| Schedule of Investments (unaudited) | BlackRock Short Maturity Municipal Bond ETF |
| January 31, 2023 | (Percentages shown are based on Net Assets) |
| Security | Par (000) | Value | ||||||
| Municipal Debt Obligations | ||||||||
| Alabama — 5.1% | ||||||||
| Black Belt Energy Gas District RB | ||||||||
| 2.28%, 12/01/48 (Put 12/01/23)(a)(b) | $ | 15,000 | $ | 14,986,635 | ||||
| 4.00%, 06/01/23 | 240 | 240,240 | ||||||
| 4.00%, 06/01/23 | 1,500 | 1,500,240 | ||||||
| 4.00%, 12/01/24 | 1,250 | 1,253,111 | ||||||
| 5.00%, 12/01/23 | 1,000 | 1,008,507 | ||||||
| 5.25%, 12/01/23 | 530 | 535,997 | ||||||
| 5.25%, 06/01/24 | 500 | 509,417 | ||||||
| 5.25%, 12/01/24 | 2,745 | 2,811,887 | ||||||
| 5.25%, 12/01/24 | 630 | 646,694 | ||||||
| 5.25%, 06/01/25 | 615 | 635,473 | ||||||
| Southeast Energy Authority A Cooperative District RB | ||||||||
| Series A, 4.00%, 10/01/23 | 450 | 450,779 | ||||||
| Series B, 4.00%, 06/01/24 | 1,200 | 1,204,222 | ||||||
| 25,783,202 | ||||||||
| Arizona — 0.7% | ||||||||
| Arizona Health Facilities Authority RB, Class B, 1.91%, 01/01/46 (Put 11/04/26)(a)(b) | 3,600 | 3,589,103 | ||||||
| California — 0.4% | ||||||||
| California Community Choice Financing Authority RB | ||||||||
| 4.00%, 02/01/24 | 500 | 501,277 | ||||||
| 4.00%, 08/01/24 | 350 | 351,538 | ||||||
| State of California GO, 5.00%, 12/01/24 | 1,190 | 1,250,788 | ||||||
| 2,103,603 | ||||||||
| Colorado — 1.0% | ||||||||
| City & County of Denver Co. Airport System Revenue RB, | ||||||||
| Series A, 5.00%, 11/15/23 | 250 | 254,849 | ||||||
| Colorado School of Mines RB, VRDN, 2.53%, 12/01/25 (Call 06/01/25)(a)(b) | 5,000 | 5,024,715 | ||||||
| 5,279,564 | ||||||||
| Connecticut — 2.5% | ||||||||
| State of Connecticut GO | ||||||||
| 2.65%, 03/01/25 (a)(b) | 4,600 | 4,752,775 | ||||||
| Series C, VRDN, 1.68%, 05/15/34 (Put 01/31/23)(b) | 7,820 | 7,820,000 | ||||||
| 12,572,775 | ||||||||
| District of Columbia — 1.7% | ||||||||
| District of Columbia, 2.43%, 03/15/23 | 4,000 | 4,002,519 | ||||||
| District of Columbia RB, 1.70%, 04/01/38 (Put 01/31/23)(b) | 2,890 | 2,890,000 | ||||||
| Tender Option Bond Trust Receipts/Certificates RB, 1.95%, 10/01/53 (Put 10/01/29)(b)(c) | 1,565 | 1,565,000 | ||||||
| 8,457,519 | ||||||||
| Florida — 4.5% | ||||||||
| County of Martin FL RB, 1.72%, 07/01/52 (Put 01/31/23)(b) | 2,500 | 2,500,000 | ||||||
| County of Miami-Dade FL Aviation Revenue RB, Series A, 5.00%, 10/01/23 | 2,500 | 2,539,188 | ||||||
| County of Palm Beach FL RB, 1.73%, 07/01/32 (Put 02/01/23)(b) | 2,800 | 2,800,000 | ||||||
| County of St. Lucie FL, 1.35%, 09/01/28 (Put 01/31/23)(b) | 11,100 | 11,100,000 | ||||||
| Miami-Dade County Industrial Development Authority RB, 0.40%, 08/01/23 | 1,000 | 981,752 | ||||||
| Pinellas County Housing Finance Authority RB, 1.68%, 10/01/48 (Put 01/31/23)(b) | 3,070 | 3,070,000 | ||||||
| 22,990,940 | ||||||||
| Georgia — 5.1% | ||||||||
| Burke County Development Authority RB, 2.25%, 10/01/32Put(b) | 2,000 | 1,993,440 | ||||||
| Security | Par (000) | Value | ||||||
| Georgia (continued) | ||||||||
| Main Street Natural Gas Inc. RB | ||||||||
| 5.00%, 05/15/24 | $ | 1,500 | $ | 1,523,401 | ||||
| 5.00%, 06/01/24 | 560 | 568,907 | ||||||
| 5.00%, 06/01/25 | 750 | 770,851 | ||||||
| 5.00%, 06/01/27 | 1,750 | 1,832,890 | ||||||
| VRDN, 2.23%, 08/01/48 (Put 12/01/23)(a)(b) | 5,000 | 4,966,335 | ||||||
| Series A, VRDN, 4.00%, 04/01/48 (Put 09/01/23)(b) | 5,685 | 5,697,837 | ||||||
| Series D, VRDN, 3.76%, 08/01/48 (Put 12/01/23)(a) | 5,000 | 4,996,390 | ||||||
| Monroe County Development Authority RB, 1.35%, 06/01/49Put(b) | 3,700 | 3,700,000 | ||||||
| 26,050,051 | ||||||||
| Illinois — 1.0% | ||||||||
| Illinois Development Finance Authority RB, 1.75%, 02/01/33 (Put 01/31/23)(b) | 2,000 | 2,000,000 | ||||||
| Illinois Finance Authority RB, 1.67%, 01/01/37 (Put 02/01/23)(b) | 3,100 | 3,100,000 | ||||||
| 5,100,000 | ||||||||
| Indiana — 4.3% | ||||||||
| Indiana Finance Authority RB | ||||||||
| 2.90%, 05/01/28 Put (b) | 2,000 | 2,000,000 | ||||||
| 4.50%, 12/15/46 (Put 11/15/23) | 12,000 | 12,022,776 | ||||||
| Indianapolis Local Public Improvement Bond Bank RB, Series A, 5.00%, 06/01/23 | 1,800 | 1,812,901 | ||||||
| Tender Option Bond Trust Receipts/Certificates RB, 2.05%, 04/01/30Put(b)(c) | 6,000 | 6,000,000 | ||||||
| 21,835,677 | ||||||||
| Iowa — 4.3% | ||||||||
| Iowa Finance Authority RB | ||||||||
| VRDN, 1.65%, 01/01/47 (Put 01/31/23)(b) | 8,400 | 8,400,000 | ||||||
| VRDN, 1.71%, 12/01/41 (Put 01/31/23)(b)(c) | 3,200 | 3,200,000 | ||||||
| VRDN, 1.70%, 05/01/23 (Put 01/31/23)(b) | 10,000 | 10,000,000 | ||||||
| 21,600,000 | ||||||||
| Kansas — 1.4% | ||||||||
| City of Burlington KS RB | ||||||||
| Series A, VRDN, 1.84%, 09/01/35 (Put 01/31/23)(b) | 4,000 | 4,000,000 | ||||||
| Series B, VRDN, 1.84%, 09/01/35 (Put 01/31/23)(b) | 3,000 | 3,000,000 | ||||||
| 7,000,000 | ||||||||
| Kentucky — 3.1% | ||||||||
| County of Meade KY RB, 2.00%, 08/01/61 (Put 01/31/23)(b) | 4,100 | 4,100,000 | ||||||
| Kentucky Economic Development Finance Authority RB, 2.90%, 04/01/31 ( 03/01/23) | 2,000 | 2,000,000 | ||||||
| Kentucky Public Energy Authority RB | ||||||||
| 4.00%, 02/01/23 | 1,000 | 1,000,000 | ||||||
| 4.00%, 12/01/49 (Put 06/01/25) | 4,000 | 4,018,320 | ||||||
| Series A, VRDN, 4.00%, 04/01/48 (Put 04/01/24)(b) | 3,930 | 3,950,094 | ||||||
| Tender Option Bond Trust Receipts/Certificates RB, 1.93%, 12/01/41 (Put 12/01/27) (AGM)(b)(c) | 500 | 500,000 | ||||||
| 15,568,414 | ||||||||
| Louisiana — 6.6% | ||||||||
| Lake Charles Harbor & Terminal District RB, 1.00%, 12/01/51Put(b) | 4,325 | 4,082,562 | ||||||
| Louisiana Offshore Terminal Authority RB, 1.65%, 09/01/27Put(b) | 400 | 393,581 | ||||||
| Louisiana Stadium & Exposition District RB, 4.00%, 07/03/23 (Call 04/01/23) | 2,325 | 2,327,755 | ||||||
| Parish of St James LA RB, Series B1, 2.13%, 11/01/40 (Put 01/31/23)(b) | 26,500 | 26,500,000 | ||||||
| 33,303,898 | ||||||||
1
| Schedule of Investments (unaudited) (continued) | BlackRock Short Maturity Municipal Bond ETF |
| January 31, 2023 | (Percentages shown are based on Net Assets) |
| Security | Par (000) | Value | ||||||
| Massachusetts — 0.9% | ||||||||
| Massachusetts Educational Financing Authority RB, 5.00%, 01/01/24 | $ | 2,500 | $ | 2,542,440 | ||||
| Massachusetts Housing Finance Agency RB | ||||||||
| Series A, 0.30%, 12/01/23 (Call 02/21/23) | 1,000 | 973,163 | ||||||
| Series A, 0.40%, 06/01/24 (Call 06/01/23) | 1,000 | 963,775 | ||||||
| 4,479,378 | ||||||||
| Michigan — 0.1% | ||||||||
| Michigan Finance Authority RB, 0.40%, 10/15/23 | 665 | 652,486 | ||||||
| Minnesota — 3.8% | ||||||||
| City of Minneapolis MN RB, 1.68%, 12/01/40 (Put 02/01/23)(b) | 9,450 | 9,450,000 | ||||||
| City of Rochester MN RB, 1.65%, 05/01/61 (Put 01/31/23)(b) | 4,800 | 4,800,000 | ||||||
| University of Minnesota, 1.91%, 03/08/23 | 5,000 | 5,004,293 | ||||||
| 19,254,293 | ||||||||
| Missouri — 0.5% | ||||||||
| County of Greene MO COP, Series A, 3.00%, 03/01/23 | 350 | 350,110 | ||||||
| RBC Municipal Products Inc. Trust RB, 1.95%, 09/01/39Put(b)(c) | 2,000 | 2,000,000 | ||||||
| 2,350,110 | ||||||||
| Nebraska — 0.6% | ||||||||
| Central Plains Energy Project RB, 5.00%, 03/01/50 (Put 01/01/24)(b) | 1,000 | 1,010,725 | ||||||
| County of Douglas NE RB, 2.19%, 07/01/35Put(a)(b) | 1,980 | 1,964,091 | ||||||
| 2,974,816 | ||||||||
| Nevada — 2.5% | ||||||||
| County of Clark Department of Aviation RB, 1.70%, 07/01/40 (Put 01/31/23)(b) | 2,600 | 2,600,000 | ||||||
| State of Nevada Department of Business & Industry RB, 3.70%, 01/01/50 (Put 01/31/24) | 10,000 | 9,936,310 | ||||||
| 12,536,310 | ||||||||
| New Jersey — 8.2% | ||||||||
| Borough of Berlin NJ GO, 4.50%, 09/26/23 | 2,212 | 2,229,253 | ||||||
| Borough of North Arlington NJ GO, 4.50%, 08/08/23 | 1,173 | 1,179,657 | ||||||
| Borough of Park Ridge NJ GO, 4.50%, 04/28/23 | 1,000 | 1,002,784 | ||||||
| Borough of Wood-Ridge NJ GO, 4.50%, 03/01/23 | 1,640 | 1,641,545 | ||||||
| New Jersey Economic Development Authority RB 5.25%, 09/01/24 (c) | 7,600 | 7,889,294 | ||||||
| Series B, 5.00%, 11/01/23 (SAP) | 1,450 | 1,472,178 | ||||||
| Series B, 5.00%, 11/01/24 | 1,010 | 1,048,895 | ||||||
| Series N-1, 5.50%, 09/01/24 (AMBAC) | 1,460 | 1,521,539 | ||||||
| Series NN, 5.00%, 03/01/23 | 1,000 | 1,001,748 | ||||||
| Series UU, 5.00%, 06/15/23 | 1,575 | 1,586,644 | ||||||
| New Jersey Health Care Facilities Financing Authority RB, 5.00%, 10/01/23 | 1,500 | 1,520,230 | ||||||
| New Jersey Higher Education Student Assistance Authority RB, 5.00%, 12/01/24 | 500 | 517,422 | ||||||
| New Jersey Housing & Mortgage Finance Agency RB, 4.00%, 04/01/23 | 1,290 | 1,290,894 | ||||||
| New Jersey Transportation Trust Fund Authority RB | ||||||||
| Series A, 5.00%, 06/15/24 | 1,575 | 1,623,929 | ||||||
| Series A, 5.00%, 12/15/24 | 1,000 | 1,041,540 | ||||||
| Series A, 5.50%, 12/15/23 | 155 | 158,451 | ||||||
| Series D, 5.00%, 12/15/23 | 470 | 478,462 | ||||||
| Series D, 5.25%, 12/15/23 | 1,275 | 1,300,671 | ||||||
| State of New Jersey GO, Series A, 4.00%, 06/01/23 | 1,290 | 1,296,129 | ||||||
| Township of Clark NJ GO, 4.50%, 08/18/23 | 2,533 | 2,550,260 | ||||||
| Township of Cranford NJ GO, 4.75%, 07/20/23 | 1,940 | 1,948,578 | ||||||
| Township of Deptford NJ RB, 4.00%, 07/11/23 | 1,800 | 1,802,680 | ||||||
| Security | Par (000) | Value | ||||||
| New Jersey (continued) | ||||||||
| Township of Plainsboro NJ GO, 4.50%, 07/26/23 | $ | 1,500 | $ | 1,508,415 | ||||
| Township of Plainsboro NJ RB, 4.00%, 07/26/23 | 1,340 | 1,342,227 | ||||||
| Township of River Vale NJ RB, 4.00%, 07/14/23 | 1,258 | 1,260,354 | ||||||
| Township of Voorhees NJ GO, 4.00%, 09/27/23 | 1,145 | 1,151,539 | ||||||
| 41,365,318 | ||||||||
| New York — 4.7% | ||||||||
| Albany Industrial Development Agency RB, 1.73%, 07/01/32 (Put 02/02/23)(b) | 800 | 800,000 | ||||||
| Amherst Development Corp. RB, 1.72%, 02/01/35 (Put 01/31/23)(b) | 1,720 | 1,720,000 | ||||||
| Genesee County Funding Corp. (The) RB, 5.00%, 12/01/23 | 150 | 152,159 | ||||||
| Nassau Health Care Corp. RB, Series C, 5.00%, 08/01/23 (GTD) | 1,425 | 1,440,842 | ||||||
| New York City Housing Development Corp. RB 0.45%, 11/01/25 (FHA) | 1,560 | 1,443,429 | ||||||
| VRDN, 1.65%, 05/01/61 (Put 01/31/23) (FHA 542 (C))(b) | 4,165 | 4,165,000 | ||||||
| New York Transportation Development Corp. RB, Series A, 5.00%, 12/01/23 | 1,250 | 1,268,671 | ||||||
| Town of Oyster Bay NY GOL, 4.00%, 03/01/23 | 425 | 425,394 | ||||||
| Triborough Bridge & Tunnel Authority RB, 3.93%, 04/01/26 (Call 10/01/25)(a)(b) | 11,000 | 11,000,000 | ||||||
| Village of Hamburg NY, 3.50%, 07/20/23 | 1,506 | 1,505,271 | ||||||
| 23,920,766 | ||||||||
| North Carolina — 1.6% | ||||||||
| North Carolina Capital Facilities Finance Agency RB, Series A, 2.90%, 07/01/34Put(b) | 8,000 | 8,000,000 | ||||||
| Ohio — 1.3% | ||||||||
| Akron Bath Copley Joint Township Hospital District RB, 5.00%, 11/15/23 | 325 | 330,269 | ||||||
| County of Miami OH GOL, 3.25%, 07/27/23 | 1,050 | 1,047,022 | ||||||
| Ohio Higher Educational Facility Commission RB, Series B, 1.89%, 12/01/42 (Put 12/01/26)(a)(b) | 5,500 | 5,458,926 | ||||||
| 6,836,217 | ||||||||
| Pennsylvania — 10.2% | ||||||||
| Allegheny County Hospital Development Authority RB, 2.03%, 11/15/23(a)(b) | 1,500 | 1,500,909 | ||||||
| Butler County Industrial Development Authority/PA RB, 1.73%, 05/01/34 (Put 02/01/23)(b) | 2,100 | 2,100,000 | ||||||
| Ephrata Area School District GO, 3.00%, 03/01/24 | 1,000 | 1,003,817 | ||||||
| Pennsylvania Economic Development Financing Authority, 2.90%, 12/01/38 (Put 01/31/23)(b) | 23,000 | 23,000,000 | ||||||
| Pennsylvania Economic Development Financing Authority RB | ||||||||
| VRDN, 2.06%, 06/01/41 (Put 06/03/24)(a)(b) | 3,000 | 2,934,726 | ||||||
| VRDN, 2.90%, 12/01/37 (Put 01/31/23)(b) | 9,070 | 9,070,000 | ||||||
| Pennsylvania Housing Finance Agency RB, 5.00%, 10/01/25 | 500 | 530,631 | ||||||
| Pennsylvania Turnpike Commission RB, 2.26%, 12/01/23 (Call 06/01/23)(a)(b) | 10,000 | 9,996,480 | ||||||
| Tender Option Bond Trust Receipts/Certificates RB, 1.93%, 10/01/41 (Put 10/01/29)(b)(c) | 1,620 | 1,620,000 | ||||||
| 51,756,563 | ||||||||
| South Carolina — 0.3% | ||||||||
| South Carolina Public Service Authority RB, 1.75%, 01/01/36 (Put 01/31/23)(b) | 700 | 700,000 | ||||||
| Tender Option Bond Trust Receipts/Certificates RB, 2.02%, 12/01/55 (Put 06/01/32) (BAM-TCRS)(b)(c) | 1,000 | 1,000,000 | ||||||
| 1,700,000 | ||||||||
2
| Schedule of Investments (unaudited) (continued) | BlackRock Short Maturity Municipal Bond ETF |
| January 31, 2023 | (Percentages shown are based on Net Assets) |
| Security |
(000) | Value | ||||||
| Tennessee — 3.3% | ||||||||
| Johnson City Health & Educational Facilities Board RB, 1.65%, 07/01/45 (Put 01/31/23)(b) | $ | 2,030 | $ | 2,030,000 | ||||
| Tender Option Bond Trust Receipts/Certificates RB, VRDN, 1.55%, 09/01/36 (Put 03/03/23)(b)(c) | 5,000 | 5,000,000 | ||||||
| Tennergy Corp./TN RB | ||||||||
| Series A, 4.00%, 03/01/23 | 375 | 374,997 | ||||||
| Series A, 4.00%, 09/01/23 | 320 | 320,136 | ||||||
| Tennergy Corp/TN RB | ||||||||
| 5.25%, 12/01/23 | 650 | 655,792 | ||||||
| 5.25%, 12/01/24 | 575 | 587,561 | ||||||
| 5.25%, 12/01/25 | 575 | 593,761 | ||||||
| Tennessee Energy Acquisition Corp. RB | ||||||||
| 4.00%, 05/01/48 ( 02/01/23) | 5,000 | 5,004,925 | ||||||
| 5.63%, 09/01/26 | 2,000 | 2,111,784 | ||||||
| Series A, 5.00%, 11/01/23 | 250 | 251,902 | ||||||
| 16,930,858 | ||||||||
| Texas — 7.4% | ||||||||
| Bexar County Housing Finance Corp. RB, 1.68%, 12/15/25 (Put 02/15/23)(b) | 2,205 | 2,205,000 | ||||||
| Fort Bend Independent School District, 2.72%, 02/22/23 | 7,500 | 7,502,535 | ||||||
| Pasadena Independent School District GO, 1.65%, 02/01/35 (Put 01/31/23)(b) | 2,400 | 2,400,000 | ||||||
| Port of Arthur Navigation District Industrial Development Corp. RB | ||||||||
| VRDN, 1.68%, 12/01/40 (Put 02/01/23)(b) | 7,000 | 7,000,000 | ||||||
| VRDN, 1.68%, 06/01/41 (Put 02/01/23)(b) | 3,000 | 3,000,000 | ||||||
| State of Texas GO, 1.70%, 12/01/43Put(b) | 9,375 | 9,375,000 | ||||||
| Texas Municipal Gas Acquisition & Supply Corp. III RB | ||||||||
| 5.00%, 12/15/23 | 4,300 | 4,352,490 | ||||||
| 5.00%, 12/15/26 | 1,850 | 1,936,769 | ||||||
| 37,771,794 | ||||||||
| Virginia — 0.1% | ||||||||
| Fairfax County Industrial Development Authority RB, 5.00%, 05/15/23 | 300 | 301,998 | ||||||
| Washington — 0.2% | ||||||||
| Washington Health Care Facilities Authority RB, 5.00%, 08/01/49 (Put 08/01/25)(b) | 800 | 829,705 | ||||||
| Wisconsin — 10.3% | ||||||||
| Eau Claire Area School District/WI REVENUE NOTES, 4.00%, 06/21/23 (Call 03/21/23) | 4,100 | 4,108,280 | ||||||
| Security | Par/ Shares (000) | Value | ||||||
| Wisconsin (continued) | ||||||||
| Jefferson School District/WI REVENUE NOTES, 4.00%, 06/28/23 (Call 03/28/23) | $ | 6,100 | $ | 6,109,369 | ||||
| Onalaska School District REVENUE NOTES, 4.00%, 07/26/23 (Call 04/26/23) | 5,450 | 5,460,835 | ||||||
| Racine Unified School District REVENUE NOTES, 4.00%, 08/09/23 (Call 05/09/23) | 13,000 | 13,041,301 | ||||||
| State of Wisconsin GO, 2.08%, 05/01/25 (Call 11/01/24)(a)(b) | 19,990 | 19,983,923 | ||||||
| Wisconsin Health & Educational Facilities Authority RB, 1.84%, 08/15/54 (Put 07/01/26)(a)(b) | 2,000 | 1,969,332 | ||||||
| Wisconsin Housing & Economic Development Authority RB | ||||||||
| VRDN, 1.68%, 03/01/41 (Put 01/31/23)(b) | 1,000 | 1,000,000 | ||||||
| VRDN, 1.68%, 04/01/46 (Put 01/31/23)(b) | 765 | 765,000 | ||||||
| 52,438,040 | ||||||||
| Total Municipal Debt Obligations — 97.7% | ||||||||
| (Cost $496,486,620) | 495,333,398 | |||||||
| Money Market Funds | ||||||||
| BlackRock Liquidity Funds: MuniCash, 1.39%(d)(e) | 40 | 40,463 | ||||||
| Total Money Market Funds — 0.0% | ||||||||
| (Cost: $40,463) | 40,463 | |||||||
| Total Investments — 97.7% | ||||||||
| (Cost: $496,527,083) | 495,373,861 | |||||||
| Other Assets Less Liabilities — 2.3% | 11,476,218 | |||||||
| Net Assets — 100.0% | $ | 506,850,079 | ||||||
| (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) | Variable rate security. Rate as of period end and maturity is the date the principal owed can be recovered through demand. |
| (c) | 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. |
| (d) | Affiliate of the Fund. |
| (e) | Annualized 7-day yield as of period end. |
Affiliates
Investments in issuers considered to be affiliate(s) of the Fund during the period ended January 31, 2023 for purposes of Section 2(a)(3) of the Investment Company Act of 1940, as amended, were as follows:
| Affiliated Issuer | Value at 10/31/22 | Purchases at Cost | Proceeds from Sale | Net Realized Gain (Loss) | Change in Unrealized Appreciation (Depreciation) | Value at 01/31/23 | Shares Held at 01/31/23 (000) | Income | Capital Gain Distributions from Underlying Funds | |||||||||||||||||||||||||||
| BlackRock Liquidity Funds: MuniCash | $ | 28,912 | $ | 11,533 | (a) | $ | — | $ | 18 | $ | — | $ | 40,463 | 40 | $ | 1,111 | $ | — | ||||||||||||||||||
| (a) | Represents net amount purchased (sold). |
3
| Schedule of Investments (unaudited) (continued) | BlackRock Short Maturity Municipal Bond ETF |
| January 31, 2023 |
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 | ||||||||||||||||
| Municipal Debt Obligations | $ | — | $ | 495,333,398 | $ | — | $ | 495,333,398 | ||||||||
| Short-Term Securities | ||||||||||||||||
| Money Market Funds | 40,463 | — | — | 40,463 | ||||||||||||
| $ | 40,463 | $ | 495,333,398 | $ | — | $ | 495,373,861 | |||||||||
Portfolio Abbreviation
| AGM | Assured Guaranty Municipal Corp. | GTD | Guaranteed |
| AMBAC | Ambac Assurance Corp. | MO | Moral Obligation |
| COP | Certificates of Participation | RB | Revenue Bond |
| FHA | Federal Housing Administration | SAP | Subject to Appropriations |
| GO | General Obligation | ||
| GOL | General Obligation Limited |
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