OMB APPROVAL OMB Number: 3235-0570 Expires: August 31, 2013 Estimated average burden hours per response.....18.9 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 811-09685 Pioneer High Yield 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: October 31 Date of reporting period: November 1, 2009 through October 31, 2010 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 SHAREOWNERS. Pioneer High Yield Fund - -------------------------------------------------------------------------------- Annual Report | October 31, 2010 - -------------------------------------------------------------------------------- Ticker Symbols: Class A TAHYX Class B TBHYX Class C PYICX Class R TYHRX Class Y TYHYX Class Z TAHZX [LOGO]PIONEER Investments(R) visit us: pioneerinvestments.com Table of Contents Letter to Shareowners 2 Portfolio Management Discussion 4 Portfolio Summary 7 Prices and Distributions 9 Performance Update 10 Comparing Ongoing Fund Expenses 16 Schedule of Investments 18 Financial Statements 48 Notes to Financial Statements 58 Report of Independent Registered Public Accounting Firm 68 Trustees, Officers and Service Providers 70 Pioneer High Yield Fund | Annual Report | 10/31/10 1 President's Letter Dear Shareowner, Through the first nine months of 2010, the U.S. economy moved forward on a slow path to recovery. But with the memory of a deep recession still lingering, businesses and consumers remained cautious about both investing and spending. While business fundamentals showed signs of improvement, there was still a reluctance to hire, and high unemployment remains a problem. Wary investors, concerned about risk, gravitated towards cash and bonds. We remain generally optimistic about the prospects for economic recovery, although it may occur more slowly than many would like. At Pioneer, we have long advocated the benefits of staying diversified and investing for the long term. This strategy has generally performed well for many investors. Bond markets certainly rewarded investors in the first nine months of 2010. While the equity markets barely budged, equities at the end of September 2010 were inexpensive relative to bonds, compared with historic levels, and represented potentially good value for long-term investors. Pioneer has not changed the basic approach to investing that we have used for more than 80 years. We remain focused on company fundamentals and risk management. Our investment process is based on careful research into individual companies, quantitative analysis, and active portfolio management. This three-pillared process, which we apply to each of our portfolios, is supported by an integrated team approach and is designed to carefully balance risk and reward. Our experienced professionals devote themselves to the careful research needed to identify investment opportunities in markets around the world. Our advice, as always, is to work closely with a trusted financial advisor to discuss your goals and work together to develop an investment strategy that meets your individual needs. There is no single best strategy that works for every investor. 2 Pioneer High Yield Fund | Annual Report | 10/31/10 We invite you to learn more about Pioneer and our time-tested approach to investing by consulting with your financial advisor or visiting us online at www.pioneerinvestments.com. We greatly appreciate your trust in us and we thank you for investing with Pioneer. Sincerely, /s/ Daniel K. Kingsbury Daniel K. Kingsbury President and CEO Pioneer Investment Management USA, Inc. 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 the opinion of Fund management as of the date of this report. These statements should not be relied upon for any other purposes. Past performance is no guarantee of future results, and there is no guarantee that market forecasts discussed will be realized. Pioneer High Yield Fund | Annual Report | 10/31/10 3 Portfolio Management Discussion | 10/31/10 High-yield bonds posted impressive returns during the 12 months ended October 31, 2010, continuing a strong run that commenced early in 2009. In the following interview, portfolio managers Tracy Wright and Andrew Feltus discuss what factors drove the high-yield market and those that influenced the performance of Pioneer High Yield Fund over the 12-month period. Mr. Feltus, senior vice president, and Ms. Wright, vice president, are responsible for the day-to-day management of the Fund's portfolio and are supported by Pioneer's fixed-income team. Q How did the Fund perform during the 12 months ended October 31, 2010? A Pioneer High Yield Fund Class A shares returned 19.66% at net asset value over the 12 months ended October 31, 2010, while the Fund's benchmarks, the Bank of America Merrill Lynch (BofA ML) High Yield Master II Index, the BofA ML All Convertibles Speculative Quality Index, and the BofA ML Index of Convertible Bonds (Speculative Quality), returned 19.26%, 26.40%, and 25.22%, respectively. Over the same period, the average return of the 483 mutual funds in Lipper's High Current Yield Funds category was 17.82%. Q What was the investment backdrop like for high-yield bonds over the 12 months ended October 31, 2010? A The high-yield asset class was helped by the Federal Reserve Board's (the Fed's) extremely accommodative monetary policy, which kept interest rates very low over the 12-month period. The demand for fixed-income investments outpaced demand for equities, and the lack of attractive yields in almost every other area of the fixed-income markets helped drive investors into the high-yield areas. Even though yields within the asset class were low due to the influence of low yields for comparable 10-year Treasury bonds, yield spreads -- the difference between yields offered by high-yield bonds over comparable Treasuries -- remained attractive. Default rates continued to decline and were projected to be about 2% this calendar year (2010) and next (2011). Many companies issuing high-yield debt also benefited from better-than-expected earnings, very strong cash flows, cleaned-up balance sheets with lower leverage, and refinancing activity that pushed maturities further into the future. Q What factors influenced the Fund's performance over the 12 months ended October 31, 2010? A Relative to the BofA ML High Yield Master II Index (the Fund's primary comparison index), the Fund benefited from strong security selection 4 Pioneer High Yield Fund | Annual Report | 10/31/10 within its portfolio's fixed-income allocation. At the industry level, overweighting real estate and underweighting utilities and health care also helped Fund performance. On the down side, the Fund lost ground due to an overweighting in capital goods, along with underweightings in banking and financial services. In terms of credit quality, our underweighting in lower-rated CCC bonds detracted from Fund performance, as those more- speculative issues outperformed. Looking at asset classes, the Fund's convertible security allocation helped performance. Holding bank loans and equities in the Fund's portfolio hurt performance, as those segments of the market underperformed high yield. Strong individual stock selection, however, helped offset the overall negative influence of holding equities. Q What was your investment strategy for the Fund during the 12 months ended October 31, 2010? A Given the Fed's extremely accommodative stance, we felt comfortable becoming more aggressive with the Fund's investments in common stocks and convertible bonds. We also continued to overweight the Fund to late- economic-cycle industries such as capital goods, because we believed market liquidity, improved earnings and better outlooks would eventually lead to increased capital spending. Q Which Fund holdings contributed the most to performance relative to the BofA ML High Yield Master II Index during the 12 months ended October 31, 2010, and which holdings detracted the most? A Bonds issued by real estate operating company Forest City Enterprises performed well during the 12-month period, due to the company's much-improved liquidity outlook. The convertible securities of industrial distributor WESCO also contributed to Fund performance, as did investments in the common stock of BE Aerospace and chemicals manufacturer Georgia Gulf, which rose due to an improved earnings outlook. Detractors from the Fund's relative performance included the common stock of drilling company Hercules Offshore, which was hurt by the disaster in the Gulf of Mexico, where the firm operates. Bonds issued by leisure/ casino firm Mashantucket Pequot (Foxwoods) declined on concerns about the company's solvency. The common stock of Scientific Games also lagged, due to the slower-than-expected adoption of lottery tickets in China. The convertible securities the Fund held in medical diagnostics provider Alere also dampened relative performance. Q What's your outlook? A We believe the U.S. will achieve gross domestic product (GDP) growth of approximately 2% to 3% in 2010, led by the corporate sector. At the margin, we feel U.S. GDP growth will be somewhat lower than we had expected at the beginning of 2010 amid reduced global growth expectations, which Pioneer High Yield Fund | Annual Report | 10/31/10 5 reflect tighter monetary policy from several emerging market countries as well as deficit-reduction measures among the highly indebted Eurozone members. We do not believe that inflation is an immediate concern, but feel it could pose a significant intermediate threat if monetary and fiscal stimulus and the deteriorating government debt situation are not managed effectively. With its new $600 billion Treasury purchase program, the Fed faces even greater inflation challenges in the intermediate term. With expected slow growth and continued high levels of unemployment in the U.S., we believe the Fed likely will maintain the current low-rate environment into 2011. We continue to see value in high yield, given attractive spreads and the generally strong financial position of corporations, as well as low default expectations for the coming year. We continue to add to the Fund's equity- sensitive convertible bond positions, believing the stock market will benefit from attractive valuations and respond positively to the Fed's quantitative easing. As always, we will focus on security selection, which we feel will represent the primary means for outperformance going forward, given a more normalized market environment relative to the past three years. Please refer to the Schedule of Investments on pages 18-47 for a full listing of Fund securities. Investments in high-yield or lower-rated securities are subject to greater-than-average risk. When interest rates rise, the prices of fixed-income securities in the Fund will generally fall. Conversely, when interest rates fall, the prices of fixed-income securities in the Fund will generally rise. Investments in the Fund are subject to possible loss due to the financial failure of the issuers of underlying securities and their inability to meet their debt obligations. These risks may increase share price volatility. Prepayment risk is the chance that mortgage-backed bonds will be paid off early if falling interest rates prompt homeowners to refinance their mortgages. 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 associated with falling interest rates. At times, the Fund's investments may represent industries or industry sectors that are interrelated or have common risks, making it more susceptible to any economic, political, or regulatory developments or other risks affecting those industries and sectors. Past performance is no guarantee of future results, and there is no guarantee that market forecasts discussed will be realized. 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 the opinion of Fund management as of the date of this report. These statements should not be relied upon for any other purposes. 6 Pioneer High Yield Fund | Annual Report | 10/31/10 Portfolio Summary | 10/31/10 Portfolio Diversification - -------------------------------------------------------------------------------- (As a percentage of total investment portfolio) [THE FOLLOWING DATA WAS REPRESENTED AS A PIE CHART IN THE PRINTED MATERIAL] U.S. Corporate Bonds 48.8% Convertible Corporate Bonds 18.2% U.S. Common Stocks 15.2% Senior Secured Loans 7.1% Temporary Cash Investments 6.3% Preferred Stocks 4.2% Asset Backed Securities 0.1% Collateralized Mortgage Obligations 0.1% Sector Distribution - -------------------------------------------------------------------------------- (As a percentage of equity holdings) [THE FOLLOWING DATA WAS REPRESENTED AS A PIE CHART IN THE PRINTED MATERIAL] Industrials 19.01% Energy 13.32% Consumer Discretionary 13.21% Health Care 12.21% Materials 12.14% Financials 11.80% Information Technology 5.96% Telecommunication Services 5.47% Consumer Staples 3.66% Utilities 3.18% Government 0.04% Pioneer High Yield Fund | Annual Report | 10/31/10 7 Portfolio Summary | 10/31/10 (continued) Quality Distribution - -------------------------------------------------------------------------------- (As a percentage of long-term securities; based on S&P ratings) [THE FOLLOWING DATA WAS REPRESENTED AS A PIE CHART IN THE PRINTED MATERIAL] AAA 0.04% BBB 1.98% BB 24.61% B 49.43% CCC 13.75% Not Rated 7.47% Cash Equivalents 2.72% 10 Largest Holdings - -------------------------------------------------------------------------------- (As a percentage of total long-term holdings) 1. Forest City Enterprises, Inc., 6.50%, 2/1/17 2.39% - -------------------------------------------------------------------------------- 2. Tesoro Corp., 6.625%, 11/1/15 2.03 - -------------------------------------------------------------------------------- 3. WESCO International, Inc., 6.0%, 9/15/29 2.02 - -------------------------------------------------------------------------------- 4. Forest City Enterprises, Inc., 7.0%, 2/31/49 1.89 - -------------------------------------------------------------------------------- 5. Nova Chemicals Corp., 7.875%, 9/15/25 1.83 - -------------------------------------------------------------------------------- 6. WESCO Distribution, Inc., 7.5%, 10/15/17 1.16 - -------------------------------------------------------------------------------- 7. Anixter International, Inc., 5.95%, 3/1/15 1.13 - -------------------------------------------------------------------------------- 8. Roper Industries, Inc., 1.4813%, 1/15/34 1.06 - -------------------------------------------------------------------------------- 9. Ford Motor Co., 4.25%, 11/15/16 1.04 - -------------------------------------------------------------------------------- 10. Alliance One International Inc., 10.0%, 7/15/16 1.04 - -------------------------------------------------------------------------------- * This list excludes temporary cash investments and derivative instruments. The portfolio is actively managed, and current holdings may be different investments. The holdings listed should not be considered recommendations to buy or sell any security listed. 8 Pioneer High Yield Fund | Annual Report | 10/31/10 Prices and Distributions | 10/31/10 Net Asset Value per Share - -------------------------------------------------------------------------------- Class 10/31/10 10/31/09 A $ 9.88 $ 8.69 - -------------------------------------------------------------------------------- B $ 9.95 $ 8.74 - -------------------------------------------------------------------------------- C $ 10.04 $ 8.83 - -------------------------------------------------------------------------------- R $ 11.03 $ 9.70 - -------------------------------------------------------------------------------- Y $ 9.88 $ 8.69 - -------------------------------------------------------------------------------- Z $ 9.86 $ 8.65 - -------------------------------------------------------------------------------- Distributions per Share: 11/1/09-4/30/10 - -------------------------------------------------------------------------------- Net Investment Short-Term Long-Term Class Income Capital Gains Capital Gains A $ 0.4740 $ -- $ -- - -------------------------------------------------------------------------------- B $ 0.3996 $ -- $ -- - -------------------------------------------------------------------------------- C $ 0.4120 $ -- $ -- - -------------------------------------------------------------------------------- R $ 0.4984 $ -- $ -- - -------------------------------------------------------------------------------- Y $ 0.5127 $ -- $ -- - -------------------------------------------------------------------------------- Z $ 0.5012 $ -- $ -- - -------------------------------------------------------------------------------- Index Definitions - -------------------------------------------------------------------------------- The Bank of America (BofA) Merrill Lynch (ML) High Yield Master II Index is a commonly accepted measure of the performance of high yield securities. The Bank of America (BofA) Merrill Lynch (ML) Index of Convertible Bonds (Speculative Quality) is a commonly accepted measure of the performance of speculative grade convertible bond securities. The Bank of America (BofA) Merrill Lynch (ML) All-Convertibles Speculative Quality Index is an unmanaged index of high-yield U.S. convertible securities, was added as a benchmark for Pioneer High Yield Fund. Index returns assume reinvestment of dividends and, unlike fund returns, do not reflect any fees, expense or sales charges. It is not possible to invest directly in an index. The indexes defined here pertain to the "Value of $10,000 Investment" and the "Value of $5 Million Investment" charts on pages 10-15. Pioneer High Yield Fund | Annual Report | 10/31/10 9 Performance Update | 10/31/10 Class A Shares Investment Returns - -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $10,000 investment made in Pioneer High Yield Fund at public offering price, compared to that of the Bank of America (BofA) Merrill Lynch (ML) High Yield Master II Index, the Bank of America (BofA) Merrill Lynch (ML) Index of Convertible Bonds (Speculative Quality), and the Bank of America (BofA) Merrill Lynch (ML) All Convertibles Speculative Quality Index. Average Annual Total Returns (As of October 31, 2010) - ------------------------------------------------------------------- Net Public Asset Value Offering Period (NAV) Price (POP) - ------------------------------------------------------------------- 10 Years 7.90% 7.41% 5 Years 6.79 5.80 1 Year 19.66 14.27 - ------------------------------------------------------------------- Expense Ratio (Per prospectus dated March 1, 2010) - ------------------------------------------------------------------- Gross Net - ------------------------------------------------------------------- 1.25% 1.25% - ------------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment BofA ML Index of Pioneer High BofA ML All Convertibles BofA ML High Yield Convertible Bonds Yield Fund Speculative Quality Index Master II Index (Speculative Quality) Index 10/00 9550 10000 10000 10000 9967 7284 10005 6805 10/02 9626 7091 9352 6625 13171 10130 12447 9464 10/04 14221 11025 13959 10301 14717 11277 14512 10536 10/06 16185 13086 16012 12226 18304 14661 17108 13697 10/08 12396 8336 12572 7788 17081 12000 18705 11211 10/10 20439 15026 22308 14039 Call 1-800-225-6292 or visit www.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. POP returns reflect deduction of maximum 4.50% sales charge. NAV returns would have been lower had sales charges been reflected. All results are historical and assume the reinvestment of dividends and capital gains. Other share classes are available for which performance and expenses will differ. Performance results reflect any applicable expense waivers in effect during the periods shown. Without such waivers Fund performance would be lower. Waivers may not be in effect for all funds. Certain fee waivers are contractual through a specified period. Otherwise, fee waivers can be rescinded at any time. See the prospectus and financial statements for more information. The performance table and graph do not reflect the deduction of fees and taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. 10 Pioneer High Yield Fund | Annual Report | 10/31/10 Performance Update | 10/31/10 Class B Shares Investment Returns - -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $10,000 investment made in Pioneer High Yield Fund, compared to that of the Bank of America (BofA) Merrill Lynch (ML) High Yield Master II Index, the Bank of America (BofA) Merrill Lynch (ML) Index of Convertible Bonds (Speculative Quality), and the Bank of America (BofA) Merrill Lynch (ML) All Convertibles Speculative Quality Index. Average Annual Total Returns (As of October 31, 2010) - --------------------------------------------------------------- If If Period Held Redeemed - --------------------------------------------------------------- 10 Years 7.12% 7.12% 5 Years 6.06 6.06 1 Year 18.83 14.83 - --------------------------------------------------------------- Expense Ratio (Per prospectus dated March 1, 2010) - --------------------------------------------------------------- Gross Net - --------------------------------------------------------------- 2.04% 2.04% - --------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment BofA ML Index of Pioneer High BofA ML All Convertibles BofA ML High Yield Convertible Bonds Yield Fund Speculative Quality Index Master II Index (Speculative Quality) Index 10/00 10000 10000 10000 10000 10345 7284 10005 6805 10/02 9910 7091 9352 6625 13473 10130 12447 9464 10/04 14446 11025 13959 10301 14823 11277 14512 10536 10/06 16194 13086 16012 12226 18175 14661 17108 13697 10/08 12228 8336 12572 7788 16740 12000 18705 11211 10/10 19892 15026 22308 14039 Call 1-800-225-6292 or visit www.pioneerinvestments.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. "If Held" results represent the percent change in net asset value per share. Returns would have been lower had sales charges been reflected. "If Redeemed" returns reflect the deduction of applicable contingent deferred sales charge (CDSC). Effective December 1, 2004, the period during which a CDSC is applied to withdrawals was shortened to 5 years. The maximum CDSC for Class B shares is 4% and declines over five years. For more complete information, please see the prospectus. Note: Shares purchased prior to December 1, 2004 remain subject to the CDSC in effect at the time you purchased those shares. For performance information for shares purchased prior to December 1, 2004, please visit www.pioneerinvestments.com. 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 taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. Pioneer High Yield Fund | Annual Report | 10/31/10 11 Performance Update | 10/31/10 Class C Shares Investment Returns - -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $10,000 investment made in Pioneer High Yield Fund, compared to that of the Bank of America (BofA) Merrill Lynch (ML) High Yield Master II Index, the Bank of America (BofA) Merrill Lynch (ML) Index of Convertible Bonds (Speculative Quality), and the Bank of America (BofA) Merrill Lynch (ML) All Convertibles Speculative Quality Index. Average Annual Total Returns (As of October 31, 2010) - --------------------------------------------------------------- If If Period Held Redeemed - --------------------------------------------------------------- 10 Years 7.12% 7.12% 5 Years 6.07 6.07 1 Year 18.79 18.79 - --------------------------------------------------------------- Expense Ratio (Per prospectus dated March 1, 2010) - --------------------------------------------------------------- Gross Net - --------------------------------------------------------------- 1.98% 1.98% - --------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment BofA ML Index of Pioneer High BofA ML All Convertibles BofA ML High Yield Convertible Bonds Yield Fund Speculative Quality Index Master II Index (Speculative Quality) Index 10/00 10000 10000 10000 10000 10350 7284 10005 6805 10/02 9919 7091 9352 6625 13466 10130 12447 9464 10/04 14437 11025 13959 10301 14819 11277 14512 10536 10/06 16186 13086 16012 12226 18186 14661 17108 13697 10/08 12225 8336 12572 7788 16750 12000 18705 11211 10/10 19897 15026 22308 14039 Call 1-800-225-6292 or visit www.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). The performance of Class C shares does not reflect the 1% front-end sales charge in effect prior to February 1, 2004. 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 High Yield Fund | Annual Report | 10/31/10 Performance Update | 10/31/10 Class R Shares Investment Returns - -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $10,000 investment made in Pioneer High Yield Fund, compared to that of the Bank of America (BofA) Merrill Lynch (ML) High Yield Master II Index, the Bank of America (BofA) Merrill Lynch (ML) Index of Convertible Bonds (Speculative Quality), and the Bank of America (BofA) Merrill Lynch (ML) All Convertibles Speculative Quality Index. Average Annual Total Returns (As of October 31, 2010) - --------------------------------------------------------------- If If Period Held Redeemed - --------------------------------------------------------------- 10 Years 7.63% 7.63% 5 Years 6.57 6.57 1 Year 19.32 19.32 - --------------------------------------------------------------- Expense Ratio (Per prospectus dated March 1, 2010) - --------------------------------------------------------------- Gross Net - --------------------------------------------------------------- 1.47% 1.47% - --------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment BofA ML Index of Pioneer High BofA ML All Convertibles BofA ML High Yield Convertible Bonds Yield Fund Speculative Quality Index Master II Index (Speculative Quality) Index 10/00 10000 10000 10000 10000 10381 7284 10005 6805 10/02 9975 7091 9352 6625 13630 10130 12447 9464 10/04 14728 11025 13959 10301 15177 11277 14512 10536 10/06 16645 13086 16012 12226 18768 14661 17108 13697 10/08 12695 8336 12572 7788 17485 12000 18705 11211 10/10 20863 15026 22308 14039 Call 1-800-225-6292 or visit www.pioneerinvestments.com for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted. The performance data quoted represents past performance, which is no guarantee of future results. Investment return and principal value will fluctuate, and shares, when redeemed, may be worth more or less than their original cost. The performance shown for Class R shares for the period prior to the commencement of operations of Class R shares on April 1, 2003, is based on the performance of the Fund's Class A shares, reduced to reflect the higher distribution and service fees of Class R shares. For the period beginning on April 1, 2003, the actual performance of Class R shares is reflected. Class R shares are not subject to sales charges and are available for limited groups of eligible investors, including institutional investors. All results are historical and assume the reinvestment of dividends and capital gains. Other share classes are available for which performance and expenses will differ. Performance results reflect any applicable expense waivers in effect during the periods shown. Without such waivers Fund performance would be lower. Waivers may not be in effect for all funds. Certain fee waivers are contractual through a specified period. Otherwise, fee waivers can be rescinded at any time. See the prospectus and financial statements for more information. The performance table and graph do not reflect the deduction of fees and taxes that a shareowner would pay on Fund distributions or the redemption of Fund shares. Pioneer High Yield Fund | Annual Report | 10/31/10 13 Performance Update | 10/31/10 Class Y Shares Investment Returns - -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $5 million investment made in Pioneer High Yield Fund, compared to that of the Bank of America (BofA) Merrill Lynch (ML) High Yield Master II Index, the Bank of America (BofA) Merrill Lynch (ML) Index of Convertible Bonds (Speculative Quality), and the Bank of America (BofA) Merrill Lynch (ML) All Convertibles Speculative Quality Index. Average Annual Total Returns (As of October 31, 2010) - --------------------------------------------------------------- If If Period Held Redeemed - --------------------------------------------------------------- 10 Years 8.31% 8.31% 5 Years 7.31 7.31 1 Year 20.16 20.16 - --------------------------------------------------------------- Expense Ratio (Per prospectus dated March 1, 2010) - --------------------------------------------------------------- Gross Net - --------------------------------------------------------------- 0.78% 0.78% - --------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $5,000,000 Investment BofA ML Index of Pioneer High BofA ML All Convertibles BofA ML High Yield Convertible Bonds Yield Fund Speculative Quality Index Master II Index (Speculative Quality) Index 10/00 5,000,000 5,000,000 5,000,000 5,000,000 10/01 5,214,132 3,641,976 5,002,717 3,402,627 10/02 5,050,316 3,545,744 4,675,849 3,312,720 10/03 6,932,164 5,065,045 6,223,678 4,732,174 10/04 7,512,251 5,512,689 6,979,477 5,150,399 10/05 7,806,899 5,638,712 7,255,806 5,268,140 10/06 8,620,806 6,543,092 8,005,986 6,113,084 10/07 9,782,756 7,330,257 8,554,134 6,848,517 10/08 6,672,537 4,168,131 6,285,826 3,894,203 10/09 9,247,195 5,999,850 9,352,480 5,605,543 10/10 11,111,137 7,513,065 11,153,990 7,019,310 Call 1-800-225-6292 or visit www.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. 14 Pioneer High Yield Fund | Annual Report | 10/31/10 Performance Update | 10/31/10 Class Z Shares Investment Returns - -------------------------------------------------------------------------------- The mountain chart on the right shows the change in value of a $10,000 investment made in Pioneer High Yield Fund, compared to that of the Bank of America (BofA) Merrill Lynch (ML) High Yield Master II Index, the Bank of America (BofA) Merrill Lynch (ML) Index of Convertible Bonds (Speculative Quality), and the Bank of America (BofA) Merrill Lynch (ML) All Convertibles Speculative Quality Index. Average Annual Total Returns (As of October 31, 2010) - --------------------------------------------------------------- If If Period Held Redeemed - --------------------------------------------------------------- 10 Years 8.03% 8.03% 5 Years 7.05 7.05 1 Year 20.35 20.35 - --------------------------------------------------------------- Expense Ratio (Per prospectus dated March 1, 2010) - --------------------------------------------------------------- Gross Net - --------------------------------------------------------------- 0.98% 0.85% - --------------------------------------------------------------- [THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL] Value of $10,000 Investment BofA ML Index of Pioneer High BofA ML All Convertibles BofA ML High Yield Convertible Bonds Yield Fund Speculative Quality Index Master II Index (Speculative Quality) Index 10/00 10000 10000 10000 10000 10432 7284 10005 6805 10/02 10075 7091 9352 6625 13786 10130 12447 9464 10/04 14885 11025 13959 10301 15404 11277 14512 10536 10/06 16941 13086 16012 12226 19179 14661 17108 13697 10/08 13089 8336 12572 7788 17994 12000 18705 11211 10/10 21655 15026 22308 14039 Call 1-800-225-6292 or visit www.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. Performance shown for Class Z shares for periods prior to the inception of Class Z shares on July 6, 2007, reflects the NAV performance of the Fund's Class A shares. The performance does not reflect differences in expenses, including the Rule 12b-1 fees, applicable to Class A shares. Since fees for Class A shares are generally higher than those of Class Z shares, the performance for Class Z shares for periods prior to their inception on July 6, 2007 would have been higher than the performance shown. Class Z 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 contractual expense limitations currently in effect through March 1, 2012, for Class Z shares. There can be no assurance that Pioneer will extend the expense limitations 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 High Yield Fund | Annual Report | 10/31/10 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 High Yield Fund Based on actual returns from May 1, 2010 through October 31, 2010. - --------------------------------------------------------------------------------------------------------------------- Share Class A B C R Y Z - --------------------------------------------------------------------------------------------------------------------- Beginning Account $1,000.00 $1,000.00 $1,000.00 $1,000.00 $1,000.00 $1,000.00 Value on 5/1/10 - --------------------------------------------------------------------------------------------------------------------- Ending Account Value $1,046.89 $1,044.66 $1,043.85 $1,045.75 $1,050.17 $1,052.93 (after expenses) on 10/31/10 - --------------------------------------------------------------------------------------------------------------------- Expenses Paid $6.09 $10.10 $9.69 $7.68 $4.08 $4.40 During Period* - --------------------------------------------------------------------------------------------------------------------- * Expenses are equal to the Fund's annualized expense ratio of 1.18%, 1.96%, 1.88%, 1.49%, 0.79% and 0.85% for class A, B, C, R, Y and Z, shares, respectively, multiplied by the average account value over the period, multiplied by 184/365 (to reflect the partial year period). 16 Pioneer High Yield Fund | Annual Report | 10/31/10 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 High Yield Fund Based on a hypothetical 5% return per year before expenses, reflecting the period from May 1, 2010 through October 31, 2010. - --------------------------------------------------------------------------------------------------------------------- Share Class A B C R Y Z - --------------------------------------------------------------------------------------------------------------------- Beginning Account $1,000.00 $1,000.00 $1,000.00 $1,000.00 $1,000.00 $1,000.00 Value on 5/1/10 - --------------------------------------------------------------------------------------------------------------------- Ending Account Value $1,019.26 $1,015.32 $1,015.73 $1,017.69 $1,021.22 $1,020.92 (after expenses) on 10/31/10 - --------------------------------------------------------------------------------------------------------------------- Expenses Paid $6.01 $9.96 $9.55 $7.58 $4.02 $4.33 During Period* - --------------------------------------------------------------------------------------------------------------------- * Expenses are equal to the Fund's annualized expense ratio of 1.18%, 1.96%, 1.88%, 1.49%, 0.79% and 0.85% for class A, B, C, R, Y and Z, shares, respectively, multiplied by the average account value over the period, multiplied by 184/365 (to reflect the partial year period). Pioneer High Yield Fund | Annual Report | 10/31/10 17 Schedule of Investments | 10/31/10 - --------------------------------------------------------------------------------------------------- Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - --------------------------------------------------------------------------------------------------- CONVERTIBLE CORPORATE BONDS -- 18.6% ENERGY -- 2.8% Coal & Consumable Fuels -- 0.9% 1,000,000 B-/NR International Coal Group, Inc., 4.0%, 4/1/17 $ 1,232,500 26,438,000 BB-/NR Massey Energy Co., 3.25%, 8/1/15 25,281,338 -------------- $ 26,513,838 - --------------------------------------------------------------------------------------------------- Oil & Gas Equipment & Services -- 0.5% 10,598,000 BB/NR Exterran Holdings, Inc., 4.25%, 6/15/14 $ 13,684,668 - --------------------------------------------------------------------------------------------------- Oil & Gas Exploration & Production -- 1.4% 12,017,000 BB-/NR Bill Barrett Corp., 5.0%, 3/15/28 (b) $ 12,257,340 25,033,000 BB/Ba3 Chesapeake Energy Corp., 2.5%, 5/15/37 21,559,671 6,135,000 B/NR Penn Virginia Corp., 4.5%, 11/15/12 6,012,300 -------------- $ 39,829,311 -------------- Total Energy $ 80,027,817 - --------------------------------------------------------------------------------------------------- MATERIALS -- 0.2% Steel -- 0.2% 5,200,000 BB+/NR Steel Dynamics, Inc., 5.125%, 6/15/14 $ 6,006,000 -------------- Total Materials $ 6,006,000 - --------------------------------------------------------------------------------------------------- CAPITAL GOODS -- 4.6% Construction & Farm Machinery & Heavy Trucks -- 1.1% 10,274,000 CCC/Caa2 Greenbrier Co., Inc., 2.375%, 5/15/26 $ 9,272,285 17,300,000 B/B1 Navistar International Corp., 3.0%, 10/15/14 20,781,625 -------------- $ 30,053,910 - --------------------------------------------------------------------------------------------------- Electrical Components & Equipment -- 1.5% 10,874,000 B/B2 General Cable Corp., 4.5%, 11/15/29 $ 11,227,405 34,357,000 BB+/Ba1 Roper Industries, Inc., 1.4813%, 1/15/34 29,589,966 -------------- $ 40,817,371 - --------------------------------------------------------------------------------------------------- Trading Companies & Distributors -- 2.0% 32,627,000 B/NR WESCO International, Inc., 6.0%, 9/15/29 $ 56,485,494 -------------- Total Capital Goods $ 127,356,775 - --------------------------------------------------------------------------------------------------- COMMERCIAL SERVICES & SUPPLIES -- 0.4% Environmental & Facilities Services -- 0.4% 9,235,000 B/Ba3 Covanta Holding Corp., 3.25%, 6/1/14 $ 10,447,094 -------------- Total Commercial Services & Supplies $ 10,447,094 - --------------------------------------------------------------------------------------------------- TRANSPORTATION -- 0.9% Airlines -- 0.1% 2,575,000 CCC+/B3 Continental Airlines, Inc., 4.5%, 1/15/15 $ 4,448,313 - --------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 18 Pioneer High Yield Fund | Annual Report | 10/31/10 - ------------------------------------------------------------------------------------------------- Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - ------------------------------------------------------------------------------------------------- Marine -- 0.8% 5,993,000 NR/NR DryShips, Inc., 0.5%, 12/1/14 $ 5,348,753 17,898,000 CCC+/Caa3 Horizon Lines, Inc., 4.25%, 8/15/12 16,376,670 -------------- $ 21,725,423 -------------- Total Transportation $ 26,173,736 - ------------------------------------------------------------------------------------------------- AUTOMOBILES & COMPONENTS -- 1.0% Automobile Manufacturers -- 1.0% 16,811,000 B/Ba3 Ford Motor Co., 4.25%, 11/15/16 $ 29,209,113 -------------- Total Automobiles & Components $ 29,209,113 - ------------------------------------------------------------------------------------------------- CONSUMER DURABLES & APPAREL -- 0.4% Homebuilding -- 0.4% 11,230,000 BB-/Ba3 D.R. Horton, Inc., 2.0%, 5/15/14 $ 12,044,175 -------------- Total Consumer Durables & Apparel $ 12,044,175 - ------------------------------------------------------------------------------------------------- RETAILING -- 0.2% Automotive Retail -- 0.2% 5,825,000 B-/Caa3 Sonic Automotive, Inc., 5.0%, 10/1/29 $ 6,560,406 -------------- Total Retailing $ 6,560,406 - ------------------------------------------------------------------------------------------------- FOOD, BEVERAGE & TOBACCO -- 0.4% Tobacco -- 0.4% 10,065,000 B-/Caa1 Alliance One International, Inc., 5.5%, 7/15/14 (144A) (b) $ 11,574,750 -------------- Total Food, Beverage & Tobacco $ 11,574,750 - ------------------------------------------------------------------------------------------------- HEALTH CARE EQUIPMENT & SERVICES -- 1.3% Health Care Services -- 1.0% 31,615,000 B+/B1 OMNICARE, Inc., 3.25%, 12/15/35 $ 28,176,869 - ------------------------------------------------------------------------------------------------- Health Care Supplies -- 0.3% 8,220,000 B-/NR Alere, Inc., 3.0%, 5/15/16 $ 7,788,450 1,240,000 B-/NR Inverness Medical Innovation, 3.0%, 5/15/16 (144A) 1,174,900 -------------- $ 8,963,350 -------------- Total Health Care Equipment & Services $ 37,140,219 - ------------------------------------------------------------------------------------------------- PHARMACEUTICALS & BIOTECHNOLOGY -- 2.2% Biotechnology -- 2.2% 9,250,000 B-/NA BioMarin Pharmaceutical, Inc., 1.875%, 4/23/17 $ 12,880,625 5,500,000 NR/NR Cubist Pharmaceuticals, Inc., 2.25%, 6/15/13 (b) 5,761,250 3,776,000 NR/NR Cubist Pharmaceuticals, Inc., 2.5%, 11/1/17 3,809,040 19,255,000 NA/NA MannKind Corp., 3.75%, 12/15/13 (b) 12,732,369 The accompanying notes are an integral part of these financial statements. Pioneer High Yield Fund | Annual Report | 10/31/10 19 Schedule of Investments | 10/31/10 (continued) - ------------------------------------------------------------------------------------------------------ Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - ------------------------------------------------------------------------------------------------------ Biotechnology -- (continued) 24,210,000 NR/NR Vertex Pharmaceuticals, Inc., 3.35%, 10/1/15 $ 25,420,500 -------------- $ 60,603,784 -------------- Total Pharmaceuticals & Biotechnology $ 60,603,784 - ------------------------------------------------------------------------------------------------------ DIVERSIFIED FINANCIALS -- 0.1% Consumer Finance -- 0.1% 4,150,000 NA/NA Dollar Financial Corp., 2.875%, 6/30/27 (144A) (b) $ 3,968,438 -------------- Total Diversified Financials $ 3,968,438 - ------------------------------------------------------------------------------------------------------ REAL ESTATE -- 0.6% Office Real Estate Investment Trust -- 0.3% 7,740,000 NR/B1 Lexington Realty Trust, 6.0%, 1/15/30 (144A) $ 9,142,875 - ------------------------------------------------------------------------------------------------------ Specialized Real Estate Investment Trust -- 0.3% 4,785,000 BB+/NR Host Hotels & Resorts LP, 2.5%, 10/15/29 $ 6,286,294 -------------- Total Real Estate $ 15,429,169 - ------------------------------------------------------------------------------------------------------ SOFTWARE & SERVICES -- 0.0% Data Processing & Outsourced Services -- 0.0% 1,200,000 NR/WD CSG Systems International, Inc., 2.5%, 6/15/24 $ 1,212,000 -------------- Total Software & Services $ 1,212,000 - ------------------------------------------------------------------------------------------------------ TECHNOLOGY HARDWARE & EQUIPMENT -- 1.5% Communications Equipment -- 0.5% 10,980,000 B/NR CommScope, Inc., 3.25%, 7/1/15 (b) $ 14,383,800 - ------------------------------------------------------------------------------------------------------ Electronic Equipment & Instruments -- 0.8% 7,125,000 B+/NR L-1 Identity Solutions, Inc., 3.75%, 5/15/27 $ 7,125,000 14,315,000 NR/NR Newport Corp., 2.5%, 2/15/12 14,368,681 -------------- $ 21,493,681 - ------------------------------------------------------------------------------------------------------ Technology Distributors -- 0.2% 1,570,000 B+/NR Anixter International, Inc., 1.0%, 2/15/13 $ 1,683,822 4,000,000 B+/NR Anixter International, Inc., 1.0%, 2/15/13 (144A) 4,290,000 -------------- $ 5,973,822 -------------- Total Technology Hardware & Equipment $ 41,851,303 - ------------------------------------------------------------------------------------------------------ SEMICONDUCTORS -- 1.2% Semiconductors 14,570,000 B+/NR ON Semiconductor Corp., 2.625%, 12/15/26 $ 15,225,650 2,155,000 BB-/NR SunPower Corp., 1.25%, 2/15/27 2,014,925 The accompanying notes are an integral part of these financial statements. 20 Pioneer High Yield Fund | Annual Report | 10/31/10 - --------------------------------------------------------------------------------------------------- Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - --------------------------------------------------------------------------------------------------- SEMICONDUCTORS -- (continued) 5,975,000 NR/NR SunPower Corp., 4.5%, 3/15/15 $ 5,497,000 12,184,000 BB-/NR SunPower Corp., 4.75%, 4/15/14 11,117,900 ---------------- $ 33,855,475 ---------------- Total Semiconductors $ 33,855,475 - --------------------------------------------------------------------------------------------------- TELECOMMUNICATION SERVICES -- 0.6% Integrated Telecommunication Services -- 0.6% 5,775,000 B+/NR MasTec, Inc., 4.25%, 121514 $ 6,172,031 8,963,000 B+/NR MasTec, Inc., 4.0%, 6/15/14 9,937,726 ---------------- $ 16,109,757 ---------------- Total Telecommunication Services $ 16,109,757 - --------------------------------------------------------------------------------------------------- UTILITIES -- 0.2% Multi-Utilities -- 0.2% 4,185,000 BB+/Ba1 CMS Energy Corp., 5.5%, 6/15/29 $ 5,770,069 ---------------- Total Utilities $ 5,770,069 - --------------------------------------------------------------------------------------------------- TOTAL CONVERTIBLE CORPORATE BONDS (Cost $430,585,305) $ 525,340,080 - --------------------------------------------------------------------------------------------------- PREFERRED STOCKS -- 4.2% ENERGY -- 0.2% Oil & Gas Exploration & Production -- 0.2% 59,180 Petroquest Energy, Inc., 6.875%, 12/31/49 $ 2,050,670 46,800 SandRidge Energy, Inc., 8.5%, 12/31/99 4,851,756 ---------------- $ 6,902,426 ---------------- Total Energy $ 6,902,426 - --------------------------------------------------------------------------------------------------- CAPITAL GOODS -- 0.3% Electrical Component & Equipment -- 0.3% 68,400 General Cable Corp., 5.75%, 11/24/13 $ 9,567,450 ---------------- Total Capital Goods $ 9,567,450 - --------------------------------------------------------------------------------------------------- HEALTH CARE EQUIPMENT & SERVICES -- 0.6% Health Care Supplies -- 0.6% 82,436 Alere, Inc., 3.0%, 12/31/49* $ 17,384,104 ---------------- Total Health Care Equipment & Services $ 17,384,104 - --------------------------------------------------------------------------------------------------- BANKS -- 0.7% Thrifts & Mortgage Finance -- 0.7% 455,732 Sovereign Capital Trust IV, 4.375%, 3/1/34 $ 18,457,146 ---------------- Total Banks $ 18,457,146 - --------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer High Yield Fund | Annual Report | 10/31/10 21 Schedule of Investments | 10/31/10 (continued) - ---------------------------------------------------------------------------------------------------- Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - ---------------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 0.5% Diversified Finance Services -- 0.5% 859,500 2009 Dole Food Automatic Common Exchange Security Trust $ 7,924,590 7,040 Bank of America Corp., 7.25%, 12/31/49 6,666,880 -------------- $ 14,591,470 -------------- Total Diversified Financials $ 14,591,470 - ---------------------------------------------------------------------------------------------------- REAL ESTATE -- 1.9% Real Estate Operating Companies -- 1.9% 899,012 Forest City Enterprises, Inc., 7.0%, 12/31/49 $ 52,929,331 -------------- Total Real Estate $ 52,929,331 - ---------------------------------------------------------------------------------------------------- TOTAL PREFERRED STOCKS (Cost $113,915,764) $ 119,831,927 - ---------------------------------------------------------------------------------------------------- Shares COMMON STOCKS -- 15.6% ENERGY -- 0.8% Integrated Oil & Gas -- 0.4% 185,100 Marathon Oil Corp. $ 6,584,007 99,500 QEP Resources, Inc. 3,286,485 -------------- $ 9,870,492 - ---------------------------------------------------------------------------------------------------- Oil & Gas Drilling -- 0.3% 2,437,937 Hercules Offshore, Inc.* $ 5,753,531 63,739 Transocean, Ltd.* 4,038,503 -------------- $ 9,792,034 - ---------------------------------------------------------------------------------------------------- Oil & Gas Exploration & Production -- 0.1% 543,713 SandRidge Energy, Inc. (b) $ 2,974,110 -------------- Total Energy $ 22,636,636 - ---------------------------------------------------------------------------------------------------- MATERIALS -- 3.7% Commodity Chemicals -- 0.9% 1,364,100 Georgia Gulf Corp.* (b) $ 27,595,743 - ---------------------------------------------------------------------------------------------------- Construction Materials -- 0.2% 146,894 Texas Industries, Inc. (b) $ 5,019,368 - ---------------------------------------------------------------------------------------------------- Diversified Chemical -- 1.4% 109,042 FMC Corp. (b) $ 7,970,970 420,080 LyondellBasell Industries NV (Class B)* 11,295,951 764,759 LyondellBasell Industries NV (Class A)* 20,541,427 -------------- $ 39,808,348 - ---------------------------------------------------------------------------------------------------- Diversified Metals & Mining -- 1.2% 305,492 Freeport-McMoRan Copper & Gold, Inc., (Class B) $ 28,923,983 2,600,200 Polymet Mining Corp.* 4,810,370 -------------- $ 33,734,353 - ---------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 22 Pioneer High Yield Fund | Annual Report | 10/31/10 - -------------------------------------------------------------------------------------------- Floating S&P/Moody's Shares Rate (d) Ratings Value - -------------------------------------------------------------------------------------------- Steel -- 0.0% 27,854 KNIA Holdings, Inc.* (f) $ 194,698 -------------- Total Materials $ 106,352,510 - -------------------------------------------------------------------------------------------- CAPITAL GOODS -- 3.8% Aerospace & Defense -- 1.8% 475,357 BE Aerospace, Inc.* (b) $ 17,474,123 266,203 DigitalGlobe, Inc.* 8,691,528 160,913 Geoeye, Inc.* (b) 7,123,619 201,875 ITT Corp. 9,526,481 468,500 Orbital Sciences Corp.* (b) 7,608,440 -------------- $ 50,424,191 - -------------------------------------------------------------------------------------------- Building Products -- 0.3% 176,212 Lennox International, Inc. $ 7,226,454 - -------------------------------------------------------------------------------------------- Construction & Farm Machinery & Heavy Trucks -- 0.2% 519,502 Commercial Vehicle Group, Inc.* (b) $ 6,976,912 - -------------------------------------------------------------------------------------------- Electrical Component & Equipment -- 0.8% 239,055 Cooper Industries Plc $ 12,531,263 321,400 General Cable Corp. (b) 8,979,916 -------------- $ 21,511,179 - -------------------------------------------------------------------------------------------- Industrial Machinery -- 0.7% 215,080 ESCO Technologies, Inc. (b) $ 7,372,942 392,965 Kennametal, Inc. 13,415,825 -------------- $ 20,788,767 - -------------------------------------------------------------------------------------------- Total Capital Goods $ 106,927,503 - -------------------------------------------------------------------------------------------- AUTOMOBILES & COMPONENTS -- 0.0% Auto Parts & Equipment -- 0.0% 872 Lear Corp.* $ 77,085 -------------- Total Automobiles & Components $ 77,085 - -------------------------------------------------------------------------------------------- CONSUMER SERVICES -- 1.2% Casinos & Gaming -- 0.5% 386,787 International Game Technology (b) $ 6,030,009 588,896 Scientific Games Corp.* (b) 4,652,278 96,200 WMS Industries Inc.* 4,197,206 -------------- $ 14,879,493 - -------------------------------------------------------------------------------------------- Restaurants -- 0.3% 314,243 Starbucks Corp. (b) $ 8,949,641 - -------------------------------------------------------------------------------------------- Specialized Consumer Services -- 0.4% 1,091,689 Service Corp. International $ 9,039,185 -------------- Total Consumer Services $ 32,868,319 - -------------------------------------------------------------------------------------------- RETAILING -- 0.3% Automotive Retail -- 0.0% 210,574 Sonic Automotive, Inc. (b) $ 2,299,468 - -------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer High Yield Fund | Annual Report | 10/31/10 23 Schedule of Investments | 10/31/10 (continued) - ------------------------------------------------------------------------------------------------ Floating S&P/Moody's Shares Rate (d) Ratings Value - ------------------------------------------------------------------------------------------------ Department Stores -- 0.3% 173,900 J.C. Penney Co., Inc. (b) $ 5,422,202 -------------- Total Retailing $ 7,721,670 - ------------------------------------------------------------------------------------------------ FOOD, BEVERAGE & TOBACCO -- 0.2% Tobacco -- 0.2% 1,334,100 Alliance One International, Inc.* (b) $ 5,896,722 -------------- Total Food, Beverage & Tobacco $ 5,896,722 - ------------------------------------------------------------------------------------------------ HEALTH CARE EQUIPMENT & SERVICES -- 0.7% Health Care Supplies -- 0.1% 70,500 Alere, Inc.* $ 2,083,275 - ------------------------------------------------------------------------------------------------ Managed Health Care -- 0.6% 226,532 Aetna, Inc. $ 6,764,246 166,600 CIGNA Corp. 5,862,654 151,300 United Healthcare Group, Inc. 5,454,365 -------------- $ 18,081,265 -------------- Total Health Care Equipment & Services $ 20,164,540 - ------------------------------------------------------------------------------------------------ PHARMACEUTICALS & BIOTECHNOLOGY -- 1.5% Life Sciences Tools & Services -- 1.5% 151,856 Bio-Rad Laboratories, Inc.* $ 13,761,191 302,262 Thermo Fisher Scientific, Inc.* 15,542,312 156,992 Waters Corp.* 11,637,817 -------------- $ 40,941,320 -------------- Total Pharmaceuticals & Biotechnology $ 40,941,320 - ------------------------------------------------------------------------------------------------ DIVERSIFIED FINANCIALS -- 0.2% Asset Management & Custody Banks -- 0.2% 150,017 Legg Mason, Inc. (b) $ 4,655,028 -------------- Total Diversified Financials $ 4,655,028 - ------------------------------------------------------------------------------------------------ REAL ESTATE -- 0.3% Mortgage Real Estate Investment Trust -- 0.3% 452,359 Annaly Capital Management, Inc. (b) $ 8,011,278 -------------- Total Real Estate $ 8,011,278 - ------------------------------------------------------------------------------------------------ SOFTWARE & SERVICES -- 0.1% Application Software -- 0.1% 95,454 Blackboard, Inc.* $ 3,984,250 -------------- Total Software & Services $ 3,984,250 - ------------------------------------------------------------------------------------------------ TECHNOLOGY HARDWARE & EQUIPMENT -- 1.1% Communications Equipment -- 0.4% 137,338 CommScope, Inc.* $ 4,348,121 108,400 Research In Motion, Ltd.* 6,173,380 -------------- $ 10,521,501 - ------------------------------------------------------------------------------------------------ The accompanying notes are an integral part of these financial statements. 24 Pioneer High Yield Fund | Annual Report | 10/31/10 - ---------------------------------------------------------------------------------------------------------- Floating S&P/Moody's Shares Rate (d) Ratings Value - ---------------------------------------------------------------------------------------------------------- Electronic Equipment & Instruments -- 0.4% 181,118 Itron, Inc.* (b) $ 11,006,541 - ---------------------------------------------------------------------------------------------------------- Electronic Manufacturing Services -- 0.3% 290,100 Tyco Electronics, Ltd. $ 9,190,368 -------------- Total Technology Hardware & Equipment $ 30,718,410 - ---------------------------------------------------------------------------------------------------------- TELECOMMUNICATION SERVICES -- 0.4% Integrated Telecommunication Services -- 0.4% 872,200 Windstream Corp. (b) $ 11,042,052 -------------- Total Telecommunication Services $ 11,042,052 - ---------------------------------------------------------------------------------------------------------- UTILITIES -- 1.3% Gas Utilities -- 0.0% 99,500 Questar Corp. $ 1,688,515 - ---------------------------------------------------------------------------------------------------------- Independent Power Producer & Energy Traders -- 0.4% 497,400 NRG Energy, Inc.* (b) $ 9,903,234 - ---------------------------------------------------------------------------------------------------------- Multi-Utilities -- 0.9% 761,634 CMS Energy Corp. (b) $ 14,002,641 147,500 Public Service Enterprise Group, Inc. 4,771,625 136,311 Sempra Energy Corp. 7,289,912 -------------- $ 26,064,178 -------------- Total Utilities $ 37,655,927 - ---------------------------------------------------------------------------------------------------------- TOTAL COMMON STOCKS (Cost $358,405,807) $ 439,653,250 - ---------------------------------------------------------------------------------------------------------- Principal Amount ($) - ---------------------------------------------------------------------------------------------------------- ASSET BACKED SECURITIES- 0.1% BANKS -- 0.1% Thrifts & Mortgage Finance -- 0.1% 2,510,000 0.68 CCC/Baa2 Bear Stearns Asset Backed Securities, Inc., Floating Rate Note, 1/25/47 $ 1,102,382 1,712,379 0.96 AAA/Caa2 FBR Securitization Trust, Floating Rate Note, 10/25/35 1,075,578 -------------- Total Banks $ 2,177,960 - ---------------------------------------------------------------------------------------------------------- TOTAL ASSET BACKED SECURITIES (Cost $2,351,329) $ 2,177,960 - ---------------------------------------------------------------------------------------------------------- COLLATERALIZED MORTGAGE OBLIGATIONS -- 0.1% TELECOMMUNICATION SERVICES -- 0.1% Integrated Telecommunication Services -- 0.1% 1,585,000 NA/B2 Global Tower Partners Acquisition, 7.87%, 5/15/37 $ 1,652,935 -------------- Total Telecommunication Services $ 1,652,935 - ---------------------------------------------------------------------------------------------------------- TOTAL COLLATERALIZED MORTGAGE OBLIGATIONS (Cost $1,203,206) $ 1,652,935 - ---------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer High Yield Fund | Annual Report | 10/31/10 25 Schedule of Investments | 10/31/10 (continued) - ------------------------------------------------------------------------------------------------- Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - ------------------------------------------------------------------------------------------------- CORPORATE BONDS -- 49.8% ENERGY -- 8.7% Coal & Consumable Fuels -- 0.4% 7,695,000 BB-/B2 Massey Energy Co., 6.875%, 12/15/13 $ 7,800,806 3,127,000 B+/Caa1 Murray Energy Co., 10.25%, 10/15/15 3,330,255 -------------- $ 11,131,061 - ------------------------------------------------------------------------------------------------- Oil & Gas Drilling -- 0.6% 15,825,000 B-/B3 Vantage Drilling Co., 11.5%, 8/1/15 $ 16,774,500 - ------------------------------------------------------------------------------------------------- Oil & Gas Equipment & Services -- 0.9% 6,323,000 B+/B1 American Petroleum, 10.25%, 5/1/15 $ 6,575,920 4,045,000 B+/B1 Complete Production Service, 8.0%, 12/15/16 4,257,363 13,565,000 B/B2 Expro Finance Luxembourg SCA, 8.5%, 12/15/16 13,361,525 -------------- $ 24,194,808 - ------------------------------------------------------------------------------------------------- Oil & Gas Exploration & Production -- 3.8% 3,425,000 BB-/B2 Berry Petroleum Corp., 6.75%, 11/1/20 $ 3,536,313 1,795,000 BB-/B1 Bill Barrett Corp., 9.875%, 7/15/16 1,974,500 2,277,000 B+/Caa2 Brigham Exploration Co., 8.75%, 10/1/18 2,459,160 2,561,000 B-/B3 Carrizo Oil & Gas, Inc., 8.625%, 10/15/18 2,580,208 3,845,000 BB/B1 Denbury Resources, Inc., 9.75%, 3/1/16 4,354,463 15,705,000 BB-/B2 Hilcorp Energy Co., 7.75%, 11/1/15 (144A) 16,176,150 6,005,000 B/B3 Linn Energy LLC, 11.75%, 5/15/17 (144A) 6,965,800 7,150,000 B/B3 Linn Energy LLC, 8.625%, 4/15/20 (144A) 7,722,000 3,830,000 BB-/B1 Plains Exploration & Production Co., 10.0%, 3/1/16 4,370,988 3,815,000 B-/B3 Quicksilver Resources, Inc., 7.125%, 4/1/16 3,652,863 13,550,000 B+/B2 Quicksilver Resources, Inc., 8.25%, 8/1/15 13,787,125 22,850,000 B+/B3 SandRidge Energy, Inc., 8.0%, 6/1/18 22,850,000 4,970,000 B+/B3 SandRidge Energy, Inc., 8.625, 4/1/15 5,081,825 7,250,000 BB-/B3 Swift Energy Co., 8.875%, 1/15/20 7,830,000 3,550,000 BB/Ba3 Whiting Petroleum, 6.5%, 10/1/18 3,807,375 -------------- $ 107,148,770 - ------------------------------------------------------------------------------------------------- Oil & Gas Refining & Marketing -- 2.6% 15,013,000 B+/B1 Holly Energy Partners LP, 6.25%, 3/1/15 $ 15,013,000 2,100,000 B+/B1 Holly Energy Partners LP, 6.25%, 3/1/15 (144A) 2,226,000 56,295,000 BB+/Ba1 Tesoro Corp., 6.625%, 11/1/15 (b) 56,857,950 -------------- $ 74,096,950 - ------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 26 Pioneer High Yield Fund | Annual Report | 10/31/10 - ------------------------------------------------------------------------------------------------- Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - ------------------------------------------------------------------------------------------------- Oil & Gas Storage & Transportation -- 0.4% 4,809,000 BB-/Ba2 Energy Transfer Equity LP, 7.5%, 10/15/20 $ 5,241,810 6,760,000 7.20 BB/Ba1 Southern Union Co., 7.2%, 11/1/66 6,236,100 -------------- $ 11,477,910 -------------- Total Energy $ 244,823,999 - ------------------------------------------------------------------------------------------------- MATERIALS -- 7.5% Aluminum -- 1.2% 3,535,000 B-/B3 CII Carbon LLC, 11.125%, 11/15/15 $ 3,755,938 13,607,120 6.83 CCC+/B3 Noranda Aluminum Acquisition, Floating Rate Note, 5/15/15 11,838,194 18,382,000 B-/B1 Novelis, Inc., 7.25%, 2/15/15 18,956,438 -------------- $ 34,550,570 - ------------------------------------------------------------------------------------------------- Commodity Chemicals -- 0.7% 14,240,000 CCC+/B3 Hexion US Finance Corp., 8.875%, 2/1/18 (144A) $ 15,290,200 6,275,000 CCC+/Caa1 Hexion US Finance Corp/Hexion Nova Scotia Finance LLC, 9.0%, 11/15/20 6,526,000 -------------- $ 21,816,200 - ------------------------------------------------------------------------------------------------- Construction Materials -- 0.4% 10,830,000 B/B3 Texas Industries, Inc., 9.25%, 8/15/20 $ 11,398,575 - ------------------------------------------------------------------------------------------------- Diversified Chemical -- 0.9% 7,410,000 B/B2 Ineos Finance Plc, 9.0%, 5/15/15 (144A) (b) $ 7,854,600 10,058,000 CCC/Caa3 Ineos Group Holdings Plc, 8.50%, 2/15/16 (144A) (b) 9,152,780 7,558,000 CCC/Caa1 Momentive Performance Materials, Inc., 9.0%, 1/15/21 7,841,425 -------------- $ 24,848,805 - ------------------------------------------------------------------------------------------------- Diversified Metals & Mining -- 0.1% 4,128,459 B/B2 Blaze Recycling & Metals LLC, 13.0%, 7/16/12 $ 3,426,621 - ------------------------------------------------------------------------------------------------- Metal & Glass Containers -- 0.9% 3,375,000 CCC+/B2 AEP Industries, Inc., 7.875%, 3/15/13 $ 3,349,688 2,290,000 CCC+/B3 BWAY Holding Co., 10.0%, 6/15/18 (144A) (b) 2,496,100 19,195,000 B+/B1 Crown Cork and Seal Co., Inc., 7.375%, 12/15/26 19,314,969 -------------- $ 25,160,757 - ------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer High Yield Fund | Annual Report | 10/31/10 27 Schedule of Investments | 10/31/10 (continued) - ------------------------------------------------------------------------------------------------- Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - ------------------------------------------------------------------------------------------------- Paper Packaging -- 0.4% 2,804,000 B-/Caa1 Graham Packaging Co. LP/GPC Capital Corp., Inc., 8.25%, 10/1/18 $ 2,902,140 7,139,000 B-/Caa1 Graham Packaging Co., 9.875%, 10/15/14 7,406,713 -------------- $ 10,308,853 - ------------------------------------------------------------------------------------------------- Paper Products -- 0.4% 11,046,000 NR/B1 ABI Escrow Corp., 10.25%, 10/15/18 (b) $ 11,791,605 325,000 B+/B1 Appleton Papers, Inc., 10.5%, 6/15/15 (144A) 313,625 -------------- $ 12,105,230 - ------------------------------------------------------------------------------------------------- Specialty Chemicals -- 1.9% 54,035,000 B+/B1 Nova Chemicals Corp., 7.875%, 9/15/25 $ 51,333,250 1,950,000 B-/B2 Omnova Solutions, Inc., 7.875%, 11/1/18 1,993,875 -------------- $ 53,327,125 - ------------------------------------------------------------------------------------------------- Steel -- 0.6% 16,805,000 CCC+/Caa2 Algoma Acquisition Corp., 9.875%, 6/15/15 (144A) $ 15,460,600 -------------- Total Materials $ 212,403,336 - ------------------------------------------------------------------------------------------------- CAPITAL GOODS -- 7.3% Aerospace & Defense -- 1.3% 18,628,000 B/B1 DynCorp International, Inc., 10.375%, 7/1/17 $ 19,047,130 15,445,000 BB-/Ba3 GeoEye, Inc., 9.625%, 10/1/15 17,201,869 -------------- $ 36,248,999 - ------------------------------------------------------------------------------------------------- Building Products -- 0.1% 1,800,000 BB/B2 USG Corp., 9.75%, 8/1/14 (144A) $ 1,881,000 - ------------------------------------------------------------------------------------------------- Construction & Engineering -- 0.4% 2,550,000 B/B2 Esco Corp., 8.625%, 12/15/13 (144A) $ 2,626,500 525,000 6.65 B/B2 Esco Corp., Floating Rate Note, 12/15/13 (144A) 505,313 9,750,000 B+/Caa1 New Enterprise Stone & Lime Co., 11.0%, 9/1/18 9,311,250 -------------- $ 12,443,063 - ------------------------------------------------------------------------------------------------- Construction & Farm Machinery & Heavy Trucks -- 1.4% 1,240,000 B/B2 Accuride Corp., 9.5%, 8/1/18 (b) $ 1,351,600 4,790,000 B+/Caa1 American Railcar, 7.5%, 3/1/14 4,849,875 16,400,000 BB+/Ba3 Case New Holland, Inc., 7.875%, 12/1/17 (144A) 18,327,000 15,775,000 CCC/Caa2 Greenbrier Co., Inc., 8.375%, 5/15/15 15,696,125 -------------- $ 40,224,600 - ------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 28 Pioneer High Yield Fund | Annual Report | 10/31/10 - ---------------------------------------------------------------------------------------------------- Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - ---------------------------------------------------------------------------------------------------- Electrical Component & Equipment -- 2.1% 31,930,000 BB/Ba2 Anixter International Corp., 5.95%, 3/1/15 $ 31,770,350 12,925,000 B/B3 Baldor Electric Co., 8.625%, 2/15/17 (b) 13,797,438 3,100,000 B/B3 Coleman Cable, Inc., 9.0%, 2/15/18 (b) 3,243,375 9,336,000 B+/Ba3 General Cable Corp., 7.125%, 4/1/17 (b) 9,569,400 -------------- $ 58,380,563 - ---------------------------------------------------------------------------------------------------- Industrial Machinery -- 0.9% 5,500,000 B/B3 Liberty Tree Recycling LLC, 11.0%, 10/1/16 $ 5,726,875 18,776,000 CCC+/B3 Mueller Water Products, Inc., 7.375%, 6/1/17 16,992,280 -------------- $ 22,719,155 - ---------------------------------------------------------------------------------------------------- Trading Companies & Distributors -- 1.1% 31,751,000 B/B1 WESCO Distribution, Inc., 7.50%, 10/15/17 $ 32,386,020 -------------- Total Capital Goods $ 204,283,400 - ---------------------------------------------------------------------------------------------------- TRANSPORTATION -- 0.6% Air Freight & Couriers -- 0.5% 8,900,000 CCC/Caa1 CEVA Group Plc, 11.5%, 4/1/18 (144A) $ 9,478,500 3,205,000 CCC/Caa1 CEVA Group Plc, 11.625%, 10/1/16 (b) 3,469,413 -------------- $ 12,947,913 - ---------------------------------------------------------------------------------------------------- Trucking -- 0.1% 4,640,000 B/B3 Syncreon Global Ireland, Ltd., 9.5%, 5/1/18 $ 4,802,400 -------------- Total Transportation $ 17,750,313 - ---------------------------------------------------------------------------------------------------- AUTOMOBILES & COMPONENTS -- 0.6% Auto Parts & Equipment -- 0.6% 9,980,000 CCC+/Caa2 Allison Transmission, Inc., 11.0%, 11/1/15 (144A) (b) $ 10,828,300 7,411,700 CCC+/Caa2 Allison Transmission, Inc., 11.25%, 11/1/15 (144A) 8,032,430 -------------- $ 18,860,730 -------------- Total Automobiles & Components $ 18,860,730 - ---------------------------------------------------------------------------------------------------- CONSUMER DURABLES & APPAREL -- 1.5% Homebuilding -- 0.4% 11,745,000 CCC/Caa2 Beazer Homes USA, Inc., 9.125%, 6/15/18 $ 11,422,013 - ---------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer High Yield Fund | Annual Report | 10/31/10 29 Schedule of Investments | 10/31/10 (continued) - -------------------------------------------------------------------------------------------------- Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - -------------------------------------------------------------------------------------------------- Housewares & Specialties -- 1.1% 6,300,000 B/Caa1 Reynolds Group Issuer, Inc., 9.0%, 4/15/19 $ 6,544,125 7,495,000 B-/Caa1 Reynolds Group Issuer, Inc., 8.5%, 5/15/18 (144A) 7,663,638 16,900,000 CCC+/Caa1 Yankee Acquisition Corp., 9.75%, 2/15/17 17,618,250 -------------- $ 31,826,013 -------------- Total Consumer Durables & Apparel $ 43,248,026 - -------------------------------------------------------------------------------------------------- CONSUMER SERVICES -- 1.0% Casinos & Gaming -- 0.9% 33,735,000 NR/WR Mashantucket Pequot Tribe, 8.5%, 11/15/15 (144A) (e) $ 4,722,900 5,648,000 B/Caa1 Pinnacle Entertainment, Inc., 8.75%, 5/15/20 5,640,940 2,970,000 BB-/B1 Scientific Games Corp., 7.875%, 6/15/16 3,059,100 10,280,000 BB-/B1 Scientific Games International, Inc., 9.25%, 6/15/19 (144A) 11,218,050 -------------- $ 24,640,990 - -------------------------------------------------------------------------------------------------- Leisure Facilities -- 0.1% 2,100,000 B-/B2 Cedar Fair LP/Canada, 9.125%, 8/1/18 $ 2,257,500 -------------- Total Consumer Services $ 26,898,490 - -------------------------------------------------------------------------------------------------- MEDIA -- 4.3% Advertising -- 0.9% 11,985,000 B+/Ba2 Interpublic Group of Cos., 10.0%, 7/15/17 $ 14,202,225 14,000,000 B-/Caa2 Sitel LLC/Sitel Finance Corp., 11.5%, 4/1/18 11,305,000 -------------- $ 25,507,225 - -------------------------------------------------------------------------------------------------- Broadcasting -- 3.1% 4,647,000 B/B2 CCO Holdings LLC/CCO Holdings Capital Corp., 7.25%, 10/30/17 $ 4,798,028 3,095,000 B/B1 Entravision Communications Corp., 8.75%, 8/1/17 3,315,519 11,575,000 B/B1 Hughes Network Systems LLC, 9.5%, 4/15/14 12,066,938 11,389,061 CCC+/Caa3 Intelsat Bermuda, Ltd., 11.5%, 2/4/17 12,314,422 10,850,000 B+/B3 Intelsat Subsidiary Holding Co., 8.5%, 1/15/13 10,944,938 4,750,000 B-/Caa1 Telesat Canada/Telesat LLC, 11.0%, 11/1/15 5,331,875 The accompanying notes are an integral part of these financial statements. 30 Pioneer High Yield Fund | Annual Report | 10/31/10 - -------------------------------------------------------------------------------------------------- Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - -------------------------------------------------------------------------------------------------- Broadcasting -- (continued) 8,990,000 B-/Caa1 Telesat Canada/Telesat LLC, 12.5%, 11/1/17 $ 10,608,200 26,462,317 CCC/Caa2 Univision Communications, Inc., 9.75%, 3/15/15 PIK (144A) 28,083,134 -------------- $ 87,463,054 - -------------------------------------------------------------------------------------------------- Publishing -- 0.3% 7,230,000 B-/Caa1 Interactive Data Corp., 10.25%, 8/1/18 $ 7,950,108 -------------- Total Media $ 120,920,387 - -------------------------------------------------------------------------------------------------- RETAILING -- 0.7% Automotive Retail -- 0.2% 4,530,000 B-/Caa1 Sonic Automotive, Inc., 9.0%, 3/15/18 $ 4,750,838 - -------------------------------------------------------------------------------------------------- Internet Retail -- 0.5% 14,040,000 B/B1 Ticketmaster, 10.75%, 8/1/16 $ 15,549,300 -------------- Total Retailing $ 20,300,138 - -------------------------------------------------------------------------------------------------- FOOD & DRUG RETAILING -- 0.4% Food Distributors -- 0.4% 12,139,000 BB-/B2 C&S Group Enterprise LLC, 8.375%, 5/1/17 (144A) (b) $ 12,139,000 -------------- Total Food & Drug Retailing $ 12,139,000 - -------------------------------------------------------------------------------------------------- FOOD, BEVERAGE & TOBACCO -- 1.0% Tobacco -- 1.0% 26,500,000 B+/B2 Alliance One International, Inc., 10.0%, 7/15/16 $ 29,150,000 -------------- Total Food, Beverage & Tobacco $ 29,150,000 - -------------------------------------------------------------------------------------------------- HOUSEHOLD & PERSONAL PRODUCTS -- 0.5% Personal Products -- 0.5% 1,950,000 B/B3 NBTY, Inc., 9.0%, 10/1/18 $ 2,071,875 10,920,000 B-/B3 Revlon Consumer Products Corp., 9.75%, 11/15/15 11,384,100 -------------- $ 13,455,975 -------------- Total Household & Personal Products $ 13,455,975 - -------------------------------------------------------------------------------------------------- HEALTH CARE EQUIPMENT & SERVICES -- 2.4% Health Care Equipment -- 0.2% 4,000,000 CCC+/Caa2 Accellent, Inc., 10.0%, 11/1/17 $ 3,970,000 - -------------------------------------------------------------------------------------------------- Health Care Facilities -- 0.2% 2,325,000 B/B3 Capella Healthcare, Inc., 9.25%, 7/1/17 $ 2,534,250 2,205,000 BB-/B2 HCA, Inc., 9.875%, 2/15/17 (b) 2,475,113 -------------- $ 5,009,363 - -------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer High Yield Fund | Annual Report | 10/31/10 31 Schedule of Investments | 10/31/10 (continued) - ------------------------------------------------------------------------------------------------- Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - ------------------------------------------------------------------------------------------------- Health Care Services -- 1.3% 2,530,000 B-/B3 BioScrip, Inc., 10.25%, 10/1/15 $ 2,675,475 7,479,000 B-/B2 Gentiva Health Services, Inc., 11.5%, 9/1/18 8,170,808 8,295,000 CCC+/Caa1 Surgical Care Affiliates LLC, 10.0%, 7/15/17 (144A) 8,543,850 17,897,387 B-/B3 Surgical Care Affiliates LLC, 8.875%, 7/15/15 (144A) PIK 18,389,565 -------------- $ 37,779,698 - ------------------------------------------------------------------------------------------------- Health Care Supplies -- 0.7% 924,000 B-/B3 Alere, Inc., 9.0%, 5/15/16 $ 986,370 4,950,000 B/Caa1 Bausch & Lomb, Inc., 9.875%, 11/1/15 5,383,125 12,229,000 B-/B3 Biomet, Inc., 10.375%, 10/15/17 13,635,335 -------------- $ 20,004,830 -------------- Total Health Care Equipment & Services $ 66,763,891 - ------------------------------------------------------------------------------------------------- PHARMACEUTICALS & BIOTECHNOLOGY -- 0.9% Biotechnology -- 0.4% 10,559,000 B+/B2 Lantheus Medical Imaging, Inc., 9.75%, 5/15/17 (144A) $ 11,034,155 - ------------------------------------------------------------------------------------------------- Life Sciences Tools & Services -- 0.5% 8,975,625 B/Caa1 Catalent Pharma Solution, Inc., 9.5%, 4/15/17 (144A) $ 9,110,259 5,836,000 B+/B3 PharmaNet Development Group, Inc., 10.875%, 4/15/17 6,069,440 -------------- $ 15,179,699 -------------- Total Pharmaceuticals & Biotechnology $ 26,213,854 - ------------------------------------------------------------------------------------------------- DIVERSIFIED FINANCIALS -- 1.1% Asset Management & Custody Banks -- 0.2% 4,650,000 B+/B1 Pinafore LLC/Pinafore, Inc., 9.0%, 10/1/18 $ 4,975,500 - ------------------------------------------------------------------------------------------------- Diversified Finance Services -- 0.2% 2,700,000 6.66 BB+/NR Caelus Re II, Ltd., Floating Rate Note, 5/24/13 $ 2,741,040 2,265,000 BB/NR Ibis Re, Ltd., 11.2775%, 5/10/12 2,460,243 -------------- $ 5,201,283 - ------------------------------------------------------------------------------------------------- Specialized Finance -- 0.7% 12,630,000 B+/B2 National Money Mart Co., 10.375%, 12/15/16 $ 13,766,700 3,000,000 CCC/Caa2 NCO Group, Inc., 11.875%, 11/15/14 2,550,000 5,070,000 7.68 CCC/Caa1 NCO Group, Inc., Floating Rate Note, 11/15/13 4,081,350 -------------- $ 20,398,050 -------------- Total Diversified Financials $ 30,574,833 - ------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 32 Pioneer High Yield Fund | Annual Report | 10/31/10 - ------------------------------------------------------------------------------------------------------ Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - ------------------------------------------------------------------------------------------------------ INSURANCE -- 2.4% Insurance Brokers -- 1.1% 19,710,000 CCC/Caa1 Alliant Holdings, Inc., 11.0%, 5/1/15 (144A) $ 20,720,138 4,950,000 CCC+/Caa1 Hub International Holdings Co., 10.25%, 6/15/15 (144A) 4,962,375 6,063,000 6.68 CCC/B3 USI Holdings Corp., Floating Rate Note, 11/15/14 5,244,495 -------------- $ 30,927,008 - ------------------------------------------------------------------------------------------------------ Multi-Line Insurance -- 0.8% 18,792,000 10.75 BB/Baa3 Liberty Mutual Group, Floating Rate Note, 6/15/58 (144A) $ 23,302,080 - ------------------------------------------------------------------------------------------------------ Reinsurance -- 0.5% 2,500,000 7.19 BB+/NR Blue Finance, Ltd., Floating Rate Note, 4/10/12 $ 2,404,000 2,000,000 8.92 BB/NR Caelus Re, Ltd., Floating Rate Note, 6/7/11 2,029,000 3,850,000 5.91 BB+/A2 Foundation Re III, Ltd., CAT Bond, Floating Rate Note, 2/3/14 3,870,405 1,675,000 12.03 NR/B3 Globecat, Ltd., CAT Bond, Floating Rate Note, 1/2/13 (144A) 1,619,055 625,000 8.78 NR/B1 Globecat, Ltd., CAT Bond, Floating Rate Note, 1/2/13 (144A) 633,438 750,000 7.20 NR/Ba2 Muteki, Ltd., CAT Bond, Floating Rate Note, 5/24/11 751,575 790,000 7.45 BB+/NA Newton Re, Ltd., CAT Bond, Floating Rate Note, 12/24/10 (144A) 791,106 1,150,000 9.75 BB/NA Newton Re, Ltd., CAT Bond, Floating Rate Note, 12/24/10 (144A) 1,158,280 -------------- $ 13,256,859 -------------- Total Insurance $ 67,485,947 - ------------------------------------------------------------------------------------------------------ REAL ESTATE -- 2.5% Real Estate Operating Companies -- 2.5% 77,045,000 B-/B3 Forest City Enterprises, Inc., 6.50%, 2/1/17 $ 67,029,150 1,140,000 B-/B3 Forest City Enterprises, Inc., 7.625%, 6/1/15 1,068,750 -------------- $ 68,097,900 - ------------------------------------------------------------------------------------------------------ Specialized Real Estate Investment Trust -- 0.0% 1,800,000 B/B2 Sabra Health Care LP/Sabra Capital Corp., 8.125%, 11/1/18 (b) $ 1,863,000 -------------- Total Real Estate $ 69,960,900 - ------------------------------------------------------------------------------------------------------ The accompanying notes are an integral part of these financial statements. Pioneer High Yield Fund | Annual Report | 10/31/10 33 Schedule of Investments | 10/31/10 (continued) - -------------------------------------------------------------------------------------------------- Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - -------------------------------------------------------------------------------------------------- SOFTWARE & SERVICES -- 0.8% Application Software -- 0.5% 8,982,000 B-/NR Nuance Communications, Inc., 2.75%, 8/15/27 $ 9,812,835 3,655,000 CCC+/Caa2 Vangent, Inc., 9.625%, 2/15/15 3,330,619 -------------- $ 13,143,454 - -------------------------------------------------------------------------------------------------- Data Processing & Outsourced Services -- 0.3% 10,500,000 B-/Caa1 First Data Corp., 9.875%, 9/24/15 (b) $ 8,872,500 - -------------------------------------------------------------------------------------------------- Internet Software & Services -- 0.0% 222,000 B-/B1 Terremark Worldwide, Inc., 12.0%, 6/15/17 $ 254,745 -------------- Total Software & Services $ 22,270,699 - -------------------------------------------------------------------------------------------------- TECHNOLOGY HARDWARE & EQUIPMENT -- 0.0% Electronic Manufacturing Services -- 0.0% 1,190,000 BB+/Ba1 Jabil Circuit, Inc., 5.625%, 12/15/20 $ 1,200,448 -------------- Total Technology Hardware & Equipment $ 1,200,448 - -------------------------------------------------------------------------------------------------- SEMICONDUCTORS -- 0.3% Semiconductor Equipment -- 0.3% 8,570,000 B-/B3 Aeroflex, Inc., 11.75%, 2/15/15 $ 9,298,450 - -------------------------------------------------------------------------------------------------- Semiconductors -- 0.0% 2,060,000 B+/Ba3 Advanced Micro Devices, Inc., 7.75%, 8/1/20 (144A) $ 2,183,600 -------------- Total Semiconductors $ 11,482,050 - -------------------------------------------------------------------------------------------------- TELECOMMUNICATION SERVICES -- 3.9% Alternative Carriers -- 1.3% 15,051,000 B/B2 Global Crossing, Ltd., 12.0%, 9/15/15 17,195,768 4,500,000 CCC+/Caa1 PAETEC Holdings Corp., 9.5%, 7/15/15 4,758,750 12,775,000 B/B1 PAETEC Holdings Corp., 8.875%, 6/30/17 (144A) $ 13,765,063 -------------- $ 35,719,581 - -------------------------------------------------------------------------------------------------- Integrated Telecommunication Services -- 2.6% 1,590,000 B+/B2 Cincinnati Bell, Inc., 7.0%, 2/15/15 $ 1,601,925 5,640,000 B+/B2 Cincinnati Bell, Inc., 8.25%, 10/15/17 5,724,600 13,820,000 B+/B2 Cincinnati Bell, Inc., 8.375%, 10/15/20 13,820,000 7,050,000 BB/Ba2 Frontier Communications Corp., 8.5%, 4/15/20 8,142,750 12,150,000 BB/Ba2 Frontier Communications Corp., 8.75%, 4/15/22 14,124,361 5,495,000 BB-/B2 GCI, Inc., 8.625%, 11/15/19 6,044,500 2,475,000 B-/B3 Global Crossing UK Finance Plc, 10.75%, 12/15/14 2,574,248 4,505,000 B+/B1 Mastec, Inc., 7.625%, 2/1/17 4,493,738 The accompanying notes are an integral part of these financial statements. 34 Pioneer High Yield Fund | Annual Report | 10/31/10 - ---------------------------------------------------------------------------------------------------- Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - ---------------------------------------------------------------------------------------------------- Integrated Telecommunication Services -- (continued) 6,675,000 B+/Ba3 Windstream Corp., 7.75%, 10/15/20 (144A) $ 7,075,500 9,445,000 B+/Ba3 Windstream Corp., 8.125%, 9/1/18 10,176,988 -------------- $ 73,778,610 -------------- Total Telecommunication Services $ 109,498,191 - ---------------------------------------------------------------------------------------------------- UTILITIES -- 1.4% Electric Utilities -- 0.6% 2,320,000 BB-/Ba2 Public Service of New Mexico, 9.25%, 5/15/15 $ 2,511,400 13,500,000 CCC/Caa2 Texas Competitive Electric Holdings Corp., 15.0%, 4/1/21 13,297,500 -------------- $ 15,808,900 - ---------------------------------------------------------------------------------------------------- Independent Power Producer & Energy Traders -- 0.8% 8,310,000 B+/B1 Calpine Corp., 7.875%, 7/31/20 $ 8,704,725 13,010,000 BB-/Ba3 Intergen NV, 9.00%, 6/30/17 14,050,800 -------------- $ 22,755,525 -------------- Total Utilities $ 38,564,425 - ---------------------------------------------------------------------------------------------------- TOTAL CORPORATE BONDS (Cost $1,349,814,906) $1,408,249,032 - ---------------------------------------------------------------------------------------------------- MUNICIPAL BONDS -- 0.0% COMMERCIAL SERVICES & SUPPLIES -- 0.0% Environmental & Facilities Services -- 0.0% 10,000,000 7.29 NR/NR Ohio Air Quality Development, Floating Rate Note, 6/8/22 (e)(f) $ 1,047,000 - ---------------------------------------------------------------------------------------------------- TOTAL MUNICIPAL BOND (Cost $10,000,000) $ 1,047,000 - ---------------------------------------------------------------------------------------------------- SENIOR FLOATING RATE LOAN INTERESTS** -- 7.3% ENERGY -- 0.3% Oil & Gas Equipment & Services -- 0.2% 870,625 5.50 NR/NR Aquilex Holdings LLC, Term Loan, 4/1/16 $ 863,007 5,282,761 8.50 B+/NR Hudson Products Holdings, Inc., Term Loan, 8/24/15 5,101,166 -------------- $ 5,964,173 - ---------------------------------------------------------------------------------------------------- Oil & Gas Exploration & Production -- 0.1% 3,469,300 4.31 B/B3 Venoco, Inc., Term Loan (Second Lien), 5/7/14 $ 3,287,885 -------------- Total Energy $ 9,252,058 - ---------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer High Yield Fund | Annual Report | 10/31/10 35 Schedule of Investments | 10/31/10 (continued) - ---------------------------------------------------------------------------------------------------- Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - ---------------------------------------------------------------------------------------------------- MATERIALS -- 0.2% Diversified Chemical -- 0.1% 2,475,000 7.50 B/B1 Ineos U.S. Finance LLC, Senior Credit Facility Term B2 Loan, 12/16/13 $ 2,534,812 2,475,000 8.00 B/B1 Ineos U.S. Finance LLC, Senior Credit Facility Term C2 Loan, 12/16/14 2,534,812 -------------- $ 5,069,624 - ---------------------------------------------------------------------------------------------------- Steel -- 0.1% 1,670,665 10.50 NR/NR Niagara Corp., Term Loan (New), 6/29/14 (f) $ 1,653,959 -------------- Total Materials $ 6,723,583 - ---------------------------------------------------------------------------------------------------- CAPITAL GOODS -- 0.4% Aerospace & Defense -- 0.2% 2,362,179 4.04 NR/NR DAE Aviation Holdings, Tranche B1 Term Loan, 7/31/14 $ 2,273,597 791,422 3.54 B-/B1 Hunter Defense Technology, Term Loan, 8/22/14 752,840 2,287,358 4.04 NR/NR Standard Aero, Ltd., Tranche B2 Term Loan, 7/31/14 2,201,582 750,673 5.50 NR/Ba2 Tasc, Inc., Tranche A Term Loan, 12/18/14 754,114 645,125 5.75 NR/Ba2 Tasc, Inc., Tranche B Term Loan, 12/18/15 650,165 -------------- $ 6,632,298 - ---------------------------------------------------------------------------------------------------- Electrical Component & Equipment -- 0.1% 1,184,050 6.5 NR/NR Scotsman Industries, Inc., Term Loan, 4/30/16 $ 1,184,790 - ---------------------------------------------------------------------------------------------------- Industrial Conglomerates -- 0.1% 1,120,000 0.00 NR/NR Goodman Group Global Group, Inc., Initial Term Loan (First Lien) $ 1,153,600 1,650,000 6.75 NR/NR Tomkins Plc, Term B Loan, 9/29/16 1,671,528 -------------- $ 2,825,128 -------------- Total Capital Goods $ 10,642,216 - ---------------------------------------------------------------------------------------------------- COMMERCIAL SERVICES & SUPPLIES -- 0.0% Environmental & Facilities Services -- 0.0% 704,675 6.00 NR/Ba3 Advanced Disposal Services, Inc., Term B Loan, 1/14/15 $ 709,079 -------------- Total Commercial Services & Supplies $ 709,079 - ---------------------------------------------------------------------------------------------------- TRANSPORTATION -- 0.2% Air Freight & Couriers -- 0.2% 1,139,913 3.29 B-/B1 CEVA Group Plc, Additional Pre Funded L/C Loan, 11/4/13 $ 1,021,170 2,776,702 3.26 NR/B1 CEVA Group Plc, EGL Term Loan, 11/4/13 2,494,403 The accompanying notes are an integral part of these financial statements. 36 Pioneer High Yield Fund | Annual Report | 10/31/10 - ---------------------------------------------------------------------------------------------------- Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - ---------------------------------------------------------------------------------------------------- Air Freight & Couriers -- (continued) 1,624,830 3.26 B-/B1 CEVA Group Plc, U.S. Term Loan (Dollars), 11/4/13 $ 1,459,638 -------------- $ 4,975,211 -------------- Total Transportation $ 4,975,211 - ---------------------------------------------------------------------------------------------------- AUTOMOBILES & COMPONENTS -- 0.5% Auto Parts & Equipment -- 0.2% 2,336,787 3.03 BB-/B2 Allison Transmission, Inc., Term Loan, 8/7/14 $ 2,247,488 285,693 2.20 NR/NR Federal Mogul Corp., Tranche C Term Loan, 12/28/15 254,312 559,959 2.20 NR/NR Federal Mogul Corp., Tranche B Term Loan, 12/29/14 498,451 2,183,208 10.50 NR/B3 HHI Group Holdings LLC, Term Loan, 3/30/15 2,215,956 -------------- $ 5,216,207 - ---------------------------------------------------------------------------------------------------- Tires & Rubber -- 0.3% 7,817,000 2.21 BB/Ba1 Goodyear Tire & Rubber Co., Term Loan (Second Lien), 4/30/14 $ 7,540,145 -------------- Total Automobiles & Components $ 12,756,352 - ---------------------------------------------------------------------------------------------------- CONSUMER DURABLES & APPAREL -- 0.0% Apparel, Accessories & Luxury Goods -- 0.0% 733,390 4.75 BBB/Ba2 Phillips-Van Heusen Corp., U.S. Tranche B Term Loan, 5/6/16 $ 740,893 -------------- Total Consumer Durables & Apparel $ 740,893 - ---------------------------------------------------------------------------------------------------- CONSUMER SERVICES -- 0.6% Casinos & Gaming -- 0.4% 10,947,753 10.50 NR/NR Gateway Casinos & Entertainment, Term Facility, 3/16/14 (e) $ 10,975,122 8,980,000 6.03 NR/NR Gateway Casinos & Entertainment, Second Lien Advance Lien, 7/16/14 (e) 1,574,306 -------------- $ 12,549,428 - ---------------------------------------------------------------------------------------------------- Education Services -- 0.1% 955,077 2.54 NR/NR Cengage Learning Acquisitions, Inc., Term Loan, 7/3/14 $ 874,383 - ---------------------------------------------------------------------------------------------------- Restaurants -- 0.1% 2,280,000 6.25 BB+/Ba2 Burger King Holdings, Inc., Tranche B Term Loan, 10/19/16 $ 2,303,655 -------------- Total Consumer Services $ 15,727,466 - ---------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. Pioneer High Yield Fund | Annual Report | 10/31/10 37 Schedule of Investments | 10/31/10 (continued) - -------------------------------------------------------------------------------------------------- Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - -------------------------------------------------------------------------------------------------- MEDIA -- 0.5% Cable & Satellite -- 0.4% 1,691,479 3.54 NR/NR Charter Communications Operating LLC, Term C Loan, 9/6/16 $ 1,663,388 4,937,625 4.50 BB-/Ba3 Mediacom Broadband LLC, Tranche F Term Loan, 10/23/17 4,896,477 3,000,000 2.76 CCC/B2 WideOpenWest LLC, Term Loan (First Lien), 6/30/14 2,797,500 -------------- $ 9,357,365 - -------------------------------------------------------------------------------------------------- Movies & Entertainment -- 0.1% 3,413,536 5.25 NR/NR Christie/AIX, Inc., Term Loan, 4/29/16 $ 3,396,468 -------------- Total Media $ 12,753,833 - -------------------------------------------------------------------------------------------------- FOOD, BEVERAGE & TOBACCO -- 0.6% Packaged Foods & Meats -- 0.6% 2,900,000 11.25 NR/NR Pierre Foods, Inc., Term Loan (First Lien), 9/29/17 $ 2,925,375 14,500,000 7.00 NR/NR Pierre Foods, Inc., Term Loan (Second Lien), 9/30/16 14,373,125 -------------- $ 17,298,500 -------------- Total Food, Beverage & Tobacco $ 17,298,500 - -------------------------------------------------------------------------------------------------- HOUSEHOLD & PERSONAL PRODUCTS -- 0.2% Household Products -- 0.1% 2,320,717 6.75 NR/NR Reynolds Group Holdings, Inc., U.S. Term Loan, 5/5/16 $ 2,343,199 1,590,000 6.25 NR/NR Reynolds Group Holdings, Inc., Incremental U.S. Term Loan, 5/5/16 1,601,921 -------------- $ 3,945,120 - -------------------------------------------------------------------------------------------------- Personal Products -- 0.1% 2,019,850 6.00 NR/NR Revlon Consumer Products Corp., Term Loan, 3/11/15 $ 2,025,981 -------------- Total Household & Personal Products $ 5,971,101 - -------------------------------------------------------------------------------------------------- HEALTH CARE EQUIPMENT & SERVICES -- 1.3% Health Care Facilities -- 0.3% 3,870,550 6.50 B+/B1 Ardent Health Services LLC, Term Loan, 9/15/15 $ 3,846,359 4,000,000 7.50 B+/Ba2 Sun HealthCare Group, Inc., Term Loan, 10/18/16 3,967,500 -------------- $ 7,813,859 - -------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 38 Pioneer High Yield Fund | Annual Report | 10/31/10 - --------------------------------------------------------------------------------------------------- Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - --------------------------------------------------------------------------------------------------- Health Care Services -- 0.7% 11,300,000 6.75 BB-/Ba2 Gentiva Health Services, Inc., Term B Borrowing Loan, 8/17/16 $ 11,380,038 6,676,450 7.25 NR/NR Prime Healthcare Services, Inc., Term B Loan, 4/28/15 6,409,392 1,233,944 6.00 BB/Ba3 RehabCare Group, Inc., Term B Loan, 11/24/15 1,239,491 1,031,228 7.00 CCC/B3 Rural/Metro Operating Co. LLC, Term Loan, 12/9/14 1,031,873 -------------- $ 20,060,794 - --------------------------------------------------------------------------------------------------- Health Care Supplies -- 0.3% 9,200,000 4.51 BB/B1 Alere, Inc., Term Loan (Second Lien), 6/26/15 $ 8,932,625 -------------- Total Health Care Equipment & Services $ 36,807,278 - --------------------------------------------------------------------------------------------------- PHARMACEUTICALS & BIOTECHNOLOGY -- 0.5% Biotechnology -- 0.5% 190,958 6.50 NR/NR Harvard Drug Group, Delayed Draw Term Loan, 4/8/16 $ 180,933 1,388,788 6.50 NR/NR Harvard Drug Group, Term Loan, 4/8/16 1,315,877 4,243,205 6.00 NR/Ba3 Warner Chilcott Corp., Term A Loan, 10/30/14 4,244,678 3,410,683 6.25 NR/Ba3 Warner Chilcott Corp., Term B-2 Loan, 4/30/15 3,430,400 1,931,534 6.25 NR/Ba3 Warner Chilcott Corp., Term B-3 Loan, 4/30/15 1,941,851 2,048,235 6.25 NR/Ba3 Warner Chilcott Corp., Term B-1 Loan, 4/30/15 2,060,076 -------------- $ 13,173,815 -------------- Total Pharmaceuticals & Biotechnology $ 13,173,815 - --------------------------------------------------------------------------------------------------- INSURANCE -- 1.2% Insurance Brokers -- 0.9% 5,164,560 3.29 NR/NR Alliant Holdings I, Inc., Term Loan, 8/21/14 $ 5,022,535 1,606,490 2.79 B/NR HUB International Holdings, Delayed Draw Term Loan, 6/13/14 1,541,206 5,836,050 6.75 B/NR HUB International Holdings, Inc., Additional Term Loan, 6/13/14 5,792,280 7,146,899 2.79 B/NR HUB International Holdings, Initial Term Loan, 6/13/14 6,856,467 The accompanying notes are an integral part of these financial statements. Pioneer High Yield Fund | Annual Report | 10/31/10 39 Schedule of Investments | 10/31/10 (continued) - ------------------------------------------------------------------------------------------------------ Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - ------------------------------------------------------------------------------------------------------ Insurance Brokers -- (continued) 6,307,508 2.76 B/B2 USI Holdings Corp., Tranche B Term Loan, 5/5/14 $ 5,918,546 1,465,200 7.00 B/B2 USI Holdings Corp., Series C New Term Loan, 5/5/14 1,438,094 -------------- $ 26,569,128 - ------------------------------------------------------------------------------------------------------ Multi-Line Insurance -- 0.3% 7,896,043 2.80 B-/NR AmWins Group, Inc., Initial Term Loan, 6/8/13 $ 7,367,995 -------------- Total Insurance $ 33,937,123 - ------------------------------------------------------------------------------------------------------ SOFTWARE & SERVICES -- 0.5% Internet Software & Services -- 0.3% 9,450,000 6.75 NR/NR SAVVIS, Inc., Term Loan, 8/4/16 $ 9,578,756 - ------------------------------------------------------------------------------------------------------ Systems Software -- 0.2% 2,430,313 8.50 CCC+/B1 Allen Systems Group, Inc., Term Loan (First Lien), 10/18/13 $ 2,443,604 910,202 5.25 BB-/Ba3 Dealer Computer Services, Inc., (R&R), Term Loan, 4/2/17 911,244 1,740,686 2.32 BB-/Ba3 Inverness Medical Innovations, Term Loan (Second Lien), 2/14/13 1,671,059 1,502,450 6.75 B+/B1 Telcordia Technologies, Inc., Term Loan, 4/30/16 1,516,771 -------------- $ 6,542,678 -------------- Total Software & Services $ 16,121,434 - ------------------------------------------------------------------------------------------------------ TELECOMMUNICATION SERVICES -- 0.1% Wireless Telecommunication Services -- 0.1% 2,770,000 3.29 B+/B3 Intelsat Jackson Holdings, Ltd., Term Loan, 2/1/14 $ 2,643,618 -------------- Total Telecommunication Services $ 2,643,618 - ------------------------------------------------------------------------------------------------------ UTILITIES -- 0.2% Electric Utilities -- 0.1% 2,494,800 3.76 B+/B2 Texas Competitive Electric Holdings Co., LLC, Delayed Draw Term Loan, 10/10/14 $ 1,951,207 - ------------------------------------------------------------------------------------------------------ The accompanying notes are an integral part of these financial statements. 40 Pioneer High Yield Fund | Annual Report | 10/31/10 - ------------------------------------------------------------------------------------------------------ Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - ------------------------------------------------------------------------------------------------------ Independent Power Producer & Energy Traders -- 0.1% 1,640,858 1.79 BB+/Baa3 NRG Energy, Inc., Original Maturity Term Loan, 2/1/13 $ 1,608,334 1,334,617 1.79 BB+/Baa3 NRG Energy, Inc., Original Maturity Credit- Linked Deposit, 2/1/13 1,308,163 -------------- $ 2,916,497 -------------- Total Utilities $ 4,867,704 - ------------------------------------------------------------------------------------------------------ TOTAL SENIOR FLOATING RATE LOAN INTERESTS (Cost $210,177,946) $ 205,101,264 - ------------------------------------------------------------------------------------------------------ TEMPORARY CASH INVESTMENTS -- 6.5% Repurchase Agreements -- 2.6% 8,095,000 0.22 NR/Aaa Bank of America, Inc., 0.22%, dated 10/29/10, repurchase price of $8,095,000 plus accrued interest on 11/1/10 collateralized by $8,232,048 Federal National Mortgage Association, 4.0%, 10/1/40 $ 8,095,000 8,095,000 0.20 NR/Aaa Bank of America, Inc., 0.2%, dated 10/29/10, repurchase price of $8,095,000 plus accrued interest on 11/1/10 collateralized by $8,147,506 U.S. Treasury Notes, 3.125%, 5/15/19 8,095,000 8,095,000 0.18 NR/Aaa Barclays Plc, 0.18%, dated 10/29/10, repurchase price of $8,095,000 plus accrued interest on 11/1/10 collateralized by $5,706,712 Federal National Mortgage Association, 4.5%, 6/1/40 - 9/1/40 $2,523,568 Freddie Mac Giant, 4.0%, 10/1/40 8,095,000 8,095,000 0.18 NR/Aaa Barclays Plc, 0.18%, dated 10/29/10, repurchase price of $8,095,000 plus accrued interest on 11/1/10 collateralized by $8,234,150 U.S. Treasury Notes, 1.375%, 2/15/12 8,095,000 8,095,000 0.23 NR/Aaa BNP Paribas SA, 0.23%, dated 10/29/10, repurchase price of $8,095,000 plus accrued interest on 11/1/10 collateralized by the following: $5,019,893 Federal National Mortgage Association (ARM), 2.673% - 5.446%, 1/1/23 - 10/1/40 $3,213,553 Federal Home Loan Mortgage Corp., 0.0% - 5.416%, 1/5/36 - 10/1/40 8,095,000 The accompanying notes are an integral part of these financial statements. Pioneer High Yield Fund | Annual Report | 10/31/10 41 Schedule of Investments | 10/31/10 (continued) - ---------------------------------------------------------------------------------------------------- Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - ---------------------------------------------------------------------------------------------------- Repurchase Agreements -- (continued) 8,095,000 0.22 NR/Aaa Deutsche Bank Securities, Inc, 0.22%, dated 10/29/10, repurchase price of $8,095,000 plus accrued interest on 11/1/10 collateralized by $8,223,529 Federal National Mortgage Association, 5.0% - 6.0%, 6/1/35 - 2/1/38 $ 8,095,000 8,095,000 0.20 NR/Aaa Deutsche Bank, 0.2%, dated 10/29/10, repurchase price of $8,095,000 plus accrued interest on 11/1/10 collateralized by $8,239,398 U.S. Treasury Notes, 0.875, 1/31/12 8,095,000 8,095,000 0.22 NR/Aaa JPMorgan Securities, Inc., 0.22%, dated 10/29/10, repurchase price of $8,095,000 plus accrued interest on 11/1/10 collateralized by $8,256,934 Freddie Mac Giant 3.5% - 11.5%, 2/1/11 - 3/1/48 8,095,000 8,095,000 0.22 NR/Aaa SG Americas Securities LLC, 0.22%, dated 10/29/10, repurchase price of $8,095,000 plus accrued interest on 11/1/10 collateralized by the following: $4,361,546 Federal National Mortgage Association, 5.5%, 11/1/37 - 12/1/39 $3,863,916 Freddie Mac Giant, 4.5% - 6.5%, 11/1/37 - 11/1/39 8,095,000 -------------- Total Repurchase Agreements (Cost $72,855,000) $ 72,855,000 - ---------------------------------------------------------------------------------------------------- Securities Lending Collateral -- 3.9% (c) Certificates of Deposit: $3,087,832 Bank of Nova Scotia, 0.37%, 9/29/11 $ 3,087,832 2,161,482 BBVA Group NY, 0.61%, 7/26/11 2,161,482 3,087,832 BNP Paribas Bank NY, 0.38%, 11/8/10 3,087,832 1,543,916 BNP Paribas Bank NY, 0.3%, 1/20/11 1,543,916 3,087,832 Canadian Imperial Bank of Commerce NY, 0.29%, 4/27/11 3,087,832 1,543,916 DNB Nor Bank ASA NY, 0.27%, 11/10/10 1,543,916 3,087,832 Nordea New York, 0.5%, 12/10/10 3,087,832 3,087,832 RoboBank Netherland NV NY, 0.44%, 8/8/11 3,087,832 3,087,832 Royal Bank of Canada NY, 0.26%, 1/21/11 3,087,832 3,087,832 SocGen NY, 0.34%, 11/10/10 3,087,832 1,543,916 Svenska NY, 0.275%, 11/12/10 1,543,916 -------------- 28,408,054 $ 28,408,054 - ---------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 42 Pioneer High Yield Fund | Annual Report | 10/31/10 - ------------------------------------------------------------------------------------------------------ Principal Floating S&P/Moody's Amount ($) Rate (d) Ratings Value - ------------------------------------------------------------------------------------------------------ Repurchase Agreements -- (continued) Commercial Paper: $ 1,852,699 American Honda Finance, 0.28%, 5/4/11 $ 1,852,699 1,241,334 American Honda Finance, 1.04%, 6/20/11 1,241,334 1,135,502 Australia & New Zealand Banking Group, 1.04%, 8/4/11 1,135,502 3,149,835 Caterpillar Financial Services Corp., 1.04%, 6/24/11 3,149,835 3,396,615 CBA, 0.31%, 1/3/11 3,396,615 2,160,645 CHARFD, 0.31%, 12/14/10 2,160,645 1,852,238 CLIPPR, 0.28%, 12/1/10 1,852,238 2,724,685 FAIRPP, 0.3%, 11/9/10 2,724,685 1,234,836 FASCO, 0.27%, 12/1/10 1,234,836 3,088,199 Federal Home Loan Bank, 0.37%, 6/1/11 3,088,199 1,543,849 GE Corp., 0.34%, 1/26/11 1,543,849 308,612 General Electric Capital Corp., 0.37%, 6/6/11 308,612 1,234,836 OLDLLC, 0.27%, 12/1/10 1,234,836 1,691,898 OLDLLC, 0.27%, 12/2/10 1,691,898 3,084,487 SEB, 0.0%, 2/7/11 3,084,487 1,542,971 SOCNAM, 0.0%, 1/14/11 1,542,971 1,543,487 SRCPP, 0.27%, 12/6/10 1,543,487 2,316,543 STRAIT, 0.25%, 12/8/10 2,316,543 1,543,082 TBLLC, 0.0%, 1/10/11 1,543,082 1,543,534 TBLLC, 0.27%, 12/2/10 1,543,534 3,087,832 Toyota Motor Credit Corp., 0.44%, 9/8/11 3,087,832 1,881,123 VARFUN, 0.35%, 1/20/11 1,881,123 1,852,758 Wachovia, 0.39%, 3/22/11 1,852,758 1,236,110 Wachovia, 0.42%, 10/15/11 1,236,110 3,087,832 Westpac, 0.31%, 07/29/11 3,087,832 -------------- $ 49,335,542 - ------------------------------------------------------------------------------------------------------ Tri-party Repurchase Agreements: 8,248,896 Barclays Capital Markets, 0.22%, 11/1/10 $ 8,248,894 6,175,664 Deutsche Bank Securities, Inc., 0.21%, 11/1/10 6,175,664 6,175,664 HSBC Bank USA NA, 0.22%, 11/1/10 6,175,664 3,087,832 RBS Securities, Inc., 0.22%, 11/1/10 3,087,832 -------------- $ 23,688,054 - ------------------------------------------------------------------------------------------------------ The accompanying notes are an integral part of these financial statements. Pioneer High Yield Fund | Annual Report | 10/31/10 43 Schedule of Investments | 10/31/10 (continued) - --------------------------------------------------------------------------------------------------- Floating S&P/Moody's Shares Rate (d) Ratings Value - --------------------------------------------------------------------------------------------------- Money Market Mutual Funds: 3,087,832 BlackRock Liquidity Temporary Cash Fund $ 3,087,832 3,087,832 Dreyfus Preferred Money Market Fund 3,087,832 3,087,832 Fidelity Prime Money Market Fund 3,087,832 -------------- $ 9,263,496 -------------- Total Securities Lending Collateral (Cost $110,695,146) $ 110,695,146 - --------------------------------------------------------------------------------------------------- TOTAL TEMPORARY CASH INVESTMENTS (Cost $183,550,146) $ 183,550,146 - --------------------------------------------------------------------------------------------------- TOTAL INVESTMENT IN SECURITIES -- 102.2% (Cost $2,660,004,409) (a) $2,886,603,594 - --------------------------------------------------------------------------------------------------- OTHER ASSETS AND LIABILITIES -- (2.2)% $ (63,073,775) - --------------------------------------------------------------------------------------------------- TOTAL NET ASSETS -- 100.0% $2,823,529,819 =================================================================================================== * Non-income producing security. NR Not rated by either S&P or Moody's. WR Withdrawn rating. PIK Represents a pay in kind security. (144A) Security is exempt from registration under Rule 144A of the Securities Act of 1933. Such securities may be resold normally to qualified institutional buyers in a transaction exempt from registration. At October 31, 2010, the value of these securities amounted to $352,603,047 or 12.5% 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 United States banks, (iii) the certificate of deposit or (iv) other base lending rates used by commercial lenders. The rate shown is the coupon rate at period end. (a) At October 31, 2010, the net unrealized loss on investments based on cost for federal income tax purposes of $2,671,229,352 was as follows: Aggregate gross unrealized gain for all investments in which there is an excess of value over tax cost $339,669,482 Aggregate gross unrealized loss for all investments in which there is an excess of tax cost over value (124,295,240) ------------ Net unrealized gain $215,374,242 ============ The accompanying notes are an integral part of these financial statements. 44 Pioneer High Yield Fund | Annual Report | 10/31/10 (b) At October 31, 2010, the following securities were out on loan: - -------------------------------------------------------------------------------------------- Principal Amount ($) Description Value - -------------------------------------------------------------------------------------------- 2,725,000 ABI Escrow Corp., 10.25%, 10/15/18 $2,908,938 491,000 Accuride Corp. , 9.5%, 8/1/18 535,190 2,425,000 Alliance One International, Inc., 5.5%, 7/15/14 (144A) 2,788,750 1,455,000 Allison Transmission, Inc., 11.0%, 11/1/15 (144A) 1,578,675 2,678,000 Baldor Electric, 8.625%, 2/15/17 2,858,765 1,571,000 Bill Barrett Corp., 5.0%, 3/15/28 1,602,420 1,000,000 BWAY Holding Co., 10.0%, 6/15/18 (144A) 1,090,000 9,945,000 C&S Group Enterprise LLC, 8.375%, 5/1/17 (144A) 9,945,000 1,000,000 CEVA Group Plc, 11.625%, 10/1/16 1,082,500 1,089,000 Coleman Cable, Inc., 9%, 2/15/18 1,139,366 2,423,000 CommScope, Inc., 3.25%, 7/1/15 3,174,130 1,282,000 Cubist Pharmaceuticals, Inc., 2.25%, 6/15/13 1,342,895 240,000 Dollar Financial Corp., 2.875%, 6/30/27 (144A) 229,500 4,920,000 First Data Corp., 9.875%, 9/24/15 4,157,400 501,000 General Cable Corp., 7.125%, 4/1/17 513,525 1,680,000 HCA, Inc., 9.875%, 2/15/17 1,885,800 3,749,250 Ineos Group Holdings Plc, 8.50%, 2/15/16 (144A) 3,411,818 1,996,000 MannKind Corp., 3.75%, 12/15/13 1,319,855 1,780,000 Sabra Health Care LP/Sabra Capital Corp., 8.125%, 11/1/18 1,842,300 1,050,000 Tesoro Corp., 6.625%, 11/1/15 1,060,500 10,925,000 Yankee Acquisition Corp., 9.75%, 2/15/17 11,389,313 The accompanying notes are an integral part of these financial statements. Pioneer High Yield Fund | Annual Report | 10/31/10 45 Schedule of Investments | 10/31/10 (continued) - -------------------------------------------------------------------------------------------- Shares Description Value - -------------------------------------------------------------------------------------------- 1,259,600 Alliance One International, Inc. * $ 5,567,432 12,500 Annaly Capital Management, Inc. 221,375 33,600 BE Aerospace, Inc. * 1,235,136 900 CMS Energy Corp. 16,547 46,500 Commercial Vehicle Group, Inc. * 624,495 91,200 ESCO Technologies, Inc. 3,126,336 3,700 FMC Corp. 270,470 69,900 General Cable Corp. 1,953,006 5,400 Geoeye, Inc. * 239,058 917,200 Georgia Gulf Corp. * 18,554,956 10,600 International Game Technology 165,254 1,800 Itron, Inc. * 28,062 172,100 J.C. Penney Co., Inc. 5,366,078 4,900 Legg Mason, Inc. 76,391 39,800 NRG Energy, Inc. * 792,418 24,000 Orbital Sciences Corp. * 389,760 538,200 SandRidge Energy, Inc. 2,943,954 50,700 Scientific Games Corp * 400,530 206,500 Sonic Automotive, Inc. 2,254,980 7,200 Starbucks Corp. 205,056 145,400 Texas Industries, Inc. 4,968,318 95,100 Windstream Corp. 1,203,966 - -------------------------------------------------------------------------------------------- Total $107,434,409 ============================================================================================ (c) Securities lending collateral is managed by Credit Suisse AG, New York Branch. (d) Debt obligation with a variable interest rate. Rate shown is rate at end of period. (e) Security is in default and is non-income producing. (f) Security is fair valued by management (see Note A). Purchases and sales of securities (excluding temporary cash investments) for the year ended October 31, 2010 aggregated $1,046,527,116 and 1,507,482,697, respectively. The accompanying notes are an integral part of these financial statements. 46 Pioneer High Yield Fund | Annual Report | 10/31/10 Various inputs are used in determining the value of the Fund's investments. These inputs are summarized in the three broad levels listed below. Highest priority is given to Level 1 inputs and lowest priority is given to Level 3. 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.) Level 3 -- significant unobservable inputs (including the Fund's own assumptions in determining fair value of investments) The following is a summary of the inputs used as of October 31, 2010, in valuing the Fund's assets: - --------------------------------------------------------------------------------------------------- Level 1 Level 2 Level 3 Total - --------------------------------------------------------------------------------------------------- Asset Backed Securities $ -- $ 2,177,960 $ -- $ 2,177,960 Collateralized Mortgage Obligations -- 1,652,935 -- 1,652,935 Corporate Bonds -- 1,408,249,032 -- 1,408,249,032 Convertible Corporate Bonds -- 525,340,080 -- 525,340,080 Preferred Stocks 14,591,470 105,240,457 -- 119,831,927 Municipal Bonds -- -- 1,047,000 1,047,000 Senior Floating Rate Loan Interests -- 203,447,305 1,653,959 205,101,264 Common Stocks 439,458,552 -- 194,698 439,653,250 Temporary Cash Investments -- 174,286,650 -- 174,286,650 Money Market Mutual Funds 9,263,496 -- -- 9,263,496 - --------------------------------------------------------------------------------------------------- Total $463,313,518 $2,420,394,419 $2,895,657 $2,886,603,594 =================================================================================================== Other Financial Instruments* $ -- $ -- $ -- $ -- =================================================================================================== The following is a reconciliation of assets valued using significant observable inputs (Level 3): - ------------------------------------------------------------------------------------------------ Senior Floating Rate Loan Common Interests Stocks Municipal Total - ------------------------------------------------------------------------------------------------ Balance as of 10/31/09 $ 1,043,970 -- -- $1,043,970 Realized gain (loss) -- -- -- -- Change in unrealized appreciation (depreciation)1 (20,484) 6 -- (20,478) Net purchases (sales) (1,022,082) -- -- (1,022,082) Transfers in and out of Level 3* 1,652,555 194,692 1,047,000 2,894,247 - ------------------------------------------------------------------------------------------------ Balance as of 10/31/10 $ 1,653,959 $194,698 $1,047,000 $2,895,657 ================================================================================================ 1 Realized gain (loss) on these securities is included in the net realized gain (loss) from investments in the Statement of Operations. * Transfers are calculated on the date of transfer. Net change in unrealized appreciation (depreciation) of investments still held as of 10/31/10 $ (9) The accompanying notes are an integral part of these financial statements. Pioneer High Yield Fund | Annual Report | 10/31/10 47 Statement of Assets and Liabilities | 10/31/10 ASSETS: Investment in securities (including securities loaned of $107,434,409) (cost $2,660,004,409) $2,886,603,594 Cash 18,789,803 Receivables -- Investment securities sold 20,427,225 Fund shares sold 13,926,741 Dividends and interest 37,050,311 Due from Pioneer Investment Management, Inc. 789 Unrealized appreciation on unfunded corporate loans 37,753 Other 185,784 - ------------------------------------------------------------------------------------------- Total assets $2,977,022,000 - ------------------------------------------------------------------------------------------- LIABILITIES: Payables -- Investment securities purchased $ 32,015,095 Fund shares repurchased 7,637,711 Dividends 2,257,722 Upon return of securities loaned 110,695,146 Due to affiliates 740,326 Accrued expenses 146,181 - ------------------------------------------------------------------------------------------- Total liabilities $ 153,492,181 - ------------------------------------------------------------------------------------------- NET ASSETS: Paid-in capital $2,852,696,460 Undistributed net investment loss 3,306,127 Accumulated net realized loss on investments (259,109,706) Net unrealized gain on investments 226,636,938 - ------------------------------------------------------------------------------------------- Total net assets $2,823,529,819 =========================================================================================== NET ASSET VALUE PER SHARE: (No par value, unlimited number of shares authorized) Class A (based on $1,584,197,814/160,309,988 shares) $ 9.88 Class B (based on $240,993,027/24,227,634 shares) $ 9.95 Class C (based on $599,656,008/59,698,194 shares) $ 10.04 Class R (based on $95,302,856/8,638,126 shares) $ 11.03 Class Y (based on $300,881,464/30,445,051 shares) $ 9.88 Class Z (based on $2,498,650/253,381 shares) $ 9.86 MAXIMUM OFFERING PRICE: Class A ($9.88 [divided by] 95.5%) $ 10.35 =========================================================================================== The accompanying notes are an integral part of these financial statements. 48 Pioneer High Yield Fund | Annual Report | 10/31/10 Statement of Operations For the Year Ended 10/31/10 INVESTMENT INCOME: Dividends (net of foreign taxes withheld of $801) $ 11,053,291 Interest 167,729,182 Income from securities loaned, net 419,265 - ----------------------------------------------------------------------------------------- Total investment income $179,201,738 - ----------------------------------------------------------------------------------------- EXPENSES: Management fees $ 17,387,985 Transfer agent fees and expenses Class A 1,560,700 Class B 614,423 Class C 659,865 Class Y 92,111 Class R 17,573 Class Z 4,011 Distribution fees Class A 3,532,123 Class B 3,019,739 Class C 5,966,816 Class R 516,836 Shareholder communication expense 2,826,877 Administrative reimbursements 859,019 Custodian fees 70,904 Registration fees 241,735 Professional fees 169,639 Printing expense 162,381 Fees and expenses of nonaffiliated trustees 92,884 Miscellaneous 330,973 - ----------------------------------------------------------------------------------------- Total expenses $ 38,126,594 Less fees waived and expenses reimbursed by Pioneer Investment Management, Inc. (2,275) - ----------------------------------------------------------------------------------------- Net expenses $ 38,124,319 - ----------------------------------------------------------------------------------------- Net investment income $141,077,419 - ----------------------------------------------------------------------------------------- REALIZED AND UNREALIZED GAIN ON INVESTMENTS Net realized gain on: Investments $ 69,169,365 Credit Default Swaps 364,861 $ 69,534,226 - ----------------------------------------------------------------------------------------- Change in net unrealized gain on: Investments $275,821,780 Unfunded Corporate loans 318,557 $276,140,337 - ----------------------------------------------------------------------------------------- Net gain on investments $345,674,563 - ----------------------------------------------------------------------------------------- Net increase in net assets resulting from operations $486,751,982 ========================================================================================= The accompanying notes are an integral part of these financial statements. Pioneer High Yield Fund | Annual Report | 10/31/10 49 Statements of Changes in Net Assets For the Years Ended 10/31/10 and 10/31/09, respectively - --------------------------------------------------------------------------------------------------------- Year Ended Year Ended 10/31/10 10/31/09 - --------------------------------------------------------------------------------------------------------- FROM OPERATIONS: Net investment income $ 141,077,419 $ 166,863,186 Net realized gain (loss) on investments 69,534,226 (311,435,025) Change in net unrealized gain on investments 276,140,337 949,634,539 - --------------------------------------------------------------------------------------------------------- Net increase (decrease) in net assets resulting from operations $ 486,751,982 $ 805,062,700 - --------------------------------------------------------------------------------------------------------- DISTRIBUTIONS TO SHAREOWNERS: Net investment income: Class A ($0.47 and $0.61 per share, respectively) $ (72,460,963) $ (89,468,028) Class B ($0.40 and $0.56 per share, respectively) (13,155,069) (28,088,184) Class C ($0.41 and $0.58 per share, respectively) (26,280,574) (40,305,401) Class R ($0.50 and $0.67 per share, respectively) (5,041,495) (7,624,335) Class Y ($0.52 and $0.65 per share, respectively) (19,799,731) (25,810,046) Class z ($0.50 and $0.65 per share, respectively) (96,374) (50,842) Net realized gain: Class A ($0.00 and $0.09 per share, respectively) -- (12,024,228) Class B ($0.00 and $0.09 per share, respectively) -- (4,927,662) Class C ($0.00 and $0.09 per share, respectively) -- (6,192,743) Class R ($0.00 and $0.09 per share, respectively) -- (941,525) Class Y ($0.00 and $0.09 per share, respectively) -- (3,391,108) Class Z ($0.00 and $0.09 per share, respectively) -- (5,411) - --------------------------------------------------------------------------------------------------------- Total distributions to shareowners $ (136,834,206) $ (218,829,513) - --------------------------------------------------------------------------------------------------------- FROM FUND SHARE TRANSACTIONS: Net proceeds from sale of shares $ 1,255,562,665 $ 1,120,458,805 Reinvestment of distributions 100,904,604 $ 154,342,860 Cost of shares repurchased (1,772,142,556) $ (1,105,819,266) - --------------------------------------------------------------------------------------------------------- Net increase (decrease) in net assets resulting from fund share transactions $ (415,675,287) $ 168,982,399 - --------------------------------------------------------------------------------------------------------- Net increase (decrease) in net assets $ (65,757,511) $ 755,215,586 NET ASSETS: Beginning of year 2,889,287,330 2,134,071,744 - --------------------------------------------------------------------------------------------------------- End of year $ 2,823,529,819 $ 2,889,287,330 - --------------------------------------------------------------------------------------------------------- Undistributed (distributions in excess of) net investment income $ 3,306,127 $ (11,431,441) - --------------------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these financial statements. 50 Pioneer High Yield Fund | Annual Report | 10/31/10 - --------------------------------------------------------------------------------------------------------- '10 Shares '10 Amount '09 Shares '09 Amount - --------------------------------------------------------------------------------------------------------- Class A Shares sold 94,387,088 $ 877,116,917 99,829,912 $681,835,019 Reinvestment of distributions 6,324,973 58,563,561 11,760,768 80,595,618 Less shares repurchased (101,272,169) (929,363,807) (84,521,880) (584,125,579) - --------------------------------------------------------------------------------------------------------- Net increase (560,108) $ 6,316,671 27,068,800 $178,305,058 ========================================================================================================= Class B Shares sold 1,522,607 $ 14,269,679 4,614,511 $ 30,519,474 Reinvestment of distributions 976,587 9,065,983 2,831,923 19,119,535 Less shares repurchased (21,378,104) (198,746,483) (18,728,332) (132,206,352) - --------------------------------------------------------------------------------------------------------- Net decrease (18,878,910) $(175,410,821) (11,281,898) $(82,567,343) ========================================================================================================= Class C Shares sold 16,824,613 $ 159,998,328 24,074,469 $159,613,308 Reinvestment of distributions 1,841,206 17,299,864 4,168,622 28,797,538 Less shares repurchased (29,726,359) (278,242,994) (25,652,386) (175,055,921) - --------------------------------------------------------------------------------------------------------- Net increase (decrease) (11,060,540) $(100,944,802) 2,590,705 $ 13,354,925 ========================================================================================================= Class R Shares sold 1,938,602 $ 19,998,238 5,177,337 $ 40,540,262 Reinvestment of distributions 467,649 4,816,792 1,055,590 8,080,989 Less shares repurchased (6,125,755) (62,993,476) (3,956,843) (31,508,458) - --------------------------------------------------------------------------------------------------------- Net increase (decrease) (3,719,504) $ (38,178,446) 2,276,084 $ 17,112,793 ========================================================================================================= Class Y Shares sold 19,675,595 $ 181,904,792 28,310,480 $206,797,888 Reinvestment of distributions 1,202,048 11,098,350 2,607,357 17,722,878 Less shares repurchased (32,748,053) (301,428,450) (24,884,401) (182,617,089) - --------------------------------------------------------------------------------------------------------- Net increase (decrease) (11,870,410) $(108,425,308) 6,033,436 $ 41,903,677 ========================================================================================================= Class Z Shares sold 246,206 $ 2,274,711 153,927 $ 1,152,854 Reinvestment of distributions 6,455 60,054 3,747 26,302 Less shares repurchased (149,462) (1,367,346) (42,673) (305,858) - --------------------------------------------------------------------------------------------------------- Net increase 103,199 $ 967,419 115,001 $ 873,298 ========================================================================================================= The accompanying notes are an integral part of these financial statements. Pioneer High Yield Fund | Annual Report | 10/31/10 51 Financial Highlights - ---------------------------------------------------------------------------------------------------------------------------------- Year Year Year Year Year Ended Ended Ended Ended Ended 10/31/10 10/31/09 10/31/08 10/31/07 10/31/06 - ---------------------------------------------------------------------------------------------------------------------------------- Class A Net asset value, beginning of period $ 8.69 $ 6.99 $ 11.51 $ 11.13 $ 11.18 - ---------------------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income $ 0.49 $ 0.54 $ 0.56 $ 0.50 $ 0.55 Net realized and unrealized gain (loss) on investments 1.17 1.87 (3.98) 0.88 0.49 - ---------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ 1.66 $ 2.41 $ (3.42) $ 1.38 $ 1.04 Distributions to shareowners: Net investment income (0.47) (0.61) (0.53) (0.51) (0.57) Net realized gain -- (0.09) (0.57) (0.49) (0.52) - ---------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ 1.19 $ 1.70 $ (4.52) $ 0.38 $ (0.05) - ---------------------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 9.88 $ 8.69 $ 6.99 $ 11.51 $ 11.13 ================================================================================================================================== Total return* 19.66% 37.79% (32.18)% 13.10% 9.98% Ratio of net expenses to average net assets+ 1.18% 1.25% 1.20% 1.10% 1.11% Ratio of net investment income to average net assets+ 5.28% 7.41% 5.63% 4.50% 5.02% Portfolio turnover rate 20% 45% 29% 27% 19% Net assets, end of period (in thousands) $1,584,198 $1,398,692 $935,580 $1,789,612 $2,192,694 Ratios with no waiver of fees by the Adviser and no reduction for fees paid indirectly: Net expenses 1.18% 1.25% 1.20% 1.10% 1.11% Net investment income 5.28% 7.41% 5.63% 4.50% 5.02% Ratios with waiver of fees by the Adviser and reduction for fees paid indirectly: Net expenses 1.18% 1.25% 1.20% 1.10% 1.10% Net investment income 5.28% 7.41% 5.63% 4.50% 5.03% ================================================================================================================================== * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions, the complete redemption of the investment at net asset value at the end of each period, and no sales charges. Total return would be reduced if sales charges were taken into account. + Ratios with no reduction for fees paid indirectly. The accompanying notes are an integral part of these financial statements. 52 Pioneer High Yield Fund | Annual Report | 10/31/10 - ---------------------------------------------------------------------------------------------------------------------------------- Year Year Year Year Year Ended Ended Ended Ended Ended 10/31/10 10/31/09 10/31/08 10/31/07 10/31/06 - ---------------------------------------------------------------------------------------------------------------------------------- Class B Net asset value, beginning of period $ 8.74 $ 7.03 $ 11.56 $ 11.18 $ 11.22 - ---------------------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income $ 0.40 $ 0.48 $ 0.49 $ 0.42 $ 0.47 Net realized and unrealized gain (loss) on investments 1.21 1.89 (3.99) 0.88 0.50 - ---------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ 1.61 $ 2.37 $ (3.50) $ 1.30 $ 0.97 Distributions to shareowners: Net investment income (0.40) (0.56) (0.46) (0.43) (0.49) Net realized gain -- (0.09) (0.57) (0.49) (0.52) - ---------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ 1.21 $ 1.71 $ (4.53) $ 0.38 $ (0.04) - ---------------------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 9.95 $ 8.74 $ 7.03 $ 11.56 $ 11.18 ================================================================================================================================== Total return* 18.83% 36.89% (32.72)% 12.23% 9.25% Ratio of net expenses to average net assets+ 1.96% 2.04% 1.91% 1.86% 1.84% Ratio of net investment income to average net assets+ 4.52% 6.84% 4.90% 3.75% 4.30% Portfolio turnover 20% 45% 29% 27% 19% Net assets, end of period (in thousands) $240,993 $376,790 $382,124 $813,963 $1,063,908 Ratios with no waiver of fees by the Adviser and no reduction for fees paid indirectly: Net expenses 1.96% 2.04% 1.91% 1.86% 1.84% Net investment income 4.52% 6.84% 4.90% 3.75% 4.30% Ratios with waiver of fees by the Adviser and reduction for fees paid indirectly: Net expenses 1.96% 2.04% 1.90% 1.85% 1.83% Net investment income 4.52% 6.84% 4.91% 3.76% 4.31% ================================================================================================================================== * 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. + Ratios with no reduction for fees paid indirectly. The accompanying notes are an integral part of these financial statements. Pioneer High Yield Fund | Annual Report | 10/31/10 53 Financial Highlights (continued) - ---------------------------------------------------------------------------------------------------------------------------------- Year Year Year Year Year Ended Ended Ended Ended Ended 10/31/10 10/31/09 10/31/08 10/31/07 10/31/06 - ---------------------------------------------------------------------------------------------------------------------------------- Class C Net asset value, beginning of period $ 8.83 $ 7.10 $ 11.68 $ 11.28 $ 11.32 - ---------------------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income $ 0.42 $ 0.49 $ 0.50 $ 0.43 $ 0.48 Net realized and unrealized gain (loss) on investments 1.20 1.91 (4.05) 0.90 0.50 - ---------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ 1.62 $ 2.40 $ (3.55) $ 1.33 $ 0.98 Distributions to shareowners: Net investment income (0.41) (0.58) (0.46) (0.44) (0.50) Net realized gain -- (0.09) (0.57) (0.49) (0.52) - ---------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ 1.21 $ 1.73 $ (4.58) $ 0.40 $ (0.04) - ---------------------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 10.04 $ 8.83 $ 7.10 $ 11.68 $ 11.28 ================================================================================================================================== Total return* 18.79% 37.01% (32.78)% 12.35% 9.22% Ratio of net expenses to average net assets+ 1.88% 1.98% 1.89% 1.85% 1.82% Ratio of net investment income to average net assets+ 4.60% 6.78% 4.94% 3.76% 4.33% Portfolio turnover rate 20% 45% 29% 27% 19% Net assets, end of period (in thousands) $599,656 $624,726 $483,992 $964,063 $1,247,550 Ratios with no waiver of fees by the Adviser and no reduction for fees paid indirectly: Net expenses 1.88% 1.98% 1.89% 1.85% 1.82% Net investment income 4.60% 6.78% 4.94% 3.76% 4.33% Ratios with waiver of fees by the Adviser and reduction for fees paid indirectly: Net expenses 1.88% 1.98% 1.89% 1.85% 1.81% Net investment income 4.60% 6.78% 4.94% 3.76% 4.34% ================================================================================================================================== * 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. + Ratios with no reduction for fees paid indirectly. The accompanying notes are an integral part of these financial statements. 54 Pioneer High Yield Fund | Annual Report | 10/31/10 - ---------------------------------------------------------------------------------------------------------------------------------- Year Year Year Year Year Ended Ended Ended Ended Ended 10/31/10 10/31/09 10/31/08 10/31/07 10/31/06 - ---------------------------------------------------------------------------------------------------------------------------------- Class R Net asset value, beginning of period $ 9.70 $ 7.79 $ 12.74 $ 12.28 $ 12.29 - ---------------------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income $ 0.49 $ 0.58 $ 0.60 $ 0.53 $ 0.56 Net realized and unrealized gain (loss) on investments 1.34 2.09 (4.42) 0.96 0.56 - ---------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ 1.83 $ 2.68 $ (3.82) $ 1.49 $ 1.12 Distributions to shareowners: Net investment income (0.50) (0.67) (0.56) (0.54) (0.61) Net realized gain -- (0.09) (0.57) (0.49) (0.52) - ---------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ 1.33 $ 1.91 $ (4.95) $ 0.46 $ (0.01) - ---------------------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 11.03 $ 9.70 $ 7.79 $ 12.74 $ 12.28 ================================================================================================================================== Total return* 19.32% 37.73% (32.36)% 12.76% 9.67% Ratio of net expenses to average net assets+ 1.49% 1.47% 1.47% 1.34% 1.45% Ratio of net investment income to average net assets+ 5.00% 7.23% 5.44% 4.24% 4.60% Portfolio turnover rate 20% 45% 29% 27% 19% Net assets, end of period (in thousands) $ 95,303 $119,846 $78,537 $98,353 $54,188 Ratios with no waiver of fees by the Adviser and no reduction for fees paid indirectly: Net expenses 1.49% 1.47% 1.47% 1.34% 1.45% Net investment income 5.00% 7.23% 5.44% 4.24% 4.60% Ratios with waiver of fees by the Adviser and reduction for fees paid indirectly: Net expenses 1.49% 1.47% 1.47% 1.34% 1.45% Net investment income 5.00% 7.23% 5.44% 4.24% 4.60% ================================================================================================================================== * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions and the complete redemption of the investment at net asset value at the end of each period. + Ratios with no reduction for fees paid indirectly. The accompanying notes are an integral part of these financial statements. Pioneer High Yield Fund | Annual Report | 10/31/10 55 Financial Highlights (continued) - -------------------------------------------------------------------------------------------------------------------------------- Year Year Year Year Year Ended Ended Ended Ended Ended 10/31/10 10/31/09 10/31/08 10/31/07 10/31/06 - -------------------------------------------------------------------------------------------------------------------------------- Class Y Net asset value, beginning of period $ 8.69 $ 6.99 $ 11.48 $ 11.11 $ 11.16 - -------------------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income $ 0.51 $ 0.57 $ 0.60 $ 0.55 $ 0.59 Net realized and unrealized gain (loss) on investments 1.19 1.87 (3.95) 0.87 0.49 - -------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ 1.70 $ 2.44 $ (3.35) $ 1.42 $ 1.08 Distributions to shareowners: Net investment income (0.51) (0.65) (0.57) (0.56) (0.61) Net realized gain -- (0.09) (0.57) (0.49) (0.52) - -------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ 1.19 $ 1.70 $ (4.49) $ 0.37 $ (0.05) - -------------------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 9.88 $ 8.69 $ 6.99 $ 11.48 $ 11.11 ================================================================================================================================ Total return* 20.16% 38.59% (31.79)% 13.48% 10.43% Ratio of net expenses to average net assets+ 0.79% 0.78% 0.76% 0.71% 0.68% Ratio of net investment income to average net assets+ 5.67% 7.95% 6.15% 4.88% 5.39% Portfolio turnover rate 20% 45% 29% 27% 19% Net assets, end of period (in thousands) $300,881 $367,933 $253,593 $317,661 $265,107 Ratios with no waiver of fees by the Adviser and no reduction for fees paid indirectly: Net expenses 0.79% 0.78% 0.76% 0.71% 0.68% Net investment income 5.67% 7.95% 6.15% 4.88% 5.39% Ratios with waiver of fees by the Adviser and reduction for fees paid indirectly: Net expenses 0.79% 0.78% 0.76% 0.71% 0.68% Net investment income 5.67% 7.95% 6.15% 4.88% 5.39% ================================================================================================================================ * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions and the complete redemption of the investment at net asset value at the end of each period. + Ratios with no reduction for fees paid indirectly. The accompanying notes are an integral part of these financial statements. 56 Pioneer High Yield Fund | Annual Report | 10/31/10 - -------------------------------------------------------------------------------------------------------------------------------- Year Year Year Ended Ended Ended 7/6/07 to 10/31/10 10/31/09 10/31/08 10/31/07 (a) - -------------------------------------------------------------------------------------------------------------------------------- Class Z Net asset value, beginning of period $ 8.65 $ 7.01 $ 11.51 $11.42 - -------------------------------------------------------------------------------------------------------------------------------- Increase (decrease) from investment operations: Net investment income $ 0.53 $ 0.58 $ 0.60 $ 0.17 Net realized and unrealized gain (loss) on investments 1.18 1.80 (3.95) 0.09 - -------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) from investment operations $ 1.71 $ 2.38 $ (3.35) $ 0.26 Distributions to shareowners: Net investment income (0.50) (0.65) (0.58) (0.17) Net realized gain -- (0.09) (0.57) -- - -------------------------------------------------------------------------------------------------------------------------------- Net increase (decrease) in net asset value $ 1.21 $ 1.64 $ (4.50) $ 0.09 - -------------------------------------------------------------------------------------------------------------------------------- Net asset value, end of period $ 9.86 $ 8.65 $ 7.01 $11.51 ================================================================================================================================ Total return* 20.35% 37.48% (31.76)% 2.35%(b) Ratio of net expenses to average net assets+ 0.85% 0.85% 0.85% 0.67%** Ratio of net investment income to average net assets+ 5.60% 7.49% 6.34% 4.92%** Portfolio turnover rate 20% 45% 29% 27%(b) Net assets, end of period (in thousands) $2,499 $1,300 $ 247 $ 101 Ratios with no waiver of fees by the Adviser and no reduction for fees paid indirectly: Net expenses 0.98% 0.98% 1.02% 0.67%** Net investment income 5.47% 7.36% 6.17% 4.92%** Ratios with waiver of fees by the Adviser and reduction for fees paid indirectly: Net expenses 0.85% 0.85% 0.85% 0.67%** Net investment income 5.60% 7.49% 6.34% 4.92%** ================================================================================================================================ (a) Class Z shares were first publicly offered on July 6, 2007. (b) Not annualized. * Assumes initial investment at net asset value at the beginning of each period, reinvestment of all distributions and the complete redemption of the investment at net asset value at the end of each period. ** Annualized. + Ratios with no reduction for fees paid indirectly. The accompanying notes are an integral part of these financial statements. Pioneer High Yield Fund | Annual Report | 10/31/10 57 Notes to Financial Statements | 10/31/10 1. Organization and Significant Accounting Policies Pioneer High Yield Fund (the Fund), a Delaware statutory trust, 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 maximize total return through a combination of income and capital appreciation. The Fund offers six classes of shares designated as Class A, Class B, Class C, Class R, Class Y and Class Z shares. Class Z shares were first publicly offered on July 6, 2007. Effective as of the close of business on December 31, 2009, Class B shares are no longer offered to new or existing shareholders, except that dividends and/or capital gain distributions may continue to be reinvested in Class B shares, and shareholders may exchange their Class B shares for Class B shares of other Pioneer funds, as permitted by existing exchange privileges. Each class of shares represents an interest in the same portfolio of investments of the Fund and has identical rights (based on relative net asset values) to assets and liquidation proceeds. Share classes can bear different rates of class-specific fees and expenses such as transfer agent and distribution fees. Differences in class-specific fees and expenses will result in differences in net investment income and, therefore, the payment of different dividends from net investment income earned by each class. The Amended and Restated Declaration of Trust of the Fund gives the Board the flexibility to specify either per share voting or dollar-weighted voting when submitting matters for shareholder approval. Under per share voting, each share of a class of the Fund is entitled to one vote. Under dollar-weighted voting, a shareholder's voting power is determined not by the number of shares owned, but by the dollar value of the shares on the record date. Each share class has exclusive voting rights with respect to matters affecting only that class, including with respect to the distribution plan for that class. There is no distribution plan for Class Y shares or Class Z shares. Class B shares convert to Class A shares approximately eight years after the date of purchase. At times, the Fund's investments may represent industries or industry sectors that are interrelated or have common risks, making the Fund susceptible to any economic, political, or regulatory developments or other risks affecting those industries or sectors. The Fund invests in below investment grade (high yield) debt securities and preferred stocks. Some of these high yield securities may be convertible into equity securities of the issuer. Debt securities rated below investment grade are commonly referred to as "junk bonds" and are considered speculative. These securities involve greater risk of loss, are subject to greater price volatility, and are less liquid, especially during periods of economic uncertainty or change, than higher rated debt securities. The Fund's prospectus 58 Pioneer High Yield Fund | Annual Report | 10/31/10 contains unaudited information regarding the Fund's principal risks. Please refer to that documents when considering the Fund's principal risks. 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, which are consistent with those policies generally accepted in the investment company industry: A. Security Valuation Security transactions are recorded as of trade date. The net asset value of the Fund is computed once daily, on each day the New York Stock Exchange (NYSE) is open, as of the close of regular trading on the NYSE. Senior floating rate loan interests (senior loans) are valued in accordance with guidelines established by the Board of Trustees at the mean between the last available bid and asked prices from one or more brokers or dealers as obtained from Loan Pricing Corporation. Senior loans for which no reliable price quotes are available will be valued by Loan Pricing Corporation through the use of pricing matrices to determine valuations. Fixed income securities with remaining maturity of more than sixty days are valued at prices supplied by independent pricing services, which consider such factors as market prices, market events, quotations from one or more brokers, Treasury spreads, yields, maturities and ratings. Valuations may be supplemented by dealers and other sources, as required. Credit default swaps are valued by an independent pricing service based upon valuation models incorporating default probabilities, estimated recovery rates, actual reported transactions, and other available market data. Equity securities that have traded on an exchange are valued at the last sale price on the principal exchange where they are traded. Equity securities that have not traded on the date of valuation, or securities for which sale prices are not available, generally are valued using the mean between the last bid and asked prices. Securities or loans for which independent pricing services are unable to supply prices or for which market prices and/or quotations are not readily available or are considered to be unreliable are valued using fair value methods pursuant to procedures adopted by the Board of Trustees. The Fund may also 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. Thus, the valuation of the Fund's securities may differ from exchange Pioneer High Yield Fund | Annual Report | 10/31/10 59 prices. At October 31, 2010 3 securities were valued using fair value methods (in addition to securities valued using prices supplied by independent pricing services representing) 0.1% of net assets. 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. Short-term fixed income securities with remaining maturities of sixty days or less generally are valued at amortized cost. Money market mutual funds are valued at net asset value. Principal amounts of mortgage-backed securities are adjusted for monthly paydowns. Premiums and discounts related to certain mortgage-backed securities are amortized or accreted in proportion to the monthly paydowns. All discounts/premiums on debt securities are accreted/amortized for financial reporting purposes over the life of the respective securities, and such accretion/amortization is included in interest income. Interest income is recorded on the accrual basis, net of unrecoverable foreign taxes withheld at the applicable country rates. Dividend income is recorded on the ex-dividend date, except that certain dividends from foreign securities where the ex-dividend date may have passed are recorded as soon as the Fund becomes aware of the ex-dividend data in the exercise of reasonable diligence. Interest income, including interest on income bearing cash accounts, is recorded on the accrual basis, net of unrecoverable foreign taxes withheld at the applicable country rates. Gains and losses on sales of investments are calculated on the identified cost method for both financial reporting and federal income tax purposes. B. 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 taxable income and net realized capital gains, if any, to its share-owners. Therefore, no federal income tax provision is required. Tax years for the prior three fiscal years are subject to examination by tax authorities. The amounts and characterizations of distributions to shareowners for financial reporting purposes are determined in accordance with federal income tax rules. Therefore, the sources of the Fund's distributions may be shown in the accompanying financial statements as from or in excess of net investment income or as from net realized gain on investment transactions, or as from paid-in capital, depending on the type of book/tax differences that may exist. At October 31, 2010, The Fund had a net capital loss carryforward of $255,741,539 of which the following amounts will expire between 2011 and 2017 if not utilized: $884,417 in 2011 and $254,857,122 in 2017. 60 Pioneer High Yield Fund | Annual Report | 10/31/10 At October 31, 2010, the Fund reclassified $10,494,355 to increase undistributed net investment income and $10,494,355 to decrease accumulated net realized loss on investments to reflect permanent book/tax differences. The reclassification has no impact on the net assets of the Fund and presents the Fund's capital accounts on a tax-basis. The tax character of distributions paid during the years ended October 31, 2010 and October 31, 2009 was as follows: - -------------------------------------------------------------------------------- 2010 2009 - -------------------------------------------------------------------------------- Distributions paid from: Ordinary income $136,834,206 $191,293,201 Long-term capital gain -- 27,536,312 - -------------------------------------------------------------------------------- Total $136,834,206 $218,829,513 ================================================================================ The following shows the components of distributable earnings on a federal income tax-basis at October 31, 2010: - -------------------------------------------------------------------------------- 2010 - -------------------------------------------------------------------------------- Distributable earnings: Undistributed ordinary income $ 13,420,625 Capital loss carryforward (255,741,539) Current year dividend payable (2,257,722) Unrealized appreciation 215,411,995 - -------------------------------------------------------------------------------- Total $(29,166,641) ================================================================================ The difference between book-basis and tax-basis unrealized appreciation is attributable to the tax deferral of losses on wash sales, interest accruals on preferred stocks, adjustments relating to catastrophe bonds, and interest on defaulted bonds. C. 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. (Uni-Credit), earned $115,639 in underwriting commissions on the sale of Class A shares during the year ended October 31, 2010. D. 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 B, Class C and Class R shares of the Fund, Pioneer High Yield Fund | Annual Report | 10/31/10 61 respectively (see Note 4). Class Y and Class Z shares do not pay distribution fees. All expenses and fees paid to the transfer agent, Pioneer Investment Management Shareholder Services, Inc. (PIMSS), for its services are allocated among the classes of shares based on the number of accounts in each class and the ratable allocation of related out-of-pocket expenses (see Note 3). The Fund declares as daily dividends substantially all of its net investment income. All dividends are paid on a monthly basis. Short-term capital gain distributions, if any, may be declared with the daily dividends. Distributions to shareowners are recorded as of the ex-dividend date. Distributions paid by the Fund with respect to each class of shares are calculated in the same manner and at the same time, except that net investment income dividends to Class A, Class B, Class C, Class R, Class Y and Class Z shares can reflect different transfer agent and distribution expense rates. E. Repurchase Agreements With respect to repurchase agreements entered into by the Fund, the value of the underlying securities (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, Pioneer Investment Management, Inc. (PIM), is responsible for determining that the value of the collateral remains at least equal to the repurchase price. F. Securities Lending The Fund lends securities in its portfolio to certain broker-dealers or other institutional investors. When entering into a securities loan transaction, the Fund typically receives cash collateral from the borrower equal to at least the value of the securities loaned, which is invested in temporary investments. Credit Suisse AG, New York Branch, as the Fund's securities lending agent, manages the Fund's securities lending collateral. The income earned on the investment of collateral is shared with the borrower and the lending agent in payment of any rebate due to the borrower with respect to the securities loan, and in compensation for the lending agent's services to the Fund. The Fund also continues to receive payments in lieu of dividends or interest on the securities loaned. Gain or loss on the value of the loaned securities that may occur during the term of the loan will be for the account of the Fund. The amount of the collateral is required to be adjusted daily to reflect any price fluctuation in the value of the loaned securities. If the required market value of the collateral is less than the value of the loaned securities, the borrower is required to deliver additional collateral for the account of the Fund prior to the close of business on that day. The Fund has the right, under the lending agreement, to terminate the loan and recover the securities from the 62 Pioneer High Yield Fund | Annual Report | 10/31/10 borrower with prior notice. The Fund is required to return the cash collateral to the borrower and could suffer a loss if the value of the collateral, as invested, has declined. G. 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 buy or sell credit default swap contracts to increase the Fund's income, to add leverage to the Fund or to hedge the risk of default on portfolio securities. When the Fund is 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 Fund as seller of protection 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 described above. When the Fund enters into a credit default swap contract, one party, 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 received by the Fund, as the protection seller, is recorded as a liability in the Fund's records. An upfront payment made by the Fund, as the protection buyer, is recorded as an asset in the Fund's records. Periodic payments received or paid by the Fund are recorded as realized gains or losses. The 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 gain or loss. 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. 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. Pioneer High Yield Fund | Annual Report | 10/31/10 63 Notes to Financial Statements | 10/31/10 The Fund had no credit default swap contracts in the portfolio at October 31, 2010. 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 0.70% of the Fund's average daily net assets up to $500 million, 0.65% of the next $500 million, 0.60% of the next $4 billion, 0.55% of the next $1 billion, 0.50% of the next $1 billion, 0.45% of the next $1 billion, 0.40% of the next $1 billion, 0.35% of the next $1 billion, and 0.30% on assets over $10 billion. For the year ended October 31, 2010, the effective management fee was equivalent to 0.47% of the Fund's average daily net assets. PIM has contractually agreed to limit ordinary operating expenses to the extent required to reduce Class Z expenses to 0.85% of the average daily net assets attributable to Class Z shares. This expense limitation is in effect through March 1, 2012 for Class Z shares. There can be no assurance that PIM will extend the expense limitation agreement for a class of shares beyond the date referred to above. In addition, under the management and administration agreements, certain other services and costs, including accounting, regulatory reporting and insurance premiums, are paid by the Fund as administrative reimbursements. Included in "Due to affiliates" reflected on the Statement of Assets and Liabilities is $152,260 in management fees, administrative costs and certain other reimbursements payable to PIM at October 31, 2010. 3. Transfer Agent PIMSS, a wholly owned indirect subsidiary of UniCredit, provides substantially all transfer agent and shareowner services to the Fund at negotiated rates. In addition, the Fund reimburses PIMSS for out-of-pocket expenses incurred by PIMSS related to shareholder communications activities such as proxy and statement mailings, outgoing phone calls and omnibus relationship contracts. For the year ended October 31, 2010, such out-of-pocket expenses by class of shares were as follows: 64 Pioneer High Yield Fund | Annual Report | 10/31/10 - -------------------------------------------------------------------------------- Shareholder Communications: - -------------------------------------------------------------------------------- Class A $1,687,074 Class B 192,485 Class C 417,127 Class R 281,746 Class Y 247,454 Class Z 991 - -------------------------------------------------------------------------------- Total $2,826,877 ================================================================================ Included in "Due to affiliates" reflected on the Statement of Assets and Liabilities is $439,233 in transfer agent fees and out-of-pocket reimbursements payable to PIMSS at October 31, 2010. 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 B, 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 B and Class C shares. The fee for Class B and 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 B and Class C shares. Pursuant to the Plan, the Fund 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 $148,833 in distribution fees payable to PFD at October 31, 2010. 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 R, Class Y and Class Z shares) may be subject to a contingent deferred sales charge (CDSC). A CDSC of 1.00% may be imposed on redemptions of certain net asset value purchases of Class A shares within 18 months of purchase (within 12 months for purchases made on or after April 1, 2009). Class B shares that are redeemed within five years of purchase are subject to a CDSC at declining rates beginning at 4.00%, based on the lower of cost or market value of shares being redeemed. Redemptions of Class C shares within one year 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 Pioneer High Yield Fund | Annual Report | 10/31/10 65 CDSC that applied to the original purchase of those shares. There is no CDSC for Class R, Class Y or Class Z shares. Proceeds from the CDSCs are paid to PFD. For the year ended October 31, 2010, CDSCs in the amount of $268,178 were paid to PFD. 5. Expense Offset Arrangements The Fund has entered into certain expense offset arrangements with PIMSS resulting in a reduction in the Fund's total expenses, due to interest earned on cash held by PIMSS. For the year ended October 31, 2010, the Fund's expenses were not reduced under such arrangements. 6. Line of Credit Facility The Fund has a $100 million committed, unsecured revolving line of credit facility. The Fund may borrow up to the lesser of $100 million or the limit set for borrowings by the Fund's prospectus and the 1940 Act. Interest on borrowings is payable at the higher of the Federal Funds Rate as in effect on that day, plus 1.25% on an annualized basis or the overnight London Interbank Offered Rate (LIBOR) as in effect on that day plus 1.25% on an annualized basis. The Fund pays a quarterly commitment fee for this facility. For the year ended October 31, 2010, the average daily amount of borrowings outstanding during the period was $3,342,510. The related weighted average annualized interest rate for the period was 1.49%, and the total interest expense on such borrowings was $101,035. As of October 31, 2010, there were no borrowings outstanding. 7. Unfunded Loan Commitments As of October 31, 2010, the fund had unfunded loan commitments of approximately $4,287,753 (excluding unrealized appreciation on those commitments of $37,753 as of October 31, 2010) which could be extended at the option of the borrower, pursuant to the following loan agreements: - ----------------------------------------------------------------------------------------- Net Unrealized Loan Shares Cost Value Gain - ----------------------------------------------------------------------------------------- Reynolds Group Holdings, Ltd., Incremental Tranche D Term Loan 4,250,000 $4,250,000 $4,287,753 $37,753 - ----------------------------------------------------------------------------------------- Total $37,753 ========================================================================================= 66 Pioneer High Yield Fund | Annual Report | 10/31/10 In addition, the Fund had the following bridge Loan commitments outstanding as of October 31, 2010: - --------------------------------------------------------------------------------------------------------- Net Unrealized Loans Shares Cost Value Gain - --------------------------------------------------------------------------------------------------------- MedAssets, Inc., Bridge Loan, 9/20/11 $10,690,760 $10,690,760 $10,690,760 $-- - --------------------------------------------------------------------------------------------------------- PAETEC Holding Corp., Senior Secured Bridge Facility Loan, 3/12/11 8,300,000 8,300,000 8,300,000 -- - --------------------------------------------------------------------------------------------------------- Total $-- ========================================================================================================= 8. Subsequent Events In preparing these financial statements, PIM has evaluated the impact of all events and transactions for potential recognition or disclosure and has determined that there were no subsequent events requiring recognition or disclosure in the financial statements. Pioneer High Yield Fund | Annual Report | 10/31/10 67 Report of Independent Registered Public Accounting Firm To the Board of Trustees and the Shareowners of Pioneer High Yield Fund - -------------------------------------------------------------------------------- We have audited the accompanying statement of assets and liabilities of Pioneer High Yield Fund (the "Fund"), including the schedule of investments, as of October 31, 2010, and the related statement of operations for the year then ended, the statements of changes in net assets for each of the two years in the period then ended, and the financial highlights for each of the periods indicated therein. These financial statements and financial highlights are the responsibility of the Fund's management. Our responsibility is to express an opinion on these financial statements and financial highlights based on our audits. We conducted our audits in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements and financial highlights are free of material misstatement. We were not engaged to perform an audit of the Fund's internal control over financial reporting. Our audits included consideration of internal control over financial reporting as a basis for designing audit procedures that are appropriate in the circumstances, but not for the purpose of expressing an opinion on the effectiveness of the Fund's internal control over financial reporting. Accordingly, we express no such opinion. An audit also includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements and financial highlights, assessing the accounting principles used and significant estimates made by management, and evaluating the overall financial statement presentation. Our procedures included confirmation of securities owned as of October 31, 2010, by correspondence with the custodian, brokers and agent banks or by other appropriate auditing procedures where replies from brokers and agent banks were not received. We believe that our audits provide a reasonable basis for our opinion. In our opinion, the financial statements and financial highlights referred to above present fairly, in all material respects, the financial position of Pioneer High Yield Fund at October 31, 2010, the results of its operations for the year then ended, the changes in its net assets for each of the two years in the period then ended, and the financial highlights for each of the periods indicated therein, in conformity with U.S. generally accepted accounting principles. /s/ Ernst & Young LLP Boston, Massachusetts December 28, 2010 68 Pioneer High Yield Fund | Annual Report | 10/31/10 ADDITIONAL INFORMATION (unaudited) The percentages of the Fund's ordinary income distributions that are exempt from nonresident alien (NRA) tax withholding resulting from qualified interest income and qualified short term gains were 73.49% and 0.0%, respectively. Pioneer High Yield Fund | Annual Report | 10/31/10 69 Trustees, Officers and Service Providers Investment Adviser Pioneer Investment Management, Inc. Custodian Brown Brothers Harriman & Co. Independent Registered Public Accounting Firm Ernst & Young LLP Principal Underwriter Pioneer Funds Distributor, Inc. Legal Counsel Bingham McCutchen LLP Shareowner Services and Transfer Agent Pioneer Investment Management Shareholder 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 www.pioneerinvestments.com. This information is also available on the Securities and Exchange Commission's web site at http://www.sec.gov. Trustees and Officers The Fund's Trustees and officers are listed below, together with their principal occupations during at least the past five years. Trustees who are interested persons of the Fund within the meaning of the 1940 Act are referred to as Interested Trustees. Trustees who are not interested persons of the Fund are referred to as Independent Trustees. Each of the Trustees, except Mr. West, serves as a trustee of each of the 57 U.S. registered investment portfolios for which Pioneer serves as investment adviser (the "Pioneer Funds"). Mr. West serves as a trustee of 44 U.S. registered investment portfolios for which Pioneer serves as investment adviser. The address for all Trustees and all officers of the Fund is 60 State Street, Boston, Massachusetts 02109. The Statement of Additional Information of the Fund includes additional information about the Trustees and is available, without charge, upon request, by calling 1-800-225-6292. 70 Pioneer High Yield Fund | Annual Report | 10/31/10 Interested Trustees - ------------------------------------------------------------------------------------------------------------------------------------ Position Held Length of Service Other Directorships Name and Age with the Fund and Term of Office Principal Occupation Held by this Trustee - ------------------------------------------------------------------------------------------------------------------------------------ John F. Cogan, Jr. (84)* Chairman of the Board, Trustee since 1999. Non-Executive Chairman and a None Trustee and President Serves until a successor director of Pioneer Investment trustee is elected or Management USA Inc. ("PIM-USA"); earlier retirement or Chairman and a director of Pioneer; removal. Chairman and Director of Pioneer Institutional Asset Management, Inc. (since 2006); Director of Pioneer Alternative Investment Management Limited (Dublin); President and a director of Pioneer Alternative Investment Management (Bermuda) Limited and affiliated funds; Deputy Chairman and a director of Pioneer Global Asset Management S.p.A. ("PGAM") (until April 2010); Director of PIOGLOBAL Real Estate Investment Fund (Russia) (until June 2006); Director of Nano-C, Inc. (since 2003); Director of Cole Management Inc. (since 2004); Director of Fiduciary Counseling, Inc.; President and Director of Pioneer Funds Distributor, Inc. ("PFD") (until May 2006); President of all of the Pioneer Funds; and Of Counsel, Wilmer Cutler Pickering Hale and Dorr LLP - ------------------------------------------------------------------------------------------------------------------------------------ Daniel K. Kingsbury (52)* Trustee and Executive Trustee since 2007. Director, CEO and President of None Vice President Serves until a successor PIM-USA (since February 2007); trustee is elected or Director and President of Pioneer earlier retirement or and Pioneer Institutional Asset removal. Management, Inc. (since February 2007); Executive Vice President of all of the Pioneer Funds (since March 2007); Director of PGAM (2007 - 2010); Head of New Europe Division, PGAM (2000 - 2005); and Head of New Markets Division, PGAM (2005 - 2007) - ------------------------------------------------------------------------------------------------------------------------------------ * Mr. Cogan and Mr. Kingsbury are Interested Trustees because they are officers or directors of the Fund's investment adviser and certain of its affiliates. Pioneer High Yield Fund | Annual Report | 10/31/10 71 Independent Trustees - ------------------------------------------------------------------------------------------------------------------------------------ Position Held Length of Service Principal Occupation During Other Directorships Name and Age with the Fund and Term of Office Past Five Years Held by this Trustee - ------------------------------------------------------------------------------------------------------------------------------------ David R. Bock (66) Trustee Trustee since 2005. Interim Chief Executive Director of Enterprise Serves until a successor Officer, Oxford Analytica, Community Investment, Inc. trustee is elected or Inc. (privately held research (privately held affordable earlier retirement or and consulting company) (2010 housing finance company) (1985 removal. - present); Managing Partner, - present); Director of Oxford Federal City Capital Advisors Analytica, Inc. (2008 - (corporate advisory services present); and Director of New company) (1997 - 2004 and 2008 York Mortgage Trust (publicly - present); Executive Vice traded mortgage REIT) (2004 - President and Chief Financial 2009) Officer, I-trax, Inc. (publicly traded health care services company) (2004 - 2007); and Executive Vice President and Chief Financial Officer, Pedestal Inc. (internet-based mortgage trading company) (2000 - 2002) - ------------------------------------------------------------------------------------------------------------------------------------ Mary K. Bush (62) Trustee Trustee since 1999. President, Bush International, Director of Marriott Serves until a successor LLC (international financial International, Inc. (2008 - trustee is elected or advisory firm) (1991 - present); Director of Discover earlier retirement or present); Managing Director, Financial Services (credit removal. Federal Housing Finance Board card issuer and electronic (oversight of Federal Home payment services) (2007 - Loan Bank system) (1989 - present); Former Director of 1991); Vice President and Head Briggs & Stratton Co. (engine of International Finance, manufacturer) (2004 - 2009); Federal National Mortgage Director of UAL Corporation Association (1988 - 1989); (airline holding company) U.S. Alternate Executive (2006 - present); Director of Director, International ManTech International Monetary Fund (1984 - 1988); Corporation (national Executive Assistant to Deputy security, defense, and Secretary of the U.S. intelligence technology firm) Treasury, U.S. Treasury (2006 - present); Member, Department (1982 - 1984); and Vice President and Team Leader in Corporate Banking, Bankers Trust Co. (1976 - 1982) - ------------------------------------------------------------------------------------------------------------------------------------ 72 Pioneer High Yield Fund | Annual Report | 10/31/10 - ------------------------------------------------------------------------------------------------------------------------------------ Position Held Length of Service Principal Occupation During Other Directorships Name and Age with the Fund and Term of Office Past Five Years Held by this Trustee - ------------------------------------------------------------------------------------------------------------------------------------ Mary K. Bush (62) (continued) Board of Governors, Investment Company Institute (2007 - present); Former Director of Brady Corporation (2000 - 2007); Former Director of Mortgage Guaranty Insurance Corporation (1991 - 2006); Former Director of Millennium Chemicals, Inc. (commodity chemicals) (2002 - 2005); Former Director, R.J. Reynolds Tobacco Holdings, Inc. (tobacco) (1999 - 2005); and Former Director of Texaco, Inc. (1997 - 2001) - ------------------------------------------------------------------------------------------------------------------------------------ Benjamin M. Friedman (66) Trustee Trustee since 2008. William Joseph Maier Professor Trustee, Mellon Institutional Serves until a successor of Political Economy, Harvard Funds Investment Trust and trustee is elected or University (1972 - present) Mellon Institutional Funds earlier retirement or Master Portfolio (oversaw 17 removal. portfolios in fund complex) (1989 - 2008) - ------------------------------------------------------------------------------------------------------------------------------------ Pioneer High Yield Fund | Annual Report | 10/31/10 73 Independent Trustees (continued) - ------------------------------------------------------------------------------------------------------------------------------------ Position Held Length of Service Principal Occupation During Other Directorships Name and Age with the Fund and Term of Office Past Five Years Held by this Trustee - ------------------------------------------------------------------------------------------------------------------------------------ Margaret B.W. Graham (63) Trustee Trustee since 1999. Founding Director, Vice None Serves until a successor President and Corporate trustee is elected or Secretary, The Winthrop Group, earlier retirement or Inc. (consulting firm) (1982 - removal. present); Desautels Faculty of Management, McGill University (1999 - present); and Manager of Research Operations and Organizational Learning, Xerox PARC, Xerox's Advance Research Center (1990 - 1994) - ------------------------------------------------------------------------------------------------------------------------------------ Thomas J. Perna (60) Trustee Trustee since 2006. Chairman and Chief Executive Director, Broadridge Finan- Serves until a successor Officer, Quadriserv, Inc. cial Solutions, Inc. (investor trustee is elected or (technol- ogy products for communications and securities earlier retirement or securities lending industry) processing provider for removal. (2008 - present); Private financial services industry) investor (2004 - 2008); and (2009 - present); and Senior Executive Vice Director, Quadriserv, Inc. President, The Bank of New (2005 - present) York (financial and securities services) (1986 - 2004) - ------------------------------------------------------------------------------------------------------------------------------------ Marguerite A. Piret (62) Trustee Trustee since 1999. President and Chief Executive Director of New America High Serves until a successor Officer, Newbury, Piret & Income Fund, Inc. (closed-end trustee is elected or Company, Inc. (investment investment company) (2004 - earlier retirement or banking firm) (1981 - present) present); and Member, Board of removal. Governors, Investment Company Institute (2000 - 2006) - ------------------------------------------------------------------------------------------------------------------------------------ Stephen K. West (82) Trustee Trustee since 1999. Senior Counsel, Sullivan & Director, The Swiss Helvetia Serves until a successor Cromwell LLP (law firm) (1998 Fund, Inc. (closed-end trustee is elected or - present); and Partner, investment company); and earlier retirement or Sullivan & Cromwell LLP (prior Director, AMVESCAP, PLC removal. to 1998) (investment manager) (1997 - 2005) - ------------------------------------------------------------------------------------------------------------------------------------ 74 Pioneer High Yield Fund | Annual Report | 10/31/10 Fund Officers - ------------------------------------------------------------------------------------------------------------------------------------ Position Held Length of Service Other Directorships Name and Age with the Fund and Term of Office Principal Occupation Held by this Officer - ------------------------------------------------------------------------------------------------------------------------------------ Christopher J. Kelley (45) Secretary Since 2010. Serves at Vice President and Associate None the discretion of the General Counsel of Pioneer Board. since January 2008 and Secretary of all of the Pioneer Funds since June 2010; Assistant Secretary of all of the Pioneer Funds from September 2003 to May 2010; and Vice President and Senior Counsel of Pioneer from July 2002 to December 2007 - ------------------------------------------------------------------------------------------------------------------------------------ Carol B. Hannigan (49) Assistant Secretary Since 2010. Serves at Fund Governance Director of None the discretion of the Pioneer since December 2006 Board. and Assistant Secretary of all the Pioneer Funds since June 2010; Manager -- Fund Governance of Pioneer from December 2003 to November 2006; and Senior Paralegal of Pioneer from January 2000 to November 2003 - ------------------------------------------------------------------------------------------------------------------------------------ Thomas Reyes (47) Assistant Secretary Since 2010. Serves at Counsel of Pioneer since June None the discretion of the 2007 and Assistant Secretary Board. of all the Pioneer Funds since June 2010; and Vice President and Counsel at State Street Bank from October 2004 to June 2007 - ------------------------------------------------------------------------------------------------------------------------------------ Mark E. Bradley (50) Treasurer Since 2008. Serves at Vice President -- Fund None the discretion of the Accounting, Administration and Board. Controllership Services of Pioneer; and Treasurer of all of the Pioneer Funds since March 2008; Deputy Treasurer of Pioneer from March 2004 to February 2008; Assistant Treasurer of all of the Pioneer Funds from March 2004 to February 2008; and Treasurer and Senior Vice President, CDC IXIS Asset Management Services, from 2002 to 2003 - ------------------------------------------------------------------------------------------------------------------------------------ Luis I. Presutti (45) Assistant Treasurer Since 2000. Serves at Assistant Vice President -- None the discretion of the Fund Accounting, Board. Administration and Controllership Services of Pioneer; and Assistant Treasurer of all of the Pioneer Funds - ------------------------------------------------------------------------------------------------------------------------------------ Gary Sullivan (52) Assistant Treasurer Since 2002. Serves at Fund Accounting Manager -- None the discretion of the Fund Accounting, Board. Administration and Controllership Services of Pioneer; and Assistant Treasurer of all of the Pioneer Funds - ------------------------------------------------------------------------------------------------------------------------------------ Pioneer High Yield Fund | Annual Report | 10/31/10 75 Fund Officers (continued) - ------------------------------------------------------------------------------------------------------------------------------------ Position Held Length of Service Other Directorships Name and Age with the Fund and Term of Office Principal Occupation Held by this Officer - ------------------------------------------------------------------------------------------------------------------------------------ David F. Johnson (30) Assistant Treasurer Since 2009. Serves at Fund Administration Manager -- None the discretion of the Fund Accounting, Board. Administration and Controllership Services since November 2008; Assistant Treasurer of all of the Pioneer Funds since January 2009; and Client Service Manager -- Institutional Investor Services at State Street Bank from March 2003 to March 2007 - ------------------------------------------------------------------------------------------------------------------------------------ Jean M. Bradley (58) Chief Compliance Since 2010. Serves at Chief Compliance Officer of None Officer the discretion of the Pioneer and of all the Pioneer Board. Funds since March 2010; Director of Adviser and Portfolio Compliance at Pioneer since October 2005; and Senior Compliance Officer for Columbia Management Advisers, Inc. from October 2003 to October 2005 - ------------------------------------------------------------------------------------------------------------------------------------ 76 Pioneer High Yield Fund | Annual Report | 10/31/10 How to Contact Pioneer We are pleased to offer a variety of convenient ways for you to contact us for assistance or information. Call us for: - -------------------------------------------------------------------------------- Account Information, including existing accounts, new accounts, prospectuses, applications and service forms 1-800-225-6292 FactFone(SM) for automated fund yields, prices, account information and transactions 1-800-225-4321 Retirement plans information 1-800-622-0176 Write to us: - -------------------------------------------------------------------------------- PIMSS, Inc. P.O. Box 55014 Boston, Massachusetts 02205-5014 Our toll-free fax 1-800-225-4240 Our internet e-mail address ask.pioneer@pioneerinvestments.com (for general questions about Pioneer only) Visit our web site: www.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. 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 10(a), 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; (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. Fees for audit services provided to the Fund, including fees associated with the filings of its Form N-1A, totaled approximately $45,486 in 2010 and approximately $43,800 in 2009. (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. There were no audit-related services in 2010 or 2009. (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. Fees for audit services provided to the Fund, including fees associated with the filings of its Form N-1A, totaled approximately $45,486 in 2010 and approximately $43,800 in 2009. (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. There were no other services provided to the Fund during the fiscal years ended October 31, 2010 and 2009. (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. Beginning with non-audit service contracts entered into on or after May 6, 2003, the effective date of the new SEC pre-approval rules, the Funds audit committee is required to pre-approve services to affiliates defined by SEC rules to the extent that the services are determined to have a direct impact on the operations or financial reporting of the Fund. For the years ended October 31, 2010 and 2009, there were no services provided to an affiliate that required the Funds audit committee pre-approval. (f) If greater than 50 percent, disclose the percentage of hours expended on the principal accountant's 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 registrant's accountant for services rendered to the registrant, and rendered to the registrant's investment adviser (not including any sub-adviser whose role is primarily portfolio management and is subcontracted with or overseen by another investment adviser), and any entity controlling, controlled by, or under common control with the adviser that provides ongoing services to the registrant for each of the last two fiscal years of the registrant. The aggregate non-audit fees for the Fund and affiliates, as previously defined, totaled approximately $8,290 in 2010 and $8,290 in 2009. 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. (h) Disclose whether the registrant's audit committee of the board of trustees has considered whether the provision of non-audit services that were rendered to the registrant's 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 registrants 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 I Investments in securities of unaffiliated issuers as of the close of the reporting period as set forth in 210.12- 12 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 registrants portfolio (Portfolio Manager). Also state each Portfolio Managers 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 registrants equity securities that is registered by the registrant pursuant to Section 12 of the Exchange Act (15 U.S.C. 781). Instruction to paragraph (a). Disclose all purchases covered by this Item, including purchases that do not satisfy the conditions of the safe harbor of Rule 10b-18 under the Exchange Act (17 CFR 240.10b-18), made in the period covered by the report. Provide disclosures covering repurchases made on a monthly basis. For example, if the reporting period began on January 16 and ended on July 15, the chart would show repurchases for the months from January 16 through February 15, February 16 through March 15, March 16 through April 15, April 16 through May 15, May 16 through June 15, and June 16 through July 15. 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 registrants board of directors, where those changes were implemented after the registrant last provided disclosure in response to the requirements of Item 7(d)(2)(ii)(G) 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 registrants board of directors since the registrant last provided disclosure in response to the requirements of Item 7(d)(2)(ii)(G) 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 officer or officers and principal financial officer or officers, or persons performing similar functions, about the effectiveness of the registrant's disclosure controls and procedures (as defined in Rule 30a-2(c) under the Act (17 CFR 270.30a-2(c))) based on their evaluation of these controls and procedures as of a date within 90 days of the filing date of the report that includes the disclosure required by this paragraph. The registrant's principal executive officer and principal financial officer have concluded that the registrant's disclosure controls and procedures are effective based on their evaluation of these controls and procedures as of a date within 90 days of the filing date of this report. (b) Disclose whether or not there were significant changes in the registrant's internal controls or in other factors that could significantly affect these controls subsequent to the date of their evaluation, including any corrective actions with regard to significant deficiencies and material weaknesses. 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. File the exhibits listed below as part of this Form. Letter or number the exhibits in the sequence indicated. (a) 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. (b) A separate certification for each principal executive officer and principal financial officer of the registrant as required by Rule 30a-2 under the Act (17 CFR 270.30a-2). 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 High Yield Fund By (Signature and Title)* /s/ John F. Cogan, Jr. John F. Cogan, Jr, President Date December 30, 2010 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/ John F. Cogan, Jr. John F. Cogan, Jr., President Date December 30, 2010 By (Signature and Title)* /s/ Mark Bradley Mark Bradley, Treasurer Date December 30, 2010 * Print the name and title of each signing officer under his or her signature.