American Century Investments®
Quarterly Portfolio Holdings
Government Bond Fund
June 30, 2024
| Government Bond - Schedule of Investments | ||
| JUNE 30, 2024 (UNAUDITED) | ||
Principal Amount ($)/Shares | Value ($) | |||||||
| U.S. GOVERNMENT AGENCY MORTGAGE-BACKED SECURITIES — 49.6% | ||||||||
| Adjustable-Rate U.S. Government Agency Mortgage-Backed Securities — 0.2% | ||||||||
| FNMA, VRN, 3.19%, (1-year RFUCC plus 1.61%), 3/1/47 | 212,844 | 202,307 | ||||||
| FNMA, VRN, 3.11%, (1-year RFUCC plus 1.61%), 4/1/47 | 293,350 | 278,501 | ||||||
| GNMA, VRN, 3.75%, (1-year H15T1Y plus 1.50%), 11/20/32 | 37,733 | 36,804 | ||||||
| GNMA, VRN, 4.25%, (1-year H15T1Y plus 2.00%), 10/20/34 | 176,649 | 175,011 | ||||||
| GNMA, VRN, 3.75%, (1-year H15T1Y plus 1.50%), 12/20/34 | 79,312 | 77,401 | ||||||
| GNMA, VRN, 4.625%, (1-year H15T1Y plus 1.50%), 3/20/35 | 93,016 | 91,981 | ||||||
| GNMA, VRN, 3.625%, (1-year H15T1Y plus 1.50%), 7/20/35 | 177,230 | 176,258 | ||||||
| GNMA, VRN, 4.625%, (1-year H15T1Y plus 1.50%), 3/20/36 | 330,279 | 326,709 | ||||||
| GNMA, VRN, 3.75%, (1-year H15T1Y plus 1.50%), 11/20/36 | 52,782 | 51,395 | ||||||
| 1,416,367 | ||||||||
| Fixed-Rate U.S. Government Agency Mortgage-Backed Securities — 49.4% | ||||||||
| FHLMC, 2.00%, 6/1/36 | 4,821,078 | 4,269,322 | ||||||
| FHLMC, 5.50%, 4/1/38 | 640,366 | 643,782 | ||||||
| FHLMC, 3.00%, 2/1/43 | 2,642,046 | 2,334,318 | ||||||
| FHLMC, 3.50%, 2/1/49 | 4,864,106 | 4,397,242 | ||||||
| FHLMC, 3.00%, 1/1/50 | 2,128,954 | 1,815,971 | ||||||
| FHLMC, 3.50%, 5/1/50 | 1,043,052 | 934,118 | ||||||
| FHLMC, 2.50%, 10/1/50 | 2,507,780 | 2,065,334 | ||||||
| FHLMC, 2.50%, 5/1/51 | 8,629,404 | 7,120,187 | ||||||
| FHLMC, 3.50%, 5/1/51 | 3,435,928 | 3,081,168 | ||||||
| FHLMC, 2.00%, 8/1/51 | 5,962,125 | 4,701,480 | ||||||
| FHLMC, 2.50%, 10/1/51 | 1,417,770 | 1,180,076 | ||||||
| FHLMC, 3.50%, 5/1/52 | 4,798,080 | 4,251,318 | ||||||
| FHLMC, 3.50%, 5/1/52 | 1,698,863 | 1,519,201 | ||||||
| FHLMC, 4.00%, 6/1/52 | 6,387,351 | 5,911,001 | ||||||
| FHLMC, 5.00%, 7/1/52 | 1,380,163 | 1,349,236 | ||||||
| FHLMC, 4.50%, 10/1/52 | 4,728,303 | 4,461,309 | ||||||
| FHLMC, 4.50%, 10/1/52 | 2,857,971 | 2,699,254 | ||||||
| FHLMC, 6.00%, 11/1/52 | 6,049,189 | 6,097,739 | ||||||
| FHLMC, 5.50%, 12/1/52 | 4,071,729 | 4,029,261 | ||||||
| FHLMC, 6.00%, 1/1/53 | 4,306,887 | 4,330,559 | ||||||
| FHLMC, 6.50%, 11/1/53 | 3,191,354 | 3,258,160 | ||||||
| FHLMC, 5.50%, 4/1/54 | 4,147,624 | 4,105,155 | ||||||
| FNMA, 3.17%, 1/1/27 | 1,500,000 | 1,439,064 | ||||||
| FNMA, 6.00%, 12/1/33 | 484,850 | 492,001 | ||||||
| FNMA, 5.50%, 8/1/34 | 616,934 | 619,428 | ||||||
| FNMA, 5.50%, 1/1/36 | 687,542 | 690,327 | ||||||
| FNMA, 2.00%, 5/1/36 | 1,702,694 | 1,510,999 | ||||||
| FNMA, 2.00%, 11/1/36 | 6,840,506 | 6,050,698 | ||||||
| FNMA, 2.50%, 12/1/36 | 5,207,585 | 4,731,957 | ||||||
| FNMA, 2.00%, 1/1/37 | 2,379,787 | 2,105,104 | ||||||
| FNMA, 6.00%, 9/1/37 | 185,702 | 189,971 | ||||||
| FNMA, 6.00%, 11/1/37 | 714,715 | 731,182 | ||||||
| FNMA, 4.50%, 4/1/39 | 196,607 | 191,055 | ||||||
| FNMA, 4.50%, 5/1/39 | 558,167 | 542,406 | ||||||
| FNMA, 6.50%, 5/1/39 | 384,641 | 396,369 | ||||||
| FNMA, 4.50%, 10/1/39 | 931,957 | 905,634 | ||||||
| FNMA, 4.50%, 6/1/41 | 877,800 | 852,995 | ||||||
| FNMA, 4.00%, 8/1/41 | 736,213 | 695,051 | ||||||
| FNMA, 4.50%, 9/1/41 | 514,654 | 499,895 | ||||||
| FNMA, 3.50%, 10/1/41 | 767,956 | 706,381 | ||||||
| FNMA, 4.00%, 12/1/41 | 2,211,376 | 2,087,241 | ||||||
| FNMA, 3.50%, 5/1/42 | 782,970 | 719,621 | ||||||
| FNMA, 3.50%, 6/1/42 | 794,172 | 728,856 | ||||||
| FNMA, 3.50%, 9/1/42 | 698,229 | 636,368 | ||||||
| FNMA, 4.00%, 11/1/45 | 534,028 | 499,032 | ||||||
| FNMA, 4.00%, 2/1/46 | 1,388,628 | 1,300,509 | ||||||
| FNMA, 4.00%, 4/1/46 | 1,807,858 | 1,693,696 | ||||||
| FNMA, 3.50%, 2/1/47 | 2,088,388 | 1,891,074 | ||||||
| FNMA, 2.50%, 10/1/50 | 5,616,002 | 4,606,652 | ||||||
| FNMA, 2.50%, 12/1/50 | 5,683,981 | 4,658,754 | ||||||
| FNMA, 2.50%, 2/1/51 | 5,613,917 | 4,649,225 | ||||||
| FNMA, 2.00%, 3/1/51 | 1,201,337 | 947,284 | ||||||
| FNMA, 4.00%, 5/1/51 | 1,297,368 | 1,206,508 | ||||||
| FNMA, 3.00%, 6/1/51 | 5,228,197 | 4,556,402 | ||||||
| FNMA, 4.00%, 8/1/51 | 1,889,997 | 1,737,267 | ||||||
| FNMA, 2.50%, 12/1/51 | 2,508,930 | 2,072,331 | ||||||
| FNMA, 2.50%, 2/1/52 | 1,330,043 | 1,094,818 | ||||||
| FNMA, 3.00%, 2/1/52 | 6,521,227 | 5,593,440 | ||||||
| FNMA, 2.00%, 3/1/52 | 6,872,639 | 5,447,915 | ||||||
| FNMA, 2.50%, 3/1/52 | 5,036,090 | 4,176,172 | ||||||
| FNMA, 3.00%, 3/1/52 | 5,998,883 | 5,191,920 | ||||||
| FNMA, 3.50%, 4/1/52 | 1,006,800 | 891,912 | ||||||
| FNMA, 4.00%, 4/1/52 | 5,098,687 | 4,700,049 | ||||||
| FNMA, 4.00%, 4/1/52 | 1,914,755 | 1,772,338 | ||||||
| FNMA, 3.00%, 5/1/52 | 5,081,527 | 4,358,107 | ||||||
| FNMA, 3.00%, 5/1/52 | 2,455,428 | 2,131,616 | ||||||
| FNMA, 3.50%, 5/1/52 | 4,752,261 | 4,229,310 | ||||||
| FNMA, 3.50%, 5/1/52 | 3,074,729 | 2,760,262 | ||||||
| FNMA, 4.00%, 5/1/52 | 5,353,263 | 4,901,172 | ||||||
| FNMA, 3.00%, 6/1/52 | 965,198 | 837,909 | ||||||
| FNMA, 3.50%, 6/1/52 | 3,875,284 | 3,480,655 | ||||||
| FNMA, 5.00%, 6/1/52 | 4,433,471 | 4,298,501 | ||||||
| FNMA, 4.50%, 7/1/52 | 1,649,548 | 1,558,004 | ||||||
| FNMA, 5.00%, 7/1/52 | 5,076,494 | 4,962,757 | ||||||
| FNMA, 4.50%, 9/1/52 | 3,003,926 | 2,856,412 | ||||||
| FNMA, 4.50%, 9/1/52 | 1,772,884 | 1,696,662 | ||||||
| FNMA, 5.00%, 9/1/52 | 2,111,008 | 2,063,705 | ||||||
| FNMA, 5.00%, 10/1/52 | 5,041,111 | 4,883,223 | ||||||
| FNMA, 5.50%, 10/1/52 | 4,522,636 | 4,472,357 | ||||||
| FNMA, 5.00%, 1/1/53 | 4,237,481 | 4,105,255 | ||||||
| FNMA, 5.50%, 1/1/53 | 2,215,573 | 2,194,102 | ||||||
| FNMA, 6.50%, 1/1/53 | 5,207,121 | 5,322,878 | ||||||
| FNMA, 6.00%, 9/1/53 | 5,649,991 | 5,682,962 | ||||||
| FNMA, 6.00%, 9/1/53 | 4,329,328 | 4,361,259 | ||||||
| GNMA, 6.00%, TBA | 4,165,000 | 4,182,948 | ||||||
| GNMA, 6.50%, TBA | 4,128,000 | 4,187,464 | ||||||
| GNMA, 6.00%, 1/20/39 | 111,477 | 115,592 | ||||||
| GNMA, 4.00%, 12/15/40 | 304,817 | 285,302 | ||||||
| GNMA, 3.50%, 6/20/42 | 1,831,347 | 1,679,841 | ||||||
| GNMA, 3.00%, 7/20/50 | 8,835,257 | 7,701,470 | ||||||
| GNMA, 2.00%, 10/20/50 | 12,133,907 | 9,833,143 | ||||||
| GNMA, 2.50%, 2/20/51 | 3,284,236 | 2,768,210 | ||||||
| GNMA, 3.50%, 2/20/51 | 573,384 | 519,018 | ||||||
| GNMA, 3.50%, 6/20/51 | 1,490,471 | 1,346,338 | ||||||
| GNMA, 2.50%, 9/20/51 | 4,929,346 | 4,146,723 | ||||||
| GNMA, 2.50%, 12/20/51 | 3,538,187 | 2,976,220 | ||||||
| GNMA, 2.50%, 1/20/52 | 4,993,949 | 4,200,124 | ||||||
| GNMA, 4.00%, 9/20/52 | 9,353,113 | 8,646,678 | ||||||
| GNMA, 4.50%, 9/20/52 | 9,271,672 | 8,831,040 | ||||||
| GNMA, 4.50%, 10/20/52 | 7,173,045 | 6,844,347 | ||||||
| GNMA, 5.00%, 4/20/53 | 4,485,484 | 4,371,134 | ||||||
| GNMA, 5.50%, 4/20/53 | 5,068,273 | 5,032,652 | ||||||
| 309,590,444 | ||||||||
TOTAL U.S. GOVERNMENT AGENCY MORTGAGE-BACKED SECURITIES (Cost $325,629,049) | 311,006,811 | |||||||
| U.S. TREASURY SECURITIES — 27.0% | ||||||||
| U.S. Treasury Bonds, 3.50%, 2/15/39 | 2,000,000 | 1,800,234 | ||||||
| U.S. Treasury Bonds, 4.375%, 11/15/39 | 1,000,000 | 989,023 | ||||||
| U.S. Treasury Bonds, 4.625%, 2/15/40 | 1,000,000 | 1,016,250 | ||||||
| U.S. Treasury Bonds, 1.375%, 11/15/40 | 2,000,000 | 1,262,734 | ||||||
| U.S. Treasury Bonds, 3.75%, 8/15/41 | 1,000,000 | 903,398 | ||||||
| U.S. Treasury Bonds, 2.375%, 2/15/42 | 4,500,000 | 3,277,266 | ||||||
| U.S. Treasury Bonds, 3.00%, 5/15/42 | 500,000 | 401,523 | ||||||
| U.S. Treasury Bonds, 3.25%, 5/15/42 | 2,300,000 | 1,913,268 | ||||||
| U.S. Treasury Bonds, 4.00%, 11/15/42 | 1,600,000 | 1,474,938 | ||||||
| U.S. Treasury Bonds, 2.875%, 5/15/43 | 2,000,000 | 1,553,750 | ||||||
| U.S. Treasury Bonds, 3.875%, 5/15/43 | 2,000,000 | 1,805,117 | ||||||
| U.S. Treasury Bonds, 3.625%, 8/15/43 | 2,000,000 | 1,738,438 | ||||||
| U.S. Treasury Bonds, 4.375%, 8/15/43 | 4,500,000 | 4,344,961 | ||||||
| U.S. Treasury Bonds, 3.75%, 11/15/43 | 2,500,000 | 2,210,352 | ||||||
| U.S. Treasury Bonds, 4.75%, 11/15/43 | 8,000,000 | 8,108,750 | ||||||
| U.S. Treasury Bonds, 4.50%, 2/15/44 | 4,000,000 | 3,925,000 | ||||||
| U.S. Treasury Bonds, 4.625%, 5/15/44 | 900,000 | 898,453 | ||||||
| U.S. Treasury Bonds, 3.00%, 11/15/44 | 3,500,000 | 2,734,512 | ||||||
| U.S. Treasury Bonds, 2.50%, 2/15/45 | 500,000 | 356,816 | ||||||
| U.S. Treasury Bonds, 3.00%, 5/15/45 | 1,600,000 | 1,244,125 | ||||||
| U.S. Treasury Bonds, 2.875%, 8/15/45 | 2,000,000 | 1,519,688 | ||||||
| U.S. Treasury Bonds, 3.00%, 11/15/45 | 1,000,000 | 774,609 | ||||||
| U.S. Treasury Bonds, 2.50%, 2/15/46 | 500,000 | 352,461 | ||||||
| U.S. Treasury Bonds, 3.375%, 11/15/48 | 1,500,000 | 1,218,574 | ||||||
| U.S. Treasury Bonds, 4.00%, 11/15/52 | 2,500,000 | 2,277,979 | ||||||
| U.S. Treasury Bonds, 4.125%, 8/15/53 | 2,000,000 | 1,862,891 | ||||||
| U.S. Treasury Bonds, 4.75%, 11/15/53 | 2,000,000 | 2,067,969 | ||||||
| U.S. Treasury Bonds, 4.625%, 5/15/54 | 4,000,000 | 4,055,938 | ||||||
| U.S. Treasury Inflation-Indexed Notes, 0.125%, 7/15/30 | 1,834,395 | 1,642,014 | ||||||
| U.S. Treasury Inflation-Indexed Notes, 1.375%, 7/15/33 | 4,439,320 | 4,193,891 | ||||||
U.S. Treasury Notes, 4.625%, 3/15/26(1) | 2,000,000 | 1,993,281 | ||||||
| U.S. Treasury Notes, 4.25%, 3/15/27 | 17,500,000 | 17,361,914 | ||||||
| U.S. Treasury Notes, 4.50%, 5/15/27 | 5,000,000 | 4,993,945 | ||||||
| U.S. Treasury Notes, 4.625%, 6/15/27 | 10,000,000 | 10,029,297 | ||||||
| U.S. Treasury Notes, 0.50%, 6/30/27 | 10,000,000 | 8,887,109 | ||||||
| U.S. Treasury Notes, 4.125%, 10/31/27 | 6,000,000 | 5,933,672 | ||||||
U.S. Treasury Notes, 3.875%, 11/30/27(1) | 2,500,000 | 2,452,783 | ||||||
| U.S. Treasury Notes, 4.00%, 1/31/29 | 400,000 | 393,914 | ||||||
| U.S. Treasury Notes, 4.00%, 10/31/29 | 9,000,000 | 8,849,531 | ||||||
| U.S. Treasury Notes, 3.875%, 11/30/29 | 7,800,000 | 7,620,234 | ||||||
| U.S. Treasury Notes, 1.50%, 2/15/30 | 3,000,000 | 2,575,547 | ||||||
| U.S. Treasury Notes, 0.625%, 8/15/30 | 2,500,000 | 2,004,102 | ||||||
| U.S. Treasury Notes, 4.875%, 10/31/30 | 13,000,000 | 13,369,687 | ||||||
| U.S. Treasury Notes, 4.375%, 11/30/30 | 3,500,000 | 3,503,555 | ||||||
| U.S. Treasury Notes, 2.875%, 5/15/32 | 3,000,000 | 2,703,457 | ||||||
| U.S. Treasury Notes, 4.125%, 11/15/32 | 7,000,000 | 6,883,516 | ||||||
| U.S. Treasury Notes, 4.50%, 11/15/33 | 5,600,000 | 5,652,937 | ||||||
| U.S. Treasury Notes, 4.375%, 5/15/34 | 2,500,000 | 2,500,977 | ||||||
TOTAL U.S. TREASURY SECURITIES (Cost $172,586,816) | 169,634,380 | |||||||
| COLLATERALIZED MORTGAGE OBLIGATIONS — 7.9% | ||||||||
| FHLMC, Series 2812, Class MF, VRN, 5.90%, (30-day average SOFR plus 0.56%), 6/15/34 | 826,283 | 824,481 | ||||||
| FHLMC, Series 3076, Class BM, SEQ, 4.50%, 11/15/25 | 106,334 | 105,256 | ||||||
| FHLMC, Series 3153, Class FJ, VRN, 5.83%, (30-day average SOFR plus 0.49%), 5/15/36 | 671,957 | 667,842 | ||||||
| FHLMC, Series 3397, Class GF, VRN, 5.95%, (30-day average SOFR plus 0.61%), 12/15/37 | 296,260 | 294,952 | ||||||
| FHLMC, Series 3417, Class FA, VRN, 5.95%, (30-day average SOFR plus 0.61%), 11/15/37 | 536,431 | 534,323 | ||||||
| FHLMC, Series 3778, Class L, SEQ, 3.50%, 12/15/25 | 940,254 | 925,720 | ||||||
| FHLMC, Series K041, Class A2, SEQ, 3.17%, 10/25/24 | 14,200,154 | 14,087,318 | ||||||
| FHLMC, Series K043, Class A2, SEQ, 3.06%, 12/25/24 | 2,639,637 | 2,606,835 | ||||||
| FHLMC, Series K752, Class A2, SEQ, 4.28%, 7/25/30 | 6,550,000 | 6,378,007 | ||||||
| FHLMC, Series KJ25, Class A2, SEQ, 2.61%, 1/25/26 | 1,065,918 | 1,038,488 | ||||||
| FHLMC, Series KPLB, Class A, SEQ, 2.77%, 5/25/25 | 8,645,000 | 8,431,530 | ||||||
| FHLMC, Series X3FX, Class A2FX, SEQ, 3.00%, 6/25/27 | 6,560,000 | 6,268,720 | ||||||
| FNMA, Series 2005-103, Class FP, VRN, 5.75%, (30-day average SOFR plus 0.41%), 10/25/35 | 686,054 | 680,500 | ||||||
| FNMA, Series 2009-89, Class FD, VRN, 6.05%, (30-day average SOFR plus 0.71%), 5/25/36 | 381,477 | 382,208 | ||||||
| FNMA, Series 2023-39, Class AI, IO, 2.00%, 7/25/52 | 14,872,173 | 1,892,396 | ||||||
| GNMA, Series 2007-5, Class FA, VRN, 5.59%, (1-month SOFR plus 0.25%), 2/20/37 | 239,739 | 239,640 | ||||||
| GNMA, Series 2010-14, Class QF, VRN, 5.89%, (1-month SOFR plus 0.56%), 2/16/40 | 1,035,395 | 1,033,848 | ||||||
| Seasoned Loans Structured Transaction Trust, Series 2021-2, Class A1D, SEQ, 2.00%, 7/25/31 | 3,314,240 | 2,934,556 | ||||||
TOTAL COLLATERALIZED MORTGAGE OBLIGATIONS (Cost $50,146,700) | 49,326,620 | |||||||
| U.S. GOVERNMENT AGENCY SECURITIES — 4.8% | ||||||||
| FHLB, 4.625%, 11/17/26 | 8,000,000 | 7,993,740 | ||||||
| FHLB, 4.75%, 4/9/27 | 2,100,000 | 2,106,501 | ||||||
| FHLB, 4.00%, 6/30/28 | 4,000,000 | 3,889,645 | ||||||
| FHLMC, 6.25%, 7/15/32 | 4,000,000 | 4,479,326 | ||||||
| FNMA, 0.875%, 8/5/30 | 5,000,000 | 4,053,037 | ||||||
| FNMA, 6.625%, 11/15/30 | 5,000,000 | 5,591,384 | ||||||
| Tennessee Valley Authority, 1.50%, 9/15/31 | 2,100,000 | 1,710,430 | ||||||
TOTAL U.S. GOVERNMENT AGENCY SECURITIES (Cost $30,710,195) | 29,824,063 | |||||||
| ASSET-BACKED SECURITIES — 4.7% | ||||||||
| Brazos Education Loan Authority, Inc., Series 2021-1, Class A1B, VRN, 6.02%, (1-month SOFR plus 0.69%), 11/25/71 | 2,141,825 | 2,127,720 | ||||||
| Brazos Education Loan Authority, Inc., Series 2021-2, Class A1A, SEQ, 2.06%, 1/25/72 | 541,398 | 492,603 | ||||||
| Brazos Education Loan Authority, Inc., Series 2021-2, Class A1B, VRN, 6.14%, (1-month SOFR plus 0.81%), 1/25/72 | 2,032,489 | 2,024,403 | ||||||
ECMC Group Student Loan Trust, Series 2017-2A, Class A, VRN, 6.50%, (30-day average SOFR plus 1.16%), 5/25/67(2) | 764,436 | 763,117 | ||||||
ECMC Group Student Loan Trust, Series 2020-2A, Class A, VRN, 6.60%, (30-day average SOFR plus 1.26%), 11/25/69(2) | 985,936 | 987,912 | ||||||
ECMC Group Student Loan Trust, Series 2021-1A, Class A1B, VRN, 6.02%, (30-day average SOFR plus 0.68%), 11/25/70(2) | 3,249,568 | 3,204,625 | ||||||
| Missouri Higher Education Loan Authority, Rev., 1.97%, 3/25/61 | 1,089,582 | 929,527 | ||||||
| Missouri Higher Education Loan Authority, Series 2021-3, Class A1B, VRN, 6.01%, (1-month SOFR plus 0.68%), 8/25/61 | 2,051,310 | 2,023,144 | ||||||
Navient Student Loan Trust, Series 2021-1A, Class A1A, SEQ, 1.31%, 12/26/69(2) | 1,870,737 | 1,657,308 | ||||||
Navient Student Loan Trust, Series 2021-1A, Class A1B, VRN, 6.05%, (30-day average SOFR plus 0.71%), 12/26/69(2) | 402,869 | 401,477 | ||||||
Navient Student Loan Trust, Series 2021-2A, Class A1A, SEQ, 1.68%, 2/25/70(2) | 313,865 | 277,088 | ||||||
Nelnet Student Loan Trust, Series 2006-1, Class A6, VRN, 6.04%, (3-month SOFR plus 0.71%), 8/23/36(2) | 3,229,917 | 3,219,444 | ||||||
Nelnet Student Loan Trust, Series 2019-5, Class A, SEQ, 2.53%, 10/25/67(2) | 1,011,958 | 923,176 | ||||||
| North Texas Higher Education Authority, Inc., Series 2021-1, Class A1B, VRN, 6.01%, (1-month SOFR plus 0.68%), 9/25/61 | 2,247,457 | 2,218,181 | ||||||
| North Texas Higher Education Authority, Inc., Series 2021-2, Class A1B, VRN, 6.03%, (1-month SOFR plus 0.68%), 10/25/61 | 4,267,086 | 4,243,435 | ||||||
Pennsylvania Higher Education Assistance Agency, Series 2021-1A, Class A, VRN, 5.97%, (30-day average SOFR plus 0.64%), 5/25/70(2) | 2,048,871 | 2,033,991 | ||||||
| U.S. Small Business Administration, Series 2017-20B, Class 1, 2.82%, 2/1/37 | 2,001,562 | 1,806,158 | ||||||
TOTAL ASSET-BACKED SECURITIES (Cost $28,822,237) | 29,333,309 | |||||||
| COMMERCIAL MORTGAGE-BACKED SECURITIES — 2.7% | ||||||||
| Citigroup Commercial Mortgage Trust, Series 2014-GC25, Class A3, SEQ, 3.37%, 10/10/47 | 228,376 | 227,966 | ||||||
| Citigroup Commercial Mortgage Trust, Series 2015-GC27, Class A4, SEQ, 2.88%, 2/10/48 | 1,957,140 | 1,947,613 | ||||||
| Citigroup Commercial Mortgage Trust, Series 2015-GC29, Class A3, SEQ, 2.94%, 4/10/48 | 2,161,864 | 2,124,591 | ||||||
| COMM Mortgage Trust, Series 2015-CR23, Class A3, SEQ, 3.23%, 5/10/48 | 1,306,096 | 1,289,442 | ||||||
| COMM Mortgage Trust, Series 2015-DC1, Class A4, SEQ, 3.08%, 2/10/48 | 1,093,899 | 1,086,182 | ||||||
| COMM Mortgage Trust, Series 2016-DC2, Class A4, SEQ, 3.50%, 2/10/49 | 1,651,388 | 1,603,871 | ||||||
| GS Mortgage Securities Trust, Series 2015-GC28, Class A4, SEQ, 3.14%, 2/10/48 | 1,246,723 | 1,242,773 | ||||||
| Wells Fargo Commercial Mortgage Trust, Series 2015-C30, Class A3, SEQ, 3.41%, 9/15/58 | 2,315,684 | 2,270,252 | ||||||
| Wells Fargo Commercial Mortgage Trust, Series 2015-LC20, Class A4, SEQ, 2.93%, 4/15/50 | 2,178,000 | 2,139,412 | ||||||
| Wells Fargo Commercial Mortgage Trust, Series 2015-LC22, Class A3, SEQ, 3.57%, 9/15/58 | 1,692,700 | 1,657,414 | ||||||
| Wells Fargo Commercial Mortgage Trust, Series 2015-NXS4, Class A3, SEQ, 3.45%, 12/15/48 | 1,415,742 | 1,378,756 | ||||||
TOTAL COMMERCIAL MORTGAGE-BACKED SECURITIES (Cost $16,686,736) | 16,968,272 | |||||||
| MUNICIPAL SECURITIES — 0.4% | ||||||||
Pasadena Rev., 4.625%, 5/1/25, Prerefunded at 100% of Par(3) (Cost $2,952,272) | 2,665,000 | 2,647,847 | ||||||
SHORT-TERM INVESTMENTS(4) — 3.5% | ||||||||
| Money Market Funds — 0.0% | ||||||||
| State Street Institutional U.S. Government Money Market Fund, Premier Class | 58,517 | 58,517 | ||||||
| Repurchase Agreements — 3.5% | ||||||||
| BMO Capital Markets Corp., (collateralized by various U.S. Treasury obligations, 2.00%, 8/15/25, valued at $1,443,753), in a joint trading account at 5.29%, dated 6/28/24, due 7/1/24 (Delivery value $1,414,957) | 1,414,334 | |||||||
| Fixed Income Clearing Corp., (collateralized by various U.S. Treasury obligations, 4.50%, 11/15/33, valued at $15,460,323), at 5.30%, dated 6/28/24, due 7/1/24 (Delivery value $15,163,694) | 15,157,000 | |||||||
| TD Securities (USA) LLC, (collateralized by various U.S. Treasury obligations, 0.375% - 3.625%, 1/31/26 - 8/31/28, valued at $5,779,839), at 5.29%, dated 6/28/24, due 7/1/24 (Delivery value $5,666,497) | 5,664,000 | |||||||
| 22,235,334 | ||||||||
TOTAL SHORT-TERM INVESTMENTS (Cost $22,293,851) | 22,293,851 | |||||||
TOTAL INVESTMENT SECURITIES — 100.6% (Cost $649,827,856) | 631,035,153 | |||||||
| OTHER ASSETS AND LIABILITIES — (0.6)% | (3,966,869) | |||||||
| TOTAL NET ASSETS — 100.0% | $ | 627,068,284 | ||||||
| FUTURES CONTRACTS PURCHASED | ||||||||||||||
| Reference Entity | Contracts | Expiration Date | Notional Amount | Unrealized Appreciation (Depreciation)^ | ||||||||||
| U.S. Treasury 2-Year Notes | 234 | September 2024 | $ | 47,787,187 | $ | (30,300) | ||||||||
| U.S. Treasury 5-Year Notes | 431 | September 2024 | 45,935,172 | 206,132 | ||||||||||
| U.S. Treasury 10-Year Notes | 61 | September 2024 | 6,709,047 | 19,522 | ||||||||||
| U.S. Treasury 10-Year Ultra Notes | 124 | September 2024 | 14,077,875 | (101,414) | ||||||||||
| U.S. Treasury Long Bonds | 20 | September 2024 | 2,366,250 | (29,664) | ||||||||||
| U.S. Treasury Ultra Bonds | 89 | September 2024 | 11,155,594 | 211,828 | ||||||||||
| $ | 128,031,125 | $ | 276,104 | |||||||||||
^Amount represents value and unrealized appreciation (depreciation).
| NOTES TO SCHEDULE OF INVESTMENTS | ||||||||
| FHLB | – | Federal Home Loan Bank | ||||||
| FHLMC | – | Federal Home Loan Mortgage Corp. | ||||||
| FNMA | – | Federal National Mortgage Association | ||||||
| GNMA | – | Government National Mortgage Association | ||||||
| H15T1Y | – | Constant Maturity U.S. Treasury Note Yield Curve Rate Index | ||||||
| IO | – | Interest Only | ||||||
| RFUCC | – | FTSE USD IBOR Consumer Cash Fallbacks | ||||||
| SEQ | – | Sequential Payer | ||||||
| SOFR | – | Secured Overnight Financing Rate | ||||||
| TBA | – | To-Be-Announced. Security was purchased on a forward commitment basis with an approximate principal amount and maturity date. Actual principal amount and maturity date will be determined upon settlement. | ||||||
| VRN | – | Variable Rate Note. The rate adjusts periodically based upon the terms set forth in the security’s offering documents. The rate shown is effective at the period end and the reference rate and spread, if any, is indicated. The security's effective maturity date may be shorter than the final maturity date shown. | ||||||
(1)Security, or a portion thereof, has been pledged at the custodian bank or with a broker for collateral requirements on forward commitments and/or futures contracts. At the period end, the aggregate value of securities pledged was $2,036,900.
(2)Security was purchased pursuant to Rule 144A or Section 4(2) under the Securities Act of 1933 and may be sold in transactions exempt from registration, normally to qualified institutional investors. The aggregate value of these securities at the period end was $13,468,138, which represented 2.1% of total net assets.
(3)Escrowed to maturity in U.S. government securities or state and local government securities.
(4)Category includes securities purchased with cash collateral received at the custodian bank for collateral requirements on forward commitments. At the period end, the aggregate value of cash deposits received was $4,879.
SUPPLEMENTARY NOTES TO SCHEDULE OF INVESTMENTS
1. Investment Valuations
The fund determines the fair value of its investments and computes its net asset value (NAV) per share at the close of regular trading (usually 4 p.m. Eastern time) on the New York Stock Exchange (NYSE) on each day the NYSE is open. The value of investments of the fund is determined by American Century Investment Management, Inc. (ACIM) (the investment advisor), as the valuation designee, pursuant to its valuation policies and procedures. The Board of Trustees oversees the valuation designee and reviews its valuation policies and procedures at least annually.
Fixed income securities are valued at the evaluated mean as provided by independent pricing services or at the mean of the most recent bid and asked prices as provided by investment dealers. U.S. Treasury, Government Agency and municipal securities are valued using market models that consider trade data, quotations from dealers and active market makers, relevant yield curve and spread data, creditworthiness, trade data or market information on comparable securities, and other relevant security specific information. Mortgage-related and asset-backed securities are valued based on models that consider trade data, prepayment and default projections, benchmark yield and spread data and estimated cash flows of each tranche of the issuer.
Open-end management investment companies are valued at the reported NAV per share. Repurchase agreements are valued at cost, which approximates fair value. Exchange-traded futures contracts are valued at the settlement price as provided by the appropriate exchange.
If the valuation designee determines that the market price for a portfolio security is not readily available or is believed by the valuation designee to be unreliable, such security is valued at fair value as determined in good faith by the valuation designee, in accordance with its policies and procedures. Circumstances that may cause the fund to determine that market quotations are not available or reliable include, but are not limited to: when there is a significant event subsequent to the market quotation; trading in a security has been halted during the trading day; or trading in a security is insufficient or did not take place due to a closure or holiday.
The valuation designee monitors for significant events occurring after the close of an investment’s primary exchange but before the fund’s NAV per share is determined. Significant events may include, but are not limited to: corporate announcements and transactions; regulatory news, governmental action and political unrest that could impact a specific investment or an investment sector; or armed conflicts, natural disasters and similar events that could affect investments in a specific country or region.
2. Fair Value Measurements
The fund's investments valuation process is based on several considerations and may use multiple inputs to determine the fair value of the investments held by the fund. In conformity with accounting principles generally accepted in the United States of America, the inputs used to determine a valuation are classified into three broad levels.
• Level 1 valuation inputs consist of unadjusted quoted prices in an active market for identical investments.
• Level 2 valuation inputs consist of direct or indirect observable market data (including quoted prices for comparable investments, evaluations of subsequent market events, interest rates, prepayment speeds, credit risk, etc.). These inputs also consist of quoted prices for identical investments initially expressed in local currencies that are adjusted through translation into U.S. dollars.
• Level 3 valuation inputs consist of unobservable data (including a fund’s own assumptions).
The level classification is based on the lowest level input that is significant to the fair valuation measurement. The valuation inputs are not necessarily an indication of the risks associated with investing in these securities or other financial instruments.
The following is a summary of the level classifications as of period end. The Schedule of Investments provides additional information on the fund's portfolio holdings.
| Level 1 | Level 2 | Level 3 | |||||||||
| Assets | |||||||||||
| Investment Securities | |||||||||||
| U.S. Government Agency Mortgage-Backed Securities | — | $ | 311,006,811 | — | |||||||
| U.S. Treasury Securities | — | 169,634,380 | — | ||||||||
| Collateralized Mortgage Obligations | — | 49,326,620 | — | ||||||||
| U.S. Government Agency Securities | — | 29,824,063 | — | ||||||||
| Asset-Backed Securities | — | 29,333,309 | — | ||||||||
| Commercial Mortgage-Backed Securities | — | 16,968,272 | — | ||||||||
| Municipal Securities | — | 2,647,847 | — | ||||||||
| Short-Term Investments | $ | 58,517 | 22,235,334 | — | |||||||
| $ | 58,517 | $ | 630,976,636 | — | |||||||
| Other Financial Instruments | |||||||||||
| Futures Contracts | $ | 437,482 | — | — | |||||||
| Liabilities | |||||||||||
| Other Financial Instruments | |||||||||||
| Futures Contracts | $ | 161,378 | — | — | |||||||
This schedule of investments provides information about the fund’s portfolio holdings as of the date on the schedule. It is unaudited, and American Century Investments assumes no obligation to update or supplement the schedule to reflect subsequent changes. More information is available in the fund’s most recent annual or semiannual shareholder report.