.S. banks, (iii) the rate of a certificate of deposit or (iv) other base lending rates used by commercial lenders. The rate shown is the coupon rate at period end. (a) At December 31, 2015, the net unrealized depreciation on investments based on cost for federal income tax purposes of $3,356,292,658 was as follows: Aggregate gross unrealized appreciation for all investments in which there is an excess of value over tax cost $ 34,954,302 Aggregate gross unrealized depreciation for all investments in which there is an excess of tax cost over value (70,398,824) ------------ Net unrealized depreciation $(35,444,522) ============ (b) Debt obligation with a variable interest rate. Rate shown is rate at end of period. (c) Security issued with a zero coupon. Income is earned through accretion of discount. (d) Security is valued using fair value methods (other than prices supplied by independent pricing services or broker-dealers). See Notes to Financial Statements -- Note 1A. (e) Structured reinsurance investment. At December 31, 2015, the value of these securities amounted to $55,634,383 or 1.7% of total net assets. See Notes To Financial Statements -- Note 1F. (f) Consists of revenue bonds unless otherwise indicated. (g) Rate to be determined. (h) Represents a General Obligation Bond. Purchases and sales of securities (excluding temporary cash investments) for the six months ended December 31, 2015 were as follows: -------------------------------------------------------------------------------- Purchases Sales -------------------------------------------------------------------------------- Long-Term U.S. Government Securities $438,842,864 $319,212,417 Other Long-Term Securities 445,495,732 364,952,674 The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 75 Schedule of Investments | 12/31/15 (unaudited) (continued) Various inputs are used in determining the value of the Fund's investments. These inputs are summarized in the three broad levels listed below. Level 1 - quoted prices in active markets for identical securities. Level 2 - other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk, etc.) See Notes to Financial Statements -- Note 1A. Level 3 - significant unobservable inputs (including the Fund's own assumptions in determining fair value of investments) See Notes to Financial Statements -- Note 1A. The following is a summary of the inputs used as of December 31, 2015, in valuing the Fund's assets: -------------------------------------------------------------------------------------------------------- Level 1 Level 2 Level 3 Total -------------------------------------------------------------------------------------------------------- Preferred Stocks $10,019,049 $ -- $ -- $ 10,019,049 Convertible Preferred Stock 6,524,346 -- -- 6,524,346 Asset Backed Securities -- 159,550,588 -- 159,550,588 Collateralized Mortgage Obligations -- 566,116,467 -- 566,116,467 Corporate Bonds Diversified Financials Other Diversified Financial Services -- -- 1,150,830 1,150,830 Insurance Reinsurance -- 92,470,306 55,634,383 148,104,689 All Other Corporate Bonds -- 1,182,314,614 -- 1,182,314,614 U.S. Government Agency Obligations -- 1,038,192,208 -- 1,038,192,208 Foreign Government Bond -- 4,562,649 -- 4,562,649 Municipal Bonds -- 76,620,892 -- 76,620,892 Senior Floating Rate Loan Interests -- 81,327,038 -- 81,327,038 Commercial Paper -- 8,369,766 -- 8,369,766 Repurchase Agreements -- 37,995,000 -- 37,995,000 -------------------------------------------------------------------------------------------------------- Total $16,543,395 $ 3,247,519,528 $ 56,785,213 $3,320,848,136 ======================================================================================================== Other Financial Instruments Net unrealized appreciation on Futures Contracts $ 2,203,831 $ -- $ -- $ 2,203,831 -------------------------------------------------------------------------------------------------------- Total Other Financial Instruments $ 2,203,831 $ -- $ -- $ 2,203,831 ======================================================================================================== The following is a summary of the fair valuation of certain Fund's assets and liabilities as of December 31, 2015. -------------------------------------------------------------------------------------------------------- Level 1 Level 2 Level 3 Total -------------------------------------------------------------------------------------------------------- Assets: Restricted cash $ -- $ 2,861,626 $ -- $ 2,861,626 Liabilities: Variation margin on Futures contracts -- (1,080,250) -- (1,080,250) -------------------------------------------------------------------------------------------------------- Total: $ -- $ 1,781,376 $ -- $ 1,781,376 ======================================================================================================== The accompanying notes are an integral part of these financial statements. 76 Pioneer Bond Fund | Semiannual Report | 12/31/15 Following is a reconciliation of assets using significant unobservable inputs (Level 3): -------------------------------------------------------------------------------------------------------- Preferred Corporate Stocks Bonds Total -------------------------------------------------------------------------------------------------------- Balance as of 6/30/15 $ 36,000 $45,277,300 $45,313,300 Realized gain (loss)(1) -- 3,068 3,068 Change in unrealized appreciation (depreciation)(2) -- 3,575,733 3,575,733 Net purchases -- 11,259,048 11,259,048 Net sales -- (5,925,936) (5,925,936) Transfers in to Level 3* -- 2,560,000 2,560,000 Transfers out of Level 3* -- -- -- Transfers in and out of Level 3 categories (36,000) 36,000 -- -------------------------------------------------------------------------------------------------------- Balance as of 12/31/15 $ -- $56,785,213 $56,785,213 ======================================================================================================== (1) Realized gain (loss) on these securities is included in the net realized gain (loss) from investments in the Statement of Operations. (2) Unrealized appreciation (depreciation) on these securities is included in the change in unrealized appreciation (depreciation) on investments in the Statement of Operations. * Transfers are calculated on the beginning of period values. During the six months ending December 31, 2015, one security having a value of $2,560,000 was transferred from Level 2 to Level 3. The change in the level designation within the fair value hierarchy was due to an improper classification of the investment type in the prior reporting period. There were no other transfers between levels 1, 2 and 3. Net change in unrealized appreciation (depreciation) of investments still held as of 12/31/15 $3,478,698 ---------- The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 77 Statement of Assets and Liabilities | 12/31/15 (unaudited) ASSETS: Investment in securities (cost $3,351,689,519) $3,320,848,136 Cash 132,492,663 Restricted Cash* 2,861,626 Receivables -- Investment securities sold 7,456,634 Fund shares sold 14,772,445 Dividends 49,524 Interest 20,271,266 Due from Pioneer Investment Management, Inc. 165,654 Net unrealized appreciation on futures contracts 2,203,831 Other assets 120,370 -------------------------------------------------------------------------------------------------------- $3,501,242,149 ======================================================================================================== LIABILITIES: Payables -- Investment securities purchased $ 142,714,403 Fund shares repurchased 16,384,668 Dividends 2,157,594 Variation margin on futures contracts 1,080,250 Due to affiliates 390,260 Accrued expenses 181,376 -------------------------------------------------------------------------------------------------------- $ 162,908,551 ======================================================================================================== NET ASSETS: Paid-in capital $3,384,812,673 Distributions in excess of net investment income (7,521,503) Accumulated net realized loss on investments, swap contracts and futures contracts (10,320,020) Net unrealized depreciation on investments (30,841,383) Net unrealized appreciation on futures contracts 2,203,831 -------------------------------------------------------------------------------------------------------- $3,338,333,598 ======================================================================================================== NET ASSET VALUE PER SHARE: (No par value, unlimited number of shares authorized) Class A (based on $1,029,070,556/108,200,167 shares) $ 9.51 Class C (based on $118,690,138/12,620,720 shares) $ 9.40 Class K (based on $295,797,586/31,111,203 shares) $ 9.51 Class R (based on $133,869,221/13,948,527 shares) $ 9.60 Class Y (based on $1,760,906,097/186,889,070 shares) $ 9.42 MAXIMUM OFFERING PRICE: Class A ($9.51 (divided by) 95.5%) $ 9.96 ======================================================================================================== * Represents restricted cash deposited at the custodian and/or counterparty for derivative trading. The accompanying notes are an integral part of these financial statements. 78 Pioneer Bond Fund | Semiannual Report | 12/31/15 Statement of Operations (unaudited) For the Six Months Ended 12/31/15 INVESTMENT INCOME: Interest $ 52,494,757 Dividends 914,127 -------------------------------------------------------------------------------------------------------- Total investment income $ 53,408,884 ======================================================================================================== EXPENSES: Management fees $ 6,545,222 Transfer agent fees Class A 122,710 Class C 14,971 Class K 1,366 Class R 5,268 Class Y 22,079 Class Z* 488 Distribution fees Class A 1,312,488 Class C 579,340 Class R 321,571 Shareholder communications expense 2,253,210 Administrative expense 508,600 Custodian fees 112,168 Registration fees 124,301 Professional fees 95,548 Printing expense 25,061 Fees and expenses of nonaffiliated Trustees 78,784 Miscellaneous 172,029 -------------------------------------------------------------------------------------------------------- Total expenses $ 12,295,204 Less fees waived and expenses reimbursed by Pioneer Investment Management, Inc. (591,010) -------------------------------------------------------------------------------------------------------- Net expenses $ 11,704,194 -------------------------------------------------------------------------------------------------------- Net investment income $ 41,704,690 -------------------------------------------------------------------------------------------------------- REALIZED AND UNREALIZED GAIN (LOSS) ON INVESTMENTS, FUTURES CONTRACTS AND SWAP CONTRACTS: Net realized gain (loss) on: Investments $ (2,218,219) Futures contracts (320,340) Swap contracts 183 $ (2,538,376) -------------------------------------------------------------------------------------------------------- Change in net unrealized appreciation (depreciation) on: Investments $ (40,313,376) Futures contracts (2,624,825) Swap contracts (34,098) $ (42,972,299) -------------------------------------------------------------------------------------------------------- Net gain(loss) on investments, futures contracts and swap contracts $ (45,510,675) -------------------------------------------------------------------------------------------------------- Net decrease in net assets resulting from operations $ (3,805,985) ======================================================================================================== * Class Z shares converted to Class Y shares on August 7, 2015. The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 79 Statements of Changes in Net Assets -------------------------------------------------------------------------------------------------------- Six Months Ended 12/31/15 Year Ended (unaudited) 6/30/15 -------------------------------------------------------------------------------------------------------- FROM OPERATIONS: Net investment income (loss) $ 41,704,690 $ 68,993,276 Net realized gain (loss) on investments, futures contracts and swap contracts (2,538,376) 23,395,756 Change in net unrealized appreciation (depreciation) on investments, futures contracts and swap contracts (42,972,299) (65,942,035) -------------------------------------------------------------------------------------------------------- Net increase (decrease) in net assets resulting from operations $ (3,805,985) $ 26,446,997 -------------------------------------------------------------------------------------------------------- DISTRIBUTIONS TO SHAREOWNERS: Net investment income: Class A ($0.14 and $0.29 per share, respectively) $ (14,989,368) $ (26,434,196) Class B ($0.00 and $0.07 per share, respectively)* -- (34,683) Class C ($0.10 and $0.21 per share, respectively) (1,229,707) (2,016,609) Class K ($0.16 and $0.32 per share, respectively) (3,670,783) (2,711,408) Class R ($0.13 and $0.26 per share, respectively) (1,679,403) (2,060,446) Class Y ($0.15 and $0.31 per share, respectively) (27,282,454) (39,612,426) Class Z ($0.03 and $0.31 per share, respectively)** (184,669) (1,526,702) Net realized gain: Class A ($0.02 and $0.04 per share, respectively) (2,297,989) (3,819,881) Class C ($0.02 and $0.04 per share, respectively) (256,680) (406,576) Class K ($0.02 and $0.04 per share, respectively) (632,921) (45,156) Class R ($0.02 and $0.04 per share, respectively) (289,802) (285,304) Class Y ($0.02 and $0.04 per share, respectively) (3,842,000) (4,943,141) Class Z ($0.00 and $0.04 per share, respectively)** -- (218,854) -------------------------------------------------------------------------------------------------------- Total distributions to shareowners $ (56,355,776) $ (84,115,382) -------------------------------------------------------------------------------------------------------- FROM FUND SHARE TRANSACTIONS Net proceeds from sale or exchange of shares $ 832,457,213 $2,251,662,439 Reinvestment of distributions 42,697,119 65,229,520 Cost of shares repurchased (637,087,406) (813,633,836) -------------------------------------------------------------------------------------------------------- Net increase in net assets resulting from Fund share transactions $ 238,066,926 $1,503,258,123 -------------------------------------------------------------------------------------------------------- Net increase in net assets $ 177,905,165 $1,445,589,738 NET ASSETS: Beginning of period $3,160,428,433 $1,714,838,695 -------------------------------------------------------------------------------------------------------- End of period $3,338,333,598 $3,160,428,433 -------------------------------------------------------------------------------------------------------- Distributions in excess of net investment income $ (7,521,503) $ (189,809) -------------------------------------------------------------------------------------------------------- * Class B shares converted to Class A shares on November 10, 2014. ** Class Z shares converted to Class Y shares on August 7, 2015. The accompanying notes are an integral part of these financial statements. 80 Pioneer Bond Fund | Semiannual Report | 12/31/15 Statements of Changes in Net Assets (continued) -------------------------------------------------------------------------------------------------------- Six Months Six Months Ended Ended 12/31/15 12/31/15 Year Ended Year Ended Shares Amount 6/30/15 6/30/15 (unaudited) (unaudited) Shares Amount -------------------------------------------------------------------------------------------------------- Class A Shares sold 18,828,223 $ 182,576,931 73,397,739 $ 722,362,397 Reinvestment of distributions 1,300,746 12,497,065 2,437,923 23,964,170 Less shares repurchased (19,823,490) (190,724,284) (39,490,108) (388,662,183) -------------------------------------------------------------------------------------------------------- Net increase 305,479 $ 4,349,712 36,345,554 $ 357,664,384 ======================================================================================================== Class B* Shares exchanged -- $ -- 12,531 $ 122,811 Reinvestment of distributions -- -- 2,761 27,063 Less shares repurchased -- -- (561,244) (5,495,479) -------------------------------------------------------------------------------------------------------- Net decrease -- $ -- (545,952) $ (5,345,605) ======================================================================================================== Class C Shares sold 2,017,591 $ 19,156,185 6,453,693 $ 62,788,125 Reinvestment of distributions 90,205 856,541 159,439 1,549,668 Less shares repurchased (1,417,036) (13,477,190) (2,176,700) (21,155,723) -------------------------------------------------------------------------------------------------------- Net increase 690,760 $ 6,535,536 4,436,432 $ 43,182,070 ======================================================================================================== Class K Shares sold 15,014,115 $ 144,658,427 19,313,507 $ 189,643,402 Reinvestment of distributions 198,271 1,903,779 110,358 1,081,971 Less shares repurchased (2,609,044) (25,103,597) (1,361,429) (13,348,774) -------------------------------------------------------------------------------------------------------- Net increase 12,603,342 $ 121,458,609 18,062,436 $ 177,376,599 ======================================================================================================== Class R Shares sold 4,103,850 $ 39,888,941 8,339,063 $ 82,666,234 Reinvestment of distributions 179,037 1,735,529 217,675 2,158,016 Less shares repurchased (2,291,430) (22,232,097) (1,440,815) (14,287,736) -------------------------------------------------------------------------------------------------------- Net increase 1,991,457 $ 19,392,373 7,115,923 $ 70,536,514 ======================================================================================================== Class Y Shares sold 46,589,690 $ 444,966,047 116,221,047 $1,131,771,954 Reinvestment of distributions 2,685,440 25,554,747 3,565,174 34,708,672 Less shares repurchased (33,799,950) (322,656,229) (37,432,755) (364,339,899) -------------------------------------------------------------------------------------------------------- Net increase 15,475,180 $ 147,864,565 82,353,466 $ 802,140,727 ======================================================================================================== Class Z** Shares sold 125,037 $ 1,210,682 6,317,443 $ 62,307,516 Reinvestment of distributions 15,392 149,458 176,815 1,739,960 Less shares repurchased (6,477,629) (62,894,009) (644,582) (6,344,042) -------------------------------------------------------------------------------------------------------- Net increase (decrease) (6,337,200) $ (61,533,869) 5,849,676 $ 57,703,434 ======================================================================================================== * Class B shares converted to Class A shares on November 10, 2014. ** Class Z shares converted to Class Y shares on August 7, 2015. The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 81 Financial Highlights ----------------------------------------------------------------------------------------------------------------------------------- Six Months Ended Year Year Year Year Year 12/31/15 Ended Ended Ended Ended Ended (unaudited) 6/30/15 6/30/14 6/30/13 6/30/12 6/30/11 ----------------------------------------------------------------------------------------------------------------------------------- Class A Net asset value, beginning of period $ 9.68 $ 9.88 $ 9.67 $ 9.73 $ 9.66 $ 9.44 ----------------------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income (loss) $ 0.12(a) $ 0.27 $ 0.35 $ 0.38 $ 0.42 $ 0.45 Net realized and unrealized gain (loss) on investments (0.13) (0.14) 0.24 (0.07) 0.13 0.21 ----------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ (0.01) $ 0.13 $ 0.59 $ 0.31 $ 0.55 $ 0.66 ----------------------------------------------------------------------------------------------------------------------------------- Distribution to shareowners: Net investment income $ (0.14) $ (0.29) $ (0.38) $ (0.37) $ (0.43) $ (0.44) Net realized gain (0.02) (0.04) -- -- (0.05) -- ----------------------------------------------------------------------------------------------------------------------------------- Total distributions $ (0.16) $ (0.33) $ (0.38) $ (0.37) $ (0.48) $ (0.44) ----------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ (0.17) $ (0.20) $ 0.21 $ (0.06) $ 0.07 $ 0.22 ----------------------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 9.51 $ 9.68 $ 9.88 $ 9.67 $ 9.73 $ 9.66 =================================================================================================================================== Total return* (0.11)% 1.32% 6.19% 3.21% 5.91% 7.08% Ratio of net expenses to average net assets 0.85%** 0.85% 0.85% 0.85% 0.85% 0.85% Ratio of net investment income (loss) to average net assets 2.41%** 2.68% 3.52% 3.77% 4.35% 4.63% Portfolio turnover rate 44%** 81% 41% 28% 21% 36% Net assets, end of period (in thousands) $1,029,071 $1,044,659 $706,962 $565,569 $453,772 $500,905 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 0.95%** 0.93% 1.00% 1.01% 1.03% 1.06% Net investment income (loss) to average net assets 2.31%** 2.60% 3.37% 3.61% 4.17% 4.42% =================================================================================================================================== * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions, the complete redemption of the investment at net asset value at the end of each period and no sales charges. Total return would be reduced if sales charges were taken into account. ** Annualized. (a) The per share data presented above is based on the average shares outstanding for the period presented. The accompanying notes are an integral part of these financial statements. 82 Pioneer Bond Fund | Semiannual Report | 12/31/15 ----------------------------------------------------------------------------------------------------------------------------------- Six Months Ended Year Year Year Year Year 12/31/15 Ended Ended Ended Ended Ended (unaudited) 6/30/15 6/30/14 6/30/13 6/30/12 6/30/11 ----------------------------------------------------------------------------------------------------------------------------------- Class C Net asset value, beginning of period $ 9.57 $ 9.77 $ 9.57 $ 9.63 $ 9.55 $ 9.34 ----------------------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income (loss) $ 0.08(a) $ 0.19 $ 0.26 $ 0.29 $ 0.33 $ 0.36 Net realized and unrealized gain (loss) on investments (0.13) (0.14) 0.23 (0.06) 0.15 0.20 ----------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ (0.05) $ 0.05 $ 0.49 $ 0.23 $ 0.48 $ 0.56 ----------------------------------------------------------------------------------------------------------------------------------- Distribution to shareowners: Net investment income $ (0.10) $ (0.21) $ (0.29) $ (0.29) $ (0.35) $ (0.35) Net realized gain (0.02) (0.04) -- -- (0.05) -- ----------------------------------------------------------------------------------------------------------------------------------- Total distributions $ (0.12) $ (0.25) $ (0.29) $ (0.29) $ (0.40) $ (0.35) ----------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ (0.17) $ (0.20) $ 0.20 $ (0.06) $ 0.08 $ 0.21 ----------------------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 9.40 $ 9.57 $ 9.77 $ 9.57 $ 9.63 $ 9.55 =================================================================================================================================== Total return* (0.50)% 0.49% 5.20% 2.33% 5.12% 6.06% Ratio of net expenses to average net assets 1.59%** 1.63% 1.73% 1.72% 1.73% 1.73% Ratio of net investment income (loss) to average net assets 1.67%** 1.89% 2.69% 2.93% 3.47% 3.75% Portfolio turnover rate 44%** 81% 41% 28% 21% 36% Net assets, end of period (in thousands) $118,690 $114,222 $73,224 $87,763 $93,737 $82,915 =================================================================================================================================== * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions, the complete redemption of the investment at net asset value at the end of each period and no sales charges. Total return would be reduced if sales charges were taken into account. ** Annualized. (a) The per share data presented above is based on the average shares outstanding for the period presented. The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 83 Financial Highlights (continued) ----------------------------------------------------------------------------------------------------------------------------------- Six Months Ended 12/20/12 12/31/15 Year Ended Year Ended to (unaudited) 6/30/15 6/30/14 6/30/13 ----------------------------------------------------------------------------------------------------------------------------------- Class K Net asset value, beginning of period $ 9.68 $ 9.87 $ 9.67 $ 9.94 ----------------------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income (loss) $ 0.13(b) $ 0.30 $ 0.40 $ 0.20 Net realized and unrealized gain (loss) on investments (0.12) (0.13) 0.20 (0.26) ----------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ 0.01 $ 0.17 $ 0.60 $ (0.06) ----------------------------------------------------------------------------------------------------------------------------------- Distribution to shareowners: Net investment income $ (0.16) $ (0.32) $ (0.40) $ (0.21) Net realized gain (0.02) (0.04) -- -- ----------------------------------------------------------------------------------------------------------------------------------- Total distributions $ (0.18) $ (0.36) $ (0.40) $ (0.21) ----------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ (0.17) $ (0.19) $ 0.20 $ (0.27) ----------------------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 9.51 $ 9.68 $ 9.87 $ 9.67 =================================================================================================================================== Total return* 0.08% 1.80% 6.37% (0.61)%(a) Ratio of net expenses to average net assets 0.47%** 0.47% 0.56% 0.57%** Ratio of net investment income (loss) to average net assets 2.79%** 3.03% 3.59% 3.86%** Portfolio turnover rate 44%** 81% 41% 28% Net assets, end of period (in thousands) $295,798 $179,135 $ 4,398 $ 10 =================================================================================================================================== * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions, the complete redemption of the investment at net asset value at the end of each period. ** Annualized. (a) Not Annualized. (b) The per share data presented above is based on the average shares outstanding for the period presented. The accompanying notes are an integral part of these financial statements. 84 Pioneer Bond Fund | Semiannual Report | 12/31/15 ----------------------------------------------------------------------------------------------------------------------------------- Six Months Ended Year Year Year Year Year 12/31/15 Ended Ended Ended Ended Ended (unaudited) 6/30/15 6/30/14 6/30/13 6/30/12 6/30/11 ----------------------------------------------------------------------------------------------------------------------------------- Class R Net asset value, beginning of period $ 9.77 $ 9.97 $ 9.76 $ 9.82 $ 9.74 $ 9.52 ----------------------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income (loss) $ 0.11(a) $ 0.25 $ 0.32 $ 0.34 $ 0.39 $ 0.41 Net realized and unrealized gain (loss) on investments (0.13) (0.15) 0.23 (0.06) 0.14 0.22 ----------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ (0.02) $ 0.10 $ 0.55 $ 0.28 $ 0.53 $ 0.63 ----------------------------------------------------------------------------------------------------------------------------------- Distribution to shareowners: Net investment income $ (0.13) $ (0.26) $ (0.34) $ (0.34) $ (0.40) $ (0.41) Net realized gain (0.02) (0.04) -- -- (0.05) -- ----------------------------------------------------------------------------------------------------------------------------------- Total distributions $ (0.15) $ (0.30) $ (0.34) $ (0.34) $ (0.45) $ (0.41) ----------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ (0.17) $ (0.20) $ 0.21 $ (0.06) $ 0.08 $ 0.22 ----------------------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 9.60 $ 9.77 $ 9.97 $ 9.76 $ 9.82 $ 9.74 =================================================================================================================================== Total return* (0.23)% 1.06% 5.75% 2.80% 5.58% 6.67% Ratio of net expenses to average net assets 1.10%** 1.10% 1.25% 1.25% 1.25% 1.24% Ratio of net investment income (loss) to average net assets 2.16%** 2.43% 3.12% 3.36% 3.94% 4.25% Portfolio turnover rate 44%** 81% 41% 28% 21% 36% Net assets, end of period (in thousands) $133,869 $116,815 $48,264 $31,169 $23,892 $20,508 Ratios with no waiver of fees and assumption of expenses by the Adviser and no reduction for fees paid indirectly: Total expenses to average net assets 1.17%** 1.21% 1.32% 1.35% 1.35% 1.24% Net investment income (loss) to average net assets 2.09%** 2.32% 3.05% 3.26% 3.84% 4.25% =================================================================================================================================== * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions, the complete redemption of the investment at net asset value at the end of each period. ** Annualized. (a) The per share data presented above is based on the average shares outstanding for the period presented. The accompanying notes are an integral part of these financial statements. Pioneer Bond Fund | Semiannual Report | 12/31/15 85 Financial Highlights (continued) ----------------------------------------------------------------------------------------------------------------------------------- Six Months Ended Year Year Year Year Year 12/31/15 Ended Ended Ended Ended Ended (unaudited) 6/30/15 6/30/14 6/30/13 6/30/12 6/30/11 ----------------------------------------------------------------------------------------------------------------------------------- Class Y Net asset value, beginning of period $ 9.59 $ 9.79 $ 9.58 $ 9.65 $ 9.57 $ 9.36 ----------------------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income (loss) $ 0.13(a) $ 0.30 $ 0.36 $ 0.39 $ 0.44 $ 0.47 Net realized and unrealized gain (loss) on investments (0.13) (0.15) 0.24 (0.07) 0.14 0.20 ----------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ -- $ 0.15 $ 0.60 $ 0.32 $ 0.58 $ 0.67 ----------------------------------------------------------------------------------------------------------------------------------- Distribution to shareowners: Net investment income $ (0.15) $ (0.31) $ (0.39) $ (0.39) $ (0.45) $ (0.46) Net realized gain (0.02) (0.04) -- -- (0.05) -- ----------------------------------------------------------------------------------------------------------------------------------- Total distributions $ (0.17) $ (0.35) $ (0.39) $ (0.39) $ (0.50) $ (0.46) ----------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ (0.17) $ (0.20) $ 0.21 $ (0.07) $ 0.08 $ 0.21 ----------------------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 9.42 $ 9.59 $ 9.79 $ 9.58 $ 9.65 $ 9.57 =================================================================================================================================== Total return* 0.01% 1.59% 6.41% 3.34% 6.27% 7.25% Ratio of net expenses to average net assets 0.58%** 0.58% 0.66% 0.66% 0.65% 0.61% Ratio of net investment income (loss) to average net assets 2.68%** 2.95% 3.72% 3.97% 4.55% 4.88% Portfolio turnover rate 44%** 81% 41% 28% 21% 36% Net assets, end of period (in thousands) $ 1,760,906 $1,644,161 $871,801 $916,182 $847,072 $717,433 =================================================================================================================================== * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions, the complete redemption of the investment at net asset value at the end of each period. ** Annualized. (a) The per share data presented above is based on the average shares outstanding for the period presented. The accompanying notes are an integral part of these financial statements. 86 Pioneer Bond Fund | Semiannual Report | 12/31/15 Notes to Financial Statements | 12/31/15 (unaudited) 1. Organization and Significant Accounting Policies Pioneer Bond Fund (the Fund) is a Delaware statutory trust. The Fund is registered under the Investment Company Act of 1940 as a diversified, open-end management investment company. The investment objective of the Fund is to seek current income consistent with preservation of capital. The Fund offers five classes of shares designated as Class A, Class C, Class K, Class R and Class Y shares. Class B shares were converted to Class A shares as of the close of business on November 10, 2014. Class Z shares were converted to Class Y shares on August 7, 2015. Each class of shares represents an interest in the same portfolio of investments of the Fund and has identical rights (based on relative net asset values) to assets and liquidation proceeds. Share classes can bear different rates of class-specific fees and expenses such as transfer agent and distribution fees. Differences in class-specific fees and expenses will result in differences in net investment income and, therefore, the payment of different dividends from net investment income earned by each class. The Amended and Restated Declaration of Trust of the Fund gives the Board the flexibility to specify either per-share voting or dollar-weighted voting when submitting matters for shareholder approval. Under per-share voting, each share of a class of the Fund is entitled to one vote. Under dollar-weighted voting, a shareholder's voting power is determined not by the number of shares owned, but by the dollar value of the shares on the record date. Each share class has exclusive voting rights with respect to matters affecting only that class, including with respect to the distribution plan for that class. There is no distribution plan for Class K or Class Y shares. The Fund's financial statements have been prepared in conformity with U.S. generally accepted accounting principles that require the management of the Fund to, among other things, make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of income, expenses and gains and losses on investments during the reporting period. Actual results could differ from those estimates. The following is a summary of significant accounting policies followed by the Fund in the preparation of its financial statements: A. Security Valuation The net asset value of the Fund is computed once daily, on each day the New York Stock Exchange (NYSE) is open, as of the close of regular trading on the NYSE. Pioneer Bond Fund | Semiannual Report | 12/31/15 87 Fixed income securities are valued by using prices supplied by independent pricing services, which consider such factors as market prices, market events, quotations from one or more brokers, Treasury spreads, yields, maturities and ratings, or may use a pricing matrix or other fair value methods or techniques to provide an estimated value of the security or instrument. A pricing matrix is a means of valuing a debt security on the basis of current market prices for other debt securities, historical trading patterns in the market for fixed income securities and/or other factors. Valuations may be supplemented by dealers and other sources, as required. Non-U.S. debt securities that are listed on an exchange will be valued at the bid price obtained from an independent third party pricing service. Loan interests are valued in accordance with guidelines established by the Board of Trustees at the mean between the last available bid and asked prices from one or more brokers or dealers as obtained from Loan Pricing Corporation, an independent third party pricing service. If price information is not available from Loan Pricing Corporation, or if the price information is deemed to be unreliable, price information will be obtained from an alternative loan interest pricing service. If no reliable price quotes are available from either the primary or alternative pricing service, broker quotes will be solicited. Event-linked bonds or catastrophe bonds are valued at the bid price obtained from an independent third party pricing service. Other insurance linked securities (including sidecars, collateralized reinsurance and industry loss warranties) may be valued at the bid price obtained from an independent pricing service, or through a third party using a pricing matrix, insurance industry valuation models, or other fair value methods or techniques to provide an estimated value of the instrument. Swap contracts, including interest rate swaps, caps and floors (other than centrally cleared swap contracts) are valued at the dealer quotations obtained from reputable International Swap Dealer association members. Centrally cleared swaps are valued at the daily settlement price provided by the central clearing counterparty. Futures contracts are generally valued at the closing settlement price established by the exchange on which they are traded. Shares of open-end registered investment companies (including money market mutual funds) are valued at such funds' net asset value. 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 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 88 Pioneer Bond Fund | Semiannual Report | 12/31/15 comprised of certain personnel of Pioneer Investment Management, Inc. (PIM), the Fund's investment adviser, pursuant to procedures adopted by the Fund's Board of Trustees. PIM's fair valuation team uses fair value methods approved by the Valuation Committee of the Board of Trustees. PIM's fair valuation team is responsible for monitoring developments that may impact fair valued securities and for discussing and assessing fair values on an ongoing basis, and at least quarterly, with the Valuation Committee of the Board of Trustees. Inputs used when applying fair value methods to value a security may include credit ratings, the financial condition of the company, current market conditions and comparable securities. The Fund may use fair value methods if it is determined that a significant event has occurred after the close of the exchange or market on which the security trades and prior to the determination of the Fund's net asset value. Examples of a significant event might include political or economic news, corporate restructurings, natural disasters, terrorist activity or trading halts. Thus, the valuation of the Fund's securities may differ significantly from exchange prices and such differences could be material. At December 31, 2015, one security was valued using fair value methods (in addition to securities valued using prices supplied by independent pricing services, broker-dealers or using a third party insurance industry pricing model) representing less than 0.1% of net assets. B. Investment Income and Transactions 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. Dividend income is recorded on the ex-dividend date, except that certain dividends from foreign securities where the ex-dividend date may have passed are recorded as soon as the Fund becomes aware of the ex-dividend data in the exercise of reasonable diligence. Interest income, including interest on income bearing cash accounts, is recorded on the accrual basis. Dividend and interest income are reported net of unrecoverable foreign taxes withheld at the applicable country rates. Security transactions are recorded as of trade date. Gains and losses on sales of investments are calculated on the identified cost method for both financial reporting and federal income tax purposes. Pioneer Bond Fund | Semiannual Report | 12/31/15 89 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, 2015, the Fund did not accrue any interest or penalties with respect to uncertain tax positions, which, if applicable, would be recorded as an income tax expense in the Statement of Operations. Tax returns filed within the prior three years remain subject to examination by Federal and State tax authorities. Distributions in excess of net investment income or net realized gains are temporary overdistributions for financial statement purposes resulting from differences in the recognition or classification of income or distributions for financial statement and tax purposes. Capital accounts within the financial statements are adjusted for permanent book/tax differences to reflect tax character, but are not adjusted for temporary differences. The tax character of current year distributions payable will be determined at the end of the current taxable year. The tax character of distributions paid during the year ended June 30, 2015 was as follows: --------------------------------------------------------------------------- 2015 --------------------------------------------------------------------------- Distributions paid from: Ordinary income $74,396,470 Long-term capital gain 9,718,912 --------------------------------------------------------------------------- Total $84,115,382 =========================================================================== The following shows the components of distributable earnings on a federal income tax basis at June 30, 2015: --------------------------------------------------------------------------- 2015 --------------------------------------------------------------------------- Distributable earnings: Undistributed ordinary income $ 3,028,838 Undistributed long-term capital gain 7,303,607 Dividends payable (1,560,199) Net unrealized appreciation 4,910,440 --------------------------------------------------------------------------- Total $13,682,686 =========================================================================== The difference between book-basis and tax-basis net unrealized appreciation is attributable to the tax deferral of losses on wash sales, adjustments relating to catastrophe bonds, the tax treatment of premium and amortization, the mark-to-market of futures contracts and credit default swaps. 90 Pioneer Bond Fund | Semiannual Report | 12/31/15 D. Fund Shares The Fund records sales and repurchases of its shares as of trade date. Pioneer Funds Distributor, Inc. (PFD), the principal underwriter for the Fund and a wholly owned indirect subsidiary of UniCredit S.p.A. (UniCredit), earned $35,221 in underwriting commissions on the sale of Class A shares during the six months ended December 31, 2015. E. Class Allocations Income, common expenses, and realized and unrealized gains and losses are calculated at the Fund level and allocated daily to each class of shares based on its respective percentage of adjusted net assets at the beginning of the day. Distribution fees are calculated based on the average daily net asset value attributable to Class A, Class C, and Class R shares of the Fund, respectively (see Note 4). Class 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. Insurance Linked Securities (ILS) Event-linked bonds are floating rate debt obligations for which the return of principal and the payment of interest are contingent on the non-occurrence of a pre-defined "trigger" event, such as a hurricane or an earthquake of a specific magnitude. The trigger event's magnitude may be based on losses to a company or industry, industry indexes or readings of scientific instruments, or may be based on specified actual losses. If a trigger event, as defined within the terms of an event-linked bond occurs, the Fund may lose a portion or all of its accrued interest and/or principal invested in such event-linked bond. The Fund is entitled to receive principal and interest payments so long as no trigger event occurs of the description and magnitude specified by the instrument. In addition to the specified trigger events, event-linked bonds may expose the Fund to other risks, including but not limited to issuer (credit) default, adverse regulatory or jurisdictional interpretations and adverse tax consequences. Pioneer Bond Fund | Semiannual Report | 12/31/15 91 The Fund's investments in ILS may include special purpose vehicles ("SPVs") or similar instruments structured to comprise a portion of a reinsurer's catastrophe-oriented business, known as quota share instruments (sometimes referred to as reinsurance sidecars), or to provide reinsurance relating to specific risks to insurance or reinsurance companies through a collateralized instrument, known as collateralized reinsurance. Structured reinsurance investments also may include industry loss warranties ("ILWs"), are subject to the same risks as event-linked bonds. In addition, because quota share instruments represent an interest in a basket of underlying reinsurance contracts, the Fund has limited transparency into the individual underlying contracts and therefore must rely upon the risk assessment and sound underwriting practices of the issuer. Accordingly, it may be more difficult for PIM to fully evaluate the underlying risk profile of the Fund's investment in quota share instruments and therefore place the Fund's assets at greater risk of loss than if PIM had more complete information. Quota share instruments and other 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. G. Risks At times, the Fund's investments may represent industries or industry sectors that are interrelated or have common risks, making the Fund more susceptible to any economic, political, or regulatory developments or other risks affecting those industries and sectors. The Fund's prospectus contains unaudited information regarding the Fund's principal risks. Please refer to that document when considering the Fund's principal risks. H. Futures Contracts The Fund may enter into futures transactions in order to attempt to hedge against changes in interest rates, securities prices and currency exchange rates or to seek to increase total return. Futures contracts are types of derivatives. All futures contracts entered into by the Fund are traded on a futures exchange. Upon entering into a futures contract, the Fund is required to deposit with a broker an amount of cash or securities equal to the minimum "initial margin" requirements of the associated futures exchange. The amount of cash deposited with the broker as collateral at December 31, 2015 was $5,065,450 and is included in "Restricted Cash" in 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. When the contract is closed, the Fund realizes a 92 Pioneer Bond Fund | Semiannual Report | 12/31/15 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. The use of 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. The average value of contracts open during the six months ended December 31, 2015 was $(567,911,300). At December 31, 2015, open futures contracts were as follows: -------------------------------------------------------------------------------------------------- Number of Contracts Unrealized Long/ Settlement Appreciation Type Counterparty (Short) Month Value (Depreciation) -------------------------------------------------------------------------------------------------- U.S. Long Bond (CBT) Citibank NA 449 3/16 $ 69,033,750 $ (79,608) U.S. Ultra Bond (CBT) Citibank NA 36 3/16 5,712,750 (33,500) U.S. 10 Year Note (CBT) Citibank NA (4,457) 3/16 (561,164,156) 2,206,289 U.S. 2 Year Note (CBT) Citibank NA (477) 3/16 (103,620,798) 124,348 U.S. 5 Year Note (CBT) Citibank NA 34 3/16 4,022,891 (13,698) -------------------------------------------------------------------------------------------------- Total $ (586,015,563) $ 2,203,831 ================================================================================================== I. Repurchase Agreements Repurchase agreements are arrangements under which the Fund purchases securities from a broker-dealer or a bank, called the counterparty, upon the agreement of the counterparty to repurchase the securities from the Fund at a later date, and at a specific price, which is typically higher than the purchase price paid by the Fund. The securities purchased serve as the Fund's collateral for the obligation of the counterparty to repurchase the securities. The value of the collateral, including accrued interest, is required to be equal to or in excess of the repurchase price. The collateral for all repurchase agreements is held in safekeeping in the customer-only account of the Fund's custodian or a subcustodian of the Fund. The Fund's investment adviser, PIM is responsible for determining that the value of the collateral remains at least equal to the repurchase price. In the event of a default by the counterparty, the Fund is entitled to sell the securities, but the Fund may not be able to sell them for the price at which they were purchased, thus causing a loss to the Fund. Additionally, if the counterparty becomes insolvent, there is some risk that the Fund will not have a right to the securities, or the immediate right to sell the securities. J. Credit Default Swap Agreements A credit default swap is a contract between a buyer of protection and a seller of protection against a pre-defined credit event. The Fund may sell or buy credit default swap contracts to seek to increase the Fund's income, or to attempt to hedge the risk of default on portfolio securities. A credit default swap index is used to hedge risk or take a position on a basket of credit Pioneer Bond Fund | Semiannual Report | 12/31/15 93 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. When the Fund enters into a credit default swap contract, the protection buyer makes an upfront or periodic payment to the protection seller in exchange for the right to receive a contingent payment. An upfront payment made by the Fund, as the protection buyer, is recorded as an asset in the Statement of Assets and Liabilities. Periodic payments received or paid by the Fund are recorded as realized gains or losses in the Statement of Operations. Credit default swap contracts are marked-to-market daily using valuations supplied by independent sources and the change in value, if any, is recorded as unrealized appreciation or depreciation in the Statement of Assets and Liabilities. Payments received or made as a result of a credit event or upon termination of the contract are recognized, net of the appropriate amount of the upfront payment, as realized gains or losses in the Statement of Operations. Credit default swap contracts involving the sale of protection may involve greater risks than if the Fund had invested in the referenced debt instrument directly. Credit default swap contracts are subject to general market risk, liquidity risk, counterparty risk and credit risk. If the Fund is a protection buyer and no credit event occurs, it will lose its investment. If the Fund is a protection seller and a credit event occurs, the value of the referenced debt instrument received by the Fund, together with the periodic payments received, may be less than the amount the Fund pays to the protection buyer, resulting in a loss to the Fund. Certain swap contracts that are cleared through a central clearinghouse are referred to as centrally cleared swaps. All payments made or received by the Fund are pursuant to a centrally cleared swap contract with the central clearing party rather than the original counterparty. Upon entering into a centrally cleared swap contract, the Fund is required to make an initial 94 Pioneer Bond Fund | Semiannual Report | 12/31/15 margin deposit, either in cash or in securities. The daily change in value on open centrally cleared contracts is recorded as variation margin on centrally cleared swaps on the Statement of Assets and Liabilities. There were no open credit default swap contracts as of December 31, 2015. The average value of swap contracts open during the six months ended December 31, 2015 was $95,639. 2. Management Agreement PIM, a wholly owned indirect subsidiary of UniCredit, manages the Fund's portfolio. Management fees are calculated daily at the annual rate of 0.40% of the Fund's average daily net assets. Prior to July 1, 2014, the annual fee paid by the fund was 0.50% of the fund's average daily net assets up to $1 billion, 0.45% of the fund's average daily net assets between $1 billion and $2 billion, and 0.40% of the fund's average daily net assets over $2 billion. For the six months ended December 31, 2015, the effective management fee (excluding waivers and/or assumption of expenses) was equal to 0.40% of the Fund's average daily net assets. PIM has contractually agreed to limit ordinary operating expenses to the extent required to reduce Fund expenses to 0.85%, 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 six months ended December 31, 2015 are reflected on the Statement of Operations. These expense limitations are in effect through November 1, 2017. There can be no assurance that PIM will extend the expense limitation agreement for a class of shares beyond the dates referred to above. In addition, under the management and administration agreements, certain other services and costs, including accounting, regulatory reporting, and insurance premiums, are paid by the Fund as administrative reimbursements. Included in "Due to affiliates" reflected on the Statement of Assets and Liabilities is $65,856 in management fees, administrative costs and certain other reimbursements payable to PIM at December 31, 2015. 3. Transfer Agent Prior to November 2, 2015, Pioneer Investment Management Shareholder Services, Inc. (PIMSS), a wholly owned indirect subsidiary of UniCredit, provided substantially all transfer agent and shareowner services to the Fund at negotiated rates. Effective November 2, 2015, Boston Financial Data services serves as the transfer agent to the fund at negotiated rates. Pioneer Bond Fund | Semiannual Report | 12/31/15 95 In addition, the Fund reimbursed the transfer agent for out-of-pocket expenses incurred by the transfer agent related to shareholder communications activities such as proxy and statement mailings, outgoing phone calls and omnibus relationship contracts. For the six months ended December 31, 2015, such out- of-pocket expenses by class of shares were as follows: -------------------------------------------------------------------------------- Shareholder Communications: -------------------------------------------------------------------------------- Class A $1,108,347 Class C 56,665 Class K 160 Class R 122,267 Class Y 958,746 Class Z 7,025 -------------------------------------------------------------------------------- Total $2,253,210 ================================================================================ Included in "Due to affiliates" reflected on the Statement of Assets and Liabilities is $300,249 in transfer agent fees and out-of-pocket reimbursements payable to the transfer agent at December 31, 2015. 4. Distribution and Service Plans The Fund has adopted a Distribution Plan pursuant to Rule 12b-1 of the Investment Company Act of 1940 with respect to its Class A, Class C and Class R shares. Pursuant to the Plan, the Fund pays PFD 0.25% of the average daily net assets attributable to Class A shares as compensation for personal services and/or account maintenance services or distribution services with regard to Class A shares. Pursuant to the Plan, the Fund also pays PFD 1.00% of the average daily net assets attributable to Class C shares. The fee for Class C shares consists of a 0.25% service fee and a 0.75% distribution fee paid as compensation for personal services and/or account maintenance services or distribution services with regard to Class C shares. Pursuant to the Plan, the Fund further pays PFD 0.50% of the average daily net assets attributable to Class R shares for distribution services. Included in "Due to affiliates" reflected on the Statement of Assets and Liabilities is $24,155 in distribution fees payable to PFD at December 31, 2015. The Fund also has adopted a separate service plan for Class R shares (Service Plan). The Service Plan authorizes the Fund to pay securities dealers, plan administrators or other service organizations that agree to provide certain services to retirement plans or plan participants holding shares of the Fund a service fee of up to 0.25% of the Fund's average daily net assets attributable to Class R shares held by such plans. In addition, redemptions of each class of shares (except Class K, Class R and Class Y shares) may be subject to a contingent deferred sales charge (CDSC). A CDSC of 1.00% may be imposed on redemptions of certain net asset value purchases of Class A shares within 12 months of purchase. Redemptions of 96 Pioneer Bond Fund | Semiannual Report | 12/31/15 Class C shares within 12 months of purchase are subject to a CDSC of 1.00%, based on the lower of cost or market value of shares being redeemed. Shares purchased as part of an exchange remain subject to any CDSC that applied to the original purchase of those shares. There is no CDSC for Class R or Class Y shares. Proceeds from the CDSC are paid to PFD. For the six months ended December 31, 2015, CDSC in the amount of $13,322 were paid to PFD. 5. Expense Offset Arrangements The Fund entered into certain expense offset arrangements with PIMSS. For the six months ended December 31, 2015, the Fund's expenses were not reduced under such arrangements. 6. Line of Credit Facility The Fund, along with certain other funds in the Pioneer Family of Funds (the Funds), participates in a committed, unsecured revolving line of credit facility. Borrowings are used solely for temporary or emergency purposes. The Fund may borrow up to the lesser of the amount available under the facility or the limits set for borrowing by the Fund's prospectus and the 1940 Act. The credit facility in effect until June 9, 2015 was in the amount of $215 million. As of June 9, 2015, the facility is in the amount of $240 million. Under such facility, depending on the type of loan, interest on borrowings is payable at the London Interbank Offered Rate (LIBOR) plus 0.85% on an annualized basis, or the alternate base rate, which is the greater of (a) the facility's administrative agent's daily announced prime rate on the borrowing date, (b) 2% plus the federal funds rate on the borrowing date and (c) 2% plus the overnight eurodollar rate on the borrowing date. The Funds pay an annual commitment fee to participate in the credit facility. The commitment fee is allocated among participating Funds based on an allocation schedule set forth in the credit agreement. During the six months ended December 31, 2015, the Fund had no borrowings under the credit agreement. 7. Additional Disclosures about Derivative Instruments and Hedging Activities: The Fund's use of derivatives subjects it to the following risks: Interest rate risk relates to the fluctuations in the value of interest-bearing securities due to changes in the prevailing levels of market interest rates. Credit risk relates to the ability of the issuer of a financial instrument to make further principal or interest payments on an obligation or commitment that it has to the Fund. Foreign exchange rate risk relates to fluctuations in the value of an asset or liability due to changes in currency exchange rates. Pioneer Bond Fund | Semiannual Report | 12/31/15 97 Equity risk relates to the fluctuations in the value of financial instruments as a result of changes in market prices (other than those arising from interest rate risk or foreign exchange risk), whether caused by factors specific to an individual investment, its issuer, or all factors affecting all instruments traded in a market or market segment. Commodity risk relates to the risk that the value of a commodity or commodity index will fluctuate based on increases or decreases in the commodities market and factors specific to a particular industry or commodity. The fair value of open derivative instruments (not considered to be hedging instruments for accounting disclosure purposes) by risk exposure at December 31, 2015 was as follows: ---------------------------------------------------------------------------------- Foreign Statement of Assets Interest Exchange Equity Commodity and Liabilities Rate Risk Credit Risk Rate Risk Risk Risk ---------------------------------------------------------------------------------- Assets Net unrealized appreciation on futures contracts $ 2,203,831 $ -- $ -- $ -- $ -- ---------------------------------------------------------------------------------- Total Value $ 2,203,831 $ -- $ -- $ -- $ -- ---------------------------------------------------------------------------------- The effect of derivative instruments (not considered to be hedging instruments for accounting disclosure purposes) on the Statement of Operations by risk exposure at December 31, 2015 was as follows: ---------------------------------------------------------------------------------- Foreign Statement of Interest Credit Exchange Equity Commodity Operations Rate Risk Risk Rate Risk Risk Risk ---------------------------------------------------------------------------------- Net realized gain (loss): Futures contracts $ (320,340) $ -- $ -- $ -- $ -- Swap contracts -- 183 -- -- -- ---------------------------------------------------------------------------------- Total Value $ (320,340) $ 183 $ -- $ -- $ -- ================================================================================== Change in net unrealized appreciation (depreciation) on Futures contracts $(2,624,825) $ -- $ -- $ -- $ -- Swap contracts -- (34,098) -- -- -- ---------------------------------------------------------------------------------- Total Value $(2,624,825) $(34,098) $ -- $ -- $ -- ================================================================================== 8. Bridge Loan Commitments Bridge loans are designed to provide temporary or "bridge" financing to a borrower pending the sale of identified assets or the arrangement of longer term loans or the issuance and sale of debt obligations. 98 Pioneer Bond Fund | Semiannual Report | 12/31/15 As of December 31, 2015, the Fund had one bridge loan commitment of $3,685,000, which could be extended at the option of the borrower, pursuant to the following loan agreement: ---------------------------------------------------------------------------------- Unrealized Loan Principal Cost Value Appreciation ---------------------------------------------------------------------------------- Charter Communications Operating Co., Bridge Loan 3,685,000 $3,685,000 $3,685,000 $ -- ---------------------------------------------------------------------------------- Total 3,685,000 $3,685,000 $3,685,000 $ -- ================================================================================== 9. Conversion of Class Z Shares As of the close of business on August 7, 2015 (the "Conversion Date"), all outstanding Class Z shares of the Fund were converted to Class Y shares. Pioneer Bond Fund | Semiannual Report | 12/31/15 99 ADDITIONAL INFORMATION Pioneer Investment Management, Inc. (the "Adviser"), each fund's investment adviser, is currently an indirect, wholly owned subsidiary of UniCredit S.p.A. ("UniCredit"). On November 11, 2015, UniCredit announced that it signed a binding master agreement with Banco Santander and affiliates of Warburg Pincus and General Atlantic (the "Private Equity Firms") with respect to Pioneer Investments ("Pioneer") and Santander Asset Management ("SAM") (the "Transaction"). The Transaction, as previously announced by UniCredit, will establish a holding company, with the name Pioneer Investments, to be owned by UniCredit (50%) and the Private Equity Firms (50% between them). The holding company will control Pioneer's U.S. operations, including PIM. The holding company also will own 66.7% of Pioneer's and SAM's combined operations outside the U.S., while Banco Santander will own directly the remaining 33.3% stake. The closing of the Transaction is expected to happen in 2016, subject to certain regulatory and other approvals. Under the Investment Company Act of 1940, completion of the Transaction will cause each fund's current investment advisory agreement with PIM to terminate. Accordingly, each fund's Board of Trustees will be asked to approve a new investment advisory agreement. If approved by the Board, each fund's new investment advisory agreement will be submitted to the shareholders of the fund for their approval. 100 Pioneer Bond Fund | Semiannual Report | 12/31/15 Approval of Investment Advisory Agreement Pioneer Investment Management, Inc. (PIM) serves as the investment adviser to Pioneer Bond Fund (the Fund) pursuant to an investment advisory agreement between PIM and the Fund. In order for PIM to remain the investment adviser of the Fund, the Trustees of the Fund must determine annually whether to renew the investment advisory agreement for the Fund. The contract review process began in January 2015 as the Trustees of the Fund agreed on, among other things, an overall approach and timeline for the process. Contract review materials were provided to the Trustees in March 2015 and July 2015. Supplemental contract review materials were provided to the Trustees in September 2015. In addition, the Trustees reviewed and discussed the Fund's performance at regularly scheduled meetings throughout the year, and took into account other information related to the Fund provided to the Trustees at regularly scheduled meetings, in connection with the review of the Fund's investment advisory agreement. In March 2015, the Trustees, among other things, discussed the memorandum provided by Fund counsel that summarized the legal standards and other considerations that are relevant to the Trustees in their deliberations regarding the renewal of the investment advisory agreement, and reviewed and discussed the qualifications of the investment management teams, as well as the level of investment by the Fund's portfolio managers in the Fund. In July 2015, the Trustees, among other things, reviewed the Fund's management fee and total expense ratios, the financial statements of PIM and its parent companies, the profitability analyses provided by PIM, and possible economies of scale. The Trustees also reviewed the profitability of the institutional business of PIM and PIM's affiliate, Pioneer Institutional Asset Management, Inc. (together with PIM, "Pioneer"), as compared to that of PIM's fund management business, and considered the differences between the fees and expenses of the Fund and the fees and expenses of Pioneer's institutional accounts, as well as the different services provided by PIM to the Fund and by Pioneer to the institutional accounts. The Trustees further considered contract review materials in September 2015. At a meeting held on September 15, 2015, based on their evaluation of the information provided by PIM and third parties, the Trustees of the Fund, including the Independent Trustees voting separately, unanimously approved the renewal of the investment advisory agreement for another year. In approving the renewal of the investment advisory agreement, the Trustees considered various factors that they determined were relevant, including the factors described below. The Trustees did not identify any single factor as the controlling factor in determining to approve the renewal of the agreement. Pioneer Bond Fund | Semiannual Report | 12/31/15 101 Nature, Extent and Quality of Services The Trustees considered the nature, extent and quality of the services that had been provided by PIM to the Fund, taking into account the investment objective and strategy of the Fund. The Trustees also reviewed PIM's investment approach for the Fund and its research process. The Trustees considered the resources of PIM and the personnel of PIM who provide investment management services to the Fund. They also reviewed the amount of non-Fund assets managed by the portfolio managers of the Fund. The Trustees considered the non-investment resources and personnel of PIM involved in PIM's services to the Fund, including PIM's compliance and legal resources and personnel. The Trustees noted the substantial attention and high priority given by PIM's senior management to the Pioneer fund complex. The Trustees considered that PIM supervises and monitors the performance of the Fund's service providers and provides the Fund with personnel (including Fund officers) and other resources that are necessary for the Fund's business management and operations. The Trustees also considered that, as administrator, PIM is responsible for the administration of the Fund's business and other affairs. The Trustees considered the fees paid to PIM for the provision of administration services. Based on these considerations, the Trustees concluded that the nature, extent and quality of services that had been provided by PIM to the Fund were satisfactory and consistent with the terms of the investment advisory agreement. Performance of the Fund In considering the Fund's performance, the Trustees regularly review and discuss throughout the year data prepared by PIM and information comparing the Fund's performance with the performance of its peer group of funds as classified by each of Morningstar, Inc. (Morningstar) and Lipper, and with the performance of the Fund's benchmark index. They also discuss the Fund's performance with PIM on a regular basis. The Trustees' regular reviews and discussions were factored into the Trustees' deliberations concerning the renewal of the advisory agreement. Management Fee and Expenses The Trustees considered information showing the fees and expenses of the Fund in comparison to the management fees and expense ratios of its peer group of funds as classified by Morningstar and also to the expense ratios of a peer group of funds selected on the basis of criteria determined by the Independent Trustees for this purpose using data provided by Strategic Insight Mutual Fund Research and Consulting, LLC (Strategic Insight), an independent third party. In all quintile rankings referred to below, first quintile is most favorable to the Fund's shareowners. 102 Pioneer Bond Fund | Semiannual Report | 12/31/15 The Trustees considered that the Fund's management fee for the most recent fiscal year was in the third quintile relative to the management fees paid by other funds in its Morningstar peer group for the comparable period. The Trustees also considered the breakpoints in the management fee schedule and the reduced fee rates above certain asset levels. The Trustees considered that the expense ratio of the Fund's Class A shares for the most recent fiscal year was in the third quintile relative to its Morningstar peer group and in the third quintile relative its Strategic Insight peer group, in each case for the comparable period. The Trustees considered that the expense ratio of the Fund's Class Y shares for the most recent fiscal year was in the third quintile relative to its Morningstar peer group and in the third quintile relative its Strategic Insight peer group, in each case for the comparable period. The Trustees noted that PIM was waiving fees and/or reimbursing expenses in order to limit the ordinary operating expenses of the Fund. The Trustees considered the impact of transfer agency, sub-transfer agency, and other non-management fee expenses on the expense ratios of the Fund. The Trustees noted that they separately review the Fund's transfer agency, sub-transfer agency and intermediary arrangements. The Trustees reviewed management fees charged by Pioneer to institutional and other clients, including publicly offered European funds sponsored by affiliates of Pioneer, unaffiliated U.S. registered investment companies (in a sub-advisory capacity), and unaffiliated foreign and domestic separate accounts. The Trustees also considered PIM's costs in providing services to the Fund and Pioneer's costs in providing services to the other clients and considered the differences in management fees and profit margins for Fund and non-Fund services. In evaluating the fees associated with Pioneer's client accounts, the Trustees took into account the respective demands, resources and complexity associated with the Fund and client accounts. The Trustees noted that, in some instances, the fee rates for those clients were lower than the management fee for the Fund and considered that, under the investment advisory agreement with the Fund, PIM performs additional services for the Fund that it does not provide to those other clients or services that are broader in scope, including oversight of the Fund's other service providers and activities related to compliance and the extensive regulatory and tax regimes to which the Fund is subject. The Trustees also considered the different entrepreneurial risks associated with PIM's management of the Fund and Pioneer's management of the other client accounts. The Trustees concluded that the management fee payable by the Fund to PIM was reasonable in relation to the nature and quality of the services provided by PIM to the Fund. Pioneer Bond Fund | Semiannual Report | 12/31/15 103 Profitability The Trustees considered information provided by PIM regarding the profitability of PIM with respect to the advisory services provided by PIM to the Fund, including the methodology used by PIM in allocating certain of its costs to the management of the Fund. The Trustees also considered PIM's profit margin in connection with the overall operation of the Fund. They further reviewed the financial results realized by PIM and its affiliates from non-fund businesses. The Trustees considered PIM's profit margins with respect to the Fund in comparison to the limited industry data available and noted that the profitability of any adviser was affected by numerous factors, including its organizational structure and method for allocating expenses. The Trustees concluded that PIM's profitability with respect to the management of the Fund was not unreasonable. Economies of Scale The Trustees considered PIM's views relating to economies of scale in connection with the Pioneer Funds as fund assets grow and the extent to which any such economies of scale are shared with funds and fund shareholders. The Trustees noted the breakpoints in the management fee schedule. The Trustees recognize that economies of scale are difficult to identify and quantify, and that, among other factors that may be relevant, are the following: fee levels, expense subsidization, investment by PIM in research and analytical capabilities and PIM's commitment and resource allocation to the Fund. The Trustees noted that profitability also may be an indicator of the availability of any economies of scale, although profitability may vary for other reasons including reductions in expenses. The Trustees concluded that economies of scale, if any, were being appropriately shared with the Funds. Other Benefits The Trustees considered the other benefits to PIM from its relationship with the Fund. The Trustees considered the character and amount of fees paid by the Fund, other than under the investment advisory agreement, for services provided by PIM and its affiliates. The Trustees further considered the revenues and profitability of PIM's businesses other than the fund business. Pioneer is the principal U.S. asset management business of Pioneer Global Asset Management, the worldwide asset management business of UniCredit Group, which manages over $150 billion in assets (including the Funds). Pioneer and the Funds receive reciprocal intangible benefits from the relationship, including mutual brand recognition and, for the Funds, direct and indirect access to the resources of a large global asset manager. The Trustees concluded that any such benefits received by Pioneer as a result of its relationship with the Funds were reasonable and their consideration of the advisory agreement between the Fund and PIM and the fees thereunder were unaffected by Pioneer's possible receipt of any such intangible benefits. 104 Pioneer Bond Fund | Semiannual Report | 12/31/15 Conclusion After consideration of the factors described above as well as other factors, the Trustees, including all of the Independent Trustees, concluded that the investment advisory agreement between PIM and the Fund, including the fees payable thereunder, was fair and reasonable and voted to approve the proposed renewal of the investment advisory agreement for the Fund. Pioneer Bond Fund | Semiannual Report | 12/31/15 105 Trustees, Officers and Service Providers Trustees Advisory Trustee Thomas J. Perna, Chairman Lorraine H. Monchak* David R. Bock Benjamin M. Friedman Officers Margaret B.W. Graham Lisa M. Jones, President and Chief Marguerite A. Piret Executive Officer Fred J. Ricciardi Mark E. Bradley, Treasurer and Kenneth J. Taubes Chief Financial Officer Christopher J. Kelley, Secretary and Chief Legal Officer Investment Adviser and Administrator Pioneer Investment Management, Inc. Custodian and Sub-Administrator Brown Brothers Harriman & Co. Principal Underwriter Pioneer Funds Distributor, Inc. Legal Counsel Morgan, Lewis & Bockius LLP Shareowner Services and Transfer Agent Boston Financial Data Services, Inc. Proxy Voting Policies and Procedures of the Fund are available without charge, upon request, by calling our toll free number (1-800-225-6292). Information regarding how the Fund voted proxies relating to portfolio securities during the most recent 12-month period ended June 30 is publicly available to shareowners at us.pioneerinvestments.com. This information is also available on the Securities and Exchange Commission's web site at www.sec.gov. * Ms. Monchak is a non-voting Advisory Trustee. 106 Pioneer Bond Fund | Semiannual Report | 12/31/15 This page for your notes. Pioneer Bond Fund | Semiannual Report | 12/31/15 107 This page for your notes. 108 Pioneer Bond Fund | Semiannual Report | 12/31/15 How to Contact Pioneer We are pleased to offer a variety of convenient ways for you to contact us for assistance or information. Call us for: -------------------------------------------------------------------------------- Account Information, including existing accounts, new accounts, prospectuses, applications and service forms 1-800-225-6292 FactFone(SM) for automated fund yields, prices, account information and transactions 1-800-225-4321 Retirement plans information 1-800-622-0176 Write to us: -------------------------------------------------------------------------------- Pioneer Funds P.O. Box 55014 Boston, Massachusetts 02205-5014 Our toll-free fax 1-800-225-4240 Our internet e-mail address ask.pioneer@pioneerinvestments.com (for general questions about Pioneer only) Visit our web site: us.pioneerinvestments.com This report must be preceded or accompanied by a prospectus. The Fund files a complete schedule of investments with the Securities and Exchange Commission for the first and third quarters for each fiscal year on Form N-Q. Shareholders may view the filed Form N-Q by visiting the Commission's web site at http://www.sec.gov. The filed form may also be viewed and copied at the Commission's Public Reference Room in Washington, DC. Information regarding the operations of the Public Reference Room may be obtained by calling 1-800-SEC-0330. [LOGO] PIONEER Investments(R) Pioneer Investment Management, Inc. 60 State Street Boston, MA 02109 us.pioneerinvestments.com Securities offered through Pioneer Funds Distributor, Inc. 60 State Street, Boston, MA 02109 Underwriter of Pioneer Mutual Funds, Member SIPC (C) 2016 Pioneer Investments 18633-10-0216 ITEM 2. CODE OF ETHICS. (a) Disclose whether, as of the end of the period covered by the report, the registrant has adopted a code of ethics that applies to the registrant's principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions, regardless of whether these individuals are employed by the registrant or a third party. If the registrant has not adopted such a code of ethics, explain why it has not done so. The registrant has adopted, as of the end of the period covered by this report, a code of ethics that applies to the registrant's principal executive officer, principal financial officer, principal accounting officer and controller. (b) For purposes of this Item, the term "code of ethics" means written standards that are reasonably designed to deter wrongdoing and to promote: (1) Honest and ethical conduct, including the ethical handling of actual or apparent conflicts of interest between personal and professional relationships; (2) Full, fair, accurate, timely, and understandable disclosure in reports and documents that a registrant files with, or submits to, the Commission and in other public communications made by the registrant; (3) Compliance with applicable governmental laws, rules, and regulations; (4) The prompt internal reporting of violations of the code to an appropriate person or persons identified in the code; and (5) Accountability for adherence to the code. (c) The registrant must briefly describe the nature of any amendment, during the period covered by the report, to a provision of its code of ethics that applies to the registrant's principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions, regardless of whether these individuals are employed by the registrant or a third party, and that relates to any element of the code of ethics definition enumerated in paragraph (b) of this Item. The registrant must file a copy of any such amendment as an exhibit pursuant to Item 10(a), unless the registrant has elected to satisfy paragraph (f) of this Item by posting its code of ethics on its website pursuant to paragraph (f)(2) of this Item, or by undertaking to provide its code of ethics to any person without charge, upon request, pursuant to paragraph (f)(3) of this Item. The registrant has made no amendments to the code of ethics during the period covered by this report. (d) If the registrant has, during the period covered by the report, granted a waiver, including an implicit waiver, from a provision of the code of ethics to the registrant's principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions, regardless of whether these individuals are employed by the registrant or a third party, that relates to one or more of the items set forth in paragraph (b) of this Item, the registrant must briefly describe the nature of the waiver, the name of the person to whom the waiver was granted, and the date of the waiver. Not applicable. (e) If the registrant intends to satisfy the disclosure requirement under paragraph (c) or (d) of this Item regarding an amendment to, or a waiver from, a provision of its code of ethics that applies to the registrant's principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions and that relates to any element of the code of ethics definition enumerated in paragraph (b) of this Item by posting such information on its Internet website, disclose the registrant's Internet address and such intention. Not applicable. (f) The registrant must: (1) File with the Commission, pursuant to Item 12(a)(1), a copy of its code of ethics that applies to the registrant's principal executive officer,principal financial officer, principal accounting officer or controller, or persons performing similar functions, as an exhibit to its annual report on this Form N-CSR (see attachment); (2) Post the text of such code of ethics on its Internet website and disclose, in its most recent report on this Form N-CSR, its Internet address and the fact that it has posted such code of ethics on its Internet website; or (3) Undertake in its most recent report on this Form N-CSR to provide to any person without charge, upon request, a copy of such code of ethics and explain the manner in which such request may be made. 	See Item 10(2) ITEM 3. AUDIT COMMITTEE FINANCIAL EXPERT. (a) (1) Disclose that the registrant's board of trustees has determined that the registrant either: (i) Has at least one audit committee financial expert serving on its audit committee; or (ii) Does not have an audit committee financial expert serving on its audit committee. The registrant's Board of Trustees has determined that the registrant has at least one audit committee financial expert. (2) If the registrant provides the disclosure required by paragraph (a)(1)(i) of this Item, it must disclose the name of the audit committee financial expert and whether that person is "independent." In order to be considered "independent" for purposes of this Item, a member of an audit committee may not, other than in his or her capacity as a member of the audit committee, the board of trustees, or any other board committee: (i) Accept directly or indirectly any consulting, advisory, or other compensatory fee from the issuer; or (ii) Be an "interested person" of the investment company as defined in Section 2(a)(19) of the Act (15 U.S.C. 80a-2(a)(19)). Ms. Marguerite A. Piret, an independent trustee, is such an audit committee financial expert. (3) If the registrant provides the disclosure required by paragraph (a)(1) (ii) of this Item, it must explain why it does not have an audit committee financial expert. Not applicable. ITEM 4. PRINCIPAL ACCOUNTANT FEES AND SERVICES. (a) Disclose, under the caption AUDIT FEES, the aggregate fees billed for each of the last two fiscal years for professional services rendered by the principal accountant for the audit of the registrant's annual financial statements or services that are normally provided by the accountant in connection with statutory and regulatory filings or engagements for those fiscal years. N/A (b) Disclose, under the caption AUDIT-RELATED FEES, the aggregate fees billed in each of the last two fiscal years for assurance and related services by the principal accountant that are reasonably related to the performance of the audit of the registrant's financial statements and are not reported under paragraph (a) of this Item. Registrants shall describe the nature of the services comprising the fees disclosed under this category. N/A (c) Disclose, under the caption TAX FEES, the aggregate fees billed in each of the last two fiscal years for professional services rendered by the principal accountant for tax compliance, tax advice, and tax planning. Registrants shall describe the nature of the services comprising the fees disclosed under this category. N/A (d) Disclose, under the caption ALL OTHER FEES, the aggregate fees billed in each of the last two fiscal years for products and services provided by the principal accountant, other than the services reported in paragraphs (a) through (c) of this Item. Registrants shall describe the nature of the services comprising the fees disclosed under this category. N/A (e) (1) Disclose the audit committee's pre-approval policies and procedures described in paragraph (c)(7) of Rule 2-01 of Regulation S-X. PIONEER FUNDS APPROVAL OF AUDIT, AUDIT-RELATED, TAX AND OTHER SERVICES PROVIDED BY THE INDEPENDENT AUDITOR SECTION I - POLICY PURPOSE AND APPLICABILITY The Pioneer Funds recognize the importance of maintaining the independence of their outside auditors. Maintaining independence is a shared responsibility involving Pioneer Investment Management, Inc ("PIM"), the audit committee and the independent auditors. The Funds recognize that a Fund's independent auditors: 1) possess knowledge of the Funds, 2) are able to incorporate certain services into the scope of the audit, thereby avoiding redundant work, cost and disruption of Fund personnel and processes, and 3) have expertise that has value to the Funds. As a result, there are situations where it is desirable to use the Fund's independent auditors for services in addition to the annual audit and where the potential for conflicts of interests are minimal. Consequently, this policy, which is intended to comply with Rule 210.2-01(C)(7), sets forth guidelines and procedures to be followed by the Funds when retaining the independent audit firm to perform audit, audit-related tax and other services under those circumstances, while also maintaining independence. Approval of a service in accordance with this policy for a Fund shall also constitute approval for any other Fund whose pre-approval is required pursuant to Rule 210.2-01(c)(7)(ii). In addition to the procedures set forth in this policy, any non-audit services that may be provided consistently with Rule 210.2-01 may be approved by the Audit Committee itself and any pre-approval that may be waived in accordance with Rule 210.2-01(c)(7)(i)(C) is hereby waived. Selection of a Fund's independent auditors and their compensation shall be determined by the Audit Committee and shall not be subject to this policy. SECTION II - POLICY ---------------- -------------------------------- ------------------------------------------------- SERVICE SERVICE CATEGORY DESCRIPTION SPECIFIC PRE-APPROVED SERVICE SUBCATEGORIES CATEGORY ---------------- -------------------------------- ------------------------------------------------- I. AUDIT Services that are directly o Accounting research assistance SERVICES related to performing the o SEC consultation, registration independent audit of the Funds statements, and reporting o Tax accrual related matters o Implementation of new accounting standards o Compliance letters (e.g. rating agency letters) o Regulatory reviews and assistance regarding financial matters o Semi-annual reviews (if requested) o Comfort letters for closed end offerings ---------------- -------------------------------- ------------------------------------------------- II. Services which are not o AICPA attest and agreed-upon procedures AUDIT-RELATED prohibited under Rule o Technology control assessments SERVICES 210.2-01(C)(4) (the "Rule") o Financial reporting control assessments and are related extensions of o Enterprise security architecture the audit services support the assessment audit, or use the knowledge/expertise gained from the audit procedures as a foundation to complete the project. In most cases, if the Audit-Related Services are not performed by the Audit firm, the scope of the Audit Services would likely increase. The Services are typically well-defined and governed by accounting professional standards (AICPA, SEC, etc.) ---------------- -------------------------------- ------------------------------------------------- ------------------------------------- ------------------------------------ AUDIT COMMITTEE APPROVAL POLICY AUDIT COMMITTEE REPORTING POLICY ------------------------------------- ------------------------------------ o "One-time" pre-approval o A summary of all such for the audit period for all services and related fees pre-approved specific service reported at each regularly subcategories. Approval of the scheduled Audit Committee independent auditors as meeting. auditors for a Fund shall constitute pre approval for these services. ------------------------------------- ------------------------------------ o "One-time" pre-approval o A summary of all such for the fund fiscal year within services and related fees a specified dollar limit (including comparison to for all pre-approved specified dollar limits) specific service subcategories reported quarterly. o Specific approval is needed to exceed the pre-approved dollar limit for these services (see general Audit Committee approval policy below for details on obtaining specific approvals) o Specific approval is needed to use the Fund's auditors for Audit-Related Services not denoted as "pre-approved", or to add a specific service subcategory as "pre-approved" ------------------------------------- ------------------------------------ SECTION III - POLICY DETAIL, CONTINUED ----------------------- --------------------------- ----------------------------------------------- SERVICE CATEGORY SERVICE CATEGORY SPECIFIC PRE-APPROVED SERVICE SUBCATEGORIES DESCRIPTION ----------------------- --------------------------- ----------------------------------------------- III. TAX SERVICES Services which are not o Tax planning and support prohibited by the Rule, o Tax controversy assistance if an officer of the Fund o Tax compliance, tax returns, excise determines that using the tax returns and support Fund's auditor to provide o Tax opinions these services creates significant synergy in the form of efficiency, minimized disruption, or the ability to maintain a desired level of confidentiality. ----------------------- --------------------------- ----------------------------------------------- ------------------------------------- ------------------------- AUDIT COMMITTEE APPROVAL POLICY AUDIT COMMITTEE REPORTING POLICY ------------------------------------- ------------------------- ------------------------------------- ------------------------- o "One-time" pre-approval o A summary of for the fund fiscal year all such services and within a specified dollar limit related fees 				 (including comparison 			 to specified dollar 			 limits) reported 			 quarterly. o Specific approval is needed to exceed the pre-approved dollar limits for these services (see general Audit Committee approval policy below for details on obtaining specific approvals) o Specific approval is needed to use the Fund's auditors for tax services not denoted as pre-approved, or to add a specific service subcategory as "pre-approved" ------------------------------------- ------------------------- SECTION III - POLICY DETAIL, CONTINUED ----------------------- --------------------------- ----------------------------------------------- SERVICE CATEGORY SERVICE CATEGORY SPECIFIC PRE-APPROVED SERVICE SUBCATEGORIES DESCRIPTION ----------------------- --------------------------- ----------------------------------------------- IV. OTHER SERVICES Services which are not o Business Risk Management support prohibited by the Rule, o Other control and regulatory A. SYNERGISTIC, if an officer of the Fund compliance projects UNIQUE QUALIFICATIONS determines that using the Fund's auditor to provide these services creates significant synergy in the form of efficiency, minimized disruption, the ability to maintain a desired level of confidentiality, or where the Fund's auditors posses unique or superior qualifications to provide these services, resulting in superior value and results for the Fund. ----------------------- --------------------------- ----------------------------------------------- --------------------------------------- ------------------------ AUDIT COMMITTEE APPROVAL POLICY AUDIT COMMITTEE REPORTING POLICY ------------------------------------- -------------------------- o "One-time" pre-approval o A summary of for the fund fiscal year within all such services and a specified dollar limit related fees 			 (including comparison 			 to specified dollar 				 limits) reported quarterly. o Specific approval is needed to exceed the pre-approved dollar limits for these services (see general Audit Committee approval policy below for details on obtaining specific approvals) o Specific approval is needed to use the Fund's auditors for "Synergistic" or "Unique Qualifications" Other Services not denoted as pre-approved to the left, or to add a specific service subcategory as "pre-approved" ------------------------------------- -------------------------- SECTION III - POLICY DETAIL, CONTINUED ----------------------- ------------------------- ----------------------------------------------- SERVICE CATEGORY SERVICE CATEGORY SPECIFIC PROHIBITED SERVICE SUBCATEGORIES DESCRIPTION ----------------------- ------------------------- ----------------------------------------------- PROHIBITED SERVICES Services which result 1. Bookkeeping or other services in the auditors losing related to the accounting records or independence status financial statements of the audit under the Rule. client* 2. Financial information systems design and implementation* 3. Appraisal or valuation services, fairness* opinions, or contribution-in-kind reports 4. Actuarial services (i.e., setting actuarial reserves versus actuarial audit work)* 5. Internal audit outsourcing services* 6. Management functions or human resources 7. Broker or dealer, investment advisor, or investment banking services 8. Legal services and expert services unrelated to the audit 9. Any other service that the Public Company Accounting Oversight Board determines, by regulation, is impermissible ----------------------- ------------------------- ----------------------------------------------- ------------------------------------------- ------------------------------ AUDIT COMMITTEE APPROVAL POLICY AUDIT COMMITTEE REPORTING POLICY ------------------------------------------- ------------------------------ o These services are not to be o A summary of all performed with the exception of the(*) services and related services that may be permitted fees reported at each if they would not be subject to audit regularly scheduled procedures at the audit client (as Audit Committee meeting defined in rule 2-01(f)(4)) level will serve as continual the firm providing the service. confirmation that has 				 not provided any restricted services. ------------------------------------------- ------------------------------ -------------------------------------------------------------------------------- GENERAL AUDIT COMMITTEE APPROVAL POLICY: o For all projects, the officers of the Funds and the Fund's auditors will each make an assessment to determine that any proposed projects will not impair independence. o Potential services will be classified into the four non-restricted service categories and the "Approval of Audit, Audit-Related, Tax and Other Services" Policy above will be applied. Any services outside the specific pre-approved service subcategories set forth above must be specifically approved by the Audit Committee. o At least quarterly, the Audit Committee shall review a report summarizing the services by service category, including fees, provided by the Audit firm as set forth in the above policy. -------------------------------------------------------------------------------- (2) Disclose the percentage of services described in each of paragraphs (b) through (d) of this Item that were approved by the audit committee pursuant to paragraph (c)(7)(i)(C) of Rule 2-01 of Regulation S-X. N/A (f) If greater than 50 percent, disclose the percentage of hours expended on the principal accountants engagement to audit the registrant's financial statements for the most recent fiscal year that were attributed to work performed by persons other than the principal accountant's full-time, permanent employees. N/A (g) Disclose the aggregate non-audit fees billed by the registrants accountant for services rendered to the registrant, and rendered to the registrants investment adviser (not including any sub-adviser whose role is primarily portfolio management and is subcontracted with or overseen by another investment adviser), and any entity controlling, controlled by, or under common control with the adviser that provides ongoing services to the registrant for each of the last two fiscal years of the registrant. N/A (h) Disclose whether the registrants audit committee of the board of trustees has considered whether the provision of non-audit services that were rendered to the registrants investment adviser (not including any subadviser whose role is primarily portfolio management and is subcontracted with or overseen by another investment adviser), and any entity controlling, controlled by, or under common control with the investment adviser that provides ongoing services to the registrant that were not pre-approved pursuant to paragraph (c)(7)(ii) of Rule 2-01 of Regulation S-X is compatible with maintaining the principal accountant's independence. The Fund's audit committee of the Board of Trustees has considered whether the provision of non-audit services that were rendered to the Affiliates (as defined) that were not pre- approved pursuant to paragraph (c)(7)(ii) of Rule 2-01 of Regulation S-X is compatible with maintaining the principal accountant's independence. ITEM 5. AUDIT COMMITTEE OF LISTED REGISTRANTS (a) If the registrant is a listed issuer as defined in Rule 10A-3 under the Exchange Act (17 CFR 240.10A-3), state whether or not the registrant has a separately-designated standing audit committee established in accordance with Section 3(a)(58)(A) of the Exchange Act (15 U.S.C. 78c(a)(58)(A)). If the registrant has such a committee, however designated, identify each committee member. If the entire board of directors is acting as the registrant's audit committee as specified in Section 3(a)(58)(B) of the Exchange Act (15 U.S.C. 78c(a)(58)(B)), so state. N/A (b) If applicable, provide the disclosure required by Rule 10A-3(d) under the Exchange Act (17 CFR 240.10A-3(d)) regarding an exemption from the listing standards for audit committees. N/A ITEM 6. SCHEDULE OF INVESTMENTS. File Schedule of Investments in securities of unaffiliated issuers as of the close of the reporting period as set forth in 210.1212 of Regulation S-X [17 CFR 210.12-12], unless the schedule is included as part of the report to shareholders filed under Item 1 of this Form. Included in Item 1 ITEM 7. DISCLOSURE OF PROXY VOTING POLICIES AND PROCEDURES FOR CLOSED-END MANAGEMENT INVESTMENT COMPANIES. A closed-end management investment company that is filing an annual report on this Form N-CSR must, unless it invests exclusively in non-voting securities, describe the policies and procedures that it uses to determine how to vote proxies relating to portfolio securities, including the procedures that the company uses when a vote presents a conflict between the interests of its shareholders, on the one hand, and those of the company's investment adviser; principal underwriter; or any affiliated person (as defined in Section 2(a)(3) of the Investment Company Act of 1940 (15 U.S.C. 80a-2(a)(3)) and the rules thereunder) of the company, its investment adviser, or its principal underwriter, on the other. Include any policies and procedures of the company's investment adviser, or any other third party, that the company uses, or that are used on the company's behalf, to determine how to vote proxies relating to portfolio securities. Not applicable to open-end management investment companies. ITEM 8. PORTFOLIO MANAGERS OF CLOSED-END MANAGEMENT INVESTMENT COMPANIES. (a) If the registrant is a closed-end management investment company that is filing an annual report on this Form N-CSR,provide the following information: (1) State the name, title, and length of service of the person or persons employed by or associated with the registrant or an investment adviser of the registrant who are primarily responsible for the day-to-day management of the registrant's portfolio ("Portfolio Manager"). Also state each Portfolio Manager's business experience during the past 5 years. Not applicable to open-end management investment companies. ITEM 9. PURCHASES OF EQUITY SECURITIES BY CLOSED-END MANAGEMENT INVESTMENT COMPANY AND AFFILIATED PURCHASERS. (a) If the registrant is a closed-end management investment company, in the following tabular format, provide the information specified in paragraph (b) of this Item with respect to any purchase made by or on behalf of the registrant or any affiliated purchaser, as defined in Rule 10b-18(a)(3) under the Exchange Act (17 CFR 240.10b-18(a)(3)), of shares or other units of any class of the registrant's equity securities that is registered by the registrant pursuant to Section 12 of the Exchange Act (15 U.S.C. 781). Not applicable to open-end management investment companies. ITEM 10. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS. Describe any material changes to the procedures by which shareholders may recommend nominees to the registrant's board of directors, where those changes were implemented after the registrant last provided disclosure in response to the requirements of Item 407(c)(2)(iv) of Regulation S-R(17 CFR 229.407)(as required by Item 22(b)(15)) of Schedule 14A (17 CFR 240.14a-101), or this Item. There have been no material changes to the procedures by which the shareholders may recommend nominees to the registrant's board of directors since the registrant last provided disclosure in response to the requirements of Item 407(c)(2)(iv) of Regulation S-R of Schedule 14(A) in its definitive proxy statement, or this item. ITEM 11. CONTROLS AND PROCEDURES. (a) Disclose the conclusions of the registrant's principal executive and principal financials officers, or persons performing similar functions, regarding the effectiveness of the registrant's disclosure controls and procedures (as defined in Rule 30a-3(c) under the Act (17 CFR 270.30a-3(c))) as of a date within 90 days of the filing date of the report that includes the disclosure required by this paragraph, based on the evaluation of these controls and procedures required by Rule 30a-3(b) under the Act (17 CFR 270.30(a)-3(b) and Rules 13a-15(b) or 15d-15(b) under the Exchange Act (17 CFR 240.13a-15(b) or 240.15d-15(b)). The registrant's principal executive officer and principal financial officer have concluded that the registrant's disclosure controls and procedures are effective based on the evaluation of these controls and procedures as of a date within 90 days of the filing date of this report. (b) Disclose any change in the registrant's internal control over financial reporting (as defined in Rule 30a-3(d) under the Act (17CFR 270.30a-3(d)) that occured during the second fiscal quarter of the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting. There were no significant changes in the registrant's internal control over financial reporting that occurred during the second fiscal quarter of the period covered by this report that have materially affected, or are reasonably likely to materially affect, the registrant's internal control over financial reporting. The registrant's principal executive officer and principal financial officer, however, voluntarily are reporting the following information: In August of 2006 the registrant's investment adviser enhanced its internal procedures for reporting performance information required to be included in prospectuses. Those enhancements involved additional internal controls over the appropriateness of performance data generated for this purpose. Such enhancements were made following an internal review which identified prospectuses relating to certain classes of shares of a limited number of registrants where, inadvertently, performance information not reflecting the deduction of applicable sales charges was included. Those prospectuses were revised, and the revised prospectuses were distributed to shareholders. ITEM 12. EXHIBITS. (a) File the exhibits listed below as part of this Form. Letter or number the exhibits in the sequence indicated. (1) Any code of ethics, or amendment thereto, that is the subject of the disclosure required by Item 2, to the extent that the registrant intends to satisfy the Item 2 requirements through filing of an exhibit. (2) A separate certification for each principal executive officer and principal financial officer of the registrant as required by Rule 30a-2(a) under the Act (17 CFR 270.30a-2(a)) , exactly as set forth below: Filed herewith. SIGNATURES [See General Instruction F] Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized. (Registrant) Pioneer Bond Fund By (Signature and Title)* /s/ Lisa M. Jones Lisa M. Jones, President & Chief Executive Officer Date February 29, 2016 Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated. By (Signature and Title)* /s/ Lisa M. Jones Lisa M. Jones, President & Chief Executive Officer Date February 29, 2016 By (Signature and Title)* /s/ Mark Bradley Mark Bradley, Treasurer & Chief Accounting & Financial Officer Date February 29, 2016 * Print the name and title of each signing officer under his or her signature.