| Schedule of Investments (unaudited) | BlackRock Ultra Short-Term Bond ETF |
| January 31, 2024 | (Percentages shown are based on Net Assets) |
| Security | Par (000) | Value | ||||||
| Asset-Backed Securities | ||||||||
| American Express Credit Account Master Trust, Class A, 4.95%, 10/15/27 | $ | 14,709 | $ | 14,762,711 | ||||
| BMW Vehicle Lease Trust | ||||||||
| 5.27%, 02/25/25 | 2,273 | 2,271,742 | ||||||
| 5.95%, 08/25/25 | 19,139 | 19,178,145 | ||||||
| CarMax Auto Owner Trust | ||||||||
| 5.23%, 01/15/26 (Call 10/15/26) | 11,369 | 11,349,715 | ||||||
| 5.34%, 12/15/25 (Call 10/15/26) | 4,873 | 4,868,837 | ||||||
| 5.95%, 11/16/26, (30-day SOFR + 0.600%)(a) | 12,180 | 12,199,488 | ||||||
| 6.08%, 12/15/26 | 13,818 | 13,914,079 | ||||||
| 6.15%, 12/15/26, (30-day SOFR + 0.800%)(a) | 710 | 711,775 | ||||||
| 6.20%, 06/15/26 (Call 11/15/26), (30-day SOFR + 0.850%)(a) | 13,767 | 13,790,763 | ||||||
| Chase Issuance Trust, 3.97%, 09/15/27 | 14,100 | 13,924,524 | ||||||
| Citibank Credit Card Issuance Trust, 5.23%, 12/08/27 | 3,474 | 3,507,549 | ||||||
| CNH Equipment Trust, 5.34%, 09/15/26 (Call 02/15/27) | 7,735 | 7,727,967 | ||||||
| Ford Credit Auto Lease Trust | ||||||||
| 5.19%, 06/15/25 (Call 08/15/25) | 1,882 | 1,879,553 | ||||||
| 5.90%, 02/15/26 | 7,684 | 7,707,356 | ||||||
| Ford Credit Auto Owner Trust, 3.44%, 02/15/25 | ||||||||
| (Call 02/15/26) | 256 | 255,395 | ||||||
| Honda Auto Receivables Owner Trust, 5.41%, 04/15/26 (Call 11/15/26) | 15,567 | 15,565,249 | ||||||
| Hyundai Auto Lease Securitization Trust | ||||||||
| 4.34%, 01/15/25 (Call 02/15/25)(b) | 610 | 608,983 | ||||||
| 5.20%, 04/15/25 (Call 05/15/25)(b) | 6,255 | 6,249,955 | ||||||
| 5.47%, 09/15/25 (Call 10/15/25)(b) | 6,181 | 6,176,860 | ||||||
| 6.10%, 09/15/25 (Call 10/15/25), | ||||||||
| (30-day SOFR + 0.750%)(a)(b) | 6,679 | 6,687,163 | ||||||
| Mercedes-Benz Auto Lease Trust, 5.24%, 11/17/25 | ||||||||
| (Call 02/15/26) | 26,745 | 26,715,649 | ||||||
| Mercedes-Benz Auto Receivables Trust, 5.92%, | ||||||||
| 11/16/26 | 10,655 | 10,724,699 | ||||||
| Nissan Auto Receivables Owner Trust | ||||||||
| 4.50%, 08/15/25 (Call 12/15/26) | 3,972 | 3,961,637 | ||||||
| 6.00%, 02/17/26 (Call 02/15/27), (30-day SOFR + 0.650%)(a) | 19,697 | 19,719,742 | ||||||
| Toyota Auto Receivables Owner Trust | ||||||||
| 5.28%, 05/15/26 (Call 06/15/27) | 11,944 | 11,930,819 | ||||||
| 5.70%, 12/15/26, (30-day SOFR + 0.350%)(a) | 22,599 | 22,603,307 | ||||||
| 5.87%, 05/15/26 (Call 06/15/27), (30-day SOFR + 0.520%)(a) | 11,365 | 11,370,967 | ||||||
| 5.90%, 11/16/26, (30-day SOFR + 0.550%)(a) | 12,091 | 12,112,012 | ||||||
| USAA Auto Owner Trust, 5.83%, 07/15/26(b) | 6,462 | 6,475,915 | ||||||
| Volkswagen Auto Lease Trust, 5.87%, 01/20/26 | 22,639 | 22,711,698 | ||||||
| Total Asset-Backed Securities — 5.2% | ||||||||
| (Cost: $311,420,000) | 311,664,254 | |||||||
| Certificates of Deposit | ||||||||
| Bank of America NA, 5.90%, 05/14/24 | 30,450 | 30,478,554 | ||||||
| Bank of Montreal | ||||||||
| 5.41%, 05/17/24 | 31,600 | 31,581,070 | ||||||
| 5.82%, 04/01/24 | 18,140 | 18,149,419 | ||||||
| 5.93%, 04/12/24 | 25,000 | 25,017,080 | ||||||
| Barclays Bank PLC | ||||||||
| 5.55%, 02/07/24 | 16,800 | 16,799,723 | ||||||
| 5.70%, 02/16/24 | 25,000 | 25,000,495 | ||||||
| Security | Par (000) | Value | ||||||
| BNP Paribas SA, 5.83%, 08/08/24 | $ | 10,860 | $ | 10,885,966 | ||||
| BNP Paribas SA/New York, 5.70%, 03/04/24 | 20,000 | 20,003,074 | ||||||
| Canadian Imperial Bank of Commerce | ||||||||
| 5.40%, 02/08/24 | 25,000 | 24,999,191 | ||||||
| 5.90%, 06/13/24 | 22,170 | 22,200,204 | ||||||
| 5.93%, 06/28/24 | 17,400 | 17,426,465 | ||||||
| 5.94%, 04/12/24 | 15,980 | 15,990,767 | ||||||
| Canadian Imperial Bank of Commerce/New York | ||||||||
| 5.81%, 02/05/24, (1-day SOFR + 0.500%)(a) | 26,350 | 26,351,520 | ||||||
| 5.99%, 07/01/24, (1-day SOFR + 0.680%)(a) | 15,500 | 15,538,448 | ||||||
| Cooperatieve Rabobank UA, 5.18%, 02/01/24 | 25,000 | 24,985,475 | ||||||
| HSBC Bank USA NA, 5.90%, 06/06/24 | 9,000 | 9,012,633 | ||||||
| Macquarie Bank Ltd., 5.84%, 05/13/24, (1-day SOFR + 0.540%)(a)(b) | 15,230 | 15,249,814 | ||||||
| Mitsubishi UFJ Trust & Banking Corp/New York, 5.86%, 06/06/24, (1-day SOFR + 0.550%)(a) | 15,220 | 15,241,224 | ||||||
| Mizuho Bank Ltd., 5.53%, 02/21/24 | 20,000 | 19,998,821 | ||||||
| Natixis SA | ||||||||
| 5.26%, 02/02/24 | 20,000 | 19,999,637 | ||||||
| 5.97%, 05/20/24 | 39,040 | 39,086,011 | ||||||
| Nordea Bank Abp/New York, 5.91%, 04/12/24, (1-day SOFR + 0.600%)(a) | 17,500 | 17,517,059 | ||||||
| Royal Bank of Canada, 5.88%, 06/27/24 | 15,400 | 15,421,043 | ||||||
| State Street Bank & Trust Co., 5.81%, 03/28/24, (1-day SOFR + 0.500%)(a) | 15,000 | 15,008,580 | ||||||
| Sumitomo Mitsui Banking Corp./New York | ||||||||
| 5.52%, 07/23/24 | 50,000 | 50,005,945 | ||||||
| 5.73%, 02/07/24, (1-day SOFR + 0.420%)(a) | 20,210 | 20,211,136 | ||||||
| Sumitomo Mitsui Trust Bank Ltd./ New York, 5.52%, 07/22/24 | 24,200 | 24,204,089 | ||||||
| Svenska Handelsbanken/New York NY, 5.86%, 04/29/24, (1-day SOFR + 0.550%)(a) | 47,390 | 47,445,553 | ||||||
| Toronto-Dominion Bank | ||||||||
| 5.33%, 02/06/24 | 20,150 | 20,149,055 | ||||||
| 5.52%, 02/22/24 | 31,600 | 31,599,787 | ||||||
| 6.00%, 08/26/24 | 9,890 | 9,925,326 | ||||||
| 6.00%, 09/09/24 | 16,000 | 16,065,171 | ||||||
| 6.05%, 07/03/24 | 15,400 | 15,430,212 | ||||||
| Wells Fargo Bank NA | ||||||||
| 5.65%, 01/30/25 | 18,000 | 17,999,987 | ||||||
| 5.95%, 07/08/24, (1-day SOFR + 0.640%)(a) | 25,000 | 25,049,885 | ||||||
| Total Certificates of Deposit — 12.8% | ||||||||
| (Cost: $769,481,335) | 770,028,419 | |||||||
| Commercial Paper | ||||||||
| Amcor Finance USA Inc., 5.45%, 02/09/24 | 10,250 | 10,236,052 | ||||||
| Amcor Flexibles North America Inc. | ||||||||
| 5.45%, 02/05/24 | 13,750 | 13,739,597 | ||||||
| 5.50%, 02/09/24 | 21,750 | 21,720,136 | ||||||
| 5.70%, 03/08/24 | 41,500 | 41,258,145 | ||||||
| 5.71%, 03/07/24 | 32,500 | 32,315,530 | ||||||
| American Electric Power Co. Inc. | ||||||||
| 5.61%, 03/04/24 | 22,500 | 22,384,871 | ||||||
| 5.62%, 03/13/24 | 30,500 | 30,301,160 | ||||||
| 5.63%, 03/19/24 | 22,750 | 22,580,376 | ||||||
| 5.64%, 03/25/24 | 4,300 | 4,263,906 | ||||||
| American Honda Finance Corp. | ||||||||
| 5.45%, 02/13/24 | 18,480 | 18,443,702 | ||||||
| 5.57%, 02/26/24 | 21,980 | 21,892,003 | ||||||
| 5.66%, 04/05/24 | 21,130 | 20,916,098 | ||||||
1
| Schedule of Investments (unaudited) (continued) | BlackRock Ultra Short-Term Bond ETF |
| January 31, 2024 | (Percentages shown are based on Net Assets) |
| Security | Par (000) | Value | ||||||
| 5.67%, 04/11/24 | $ | 11,750 | $ | 11,620,166 | ||||
| ANZ New Zealand Int’l Ltd./London, 5.33%, 07/03/24 | 24,500 | 23,953,900 | ||||||
| BASF SE, 5.44%, 03/28/24 | 44,250 | 43,872,433 | ||||||
| Bell Telephone Co. of Canada or Bell Canada (The), | ||||||||
| 5.53%, 05/03/24 | 26,250 | 25,880,246 | ||||||
| BPCE SA, 5.56%, 08/01/24 | 9,950 | 9,953,182 | ||||||
| Brighthouse Financial Short Term Funding LLC, | ||||||||
| 5.62%, 05/20/24 | 9,250 | 9,093,767 | ||||||
| Brookfield BRP Holdings Canada Inc. | ||||||||
| 5.43%, 02/06/24 | 8,750 | 8,742,083 | ||||||
| 5.44%, 02/08/24 | 8,000 | 7,990,335 | ||||||
| 5.48%, 02/13/24 | 3,250 | 3,243,582 | ||||||
| Brookfield Infrastructure Holdings Canada Inc., | ||||||||
| 5.42%, 02/01/24 | 9,250 | 9,248,607 | ||||||
| CDP Financial Inc. | ||||||||
| 5.35%, 02/23/24 | 31,400 | 31,292,999 | ||||||
| 5.36%, 06/07/24 | 2,464 | 2,417,942 | ||||||
| Citigroup Global Markets Inc., 5.26%, 09/23/24 | 41,480 | 40,098,570 | ||||||
| Commonwealth Bank of Australia | ||||||||
| 5.22%, 07/26/24 | 26,500 | 25,836,685 | ||||||
| 5.82%, 03/18/24, (1-day SOFR + 0.500%)(a)(b) | 15,400 | 15,408,128 | ||||||
| CVS Health Corp., 5.42%, 02/09/24 | 29,750 | 29,709,741 | ||||||
| DNB Bank ASA | ||||||||
| 5.29%, 06/13/24 | 16,000 | 15,691,280 | ||||||
| 5.29%, 07/30/24 | 45,880 | 44,691,981 | ||||||
| Duke Energy Corp., 5.67%, 04/16/24 | 18,000 | 17,786,997 | ||||||
| Federation des Caisses Desjardins du Quebec, 5.43%, 03/11/24 | 36,250 | 36,032,634 | ||||||
| Fidelity National Information Services Inc. | ||||||||
| 5.43%, 02/06/24 | 15,000 | 14,986,429 | ||||||
| 5.45%, 02/09/24 | 11,320 | 11,304,598 | ||||||
| FMS Wertmanagement | ||||||||
| 5.37%, 05/02/24 | 24,250 | 23,921,853 | ||||||
| 5.37%, 05/03/24 | 23,500 | 23,178,695 | ||||||
| HSBC USA Inc. | ||||||||
| 5.58%, 01/21/25 | 23,570 | 22,338,306 | ||||||
| 5.60%, 11/27/24 | 15,330 | 14,643,990 | ||||||
| Hyundai Capital America, 5.62%, 03/12/24 | 12,000 | 11,923,749 | ||||||
| ING U.S. Funding LLC, 5.39%, 06/07/24 | 32,020 | 31,417,519 | ||||||
| Intercontinental Exchange Inc. | ||||||||
| 5.69%, 02/02/24 | 7,250 | 7,247,709 | ||||||
| 5.70%, 02/07/24 | 18,500 | 18,479,520 | ||||||
| 5.70%, 02/09/24 | 20,900 | 20,870,259 | ||||||
| 5.70%, 02/13/24 | 11,000 | 10,977,395 | ||||||
| 5.71%, 02/21/24 | 8,000 | 7,973,456 | ||||||
| 5.71%, 02/23/24 | 28,750 | 28,645,551 | ||||||
| JP Morgan Securities LLC, 5.52%, 03/25/24 | 16,000 | 15,868,576 | ||||||
| Keurig Dr Pepper Inc. | ||||||||
| 5.48%, 02/13/24 | 6,250 | 6,237,662 | ||||||
| 5.61%, 03/11/24 | 34,830 | 34,614,312 | ||||||
| 5.63%, 03/27/24 | 12,750 | 12,639,356 | ||||||
| 5.63%, 03/28/24 | 12,250 | 12,141,791 | ||||||
| LSEGA Financing PLC | ||||||||
| 5.46%, 02/21/24 | 6,750 | 6,728,572 | ||||||
| 5.59%, 04/11/24 | 17,500 | 17,309,150 | ||||||
| 5.59%, 04/12/24 | 10,250 | 10,136,717 | ||||||
| LVMH Moet Hennessy Louis Vuitton SE | ||||||||
| 5.32%, 02/09/24 | 15,681 | 15,660,181 | ||||||
| 5.32%, 02/12/24 | 8,190 | 8,175,499 | ||||||
| 5.35%, 05/23/24 | 9,243 | 9,090,432 | ||||||
| 5.36%, 05/17/24 | 16,700 | 16,438,186 | ||||||
| Security | Par (000) | Value | ||||||
| Macquarie Bank Ltd. | ||||||||
| 5.39%, 02/12/24 | $ | 17,500 | $ | 17,468,591 | ||||
| 5.55%, 05/13/24 | 30,000 | 29,530,669 | ||||||
| 5.55%, 05/16/24 | 17,500 | 17,218,627 | ||||||
| Marriott International Inc./MD | ||||||||
| 5.53%, 02/08/24 | 19,450 | 19,426,146 | ||||||
| 5.59%, 02/14/24 | 12,000 | 11,973,993 | ||||||
| 5.60%, 02/15/24 | 4,250 | 4,240,115 | ||||||
| 5.61%, 02/28/24 | 14,000 | 13,939,141 | ||||||
| 5.61%, 02/29/24 | 13,750 | 13,688,143 | ||||||
| 5.61%, 03/04/24 | 10,500 | 10,446,273 | ||||||
| 5.64%, 02/22/24 | 2,750 | 2,740,561 | ||||||
| Microchip Technology Inc., 5.60%, 02/09/24 | 21,000 | 20,970,649 | ||||||
| Mizuho Bank Ltd., 5.80%, 05/03/24 | 40,075 | 40,110,319 | ||||||
| Mizuho Bank Ltd/New York NY, 5.49%, 07/25/24 | 30,000 | 30,004,410 | ||||||
| Mohawk Industries Inc., 5.65%, 03/26/24 | 30,350 | 30,090,184 | ||||||
| MUFG Bank Ltd., 5.76%, 08/15/24 | 18,725 | 18,763,964 | ||||||
| MUFG Bank Ltd./New York, 5.44%, 04/12/24 | 25,700 | 25,423,458 | ||||||
| National Australia Bank Ltd., 5.58%, 03/01/24, (1-day SOFR + 0.250%)(a)(b) | 20,000 | 20,003,160 | ||||||
| National Bank of Canada, 5.36%, 02/23/24 | 33,438 | 33,323,840 | ||||||
| NatWest Markets PLC, 5.55%, 05/20/24 | 15,920 | 15,654,353 | ||||||
| NextEra Energy Capital Holdings Inc. | ||||||||
| 5.43%, 02/02/24 | 23,849 | 23,841,802 | ||||||
| 5.53%, 02/20/24 | 24,500 | 24,424,942 | ||||||
| Nordea Bank Abp/New York NY, 5.63%, 05/20/24, | ||||||||
| (1-day SOFR + 0.320%)(a) | 49,250 | 49,282,653 | ||||||
| Nutrien Ltd., 5.52%, 02/14/24 | 8,000 | 7,982,849 | ||||||
| Penske Truck Leasing Co. LP | ||||||||
| 5.51%, 02/06/24 | 12,000 | 11,988,983 | ||||||
| 5.59%, 02/13/24 | 7,500 | 7,484,896 | ||||||
| 5.61%, 02/15/24 | 12,000 | 11,972,005 | ||||||
| 5.62%, 02/16/24 | 3,500 | 3,491,281 | ||||||
| 5.66%, 02/22/24 | 9,750 | 9,716,382 | ||||||
| 5.69%, 02/26/24 | 23,430 | 23,334,035 | ||||||
| 5.71%, 02/28/24 | 4,500 | 4,480,101 | ||||||
| PPG Industries Inc., 5.48%, 02/13/24 | 11,350 | 11,327,594 | ||||||
| Ryder System Inc. | ||||||||
| 5.48%, 02/13/24 | 13,250 | 13,223,832 | ||||||
| 5.53%, 02/20/24 | 1,460 | 1,455,527 | ||||||
| 5.55%, 02/23/24 | 10,500 | 10,462,875 | ||||||
| Sanofi SA | ||||||||
| 5.36%, 03/19/24 | 10,000 | 9,929,040 | ||||||
| 5.38%, 04/08/24 | 15,419 | 15,263,804 | ||||||
| Societe Generale SA, 5.38%, 04/24/24 | 27,160 | 26,823,107 | ||||||
| Spire Inc. | ||||||||
| 5.43%, 02/06/24 | 25,400 | 25,377,019 | ||||||
| 5.53%, 02/20/24 | 7,250 | 7,227,789 | ||||||
| Suncorp-Metway Ltd. | ||||||||
| 5.68%, 05/28/24 | 27,250 | 26,751,937 | ||||||
| 5.69%, 05/08/24 | 29,000 | 28,557,300 | ||||||
| Toyota Industries Commercial Finance Inc. | ||||||||
| 5.29%, 02/05/24 | 6,053 | 6,048,555 | ||||||
| 5.42%, 04/22/24 | 7,510 | 7,418,402 | ||||||
| United Overseas Bank Ltd., 5.48%, 04/16/24 | 10,540 | 10,419,355 | ||||||
| Volvo Treasury North America LP, 5.67%, 04/17/24 | 27,830 | 27,496,321 | ||||||
| Vulcan Materials Co. | ||||||||
| 5.45%, 02/06/24 | 15,000 | 14,986,379 | ||||||
| 5.46%, 02/08/24 | 20,500 | 20,475,148 | ||||||
| VW Credit Inc. | ||||||||
| 5.43%, 02/06/24 | 6,500 | 6,494,119 | ||||||
| 5.62%, 03/07/24 | 9,000 | 8,949,744 | ||||||
2
| Schedule of Investments (unaudited) (continued) | BlackRock Ultra Short-Term Bond ETF |
| January 31, 2024 | (Percentages shown are based on Net Assets) |
| Security | Par (000) | Value | ||||||
| 5.63%, 03/18/24 | $ | 15,650 | $ | 15,535,758 | ||||
| 5.67%, 05/21/24 | 31,000 | 30,466,894 | ||||||
| 5.69%, 05/01/24 | 21,320 | 21,017,747 | ||||||
| Westpac Banking Corp., 5.39%, 05/06/24 | 34,270 | 33,784,225 | ||||||
| Westpac Securities NZ Ltd./London, 5.36%, 02/23/24 | 10,000 | 9,965,859 | ||||||
| Total Commercial Paper — 33.8% | ||||||||
| (Cost: $2,027,549,911) | 2,028,041,152 | |||||||
| Corporate Bonds & Notes | ||||||||
| Aerospace & Defense — 0.2% | ||||||||
| Lockheed Martin Corp., 4.95%, 10/15/25 (Call 09/15/25) | 6,195 | 6,226,368 | ||||||
| RTX Corp., 5.00%, 02/27/26 (Call 01/27/26) | 5,590 | 5,617,180 | ||||||
| 11,843,548 | ||||||||
| Agriculture — 0.8% | ||||||||
| Cargill Inc. | ||||||||
| 0.40%, 02/02/24 (Call 01/29/24)(b)(c) | 10,165 | 10,165,000 | ||||||
| 3.50%, 04/22/25 (Call 01/29/24)(b) | 6,825 | 6,715,986 | ||||||
| 4.88%, 10/10/25 (Call 09/10/25)(b) | 14,235 | 14,291,634 | ||||||
| Philip Morris International Inc., 5.13%, 11/15/24 | 16,000 | 15,981,570 | ||||||
| 47,154,190 | ||||||||
| Auto Manufacturers — 6.4% | ||||||||
| American Honda Finance Corp. | ||||||||
| 0.75%, 08/09/24 | 3,235 | 3,159,537 | ||||||
| 6.02%, 01/10/25, (1-day SOFR + 0.670%)(a)(c) | 15,000 | 15,037,517 | ||||||
| BMW U.S. Capital LLC | ||||||||
| 0.75%, 08/12/24(b)(c) | 2,925 | 2,852,878 | ||||||
| 0.80%, 04/01/24(b)(c) | 3,350 | 3,323,871 | ||||||
| 5.74%, 08/12/24, (1-day SOFR + 0.380%)(a)(b) | 19,960 | 19,961,011 | ||||||
| 5.87%, 04/01/24, (1-day SOFR + 0.530%)(a)(b) | 15,615 | 15,623,120 | ||||||
| Daimler Truck Finance North America LLC | ||||||||
| 5.00%, 01/15/27(b) | 10,660 | 10,720,117 | ||||||
| 5.20%, 01/17/25(b) | 9,295 | 9,293,020 | ||||||
| 5.60%, 08/08/25(b) | 10,155 | 10,234,145 | ||||||
| Hyundai Capital America | ||||||||
| 0.88%, 06/14/24(b)(c) | 15,998 | 15,710,278 | ||||||
| 1.00%, 09/17/24(b) | 14,408 | 13,989,079 | ||||||
| 5.25%, 01/08/27(b) | 12,500 | 12,598,435 | ||||||
| 5.80%, 06/26/25(b) | 7,590 | 7,643,220 | ||||||
| 5.95%, 09/21/26(b)(c) | 15,400 | 15,702,280 | ||||||
| 6.25%, 11/03/25(b) | 15,600 | 15,854,273 | ||||||
| 6.51%, 08/04/25, (1-day SOFR + 1.150%)(b)(c) | 14,525 | 14,538,467 | ||||||
| Mercedes-Benz Finance North America LLC | ||||||||
| 4.90%, 01/09/26(b) | 15,240 | 15,280,001 | ||||||
| 5.38%, 08/01/25(b) | 15,290 | 15,432,249 | ||||||
| 6.02%, 01/09/26, (1-day SOFR + 0.670%)(b) | 15,240 | 15,256,002 | ||||||
| PACCAR Financial Corp., 3.15%, 06/13/24 | 8,865 | 8,793,820 | ||||||
| Toyota Motor Credit Corp. | ||||||||
| 0.50%, 06/18/24 | 4,000 | 3,926,114 | ||||||
| 2.50%, 03/22/24 | 15,000 | 14,938,482 | ||||||
| 3.65%, 08/18/25 | 13,145 | 12,945,145 | ||||||
| 4.40%, 09/20/24 | 15,000 | 14,919,426 | ||||||
| 5.64%, 09/13/24, (1-day SOFR + 0.290%)(a) | 12,000 | 12,000,883 | ||||||
| 5.83%, 08/22/24, (1-day SOFR + 0.520%)(a)(c) | 15,110 | 15,124,986 | ||||||
| 5.87%, 10/16/24, (1-day SOFR + 0.550%)(a)(c) | 23,010 | 23,040,638 | ||||||
| 5.93%, 06/13/24, (1-day SOFR + 0.620%)(a)(c) | 15,210 | 15,225,375 | ||||||
| 5.96%, 03/22/24, (1-day SOFR + 0.620%)(a) | 10,000 | 10,004,805 | ||||||
| Security | Par (000) | Value | ||||||
| Auto Manufacturers (continued) | ||||||||
| Volkswagen Group of America Finance LLC | ||||||||
| 5.80%, 09/12/25(b) | $ | 10,000 | $ | 10,096,424 | ||||
| 6.30%, 06/07/24, (1-day SOFR + 0.950%)(a)(b) | 12,380 | 12,393,638 | ||||||
| 385,619,236 | ||||||||
| Auto Parts & Equipment — 0.0% | ||||||||
| Aptiv PLC, 2.40%, 02/18/25 (Call 01/09/24) | 3,275 | 3,178,655 | ||||||
| Banks — 15.0% | ||||||||
| Australia & New Zealand Banking Group Ltd. | ||||||||
| 4.83%, 02/03/25(b)(c) | 14,970 | 14,932,618 | ||||||
| 5.09%, 12/08/25 | 10,810 | 10,885,028 | ||||||
| 6.09%, 07/03/25, (1-day SOFR + 0.750%)(b) | 14,655 | 14,700,650 | ||||||
| Australia & New Zealand Banking Group Ltd./New | ||||||||
| York NY | ||||||||
| 4.75%, 01/18/27 | 15,240 | 15,307,683 | ||||||
| 5.67%, 10/03/25 | 15,000 | 15,233,762 | ||||||
| Banco Santander SA | ||||||||
| 3.89%, 05/24/24 | 15,800 | 15,724,262 | ||||||
| 5.74%, 06/30/24, (1-year CMT + 0.450%)(a) | 8,200 | 8,204,857 | ||||||
| Bank of America Corp. | ||||||||
| 5.76%, 06/14/24 (Call 05/14/24), (1-day SOFR + 0.410%)(a)(c) | 18,580 | 18,571,862 | ||||||
| Series 2025, 6.02%, 02/04/25 (Call 02/04/24), (1-day SOFR + 0.660%)(a) | 15,000 | 15,000,117 | ||||||
| Banque Federative du Credit Mutuel SA | ||||||||
| 4.94%, 01/26/26(b) | 17,400 | 17,364,395 | ||||||
| 5.09%, 01/23/27(b)(c) | 15,260 | 15,373,529 | ||||||
| BPCE SA | ||||||||
| 5.10%, 01/26/26(b) | 15,230 | 15,268,920 | ||||||
| 5.20%, 01/18/27(b) | 9,455 | 9,527,594 | ||||||
| Citibank NA | ||||||||
| 5.49%, 12/04/26 (Call 11/04/26)(c) | 15,380 | 15,673,124 | ||||||
| 6.15%, 09/29/25 (Call 08/29/25), (1-day SOFR + 0.805%) | 15,440 | 15,486,280 | ||||||
| Citigroup Inc., 4.14%, 05/24/25 (Call 05/24/24), (1-day SOFR + 1.372%)(a) | 4,770 | 4,746,225 | ||||||
| Commonwealth Bank of Australia, 6.09%, 03/14/25, (1-day SOFR + 0.740%)(a)(b) | 13,580 | 13,624,312 | ||||||
| Commonwealth Bank of Australia/New York | ||||||||
| 5.08%, 01/10/25(c) | 17,800 | 17,802,335 | ||||||
| 5.50%, 09/12/25 | 15,210 | 15,390,960 | ||||||
| Cooperatieve Rabobank UA/NY | ||||||||
| 3.88%, 08/22/24 | 16,800 | 16,663,363 | ||||||
| 5.50%, 07/18/25 | 15,300 | 15,467,950 | ||||||
| Credit Suisse AG/New York NY | ||||||||
| 0.50%, 02/02/24 | 5,335 | 5,335,000 | ||||||
| 5.75%, 02/02/24, (1-day SOFR + 0.390%)(a) | 15,000 | 15,000,000 | ||||||
| Deutsche Bank AG/New York NY, 4.16%, 05/13/25 | 6,905 | 6,825,476 | ||||||
| JPMorgan Chase & Co. | ||||||||
| 3.85%, 06/14/25 (Call 06/14/24), (1-day SOFR + 0.980%)(a) | 16,100 | 15,976,547 | ||||||
| 5.55%, 12/15/25 (Call 12/15/24), (1-day SOFR + 1.070%)(a) | 18,135 | 18,145,172 | ||||||
| JPMorgan Chase Bank N.A., 5.11%, 12/08/26 (Call 11/08/26) | 12,000 | 12,153,411 | ||||||
| KeyBank NA, 4.70%, 01/26/26 (Call 12/26/25) | 3,275 | 3,209,914 | ||||||
| KeyBank NA/Cleveland OH | ||||||||
| 4.15%, 08/08/25 | 5,370 | 5,250,907 | ||||||
| 5.67%, 06/14/24 (Call 01/29/24), (1-day SOFR + 0.320%)(a) | 10,000 | 9,939,160 | ||||||
3
| Schedule of Investments (unaudited) (continued) | BlackRock Ultra Short-Term Bond ETF |
| January 31, 2024 | (Percentages shown are based on Net Assets) |
| Security | Par (000) | Value | ||||||
| Banks (continued) | ||||||||
| 5.67%, 06/14/24 (Call 01/29/24), (1-day SOFR + 0.320%)(a)(c) | $ | 15,565 | $ | 15,465,288 | ||||
| Macquarie Bank Ltd., 5.39%, 12/07/26(b) | 6,210 | 6,284,474 | ||||||
| Mitsubishi UFJ Financial Group Inc. | ||||||||
| 4.79%, 07/18/25 (Call 07/18/24), (1-year CMT + 1.700%)(a) | 9,010 | 8,971,856 | ||||||
| 5.06%, 09/12/25 (Call 09/12/24), (1-year CMT + 1.550%)(a) | 15,675 | 15,628,869 | ||||||
| 5.72%, 02/20/26 (Call 02/20/25), (1-year CMT + 1.080%)(a) | 12,775 | 12,824,712 | ||||||
| Morgan Stanley | ||||||||
| 0.79%, 05/30/25 (Call 05/30/24), (1-day SOFR + 0.525%)(a) | 10,880 | 10,675,309 | ||||||
| 3.62%, 04/17/25 (Call 04/17/24), (1-day SOFR + 1.160%)(a) | 6,865 | 6,835,460 | ||||||
| 6.51%, 04/17/25 (Call 04/17/24), (1-day SOFR + 0.950%)(a) | 10,000 | 10,012,955 | ||||||
| Morgan Stanley Bank NA, 5.48%, 07/16/25 (Call 06/16/25) | 7,520 | 7,597,840 | ||||||
| National Australia Bank Ltd., 5.90%, 01/29/26, (1-day SOFR + 0.550%)(b) | 15,220 | 15,232,215 | ||||||
| National Australia Bank Ltd./New York | ||||||||
| 4.75%, 12/10/25 | 10,290 | 10,305,480 | ||||||
| 4.97%, 01/12/26 | 17,800 | 17,888,675 | ||||||
| 5.20%, 05/13/25 | 13,305 | 13,373,996 | ||||||
| National Securities Clearing Corp., 5.15%, 05/30/25(b) | 5,105 | 5,132,667 | ||||||
| Nordea Bank Abp | ||||||||
| 3.60%, 06/06/25(b) | 10,665 | 10,483,447 | ||||||
| 4.75%, 09/22/25(b) | 16,900 | 16,854,205 | ||||||
| PNC Financial Services Group Inc. (The), 5.67%, 10/28/25 (Call 10/28/24), (1-day SOFR + 1.090%)(a) | 15,526 | 15,520,439 | ||||||
| Societe Generale SA, 4.35%, 06/13/25(b)(c) | 15,000 | 14,859,070 | ||||||
| Sumitomo Mitsui Financial Group Inc., 5.46%, 01/13/26 | 17,800 | 17,984,435 | ||||||
| Sumitomo Mitsui Trust Bank Ltd. | ||||||||
| 0.80%, 09/16/24(b)(c) | 12,000 | 11,655,868 | ||||||
| 2.55%, 03/10/25(b)(c) | 10,000 | 9,719,197 | ||||||
| 5.65%, 09/14/26(b) | 12,000 | 12,204,432 | ||||||
| 5.79%, 09/16/24, (1-day SOFR + 0.440%)(a)(b) | 15,000 | 14,990,786 | ||||||
| 9.59%, 02/13/24, (1-day SOFR + 0.410%)(a) | 30,000 | 30,003,401 | ||||||
| Sumitomo Mitsui Trust Bank Ltd./ New York, 5.49%, 08/01/24 | 14,750 | 14,749,768 | ||||||
| Svenska Handelsbanken AB | ||||||||
| 0.55%, 06/11/24(b) | 4,780 | 4,696,940 | ||||||
| 3.65%, 06/10/25(b)(c) | 15,900 | 15,645,533 | ||||||
| UBS AG | ||||||||
| 5.80%, 09/11/25 | 8,000 | 8,104,157 | ||||||
| 6.28%, 09/11/25, (1-day SOFR + 0.930%) | 8,000 | 8,021,643 | ||||||
| UBS AG/London | ||||||||
| 0.45%, 02/09/24(b) | 7,000 | 6,992,825 | ||||||
| 0.70%, 08/09/24(b)(c) | 4,330 | 4,222,010 | ||||||
| 1.38%, 01/13/25 (Call 12/13/24)(b) | 6,970 | 6,718,167 | ||||||
| 5.72%, 02/09/24, (1-day SOFR + 0.360%)(a)(b) | 5,000 | 5,000,000 | ||||||
| 5.81%, 08/09/24, (1-day SOFR + 0.450%)(a)(b) | 8,470 | 8,476,539 | ||||||
| UBS Group AG, 4.49%, 08/05/25 (Call 08/05/24), (1-year CMT + 1.600%)(a)(b) | 8,810 | 8,757,359 | ||||||
| Wells Fargo Bank NA | ||||||||
| 4.81%, 01/15/26 (Call 12/15/25)(c) | 15,250 | 15,278,049 | ||||||
| 5.55%, 08/01/25 (Call 07/01/25) | 15,230 | 15,389,533 | ||||||
| Security | Par (000) | Value | ||||||
| Banks (continued) | ||||||||
| 6.05%, 01/15/26 (Call 12/15/25), (1-day SOFR + 0.710%) | $ | 15,250 | $ | 15,259,912 | ||||
| Westpac Banking Corp. | ||||||||
| 1.02%, 11/18/24 | 3,550 | 3,437,703 | ||||||
| 5.35%, 10/18/24 | 17,600 | 17,617,917 | ||||||
| 5.66%, 11/18/24, (1-day SOFR + 0.300%)(a) | 23,886 | 23,887,863 | ||||||
| 6.08%, 11/17/25, (1-day SOFR + 0.720%) | 15,440 | 15,485,287 | ||||||
| 901,031,694 | ||||||||
| Beverages — 0.5% | ||||||||
| PepsiCo Inc. | ||||||||
| 5.25%, 11/10/25 | 15,440 | 15,636,275 | ||||||
| 5.76%, 11/12/24, (1-day SOFR + 0.400%)(a) | 11,665 | 11,685,524 | ||||||
| 27,321,799 | ||||||||
| Chemicals — 0.4% | ||||||||
| Linde Inc./CT, 4.80%, 12/05/24 | 17,700 | 17,669,588 | ||||||
| Sherwin-Williams Co. (The), 4.05%, 08/08/24 | 7,310 | 7,259,170 | ||||||
| 24,928,758 | ||||||||
| Computers — 0.3% | ||||||||
| Hewlett Packard Enterprise Co., 5.90%, 10/01/24 | 15,400 | 15,420,548 | ||||||
| Cosmetics & Personal Care — 0.2% | ||||||||
| Haleon U.S. Capital LLC, 3.02%, 03/24/24 (Call 01/16/24) | 9,235 | 9,198,874 | ||||||
| Unilever Capital Corp., 0.63%, 08/12/24 (Call 01/16/24)(c) | 5,975 | 5,829,042 | ||||||
| 15,027,916 | ||||||||
| Diversified Financial Services — 1.6% | ||||||||
| American Express Co. | ||||||||
| 3.38%, 05/03/24 | 44,833 | 44,579,193 | ||||||
| 6.28%, 03/04/25 (Call 02/01/25), (1-day SOFR + 0.930%)(a) | 8,235 | 8,285,726 | ||||||
| 6.34%, 10/30/26 (Call 10/30/25), (1-day SOFR + 1.330%) | 15,700 | 16,022,262 | ||||||
| Capital One Financial Corp., 4.17%, 05/09/25 (Call 05/09/24), (1-day SOFR + 1.370%)(a) | 15,800 | 15,729,331 | ||||||
| CDP Financial Inc., 4.50%, 02/13/26(b)(c) | 9,219 | 9,217,851 | ||||||
| LSEGA Financing PLC, 0.65%, 04/06/24 (Call 03/06/24)(b) | 3,895 | 3,859,810 | ||||||
| 97,694,173 | ||||||||
| Electric — 2.1% | ||||||||
| Florida Power & Light Co., 4.45%, 05/15/26 (Call 04/15/26) | 7,965 | 7,964,544 | ||||||
| National Rural Utilities Cooperative Finance Corp. | ||||||||
| 6.06%, 05/07/25, (1-day SOFR + 0.700%) | 15,580 | 15,636,930 | ||||||
| Series D, 5.68%, 10/18/24, | ||||||||
| (1-day SOFR + 0.330%)(a) | 5,000 | 4,996,898 | ||||||
| NextEra Energy Capital Holdings Inc. | ||||||||
| 2.94%, 03/21/24 (Call 01/29/24) | 15,000 | 14,954,811 | ||||||
| 4.26%, 09/01/24 | 28,679 | 28,454,132 | ||||||
| 6.05%, 03/01/25 | 11,420 | 11,516,260 | ||||||
| 6.10%, 01/29/26, (1-day SOFR + 0.760%) | 15,380 | 15,396,764 | ||||||
| WEC Energy Group Inc. | ||||||||
| 4.75%, 01/09/26 (Call 12/09/25)(c) | 10,000 | 9,976,648 | ||||||
| 5.00%, 09/27/25 (Call 08/27/25) | 7,465 | 7,465,271 | ||||||
| Wisconsin Public Service Corp., 5.35%, 11/10/25 | ||||||||
| (Call 10/10/25) | 8,520 | 8,605,264 | ||||||
| 124,967,522 | ||||||||
| Electronics — 0.0% | ||||||||
| Amphenol Corp., 4.75%, 03/30/26 | 2,840 | 2,845,598 | ||||||
4
| Schedule of Investments (unaudited) (continued) | BlackRock Ultra Short-Term Bond ETF |
| January 31, 2024 | (Percentages shown are based on Net Assets) |
| Security | Par (000) | Value | ||||||
| Food — 1.0% | ||||||||
| Hormel Foods Corp., 0.65%, 06/03/24 (Call 01/16/24) | $ | 12,125 | $ | 11,928,251 | ||||
| Nestle Holdings Inc. | ||||||||
| 0.61%, 09/14/24 (Call 01/29/24)(b)(c) | 35,000 | 33,996,877 | ||||||
| 4.00%, 09/12/25 (Call 08/12/25)(b)(c) | 17,000 | 16,858,648 | ||||||
| 62,783,776 | ||||||||
| Health Care - Products — 0.2% | ||||||||
| Thermo Fisher Scientific Inc., 5.00%, 12/05/26 (Call 11/05/26) | 10,000 | 10,131,458 | ||||||
| Health Care - Services — 0.9% | ||||||||
| Roche Holdings Inc. | ||||||||
| 1.88%, 03/08/24(b) | 15,000 | 14,950,640 | ||||||
| 5.27%, 11/13/26 (Call 10/13/26)(b) | 13,170 | 13,438,395 | ||||||
| 5.59%, 03/05/24, (1-day SOFR + 0.240%)(a)(b) | 5,370 | 5,370,013 | ||||||
| UnitedHealth Group Inc., 5.00%, 10/15/24 | 17,600 | 17,569,033 | ||||||
| 51,328,081 | ||||||||
| Insurance — 3.3% | ||||||||
| Athene Global Funding, 2.51%, 03/08/24(b)(c) | 10,000 | 9,966,943 | ||||||
| MassMutual Global Funding II | ||||||||
| 4.15%, 08/26/25(b) | 7,302 | 7,238,092 | ||||||
| 6.33%, 07/10/26, (1-day SOFR + 0.980%)(b) | 15,252 | 15,351,470 | ||||||
| Metropolitan Life Global Funding I | ||||||||
| 0.55%, 06/07/24(b)(c) | 3,590 | 3,532,657 | ||||||
| 5.00%, 01/06/26(b) | 10,000 | 10,037,727 | ||||||
| New York Life Global Funding | ||||||||
| 3.15%, 06/06/24(b) | 8,400 | 8,333,895 | ||||||
| 3.60%, 08/05/25(b) | 16,500 | 16,249,363 | ||||||
| 5.78%, 06/06/24, (1-day SOFR + 0.430%)(a)(b) | 9,130 | 9,136,041 | ||||||
| 5.93%, 01/16/26, (1-day SOFR + 0.580%)(b) | 25,000 | 25,022,055 | ||||||
| 6.05%, 06/13/25, (1-day SOFR + 0.700%)(b) | 18,500 | 18,565,992 | ||||||
| Northwestern Mutual Global Funding | ||||||||
| 4.00%, 07/01/25(b) | 16,300 | 16,128,321 | ||||||
| 6.05%, 06/13/25, (1-day SOFR + 0.700%)(b) | 15,400 | 15,426,438 | ||||||
| Pacific Life Global Funding II, 6.20%, 06/16/25, (1-day SOFR + 0.860%)(b) | 14,705 | 14,735,822 | ||||||
| Principal Life Global Funding II | ||||||||
| 0.75%, 08/23/24(b) | 660 | 643,582 | ||||||
| 5.74%, 08/23/24, (1-day SOFR + 0.380%)(a)(b) | 635 | 634,861 | ||||||
| Protective Life Global Funding | ||||||||
| 4.99%, 01/12/27(b)(c) | 15,250 | 15,338,985 | ||||||
| 5.37%, 01/06/26(b) | 10,000 | 10,092,392 | ||||||
| 196,434,636 | ||||||||
| Internet — 0.8% | ||||||||
| Amazon.com Inc. | ||||||||
| 2.73%, 04/13/24 | 20,000 | 19,884,741 | ||||||
| 3.00%, 04/13/25 | 10,000 | 9,797,375 | ||||||
| eBay Inc., 5.90%, 11/22/25 (Call 10/22/25) | 17,600 | 17,887,024 | ||||||
| 47,569,140 | ||||||||
| Machinery — 1.7% | ||||||||
| Caterpillar Financial Services Corp. | ||||||||
| 4.35%, 05/15/26 | 15,800 | 15,751,851 | ||||||
| 5.60%, 05/17/24, (1-day SOFR + 0.245%)(a) | 10,000 | 10,002,810 | ||||||
| 5.62%, 09/13/24, (1-day SOFR + 0.270%)(a)(c) | 15,620 | 15,626,894 | ||||||
| 5.81%, 11/14/24, (1-day SOFR + 0.450%)(a)(c) | 15,570 | 15,600,077 | ||||||
| John Deere Capital Corp. | ||||||||
| 3.40%, 06/06/25 | 10,390 | 10,226,267 | ||||||
| 4.80%, 01/09/26 | 17,800 | 17,895,295 | ||||||
| 5.55%, 10/11/24, (1-day SOFR + 0.200%)(a) | 14,290 | 14,286,592 | ||||||
| 99,389,786 | ||||||||
| Security | Par (000) | Value | ||||||
| Machinery - Diversified — 0.3% | ||||||||
| John Deere Capital Corp., 5.83%, 10/22/25, (1-day SOFR + 0.480%) | $ | 15,240 | $ | 15,265,876 | ||||
| Manufacturing — 0.3% | ||||||||
| Siemens Financieringsmaatschappij NV, 5.78%, 03/11/24, (1-day SOFR + 0.430%)(a)(b) | 18,980 | 18,982,744 | ||||||
| Media — 0.0% | ||||||||
| Comcast Corp., 5.25%, 11/07/25 | 2,950 | 2,983,755 | ||||||
| Oil & Gas — 0.3% | ||||||||
| ConocoPhillips Co., 2.13%, 03/08/24 (Call 01/09/24) | 16,000 | 15,942,556 | ||||||
| Pharmaceuticals — 0.8% | ||||||||
| Merck & Co. Inc., 2.75%, 02/10/25 (Call 11/10/24) | 17,000 | 16,639,907 | ||||||
| Pfizer Investment Enterprises Pte. Ltd., 4.65%, 05/19/25 | 31,500 | 31,434,480 | ||||||
| 48,074,387 | ||||||||
| Pipelines — 0.9% | ||||||||
| Enbridge Inc. | ||||||||
| 2.15%, 02/16/24(c) | 5,530 | 5,521,607 | ||||||
| 5.99%, 02/16/24, (1-day SOFR + 0.630%)(a) | 10,125 | 10,126,059 | ||||||
| Enterprise Products Operating LLC, 5.05%, 01/10/26 | 12,365 | 12,455,556 | ||||||
| TransCanada PipeLines Ltd., 1.00%, 10/12/24 (Call 09/12/24) | 27,205 | 26,367,937 | ||||||
| 54,471,159 | ||||||||
| Real Estate Investment Trusts — 0.2% | ||||||||
| Public Storage Operating Co., 5.95%, 07/25/25, (1-day SOFR + 0.600%) | 11,250 | 11,277,259 | ||||||
| Retail — 0.9% | ||||||||
| Home Depot Inc. (The), 4.00%, 09/15/25 (Call 08/15/25) | 5,170 | 5,126,007 | ||||||
| Lowe’s Companies Inc. | ||||||||
| 4.40%, 09/08/25 | 11,510 | 11,438,234 | ||||||
| 4.80%, 04/01/26 (Call 03/01/26) | 6,660 | 6,667,666 | ||||||
| Starbucks Corp., 5.78%, 02/14/24 (Call 01/09/24), (1-day SOFR + 0.420%)(a) | 11,515 | 11,515,392 | ||||||
| Walmart Inc., 3.90%, 09/09/25 | 20,000 | 19,820,564 | ||||||
| 54,567,863 | ||||||||
| Semiconductors — 0.3% | ||||||||
| Analog Devices Inc., 5.59%, 10/01/24, (1-day SOFR + 0.250%)(a) | 15,330 | 15,326,464 | ||||||
| NVIDIA Corp., 0.58%, 06/14/24 (Call 01/09/24) | 5,305 | 5,212,435 | ||||||
| 20,538,899 | ||||||||
| Software — 0.3% | ||||||||
| Intuit Inc., 5.25%, 09/15/26 (Call 08/15/26) | 11,165 | 11,375,483 | ||||||
| Salesforce Inc., 0.63%, 07/15/24 (Call 01/09/24) | 9,415 | 9,214,704 | ||||||
| 20,590,187 | ||||||||
| Telecommunications — 0.6% | ||||||||
| Bell Telephone Co. of Canada or Bell Canada, Series US-3, 0.75%, 03/17/24(c) | 21,081 | 20,954,546 | ||||||
| NTT Finance Corp. | ||||||||
| 0.58%, 03/01/24(b) | 6,005 | 5,979,488 | ||||||
| 4.14%, 07/26/24(b)(c) | 2,830 | 2,811,326 | ||||||
5
| Schedule of Investments (unaudited) (continued) | BlackRock Ultra Short-Term Bond ETF |
| January 31, 2024 | (Percentages shown are based on Net Assets) |
| Security | Par (000) | Value | ||||||
| Telecommunications (continued) | ||||||||
| Verizon Communications Inc., 0.75%, 03/22/24 | $ | 3,580 | $ | 3,556,209 | ||||
| 33,301,569 | ||||||||
| Total Corporate Bonds & Notes — 40.3% | ||||||||
| (Cost: $2,421,750,815) | 2,420,666,768 | |||||||
| Municipal Debt Obligations | ||||||||
| Illinois — 0.1% | ||||||||
| State of Illinois GO, 5.25%, 05/01/25 | 5,865 | 5,890,583 | ||||||
| New York — 0.0% | ||||||||
| Taxable Municipal Funding Trust RB | ||||||||
| VRDN, 5.60%, 01/16/25 (Put 01/31/24)(b)(d) | 725 | 725,000 | ||||||
| VRDN, 5.60%, 09/01/30 (Put 05/01/25)(b)(d) | 2,440 | 2,440,000 | ||||||
| 3,165,000 | ||||||||
| Total Municipal Debt Obligations — 0.1% | ||||||||
| (Cost $9,030,000) | 9,055,583 | |||||||
| Repurchase Agreements(a)(e) | ||||||||
| Bank of America Securities Inc., 5.43%, 02/01/24 (Purchased on 01/31/24 to be repurchased at $10,001,508, collateralized by non-agency mortgage-backed security, 2.50% to 7.62%, due 06/15/35 to 11/25/63, par and fair value of $100,916,182 and $84,686,246, respectively) | 10,000 | 10,000,000 | ||||||
| Bank of America Securities Inc., 5.63%, 02/01/24 (Purchased on 01/31/24 to be repurchased at $54,758,562, collateralized by non-agency mortgage-backed security, 2.50% to 9.67%, due 08/15/27 to 08/15/61, par and fair value of $111,001,478 and $58,582,500, respectively) | 54,750 | 54,750,000 | ||||||
| Bank of America Securities Inc., 5.81%, 02/01/24 (Purchased on 01/31/24 to be repurchased at $10,001,614, collateralized by non-agency mortgage-backed security, 5.89% to 6.23%, due 09/22/35 to 03/22/37, par and fair value of $24,846,000 and $10,700,187, respectively) | 10,000 | 10,000,000 | ||||||
| BNP Paribas, 5.68%, 02/01/24 (Purchased on 01/31/24 to be repurchased at $36,755,798, collateralized by non-agency mortgage-backed security, 2.00% to 10.75%, due 08/01/24 to 12/31/79, par and fair value of $42,007,069 and $40,340,896, respectively) | 36,750 | 36,750,000 | ||||||
| Citigroup Global Markets Inc, 5.62%, 02/01/24 (Purchased on 01/31/24 to be repurchased at $9,001,405, collateralized by non-agency mortgage-backed security, 2.50% to 6.70%, due 11/15/34 to 02/25/52, par and fair value of $38,989,408 and $10,326,189, respectively) | 9,000 | 9,000,000 | ||||||
| Citigroup Global Markets Inc, 5.64%, 02/01/24 (Purchased on 01/31/24 to be repurchased at $12,001,880, collateralized by non-agency mortgage-backed security, 2.50% to 5.50%, due 03/25/47 to 03/25/62, par and fair value of $17,491,536 and $13,800,000, respectively) | 12,000 | 12,000,000 | ||||||
| Security | Par (000) | Value | ||||||
| Goldman Sachs & Co. LLC, 5.83%, 02/01/24 (Purchased on 01/31/24 to be repurchased at $90,014,575, collateralized by non-agency mortgage-backed security, 2.20% to 9.50%, due 06/27/24 to 01/18/82, par and fair value of $141,218,600 and $96,346,142, respectively) | $ | 90,000 | $ | 90,000,000 | ||||
| Mizuho Securities USA Inc., 5.76%, 02/01/24 (Purchased on 01/31/24 to be repurchased at $6,000,960, collateralized by non-agency mortgage-backed security, 5.89% to 10.62%, due 12/25/29 to 08/25/35, par and fair value of $12,084,591 and $6,900,000, respectively) | 6,000 | 6,000,000 | ||||||
| Mizuho Securities USA Inc., 5.86%, 02/01/24 (Purchased on 01/31/24 to be repurchased at $30,004,883, collateralized by non-agency mortgage-backed security, 4.00% to 8.73%, due 03/20/25 to 07/25/49, par and fair value of $36,575,000 and $33,126,518, respectively) | 30,000 | 30,000,000 | ||||||
| Wells Fargo Securities, 5.71%, 02/01/24 (Purchased on 01/31/24 to be repurchased at $77,012,213, collateralized by non-agency mortgage-backed security, 2.50% to 7.62%, due 06/15/35 to 05/25/63, par and fair value of $100,916,182 and $84,686,246, respectively) | 77,000 | 77,000,000 | ||||||
| Total Repurchase Agreements — 5.6% | ||||||||
| (Cost: $335,500,000) | 335,500,000 | |||||||
| U.S. Government Obligations | ||||||||
| U.S. Government Obligations — 1.5% | ||||||||
| U.S. Treasury Bill, 5.50%, 03/05/24(c)(f) | 25,000 | 24,879,573 | ||||||
| U.S. Treasury Note/Bond | ||||||||
| 4.75%, 07/31/25 | 30,890 | 31,034,797 | ||||||
| 5.00%, 08/31/25 | 15,530 | 15,673,774 | ||||||
| 5.00%, 09/30/25 | 15,500 | 15,659,843 | ||||||
| Total U.S. Government Obligations — 1.5% | ||||||||
| (Cost: $86,529,185) | 87,247,987 | |||||||
| Shares | ||||||||
| Money Market Funds | ||||||||
| BlackRock Cash Funds: Institutional, SL Agency Shares, 5.51%(g)(h)(i) | 58,773,578 | 58,808,843 | ||||||
| Total Money Market Funds — 1.0% | ||||||||
| (Cost: $58,789,252) | 58,808,843 | |||||||
| Total Investments — 100.3% | ||||||||
| (Cost: $6,020,050,498) | 6,021,013,006 | |||||||
| Liabilities in Excess of Other Assets — (0.3)% | (15,756,197 | ) | ||||||
| Net Assets — 100.0% | $ | 6,005,256,809 | ||||||
| (a) | Variable rate security. Interest rate resets periodically. The rate shown is the effective interest rate as of period end. Security description also includes the reference rate and spread if published and available. |
| (b) | Security exempt from registration pursuant to Rule 144A under the Securities Act of 1933, as amended. These securities may be resold in transactions exempt from registration to qualified institutional investors. |
| (c) | All or a portion of this security is on loan. |
| (d) | Variable rate security. Rate as of period end and maturity is the date the principal owed can be recovered through demand. |
6
| Schedule of Investments (unaudited) (continued) | BlackRock Ultra Short-Term Bond ETF |
| January 31, 2024 |
| (e) | Maturity date represents next reset date. |
| (f) | Rates are discount rates or a range of discount rates as of period end. |
| (g) | Affiliate of the Fund. |
| (h) | Annualized 7-day yield as of period end. |
| (i) | All or a portion of this security was purchased with the cash collateral from loaned securities. |
Affiliates
Investments in issuers considered to be affiliate(s) of the Fund during the period ended January 31, 2024 for purposes of Section 2(a)(3) of the Investment Company Act of 1940, as amended, were as follows:
| Affiliated Issuer | Value at 10/31/23 | Purchases at Cost | Proceeds from Sale | Net Realized Gain (Loss) | Change in Unrealized Appreciation (Depreciation) | Value at 01/31/24 | Shares Held at 01/31/24 | Income | Capital Gain Distributions from Underlying Funds | |||||||||||||||||||||||||||
| BlackRock Cash Funds: Institutional, SL Agency Shares | $ | 123,152,749 | $ | — | $ | (64,355,695 | )(a) | $ | 17,789 | $ | (6,000) | $ | 58,808,843 | 58,773,578 | $ | 57,582 | (b) | $ | — | |||||||||||||||||
| BlackRock Cash Funds: Treasury, SL Agency Shares(c) | — | 0 | (a) | — | — | — | — | — | 141,551 | — | ||||||||||||||||||||||||||
| $ | 17,789 | $ | (6,000) | $ | 58,808,843 | $ | 199,133 | $ | — | |||||||||||||||||||||||||||
| (a) | Represents net amount purchased (sold). |
| (b) | All or a portion represents securities lending income earned from the reinvestment of cash collateral from loaned securities, net of fees and collateral investment expenses, and other payments to and from borrowers of securities. |
| (c) | As of period end, the entity is no longer held. |
Fair Value Hierarchy as of Period End
Various inputs are used in determining the fair value of financial instruments. These inputs to valuation techniques are categorized into a fair value hierarchy consisting of three broad levels for financial reporting purposes as follows:
| ● | Level 1 – Unadjusted price quotations in active markets/exchanges for identical assets or liabilities that each Fund has the ability to access; |
| ● | Level 2 – Other observable inputs (including, but not limited to, quoted prices for similar assets or liabilities in markets that are active, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the assets or liabilities (such as interest rates, yield curves, volatilities, prepayment speeds, loss severities, credit risks and default rates) or other market-corroborated inputs); and |
| ● | Level 3 – Unobservable inputs based on the best information available in the circumstances, to the extent observable inputs are not available (including the Valuation Committee’s assumptions used in determining the fair value of financial instruments). |
The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). Accordingly, the degree of judgment exercised in determining fair value is greatest for instruments categorized in Level 3. The inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, for disclosure purposes, the fair value hierarchy classification is determined based on the lowest level input that is significant to the fair value measurement in its entirety. Investments classified within Level 3 have significant unobservable inputs used by the Valuation Committee in determining the price for Fair Valued Investments. Level 3 investments include equity or debt issued by privately held companies or funds. There may not be a secondary market, and/or there are a limited number of investors. The categorization of a value determined for financial instruments is based on the pricing transparency of the financial instruments and is not necessarily an indication of the risks associated with investing in those securities. For information about the Fund’s policy regarding valuation of financial instruments, refer to its most recent financial statements.
The following table summarizes the Fund’s financial instruments categorized in the fair value hierarchy. The breakdown of the Fund’s financial instruments into major categories is disclosed in the Schedule of Investments above.
| Level 1 | Level 2 | Level 3 | Total | |||||||||||||
| Assets | ||||||||||||||||
| Investments | ||||||||||||||||
| Long-Term Investments | ||||||||||||||||
| Asset-Backed Securities | $ | — | $ | 311,664,254 | $ | — | $ | 311,664,254 | ||||||||
| Certificates of Deposit | — | 770,028,419 | — | 770,028,419 | ||||||||||||
| Commercial Paper | — | 2,028,041,152 | — | 2,028,041,152 | ||||||||||||
| Corporate Bonds & Notes | — | 2,420,666,768 | — | 2,420,666,768 | ||||||||||||
| Municipal Debt Obligations | — | 9,055,583 | — | 9,055,583 | ||||||||||||
| Repurchase Agreements | — | 335,500,000 | — | 335,500,000 | ||||||||||||
| U.S. Government & Agency Obligations | — | 87,247,987 | — | 87,247,987 | ||||||||||||
7
| Schedule of Investments (unaudited) (continued) | BlackRock Ultra Short-Term Bond ETF |
| January 31, 2024 |
Fair Value Hierarchy as of Period End (continued)
| Level 1 | Level 2 | Level 3 | Total | |||||||||||||
| Short-Term Securities | ||||||||||||||||
| Money Market Funds | $ | 58,808,843 | $ | — | $ | — | $ | 58,808,843 | ||||||||
| $ | 58,808,843 | $ | 5,962,204,163 | $ | — | $ | 6,021,013,006 | |||||||||
| Portfolio Abbreviation | |
| CMT | Constant Maturity Treasury |
| GO | General Obligation |
| RB | Revenue Bond |
| SOFR | Secured Overnight Financing Rate |
8