Pioneer High Yield Fund Schedule of Investments | January 31, 2021 Ticker Symbols: Class A TAHYX Class C PYICX Class R TYHRX Class Y TYHYX Schedule of Investments | 1/31/21 (unaudited) Shares Value UNAFFILIATED ISSUERS - 98.1% COMMON STOCKS - 0.5% of Net Assets Energy Equipment & Services - 0.4% 142,597(a) FTS International, Inc. $ 2,404,185 Total Energy Equipment & Services $ 2,404,185 Oil, Gas & Consumable Fuels - 0.1% 23 Amplify Energy Corp. $ 42 6,967,063^(a) Ascent CNR Corp. 209,012 30,000(a) Whiting Petroleum Corp. 610,200 Total Oil, Gas & Consumable Fuels $ 819,254 TOTAL COMMON STOCKS (Cost $5,666,134) $ 3,223,439 CONVERTIBLE PREFERRED STOCK - 0.3% of Net Assets Banks - 0.3% 1,561(b) Wells Fargo & Co., 7.5% $ 2,254,084 Total Banks $ 2,254,084 TOTAL CONVERTIBLE PREFERRED STOCK (Cost $1,767,832) $ 2,254,084 Principal Amount USD ($) COLLATERALIZED MORTGAGE OBLIGATION - 0.0%† of Net Assets 213,341 Global Mortgage Securitization, Ltd., Series 2004-A, Class B1, 5.25%, 11/25/32 (144A) $ 132,651 TOTAL COLLATERALIZED MORTGAGE OBLIGATION (Cost $207,110) $ 132,651 CONVERTIBLE CORPORATE BONDS - 3.3% of Net Assets Airlines - 0.5% 2,603,000 Air Canada, 4.0%, 7/1/25 (144A) $ 3,533,572 Total Airlines $ 3,533,572 Biotechnology - 0.3% 1,714,000 Insmed, Inc., 1.75%, 1/15/25 $ 2,072,077 Total Biotechnology $ 2,072,077 Commercial Services - 0.2% 1,248,750 Macquarie Infrastructure Corp., 2.0%, 10/1/23 $ 1,230,147 Total Commercial Services $ 1,230,147 Computers - 0.4% 2,070,000 Pure Storage, Inc., 0.125%, 4/15/23 $ 2,332,745 Total Computers $ 2,332,745 Engineering & Construction - 0.3% 1,765,000 Dycom Industries, Inc., 0.75%, 9/15/21 $ 1,889,805 Total Engineering & Construction $ 1,889,805 Healthcare-Products - 0.3% 1,775,000 Integra LifeSciences Holdings Corp., 0.5%, 8/15/25 (144A) $ 1,990,861 Total Healthcare-Products $ 1,990,861 Internet - 0.3% 1,755,000 Palo Alto Networks, Inc., 0.375%, 6/1/25 (144A) $ 2,315,086 Total Internet $ 2,315,086 Leisure Time - 0.2% 915,000 Royal Caribbean Cruises, Ltd., 4.25%, 6/15/23 (144A) $ 1,111,362 Total Leisure Time $ 1,111,362 Media - 0.2% 1,596,000 DISH Network Corp., 3.375%, 8/15/26 $ 1,471,660 Total Media $ 1,471,660 Pharmaceuticals - 0.5% 2,035,000 Revance Therapeutics, Inc., 1.75%, 2/15/27 (144A) $ 2,171,816 2,122,000 Tricida, Inc., 3.5%, 5/15/27 (144A) 1,028,648 Total Pharmaceuticals $ 3,200,464 REITs - 0.1% 473,000 Summit Hotel Properties, Inc., 1.5%, 2/15/26 $ 465,311 Total REITs $ 465,311 TOTAL CONVERTIBLE CORPORATE BONDS (Cost $19,596,863) $ 21,613,090 CORPORATE BONDS - 87.3% of Net Assets Advertising - 1.4% 300,000 Clear Channel International BV, 6.625%, 8/1/25 (144A) $ 315,750 990,000 Lamar Media Corp., 3.625%, 1/15/31 (144A) 998,663 5,857,000(c) MDC Partners, Inc., 7.5%, 5/1/24 (144A) 5,974,140 1,080,000 Outfront Media Capital LLC/Outfront Media Capital Corp., 4.25%, 1/15/29 (144A) 1,071,900 975,000 Outfront Media Capital LLC/Outfront Media Capital Corp., 6.25%, 6/15/25 (144A) 1,032,281 Total Advertising $ 9,392,734 Aerospace & Defense - 0.1% 475,000 Triumph Group, Inc., 8.875%, 6/1/24 (144A) $ 522,538 Total Aerospace & Defense $ 522,538 Airlines - 1.1% 2,036,000 Delta Air Lines, Inc., 3.75%, 10/28/29 $ 1,996,460 225,000 Delta Air Lines, Inc., 7.375%, 1/15/26 258,348 850,000 Delta Air Lines, Inc./SkyMiles IP, Ltd., 4.75%, 10/20/28 (144A) 940,401 Pioneer High Yield Fund | 1/31/21 Schedule of Investments | 1/31/21 (unaudited) (continued) Principal Amount USD ($) Value Airlines - (continued) 650,000 Hawaiian Brand Intellectual Property Ltd./HawaiianMiles Loyalty Ltd., 5.75%, 1/20/26 (144A) $ 673,969 2,430,000 Mileage Plus Holdings LLC/Mileage Plus Intellectual Property Assets, Ltd., 6.5%, 6/20/27 (144A) 2,657,812 662,000 United Airlines Holdings, Inc., 4.875%, 1/15/25 640,568 Total Airlines $ 7,167,558 Apparel - 0.2% 1,180,000 Wolverine World Wide, Inc., 6.375%, 5/15/25 (144A) $ 1,253,750 Total Apparel $ 1,253,750 Auto Manufacturers - 2.9% 2,345,000 Allison Transmission, Inc., 3.75%, 1/30/31 (144A) $ 2,340,603 1,480,000 Ford Motor Credit Co. LLC, 3.375%, 11/13/25 1,511,006 730,000 Ford Motor Credit Co. LLC, 4.0%, 11/13/30 746,885 3,110,000 Ford Motor Credit Co. LLC, 4.125%, 8/17/27 3,273,275 3,095,000 Ford Motor Credit Co. LLC, 4.134%, 8/4/25 3,250,106 1,635,000 Ford Motor Credit Co. LLC, 4.542%, 8/1/26 1,749,450 1,825,000 Ford Motor Credit Co. LLC, 5.113%, 5/3/29 2,008,663 4,221,000 JB Poindexter & Co., Inc., 7.125%, 4/15/26 (144A) 4,495,365 Total Auto Manufacturers $ 19,375,353 Auto Parts & Equipment - 1.5% 4,585,000 American Axle & Manufacturing, Inc., 6.25%, 3/15/26 $ 4,688,162 1,700,000 American Axle & Manufacturing, Inc., 6.5%, 4/1/27 1,778,285 3,198,000 Dealer Tire LLC/DT Issuer LLC, 8.0%, 2/1/28 (144A) 3,397,875 315,000 Meritor, Inc., 4.5%, 12/15/28 (144A) 319,725 Total Auto Parts & Equipment $ 10,184,047 Banks - 2.3% 1,575,000(b)(d) Citigroup, Inc., 4.7% (SOFRRATE + 323 bps) $ 1,610,437 3,568,000 Freedom Mortgage Corp., 8.125%, 11/15/24 (144A) 3,701,800 2,396,000 Freedom Mortgage Corp., 8.25%, 4/15/25 (144A) 2,503,820 1,600,000(b)(d) Intesa Sanpaolo S.p.A., 7.7% (5 Year USD Swap Rate + 546 bps) (144A) 1,796,000 2,195,000(b)(d) JPMorgan Chase & Co., 4.6% (SOFRRATE + 313 bps) 2,258,655 3,538,000 Provident Funding Associates LP/PFG Finance Corp., 6.375%, 6/15/25 (144A) 3,608,760 Total Banks $ 15,479,472 Building Materials - 2.9% 270,000 Builders FirstSource, Inc., 5.0%, 3/1/30 (144A) $ 288,563 2,553,000 Builders FirstSource, Inc., 6.75%, 6/1/27 (144A) 2,747,666 3,035,000 Cornerstone Building Brands, Inc., 6.125%, 1/15/29 (144A) 3,171,575 1,420,000 CP Atlas Buyer, Inc., 7.0%, 12/1/28 (144A) 1,454,620 585,000 Forterra Finance LLC/FRTA Finance Corp., 6.5%, 7/15/25 (144A) 623,025 1,670,000 JELD-WEN, Inc., 6.25%, 5/15/25 (144A) 1,791,075 4,458,000 Patrick Industries, Inc., 7.5%, 10/15/27 (144A) 4,870,365 520,000 Standard Industries, Inc., 4.375%, 7/15/30 (144A) 551,850 203,000 Summit Materials LLC/Summit Materials Finance Corp., 5.125%, 6/1/25 (144A) 206,806 130,000 Summit Materials LLC/Summit Materials Finance Corp., 5.25%, 1/15/29 (144A) 136,825 2,918,000 Summit Materials LLC/Summit Materials Finance Corp., 6.5%, 3/15/27 (144A) 3,093,080 Total Building Materials $ 18,935,450 Chemicals - 2.9% 2,860,000 Element Solutions, Inc., 3.875%, 9/1/28 (144A) $ 2,879,519 1,480,000 Hexion, Inc., 7.875%, 7/15/27 (144A) 1,581,750 EUR 425,000 INEOS Quattro Finance 1 Plc, 3.75%, 7/15/26 (144A) 522,510 EUR 1,095,000 INEOS Quattro Finance 2 Plc, 2.5%, 1/15/26 (144A) 1,328,509 555,000 INEOS Quattro Finance 2 Plc, 3.375%, 1/15/26 (144A) 557,081 1,800,000 Ingevity Corp., 3.875%, 11/1/28 (144A) 1,804,698 1,040,000 Kraton Polymers LLC/Kraton Polymers Capital Corp., 4.25%, 12/15/25 (144A) 1,045,200 2,580,000 OCI NV, 4.625%, 10/15/25 (144A) 2,669,849 690,000 OCI NV, 5.25%, 11/1/24 (144A) 715,875 1,976,000 Olin Corp., 5.0%, 2/1/30 2,070,176 1,218,000 Tronox, Inc., 6.5%, 5/1/25 (144A) 1,306,305 2,760,000 Tronox, Inc., 6.5%, 4/15/26 (144A) 2,846,250 Total Chemicals $ 19,327,722 Coal - 1.0% 6,274,000 SunCoke Energy Partners LP/SunCoke Energy Partners Finance Corp., 7.5%, 6/15/25 (144A) $ 6,415,165 Total Coal $ 6,415,165 Commercial Services - 4.4% 1,410,000 Allied Universal Holdco LLC/Allied Universal Finance Corp., 6.625%, 7/15/26 (144A) $ 1,510,392 3,405,000 Allied Universal Holdco LLC/Allied Universal Finance Corp., 9.75%, 7/15/27 (144A) 3,711,450 1,710,000 APX Group, Inc., 6.75%, 2/15/27 (144A) 1,821,150 2,030,000 Brink's Co., 5.5%, 7/15/25 (144A) 2,156,875 4,015,000 Cardtronics, Inc./Cardtronics USA, Inc., 5.5%, 5/1/25 (144A) 4,160,544 295,000 Garda World Security Corp., 4.625%, 2/15/27 (144A) 299,425 4,714,000 Garda World Security Corp., 9.5%, 11/1/27 (144A) 5,173,615 975,000 Prime Security Services Borrower LLC/Prime Finance, Inc., 5.25%, 4/15/24 (144A) 1,037,156 1,870,000 Prime Security Services Borrower LLC/Prime Finance, Inc., 5.75%, 4/15/26 (144A) 2,047,276 4,165,000 Prime Security Services Borrower LLC/Prime Finance, Inc., 6.25%, 1/15/28 (144A) 4,435,725 2,279,000 Sotheby's, 7.375%, 10/15/27 (144A) 2,472,715 Total Commercial Services $ 28,826,323 Pioneer High Yield Fund | 1/31/21 Schedule of Investments | 1/31/21 (unaudited) (continued) Principal Amount USD ($) Value Computers - 1.0% 1,120,000 Booz Allen Hamilton, Inc., 3.875%, 9/1/28 (144A) $ 1,150,800 237,000 Diebold Nixdorf, Inc., 8.5%, 4/15/24 241,740 2,605,000 Diebold Nixdorf, Inc., 9.375%, 7/15/25 (144A) 2,881,781 1,275,000 NCR Corp., 5.0%, 10/1/28 (144A) 1,310,063 635,000 NCR Corp., 5.25%, 10/1/30 (144A) 663,575 290,000 NCR Corp., 8.125%, 4/15/25 (144A) 317,550 Total Computers $ 6,565,509 Cosmetics/Personal Care - 0.5% 3,080,000 Edgewell Personal Care Co., 5.5%, 6/1/28 (144A) $ 3,294,768 Total Cosmetics/Personal Care $ 3,294,768 Diversified Financial Services - 1.7% 2,360,000 Alliance Data Systems Corp., 4.75%, 12/15/24 (144A) $ 2,395,400 3,250,000 Avation Capital SA, 6.5%, 5/15/21 (144A) 2,388,750 3,305,637(e) Global Aircraft Leasing Co., Ltd., 6.5% (7.25% PIK 6.50% cash), 9/15/24 (144A) 2,958,545 1,900,000 Nationstar Mortgage Holdings, Inc., 5.125%, 12/15/30 (144A) 1,971,250 1,275,000 Nationstar Mortgage Holdings, Inc., 5.5%, 8/15/28 (144A) 1,316,438 Total Diversified Financial Services $ 11,030,383 Electric - 2.3% 875,000 Calpine Corp., 4.625%, 2/1/29 (144A) $ 883,750 875,000 Calpine Corp., 5.0%, 2/1/31 (144A) 899,062 1,133,000 Calpine Corp., 5.25%, 6/1/26 (144A) 1,169,822 915,000 NRG Energy, Inc., 3.375%, 2/15/29 (144A) 935,954 1,315,000 NRG Energy, Inc., 3.625%, 2/15/31 (144A) 1,369,244 235,288 NSG Holdings LLC/NSG Holdings, Inc., 7.75%, 12/15/25 (144A) 249,948 390,000 Pattern Energy Operations LP/Pattern Energy Operations, Inc., 4.5%, 8/15/28 (144A) 412,464 2,830,000 Talen Energy Supply LLC, 7.625%, 6/1/28 (144A) 3,049,325 3,285,000 Talen Energy Supply LLC, 10.5%, 1/15/26 (144A) 3,022,200 2,852,000 Vistra Operations Co.