Schedule of Investments (unaudited)	BlackRock Ultra Short-Term Bond ETF
January 31, 2023	(Percentages shown are based on Net Assets)

	Par
Security		(000)		Value
Asset-Backed Securities
American Express Credit Account Master Trust, 4.95%, 10/15/27	$	14,709	$	14,924,588
BMW Vehicle Owner Trust, 2.52%, 12/26/24 (Call 11/25/25)		10,611		10,498,330
CarMax Auto Owner Trust
2.81%, 05/15/25 (Call 08/15/25)		2,592		2,567,975
5.23%, 01/15/26		20,200		20,190,542
Carmax Auto Owner Trust 2022-4, 5.34%, 12/15/25
(Call 10/15/26)		12,861		12,895,833
Chase Issuance Trust, 3.97%, 09/15/27		14,100		13,955,558
Ford Credit Auto Lease Trust
0.24%, 04/15/24 (Call 01/15/24)		965		963,533
2.78%, 10/15/24 (Call 10/15/24)		3,278		3,250,640
5.19%, 06/15/25		3,875		3,872,563
Ford Credit Auto Owner Trust
0.73%, 09/15/24 (Call 09/15/25)		4,569		4,521,632
3.44%, 02/15/25 (Call 12/15/25)		8,760		8,692,227
Honda Auto Receivables Owner Trust, 1.44%, 10/15/24
(Call 08/15/25)		10,588		10,420,121
Hyundai Auto Lease Securitization Trust
0.24%, 01/16/24 (Call 03/15/24)(a)		3,891		3,874,191
0.81%, 04/15/24 (Call 06/15/24)(a)		5,611		5,545,220
2.75%, 10/15/24 (Call 10/15/24)(a)		15,678		15,487,743
4.34%, 01/15/25 (Call 02/15/25)(a)		2,378		2,364,289
5.20%, 04/15/25		11,100		11,099,226
Nissan Auto Receivables Owner Trust, 4.50%, 08/15/25
(Call 09/15/26)		9,440		9,398,316
Toyota Auto Receivables Owner Trust, 2.35%, 01/15/25
(Call 04/15/26)		7,123		7,044,806
Total Asset-Backed Securities — 2.4%
(Cost: $162,318,225)				161,567,333

Certificates of Deposit
Banco Santander SA, 5.10%, 05/03/23, (1 day SOFR + 0.800%)(b)	10,000	10,013,677
Bank of Montreal, 5.40%, 10/13/23	25,000	25,040,153
Bank of Montreal/Chicago IL, 5.00%, 07/13/23, (1 day SOFR + 0.700%)(b)	7,000	7,013,480
Bank of Nova Scotia (The), 4.05%, 07/14/23	20,000	19,902,178
Barclays Bank PLC/NY
1.65%, 03/03/23	15,000	14,961,872
2.98%, 06/01/23	8,750	8,694,547
4.00%, 07/13/23	15,000	14,920,932
4.61%, 02/03/23, (1 day SOFR + 0.300%)(b)	30,000	30,000,511
4.95%, 06/08/23, (1 day SOFR + 0.650%)(b)	15,000	15,016,847
Bayerische Landesbank/New York, 0.90%, 06/27/23	15,000	14,759,590
Canadian Imperial Bank of Commerce
4.58%, 03/03/23, (1 day SOFR + 0.280%)(b)	30,000	30,003,796
4.65%, 09/14/23	17,000	16,949,101
CDP Financial Inc.
4.91%, 06/27/23	7,900	7,744,676
4.99%, 07/20/23	14,077	13,753,002
Citibank NA
3.77%, 05/01/23	15,000	14,960,721
3.85%, 07/28/23	10,000	9,939,294
4.93%, 09/21/23(b)	10,000	10,017,273
Kookmin Bank/New York
4.62%, 02/09/23, (1 day SOFR + 0.320%)(b)	10,000	10,000,518
4.62%, 02/21/23, (1 day SOFR + 0.320%)(b)	20,000	20,001,389

	Par
Security		(000)		Value
Landesbank Baden-Wuerttemberg, 4.79%, 02/03/23, (1 day SOFR + 0.490%)(b)	$	17,500	$	17,500,618
Lloyds Bank Corporate Markets PLC
4.82%, 05/15/23		8,000		7,890,176
5.24%, 10/12/23		15,000		15,000,148
Lloyds Bank Corporate Markets PLC/New York NY
2.81%, 05/11/23		15,000		14,912,423
4.59%, 02/03/23, (1 day SOFR + 0.280%)(b)		25,000		25,000,320
Mizuho Bank Ltd.
5.11%, 04/26/23, (1 day SOFR + 0.800%)(b)		25,000		25,039,345
5.11%, 04/27/23, (1 day SOFR + 0.800%)(b)		12,500		12,519,873
Mizuho Bank Ltd./New York NY, 4.87%, 02/01/23, (1 day SOFR + 0.570%)(b)		30,000		30,000,427
Natixis SA/New York NY, 4.58%, 02/07/23, (1 day SOFR + 0.280%)(b)		10,000		10,000,382
Royal Bank of Canada, 4.05%, 08/22/23		25,000		24,842,290
Standard Chartered Bank/New York
4.60%, 03/13/23, (1 day SOFR + 0.300%)(b)		30,000		30,008,444
4.65%, 05/01/23, (1 day SOFR + 0.350%)(b)		25,000		25,009,525
4.72%, 07/28/23, (1 day SOFR + 0.420%)(b)		15,000		15,014,223
Sumitomo Mitsui Banking Corp.
2.70%, 04/25/23		50,000		49,758,236
5.00%, 09/28/23(b)		15,000		15,037,327
Swedbank AB, 4.96%, 04/25/23, (1 day SOFR + 0.650%)(b)		35,000		35,037,378
Toronto-Dominion Bank
2.69%, 04/28/23		10,000		9,951,264
3.70%, 05/01/23		10,000		9,974,613
4.35%, 09/13/23		17,000		16,915,390
4.43%, 05/01/23		15,000		15,022,236
5.20%, 10/11/23		25,000		24,994,351
Versailles Commercial Paper LLC
4.83%, 06/05/23		14,805		14,560,666
4.99%, 07/05/23		25,000		24,474,399
Westpac Banking Corp., 4.22%, 09/06/23		17,000		16,910,985
Total Certificates of Deposit — 11.5%
(Cost: $780,201,326)				779,068,596
Commercial Paper
ABN AMRO Funding USA LLC, 5.20%, 10/13/23		6,847		6,603,775
Alinghi Funding Co. LLC, 4.75%, 04/18/23(a)		33,500		33,163,232
Amcor Finance USA Inc.
4.94%, 02/16/23		43,810		43,714,105
4.99%, 03/03/23		27,000		26,884,378
Amcor Flexibles North America Inc., 4.61%, 02/03/23		14,099		14,093,582
American Electric Power Co. Inc.
4.71%, 02/07/23		25,980		25,956,207
4.73%, 02/13/23		27,500		27,453,068
4.74%, 02/14/23		39,250		39,177,832
4.83%, 03/13/23		15,000		14,917,880
American Honda Finance Corp.
4.77%, 02/16/23		18,000		17,961,904
4.79%, 03/06/23		20,000		19,909,938
4.79%, 03/08/23		25,000		24,880,700
4.94%, 04/10/23		17,600		17,434,875
ASB Bank Ltd.
5.04%, 08/11/23		20,000		19,476,480
5.08%, 09/12/23		15,000		14,539,960
AT&T Inc., 4.88%, 03/29/23		17,875		17,738,074

 1

Schedule of Investments (unaudited) (continued)	BlackRock Ultra Short-Term Bond ETF
January 31, 2023	(Percentages shown are based on Net Assets)

	Par
Security		(000)		Value
Australia & New Zealand Banking Group Ltd., 4.96%, 06/08/23, (1 day SOFR + 0.660%)(a)(b)	$	35,000	$	35,056,569
Bank of Montreal, 2.80%, 05/12/23		12,000		11,934,497
Barton Capital SA
4.54%, 02/15/23		10,000		9,981,121
4.57%, 02/24/23		28,419		28,332,606
4.70%, 03/29/23		5,000		4,963,085
4.75%, 04/24/23		25,000		24,729,097
Bell Telephone Co. of Canada or Bell Canada, 4.59%, 02/13/23		5,398		5,389,070
BPCE SA
4.49%, 02/22/23		10,000		9,972,610
4.51%, 03/01/23		13,500		13,451,084
Brighthouse Financial Short Term Funding LLC
4.53%, 02/21/23		17,335		17,289,354
5.44%, 10/16/23		8,720		8,392,590
5.55%, 11/14/23		4,413		4,225,977
Brookfield BRP Holdings Canada Inc., 4.68%, 02/06/23		12,000		11,990,638
Brookfield Infrastructure Holdings Canada Inc.
4.87%, 03/14/23		20,000		19,887,067
4.90%, 03/21/23		20,428		20,292,785
Canadian Imperial Bank of Commerce, 4.97%, 06/05/23(b)		35,000		35,064,580
CDP Financial Inc.
5.04%, 08/10/23		25,000		24,349,141
5.08%, 09/07/23		10,000		9,700,335
CenterPoint Energy Resources Corp.
4.74%, 02/09/23		23,000		22,972,803
4.76%, 02/22/23		25,000		24,927,431
4.77%, 02/23/23		25,000		24,924,100
Citigroup Global Markets Inc., 4.78%, 04/11/23		30,000		29,723,908
Collateralized Commercial Paper V Co. LLC, 4.84%, 02/21/23, (1 day SOFR + 0.540%)(b)		28,200		28,205,527
Commonwealth Bank of Australia, 4.90%, 07/13/23,  (1 day SOFR + 0.600%)(a)(b)		35,000		35,050,143
Credit Industriel et Commercial, 5.06%, 07/19/23		19,358		19,363,379
Credit Industriel et Commercial/New York
4.51%, 03/08/23		25,000		24,887,650
4.70%, 05/04/23		15,500		15,314,167
DNB Bank ASA
4.46%, 03/02/23		10,000		9,962,958
4.63%, 04/28/23		10,000		9,889,365
Dominion Energy Inc., 4.73%, 02/27/23		8,896		8,864,535
E.ON SE
4.60%, 02/03/23		12,940		12,935,044
4.77%, 02/24/23		9,895		9,863,633
Enbridge U.S. Inc., 4.77%, 02/02/23		20,000		19,994,707
Enel Finance America LLC, 5.16%, 03/20/23		17,600		17,479,757
Engie SA, 4.66%, 03/08/23		15,000		14,930,430
Evergy Kansas Central Inc., 4.57%, 02/02/23		14,350		14,346,359
Eversource Energy, 4.55%, 02/06/23.		23,452		23,434,239
Fidelity National Information Services Inc.
4.57%, 02/02/23		30,000		29,992,393
4.68%, 02/06/23		20,000		19,984,423
4.72%, 02/13/23		10,595		10,576,987
4.72%, 02/14/23		16,193		16,163,340
4.74%, 02/27/23		9,705		9,670,593
Fiserv Inc.
4.61%, 02/03/23		20,000		19,992,315
4.70%, 02/06/23		13,500		13,489,441
4.74%, 02/14/23		10,455		10,435,769
4.74%, 02/16/23		4,545		4,535,439

	Par
Security		(000)		Value
4.77%, 03/01/23	$	35,000	$	34,866,105
4.82%, 03/13/23		14,116		14,038,929
Glencove Funding LLC, 4.52%, 02/17/23		31,933		31,865,007
HSBC Bank PLC, 5.16%, 11/01/23,  (1 day SOFR + 0.850%)(a)(b)		20,000		20,068,195
HSBC USA Inc.
5.24%, 08/14/23		15,000		14,586,031
5.27%, 09/07/23		20,000		19,379,135
5.32%, 10/17/23		29,412		28,327,958
Hyundai Capital America
4.76%, 02/21/23		20,140		20,084,231
4.76%, 02/22/23		9,090		9,063,614
4.78%, 02/27/23		9,881		9,845,710
4.78%, 02/28/23		25,000		24,907,347
4.81%, 03/07/23		15,000		14,930,190
ING U.S. Funding LLC
4.50%, 02/22/23		25,000		24,931,387
5.07%, 08/22/23		25,000		24,305,571
Kookmin Bank, 4.78%, 04/25/23		25,000		24,724,433
Korea Development Bank, 5.13%, 10/06/23		9,745		9,412,360
Korea Development Bank (The), 4.82%, 05/26/23		12,500		12,310,570
Korea Development Bank/New York NY, 4.45%, 02/06/23		7,500		7,494,445
La Fayette Asset Securitization LLC
4.31%, 02/01/23		13,666		13,664,365
4.36%, 02/03/23		16,304		16,298,075
Landesbank Baden-Wuerttemberg, 4.51%, 02/14/23		40,000		39,930,016
Liberty Street Funding LLC
4.50%, 02/14/23		20,000		19,965,023
4.57%, 02/28/23		10,000		9,964,596
Lime Funding LLC, 4.55%, 02/24/23		13,699		13,657,565
Lloyds Bank PLC, 4.47%, 02/07/23		21,250		21,231,530
LMA-Americas LLC
4.59%, 02/21/23		12,903		12,868,565
4.75%, 05/02/23		32,447		32,062,414
Mackinac Funding Co. LLC, 4.76%, 04/12/23		10,000		9,907,049
Macquarie Bank Ltd.
4.48%, 01/09/24, (1 day SOFR + 0.640%)(a)(b)		15,000		15,025,050
4.63%, 02/28/23, (1 day SOFR + 0.300%)(a)(b)		25,000		25,004,069
5.05%, 04/25/23, (1 day SOFR + 0.750%)(a)(b)		25,000		25,031,884
5.14%, 08/17/23		10,000		9,725,110
Marriott International Inc.
5.32%, 02/22/23		16,095		16,050,122
5.34%, 03/01/23		9,035		9,001,199
Mercedes-Benz Finance North America LLC
4.68%, 02/06/23		40,000		39,968,793
4.78%, 02/27/23		10,000		9,964,285
Mitsubishi HC Capital America Inc.
4.64%, 02/03/23		19,925		19,917,302
4.72%, 02/06/23		13,000		12,989,771
4.76%, 02/08/23		13,130		13,116,132
Mitsubishi HC Finance America LLC, 4.57%, 02/02/23		3,800		3,799,036
Mohawk Industries Inc., 4.57%, 02/02/23		7,600		7,598,072
Mondelez International Inc., 4.68%, 02/06/23		16,989		16,975,746
Mont Blanc Capital Corp., 4.73%, 04/20/23		7,895		7,813,901
National Australia Bank Ltd.
4.31%, 02/01/23		15,000		14,998,203
4.50%, 02/24/23		17,000		16,949,147
4.63%, 05/03/23(a)(b)		25,000		25,030,210
4.70%, 04/05/23, (1 day SOFR + 0.400%)(a)(b)		25,000		25,005,225
4.80%, 03/14/23, (1 day SOFR + 0.500%)(a)(b)		10,000		10,004,112

2

Schedule of Investments (unaudited) (continued)	BlackRock Ultra Short-Term Bond ETF
January 31, 2023	(Percentages shown are based on Net Assets)

	Par
Security		(000	)		Value
National Rural Utilities Cooperative Finance Corp., 4.49%, 02/16/23	$	10,000		$	9,980,062
NextEra Energy Capital Holdings Inc., 4.73%, 02/08/23		20,000			19,978,978
Nordea Bank Abp, 5.03%, 08/01/23, (1 day SOFR + 0.730%)(a)(b)		30,000			30,071,820
Norinchukin Bank, 4.70%, 02/24/23		25,000			25,002,011
Nutrien Ltd.
4.77%, 02/21/23		5,743			5,727,054
4.78%, 02/23/23		4,257			4,244,049
4.82%, 03/09/23		6,780			6,746,566
4.87%, 03/20/23		17,065			16,955,010
Penske Truck Leasing Co. LP, 4.78%, 02/07/23		25,000			24,976,764
Podium Funding Trust, 4.85%, 05/08/23		23,000			22,703,339
Pricoa Short Term Funding LLC
5.16%, 09/13/23		15,000			14,531,719
5.23%, 10/18/23		9,130			8,797,800
Pure Grove Funding, 5.35%, 01/08/24		20,000			19,032,330
Raytheon Technologies Corp., 4.68%, 02/06/23		34,500			34,473,084
Reckitt Benckiser Treasury Services PLC, 4.70%, 02/27/23		8,390			8,360,520
Salisbury Receivables Co. LLC, 4.34%, 02/02/23		30,000			29,992,765
Skandinaviska Enskilda Banken AB
4.68%, 04/05/23, (1 day SOFR + 0.380%)(a)(b)		25,000			25,007,500
5.02%, 06/01/23(a)(b)		35,000			35,060,465
5.05%, 08/02/23(a)(b)		17,500			17,543,693
Skandinaviska Enskilda Banken AB/New York NY, 4.82%, 04/12/23, (1 day SOFR + 0.510%)(b)		20,000			20,014,665
Spire Inc.
4.74%, 02/15/23		4,500			4,491,129
4.75%, 02/17/23		8,800			8,780,319
4.77%, 02/23/23		13,500			13,459,014
4.79%, 03/02/23		20,570			20,488,234
Suncorp-Metway Ltd.
4.97%, 04/17/23		15,228			15,069,864
5.43%, 07/31/23		15,000			14,601,725
Svenska Handelsbanken AB
4.50%, 02/27/23		30,000			29,899,132
4.51%, 03/06/23		25,000			24,893,986
5.05%, 07/28/23, (1 day SOFR + 0.750%)(a)(b)		25,000			25,060,721
TELUS Corp.
4.57%, 02/02/23		23,850			23,843,949
4.68%, 02/06/23		19,231			19,215,997
4.81%, 03/08/23		11,177			11,123,462
4.86%, 03/20/23		13,795			13,706,160
4.99%, 04/17/23		11,913			11,788,786
5.00%, 04/18/23		8,987			8,891,965
Toronto-Dominion Bank, 4.49%, 02/17/23		20,000			19,957,689
TransCanada PipeLines Ltd.
4.54%, 02/01/23		50,150			50,143,677
4.68%, 02/06/23		19,190			19,175,029
4.72%, 02/10/23		10,670			10,656,016
4.77%, 02/23/23		4,918			4,903,069
4.80%, 03/06/23		10,852			10,802,978
UBS AG/London, 4.97%, 09/26/23(a)(b)		10,000			10,009,973
Union Electric Co.
4.72%, 02/13/23		7,850			7,836,654
4.72%, 02/14/23		16,071			16,041,563
Victory Receivables Corp.
4.32%, 02/01/23		15,000			14,998,198
4.48%, 02/08/23		15,000			14,985,087
Virginia Electric and Power Co., 4.59%, 02/13/23		13,235			13,213,106

	Par
Security		(000)		Value
VW Credit Inc.
4.60%, 02/03/23	$	13,740	$	13,734,738
4.82%, 03/09/23		12,765		12,702,118
Waste Management Inc., 4.68%, 02/06/23		9,447		9,439,642
Westpac Banking Corp., 4.50%, 03/03/23		5,000		4,980,685
Total Commercial Paper — 42.5%
(Cost: $2,878,417,410)				2,877,571,675
Corporate Bonds & Notes
Aerospace & Defense — 0.2%
Lockheed Martin Corp., 4.95%, 10/15/25 (Call 09/15/25)(c)		6,195		6,290,807
Raytheon Technologies Corp., 3.65%, 08/16/23
(Call 07/16/23)		4,000		3,970,822
				10,261,629
Agriculture — 0.7%
Cargill Inc.
0.40%, 02/02/24 (Call 01/02/24)(a)(c)		10,165		9,715,809
3.50%, 04/22/25 (Call 04/22/23)(a)		6,825		6,643,294
4.88%, 10/10/25 (Call 09/10/25)(a)		14,235		14,324,906
Philip Morris International Inc., 5.13%, 11/15/24		16,000		16,111,965
				46,795,974
Auto Manufacturers — 4.6%
American Honda Finance Corp.
0.65%, 09/08/23(c)		20,000		19,487,554
0.75%, 08/09/24		3,235		3,048,829
0.88%, 07/07/23(c)		7,025		6,906,217
4.81%, 02/22/23, (3 mo. LIBOR US + 0.150%)(b)(c)		8,820		8,819,534
5.15%, 09/08/23, (3 mo. LIBOR US + 0.420%)(b)		5,790		5,798,413
BMW U.S. Capital LLC
0.75%, 08/12/24(a)		2,925		2,756,965
0.80%, 04/01/24(a)		3,350		3,199,386
4.51%, 08/12/24, (1 day SOFR + 0.380%)(a)(b)		19,960		19,820,337
4.84%, 04/01/24, (1 day SOFR + 0.530%)(a)(b)		15,615		15,565,403
Daimler Finance North America LLC
0.75%, 03/01/24(a)		26,690		25,506,004
1.75%, 03/10/23(a)(c)		13,184		13,142,567
Daimler Truck Finance North America LLC, 5.20%, 01/17/25		9,295		9,343,016
Daimler Trucks Finance North America LLC, 1.13%, 12/14/23(a)		4,000		3,866,420
Hyundai Capital America
0.80%, 04/03/23(a)		21,620		21,471,471
0.80%, 01/08/24(a)		3,000		2,878,618
2.38%, 02/10/23(a)		7,560		7,555,394
Hyundai Capital Services Inc., 0.75%, 09/15/23(a)		20,000		19,103,750
PACCAR Financial Corp.
0.80%, 06/08/23		2,760		2,722,211
3.15%, 06/13/24		8,865		8,701,533
Toyota Motor Credit Corp.
0.50%, 06/18/24		4,000		3,777,401
2.50%, 03/22/24		15,000		14,642,294
2.90%, 03/30/23(c)		10,000		9,973,509
3.65%, 08/18/25		13,145		12,855,006
4.40%, 09/20/24		15,000		14,928,421
4.51%, 02/13/23, (1 day SOFR + 0.200%)(b)(c)		22,277		22,276,053
4.58%, 09/13/24, (1 day SOFR + 0.290%)(b)		12,000		11,968,764
4.93%, 03/22/24, (1 day SOFR + 0.320%)(b)		10,000		10,023,090

 3

Schedule of Investments (unaudited) (continued)	BlackRock Ultra Short-Term Bond ETF
January 31, 2023	(Percentages shown are based on Net Assets)

	Par
Security		(000)		Value
Auto Manufacturers (continued)
Volkswagen Group of America Finance LLC, 5.21%, 06/07/24(a)(b)	$	12,380	$	12,368,574
				312,506,734
Auto Parts & Equipment — 0.1%
Aptiv PLC/Aptiv Corp., 2.40%, 02/18/25 (Call 02/18/23)		3,275		3,124,954
Banks — 13.1%
Australia & New Zealand Banking Group Ltd.
4.83%, 02/03/25		14,970		14,991,198
5.09%, 12/08/25		10,810		10,928,971
Banco Santander SA
0.70%, 06/30/24 (Call 06/30/23)(b)		8,200		8,029,276
3.89%, 05/24/24		15,800		15,566,390
Bank of America Corp.
0.52%, 06/14/24 (Call 06/14/23),  (1 day SOFR + 0.410%)(b)		18,580		18,244,645
Series 2025, 4.76%, 02/04/25 (Call 02/04/24),  (1 day SOFR + 0.660%)(b)		15,000		14,900,373
Bank of New York Mellon Corp. (The), 3.43%, 06/13/25
(Call 06/13/24)(b)		16,100		15,825,970
Banque Federative du Credit Mutuel SA, 4.93%, 01/26/26(a)		17,400		17,386,670
Canadian Imperial Bank of Commerce, 3.50%, 09/13/23(c)		4,500		4,463,841
Citigroup Inc., 4.14%, 05/24/25 (Call 05/24/24),  (1 day SOFR + 1.372%)(b)(c)		4,770		4,716,084
Commonwealth Bank of Australia, 5.08%, 01/10/25(c)		17,800		17,938,375
Cooperatieve Rabobank UA/NY, 3.88%, 08/22/24		16,800		16,598,925
Credit Suisse AG/New York NY
0.50%, 02/02/24		5,335		5,012,790
1.00%, 05/05/23		5,000		4,940,273
4.70%, 02/02/24, (1 day SOFR + 0.390%)(b)		15,000		14,665,830
4.73%, 07/10/23, (1 day SOFR + 0.420%)(b)		14,000		13,983,261
4.85%, 01/19/24, (1 day SOFR + 0.540%)(b)		10,000		9,962,913
Deutsche Bank AG/New York NY
4.16%, 05/13/25(c)		6,905		6,815,718
Series E, 0.96%, 11/08/23		20,815		20,183,102
Series E, 4.59%, 11/08/23, (1 day SOFR + 0.500%)(b)		16,220		16,171,255
Goldman Sachs Group Inc. (The)
0.52%, 03/08/23		20,000		19,913,207
1.22%, 12/06/23 (Call 02/06/23)		12,000		11,629,855
HSBC Holdings PLC, 1.16%, 11/22/24 (Call 11/22/23),  (1 day SOFR + 0.580%)(b)		6,995		6,744,297
JPMorgan Chase & Co.
0.70%, 03/16/24 (Call 03/16/23),  (1 day SOFR + 0.580%)(b)		4,000		3,976,675
3.85%, 06/14/25 (Call 06/14/24)(b)(c)		16,100		15,818,250
4.88%, 03/16/24 (Call 03/16/23), (1 day SOFR + 0.580%)(b)(c)		20,000		20,004,140
KeyBank NA, 4.70%, 01/26/26		3,275		3,278,996
KeyBank NA/Cleveland OH
0.43%, 06/14/24 (Call 06/14/23), (1 day SOFR + 0.320%)(b)		10,000		9,798,068
4.15%, 08/08/25(c)		5,370		5,308,292
4.63%, 06/14/24 (Call 06/14/23), (1 day SOFR + 0.320%)(b)		15,565		15,525,076
Korea Development Bank (The), 5.02%, 02/18/23, (3 mo. LIBOR US + 0.350%)(b)		16,455		16,463,228
Macquarie Bank Ltd., 4.61%, 04/06/23, (1 day SOFR + 0.300%)(a)(b)		15,000		15,001,485

	Par
Security		(000)		Value
Banks (continued)
Mitsubishi UFJ Financial Group Inc.
4.79%, 07/18/25 (Call 07/18/24)(b)	$	9,010	$	8,963,286
5.06%, 09/12/25 (Call 09/12/24)(b)		15,675		15,655,833
Morgan Stanley
0.73%, 04/05/24 (Call 04/05/23), (1 day SOFR + 0.616%)(b)		30,000		29,739,957
3.62%, 04/17/25 (Call 04/17/24), (1 day SOFR + 1.160%)(b)		6,865		6,740,835
3.75%, 02/25/23		15,384		15,369,070
4.58%, 11/10/23 (Call 10/10/23), (1 day SOFR + 0.466%)(b)(c)		15,000		14,992,650
4.76%, 01/25/24 (Call 12/25/23), (1 day SOFR + 0.455%)(b)		10,000		9,990,190
4.93%, 01/24/25 (Call 01/24/24), (3 mo. LIBOR US + 0.140%)(b)		15,000		14,915,550
5.47%, 04/17/25 (Call 04/17/24), (1 day SOFR + 0.950%)(b)		10,000		10,025,540
MUFG Bank Ltd., 4.85%, 05/31/23(b)		25,000		25,024,819
National Australia Bank Ltd., 4.97%, 01/12/26		17,800		18,011,080
Nordea Bank Abp
1.00%, 06/09/23(a)		3,135		3,092,401
3.60%, 06/06/25(a)		10,665		10,365,835
4.75%, 09/22/25(a)		16,900		16,887,028
PNC Financial Services Group Inc. (The), 5.67%, 10/28/25
(Call 10/28/24)(b)		15,526		15,733,223
Societe Generale SA, 4.35%, 06/13/25(a)(c)		15,000		14,763,065
Sumitomo Mitsui Financial Group Inc.
0.51%, 01/12/24		3,580		3,428,982
5.46%, 01/13/26		17,800		18,079,624
Sumitomo Mitsui Trust Bank Ltd.
0.80%, 09/12/23(a)(c)		12,744		12,415,579
0.80%, 09/16/24(a)(c)		12,000		11,182,570
2.55%, 03/10/25(a)(c)		10,000		9,481,703
4.75%, 09/16/24, (1 day SOFR + 0.440%)(a)(b)		15,000		14,940,712
Svenska Handelsbanken AB
0.63%, 06/30/23(a)		6,310		6,198,959
3.65%, 06/10/25(a)(c)		15,900		15,484,643
Swedbank AB
0.60%, 09/25/23(a)(c)		14,500		14,076,020
1.30%, 06/02/23(a)		6,680		6,598,237
Truist Bank
1.25%, 03/09/23 (Call 02/09/23)		15,000		14,946,333
4.51%, 01/17/24 (Call 03/03/23), (1 day SOFR + 0.200%)(b)		45,000		44,884,109
UBS AG/London
0.38%, 06/01/23(a)(c)		4,440		4,372,460
0.45%, 02/09/24(a)		7,000		6,681,671
0.70%, 08/09/24(a)		4,330		4,062,139
1.38%, 01/13/25 (Call 12/13/24)(a)(c)		6,970		6,536,531
4.48%, 02/09/24, (1 day SOFR + 0.360%)(a)(b)		5,000		4,996,472
4.56%, 06/01/23, (1 day SOFR + 0.320%)(a)(b)		8,470		8,470,084
4.57%, 08/09/24, (1 day SOFR + 0.450%)(a)(b)		8,470		8,459,573
UBS Group AG, 4.49%, 08/05/25 (Call 08/05/24)(a)(b)(c)		8,810		8,724,376
Westpac Banking Corp.
1.02%, 11/18/24		3,550		3,331,103
4.47%, 11/18/24, (1 day SOFR + 0.300%)(b)		12,445		12,400,071
5.35%, 10/18/24		17,600		17,823,279
				882,633,021
Beverages — 0.8%
Coca-Cola Europacific Partners PLC, 0.50%, 05/05/23(a)(c)		52,207		51,615,595

4

Schedule of Investments (unaudited) (continued)	BlackRock Ultra Short-Term Bond ETF
January 31, 2023	(Percentages shown are based on Net Assets)

	Par
Security		(000)		Value
Beverages (continued)
PepsiCo Inc., 0.75%, 05/01/23	$	1,615	$	1,598,804
				53,214,399
Biotechnology — 0.2%
Gilead Sciences Inc., 0.75%, 09/29/23 (Call 02/13/23)		15,971		15,531,405
Chemicals — 0.5%
Ecolab Inc., 0.90%, 12/15/23 (Call 03/03/23)(c)		8,800		8,491,623
Linde Inc., 4.80%, 12/05/24		17,700		17,777,280
Sherwin-Williams Co. (The), 4.05%, 08/08/24(c)		7,310		7,226,870
				33,495,773
Cosmetics & Personal Care — 0.3%
GSK Consumer Healthcare Capital U.S. LLC
3.02%, 03/24/24 (Call 03/24/23)		9,235		9,024,089
5.20%, 03/24/24 (Call 03/24/23)(b)		2,150		2,145,582
Unilever Capital Corp., 0.63%, 08/12/24 (Call 03/03/23)(c)		5,975		5,629,376
				16,799,047
Diversified Financial Services — 0.8%
American Express Co.
0.75%, 11/03/23(c)		10,000		9,717,234
3.38%, 05/03/24		7,600		7,469,193
4.29%, 11/03/23, (1 day SOFR + 0.230%)(b)		10,000		9,986,546
5.18%, 03/04/25 (Call 02/01/25), (1 day SOFR + 0.930%)(b)(c)		8,235		8,260,593
Capital One Financial Corp., 4.17%, 05/09/25
(Call 05/09/24)(b)		15,800		15,542,546
LSEGA Financing PLC, 0.65%, 04/06/24 (Call 03/06/24)(a)		3,895		3,688,824
				54,664,936
Electric — 3.7%
Dominion Energy Inc., Series D, 5.30%, 09/15/23
(Call 02/21/23), (3 mo. LIBOR US + 0.530%)(b)		30,560		30,597,559
Duke Energy Corp., 4.54%, 06/10/23, (1 day SOFR + 0.250%)(b)		14,765		14,749,382
Eversource Energy, 4.39%, 08/15/23, (1 day SOFR + 0.250%)(b)(c)		23,850		23,798,964
Florida Power & Light Co.
4.35%, 05/10/23 (Call 02/13/23), (1 day SOFR + 0.250%)(b)		11,020		11,008,758
4.69%, 01/12/24 (Call 02/13/23), (1 day SOFR + 0.250%)(b)(c)		8,240		8,221,140
National Rural Utilities Cooperative Finance Corp.
4.49%, 08/07/23, (1 day SOFR + 0.330%)(b)		16,150		16,142,892
Series D, 4.64%, 10/18/24, (1 day SOFR + 0.330%)(b)		5,000		4,941,104
NextEra Energy Capital Holdings Inc.
0.65%, 03/01/23		6,888		6,867,023
2.94%, 03/21/24 (Call 03/03/23)(c)		15,000		14,695,163
4.26%, 09/01/24		10,000		9,914,118
4.46%, 11/03/23 (Call 03/03/23), (1 day SOFR + 0.400%)(b)		30,000		29,958,000
4.78%, 03/01/23, (1 day SOFR + 0.540%)(b)		9,305		9,305,265
PPL Electric Utilities Corp.
4.64%, 06/24/24 (Call 02/13/23), (1 day SOFR + 0.330%)(b)		8,065		7,971,472
4.97%, 09/28/23 (Call 02/13/23), (3 mo. LIBOR US + 0.250%)(b)		8,710		8,676,590
WEC Energy Group Inc.
0.55%, 09/15/23(c)		21,955		21,365,056
4.75%, 01/09/26 (Call 12/09/25)		10,000		10,024,068
5.00%, 09/27/25 (Call 08/27/25)		7,465		7,504,049

	Par
Security		(000)		Value
Electric (continued)
Wisconsin Public Service Corp., 5.35%, 11/10/25
(Call 10/10/25)(c)	$	8,520	$	8,668,485
Xcel Energy Inc., 0.50%, 10/15/23 (Call 09/15/23)		7,560		7,337,655
				251,746,743
Food — 1.2%
Hormel Foods Corp., 0.65%, 06/03/24 (Call 03/03/23)		12,125		11,498,291
Nestle Holdings Inc.
0.61%, 09/14/24 (Call 09/14/23)(a)		35,000		32,837,850
4.00%, 09/12/25(a)(c)		17,000		16,818,019
Walmart Inc., 3.90%, 09/09/25		20,000		19,893,794
				81,047,954
Gas — 0.7%
Atmos Energy Corp.
0.63%, 03/09/23 (Call 02/16/23)(c)		8,175		8,141,211
5.10%, 03/09/23 (Call 03/03/23),
(3 mo. LIBOR US + 0.380%)(b)(c)		23,770		23,768,719
CenterPoint Energy Resources Corp., 0.70%, 03/02/23(c)		15,935		15,885,328
				47,795,258
Health Care - Products — 0.9%
Thermo Fisher Scientific Inc.
0.80%, 10/18/23 (Call 03/03/23)(c)		30,000		29,149,041
4.66%, 04/18/23 (Call 03/03/23), (1 day SOFR + 0.350%)(b)(c)		20,000		19,999,208
4.84%, 10/18/24 (Call 03/03/23), (1 day SOFR + 0.530%)(b)		9,215		9,191,398
				58,339,647
Health Care - Services — 1.0%
Roche Holdings Inc.
1.88%, 03/08/24(a)		15,000		14,543,054
4.49%, 03/05/24, (1 day SOFR + 0.240%)(a)(b)		5,370		5,358,112
4.62%, 09/11/23, (1 day SOFR + 0.240%)(a)(b)		15,000		15,000,897
UnitedHealth Group Inc.
0.55%, 05/15/24 (Call 02/13/23)		15,135		14,367,499
5.00%, 10/15/24		17,600		17,777,810
				67,047,372
Insurance — 2.7%
Athene Global Funding, 2.51%, 03/08/24(a)		10,000		9,645,164
Brighthouse Financial Global Funding
1.20%, 12/15/23(a)		17,000		16,389,340
4.51%, 02/24/23, (1 day SOFR + 0.310%)(a)(b)(c)		23,890		23,886,475
MassMutual Global Funding II
0.85%, 06/09/23(a)		8,328		8,212,584
4.15%, 08/26/25(a)		7,302		7,209,033
Metropolitan Life Global Funding I
0.55%, 06/07/24(a)(c)		3,590		3,382,318
4.63%, 01/07/24, (1 day SOFR + 0.320%)(a)(b)		27,000		26,938,339
5.00%, 01/06/26(c)		10,000		10,132,140
New York Life Global Funding
3.15%, 06/06/24(a)		8,400		8,224,176
3.60%, 08/05/25(a)(c)		16,500		16,077,107
4.68%, 06/06/24(a)(b)		9,130		9,136,727
Northwestern Mutual Global Funding, 4.00%, 07/01/25(a)		16,300		16,073,213
Principal Life Global Funding II
0.75%, 08/23/24(a)(c)		660		618,594
4.58%, 08/23/24, (1 day SOFR + 0.380%)(a)(b)		635		628,065
Protective Life Global Funding
0.63%, 10/13/23(a)(c)		4,820		4,676,216
4.86%, 03/31/23(a)(b)		9,525		9,524,393

 5

Schedule of Investments (unaudited) (continued)	BlackRock Ultra Short-Term Bond ETF
January 31, 2023	(Percentages shown are based on Net Assets)

	Par
Security		(000)		Value
Insurance (continued)
5.37%, 01/06/26(a)(c)	$	10,000	$	10,183,942
				180,937,826
Internet — 0.8%
Amazon.com Inc.
0.25%, 05/12/23(c)		9,205		9,092,415
2.73%, 04/13/24		20,000		19,549,277
3.00%, 04/13/25		10,000		9,707,499
eBay Inc., 5.90%, 11/22/25 (Call 10/22/25)		17,600		18,179,550
				56,528,741
Machinery — 1.6%
Caterpillar Financial Services Corp.
0.95%, 01/10/24		20,000		19,289,397
4.41%, 05/17/24, (1 day SOFR + 0.245%)(b)		10,000		9,996,382
4.56%, 09/13/24, (1 day SOFR + 0.270%)(b)		15,620		15,578,607
John Deere Capital Corp.
0.90%, 01/10/24		3,605		3,475,291
3.40%, 06/06/25		10,390		10,141,997
4.43%, 07/10/23, (1 day SOFR + 0.120%)(b)(c)		7,330		7,322,968
4.51%, 10/11/24, (1 day SOFR + 0.200%)(b)(c)		14,290		14,215,035
4.80%, 01/09/26		17,800		18,030,842
Rockwell Automation Inc., 0.35%, 08/15/23 (Call 02/13/23)		9,050		8,835,475
				106,885,994
Manufacturing — 0.3%
Siemens Financieringsmaatschappij NV, 4.72%, 03/11/24, (1 day SOFR + 0.430%)(a)(b)(c)		18,980		18,975,836
Media — 0.0%
Comcast Corp., 5.25%, 11/07/25(c)		2,950		3,013,174
Oil & Gas — 0.8%
Chevron Corp., 1.14%, 05/11/23(c)		4,510		4,465,518
Chevron USA Inc., 4.85%, 08/11/23, (3 mo. LIBOR US + 0.200%)(b)(c)		37,065		37,058,711
ConocoPhillips Co., 2.13%, 03/08/24 (Call 03/03/23)		16,000		15,552,004
				57,076,233
Pharmaceuticals — 0.6%
AstraZeneca PLC, 0.30%, 05/26/23		24,000		23,660,894
Merck & Co. Inc., 2.75%, 02/10/25 (Call 11/10/24)		17,000		16,466,911
				40,127,805
Pipelines — 1.0%
Enbridge Inc.
0.55%, 10/04/23(c)		5,380		5,219,783
2.15%, 02/16/24		5,530		5,365,974
4.56%, 02/17/23, (1 day SOFR + 0.400%)(b)		11,350		11,349,501
4.79%, 02/16/24, (1 day SOFR + 0.630%)(b)		10,125		10,089,610
Enterprise Products Operating LLC, 5.05%, 01/10/26		12,365		12,544,558
TransCanada PipeLines Ltd., 1.00%, 10/12/24
(Call 09/12/24)(c)		27,205		25,451,771
				70,021,197
Retail — 0.4%
Home Depot Inc. (The), 4.00%, 09/15/25 (Call 08/15/25)(c)		5,170		5,145,970
Lowe’s Companies Inc., 4.40%, 09/08/25(c)		11,510		11,459,452
McDonald’s Corp., 3.35%, 04/01/23 (Call 03/01/23)(c)		1,263		1,260,673
Starbucks Corp., 4.55%, 02/14/24 (Call 02/14/23), (1 day SOFR + 0.420%)(b)		11,515		11,486,899
				29,352,994
Savings & Loans — 0.2%
Nationwide Building Society, 0.55%, 01/22/24(a)		16,520		15,795,527

	Par
Security		(000)		Value
Semiconductors — 0.7%
Analog Devices Inc., 4.56%, 10/01/24, (1 day SOFR + 0.250%)(b)	$	15,330	$	15,142,592
NVIDIA Corp.
0.31%, 06/15/23 (Call 03/03/23)		28,000		27,542,454
0.58%, 06/14/24 (Call 06/14/23)		5,305		5,026,304
				47,711,350
Software — 0.2%
Adobe Inc., 1.70%, 02/01/23		4,010		4,010,000
salesforce.com Inc., 0.63%, 07/15/24 (Call 03/03/23)		9,415		8,888,104
				12,898,104
Telecommunications — 0.7%
Bell Telephone Co. of Canada or Bell Canada (The), Series US-3, 0.75%, 03/17/24		21,081		20,122,918
NTT Finance Corp.
0.58%, 03/01/24(a)		6,005		5,727,346
4.14%, 07/26/24(a)		2,830		2,798,291
Verizon Communications Inc.
0.75%, 03/22/24		3,580		3,417,813
4.81%, 03/22/24, (1 day SOFR + 0.500%)(b)		16,955		16,918,451
				48,984,819
Total Corporate Bonds & Notes — 38.8%
(Cost: $2,656,371,057)				2,623,314,446
Municipal Debt Obligations
Alabama — 0.1%
Alabama Federal Aid Highway Finance Authority RB, 0.45%, 09/01/23		3,545		3,452,465
California — 0.0%
Port of Oakland RB, 0.82%, 05/01/23		400		395,545
New York — 1.6%
Deutsche Bank Spears/Lifers Trust RB, 4.52%, 04/01/31
(Put 02/08/23)(a)(d)		51,500		51,500,000
Long Island Power Authority RB
0.36%, 03/01/23 Call		6,800		6,774,588
0.76%, 03/01/23 Call		1,290		1,285,681
Mizuho Floater/Residual Trust RB
VRDN, 4.09%, 02/01/23 (Put 02/01/23)(a)(d)		9,200		9,200,000
VRDN, 4.09%, 02/15/41 (Put 03/03/23)(a)(d)		4,726		4,726,192
VRDN, 4.24%, 03/01/31 Put (a)(d)		18,000		18,000,000
New York State Dormitory Authority RB, 2.01%, 03/15/23		1,765		1,758,861
Port Authority of New York & New Jersey RB, Series AAA, 1.09%, 07/01/23		12,570		12,375,379
Taxable Municipal Funding Trust RB
VRDN, 4.22%, 01/16/25 (Put 01/31/23)(a)(d)		1,085		1,085,000
VRDN, 4.22%, 09/01/30 (Put 05/01/25)(a)(d)		4,340		4,340,000
				111,045,701
Total Municipal Debt Obligations — 1.7%
(Cost $115,221,192)				114,893,711

6

Schedule of Investments (unaudited) (continued)	BlackRock Ultra Short-Term Bond ETF
January 31, 2023	(Percentages shown are based on Net Assets)

	Par
Security		(000)		Value
Repurchase Agreements(b)(e)
Bank of America Securities Inc., 4.64%, 02/01/23 (Purchased on 01/31/22 to be repurchased at $35,004,511, collateralized by U.S. Government Agency mortgage-backed security, 1.25% to 9.81%, due 11/25/23 to 09/25/48, par and fair value of $129,280,740 and $42,000,000, respectively)	$	35,000	$	35,000,000
Bank of America Securities Inc., 4.82%, 02/01/23 (Purchased on 01/31/23 to be repurchased at $7,000,937, collateralized by non-agency mortgage-backed security, 3.64%, due 10/25/59, par and fair value of $10,568,683 and $8,400,001, respectively)		7,000		7,000,000
BNP Paribas, 4.67%, 02/01/23 (Purchased on 01/31/23 to be repurchased at $20,002,594, collateralized by non-agency mortgage-backed security, 2.38% to 11.50%, due 06/15/23 to 03/15/42, par and fair value of $23,465,469 and $21,988,452, respectively)		20,000		20,000,000
Citigroup Global Markets Inc., 4.61%, 02/01/23 (Purchased on 01/31/23 to be repurchased at $9,001,153, collateralized by non-agency mortgage-backed security, 1.07% to 3.75%, due 07/25/62 to 07/25/68, par and fair value of $20,875,372 and $10,423,165, respectively)		9,000		9,000,000
Citigroup Global Markets Inc., 4.63%, 02/01/23 (Purchased on 01/31/23 to be repurchased at $12,001,543, collateralized by non-agency mortgage-backed security, 1.24% to 3.18%, due 05/25/51 to 07/25/68, par and fair value of $16,761,045 and $12,649,265, respectively)		12,000		12,000,000
Credit Suisse Securities (USA) LLC, 4.80%, 02/01/23 (Purchased on 01/31/23 to be repurchased at $17,002,267, collateralized by non-agency mortgage-backed security, 0.00% to 6.68%, due 11/25/30 to 02/15/68, par and fair value of $691,105,199 and $19,550,000, respectively)		17,000		17,000,000
Credit Suisse Securities (USA) LLC, 4.90%, 02/01/23 (Purchased on 01/31/23 to be repurchased at $16,002,178, collateralized by non-agency mortgage-backed security, 0.00% to 6.81%, due 04/17/31 to 12/27/60, par and fair value of $171,787,291 and $18,400,000, respectively)		16,000		16,000,000
Credit Suisse Securities (USA) LLC, 5.05%, 02/01/23 (Purchased on 01/31/23 to be repurchased at  $16,002,244, collateralized by non-agency mortgage-backed security, 0.00% to 8.35%, due 01/25/26 to 06/15/61, par and fair value of $778,084,930 and $18,399,081, respectively)		16,000		16,000,000
Goldman Sachs & Co. LLC, 4.82%, 02/01/23 (Purchased on  01/31/23 to be repurchased at $60,008,033, collateralized by non-agency mortgage-backed security, 3.13% to 9.03%, due 12/15/23 to 12/31/79, par and fair value of $66,973,923 and $63,403,792, respectively)		60,000		60,000,000

	Par/
	Shares
Security		(000)		Value
Mizuho Securities USA Inc., 4.77%, 02/01/23 (Purchased  on 01/31/23 to be repurchased at $6,000,795, collateralized by non-agency mortgage-backed security, 1.11%, due 10/31/28, par and fair value of $125,297,299 and $6,180,000, respectively)	$	6,000	$	6,000,000
Mizuho Securities USA Inc., 4.87%, 02/01/23 (Purchased on 01/31/23 to be repurchased at $30,004,058, collateralized by non-agency mortgage-backed security, 2.31% to 5.22%, due 07/25/49 to 11/20/51, par and fair value of $38,796,696 and $34,500,000, respectively)		30,000		30,000,000
Total Repurchase Agreements — 3.4%
(Cost: $228,000,000)				228,000,000
U.S. Government Obligations
U.S. Government Obligations — 0.2%
U.S. Treasury Note/Bond, 0.25%, 09/30/23		10,000		9,706,641
Total U.S. Government Obligations — 0.2%
(Cost: $9,996,052)				9,706,641
Money Market Funds
BlackRock Cash Funds: Institutional, SL Agency Shares, 4.56%(f)(g)(h)		43,434		43,460,512
Total Money Market Funds — 0.6%
(Cost: $43,427,960)				43,460,512
Total Investments — 101.1%
(Cost: $6,873,953,222)				6,837,582,914
Liabilities in Excess of Other Assets — (1.1)%				(73,502,929	)
Net Assets — 100.0%			$	6,764,079,985

^(a) 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.

^(b) 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.

^(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.

^(e) Maturity date represents next reset date.

^(f) Affiliate of the Fund.

^(g) Annualized 7-day yield as of period end.

^(h) All or a portion of this security was purchased with the cash collateral from loaned securities.

 7

Schedule of Investments (unaudited) (continued)	BlackRock Ultra Short-Term Bond ETF
January 31, 2023

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 Cash Funds: Institutional, SL  Agency Shares	$	56,987,823	$	—		$	(13,570,242	)(a)	$	8,598	$	34,333	$	43,460,512		43,434	$	54,382	(b)	$	—
BlackRock Cash Funds: Treasury, SL Agency Shares(c)		—		0	(a)		—			—		—		—		—		16,871			—
									$	8,598	$	34,333	$	43,460,512			$	71,253		$	—

^(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.

8

Schedule of Investments (unaudited) (continued)	BlackRock Ultra Short-Term Bond ETF
January 31, 2023

Fair Value Hierarchy as of Period End (continued)

	Level 1		Level 2		Level 3		Total
Assets
Investments
Long-Term Investments
Asset-Backed Securities	$	—	$	161,567,333	$	—	$	161,567,333
Certificates of Deposit		—		779,068,596		—		779,068,596
Commercial Paper		—		2,877,571,675		—		2,877,571,675
Corporate Bonds & Notes		—		2,623,314,446		—		2,623,314,446
Municipal Debt Obligations		—		114,893,711		—		114,893,711
Repurchase Agreements		—		228,000,000		—		228,000,000
U.S. Government & Agency Obligations		—		9,706,641		—		9,706,641
Short-Term Securities
Money Market Funds		43,460,512		—		—		43,460,512
	$	43,460,512	$	6,794,122,402	$	—	$	6,837,582,914

Portfolio Abbreviation
LIBOR	London Interbank Offered Rate
RB	Revenue Bond
SOFR	Secured Overnight Financing Rate

 9