Schedule of Investments  (unaudited) April 30, 2023 BlackRock Future Health ETF (Percentages shown are based on Net Assets)

Security	Shares		Value
Common Stocks
Biotechnology — 34.7%
4D Molecular Therapeutics Inc.(a)		265	$	4,773
Abcam PLC, SP ADR(a)		3,650		59,458
Alkermes PLC(a)		2,934		83,766
Allakos Inc.(a)		370		1,573
Alnylam Pharmaceuticals Inc.(a)		446		88,843
Apellis Pharmaceuticals Inc.(a)		435		36,292
Arcus Biosciences Inc.(a)		215		3,838
Arcutis Biotherapeutics Inc.(a)(b)		900		12,456
Argenx SE, ADR(a)		54		20,946
Arrowhead Pharmaceuticals Inc.(a)		230		8,144
Aura Biosciences Inc.(a)		320		2,893
Bavarian Nordic A/S(a)		210		5,775
BeiGene Ltd., ADR(a)(b)		220		56,091
Biogen Inc.(a)		200		60,846
Biohaven Ltd., NVS(a)		225		2,943
BioMarin Pharmaceutical Inc.(a)		1,000		96,040
Biomea Fusion Inc.(a)		446		13,144
Blueprint Medicines Corp.(a)		907		46,302
Bridgebio Pharma Inc.(a)(b)		180		2,614
Cerevel Therapeutics Holdings Inc.(a)		732		21,257
CRISPR Therapeutics AG(a)(b)		240		11,746
CureVac NV(a)		700		5,159
Decibel Therapeutics Inc.(a)		353		1,137
Design Therapeutics Inc.(a)		183		1,180
Exact Sciences Corp.(a)		644		41,261
Exelixis Inc.(a)		1,434		26,242
FibroGen Inc.(a)		179		3,064
Frequency Therapeutics Inc.(a)		630		251
Galapagos NV, ADR(a)		442		17,238
Galecto Inc.(a)		610		1,074
Genmab A/S(a)		84		34,521
Genmab A/S, ADR(a)(b)		272		11,155
Gilead Sciences Inc.		1,298		106,709
Halozyme Therapeutics Inc.(a)		615		19,760
Horizon Therapeutics PLC(a)		200		22,232
Immunocore Holdings PLC(a)(b)		930		53,986
ImmunoGen Inc.(a)		693		3,735
Incyte Corp.(a)		989		73,591
Ionis Pharmaceuticals Inc.(a)(b)		1,146		40,534
Iovance Biotherapeutics Inc.(a)		460		2,594
IVERIC bio Inc.(a)		235		7,729
Karuna Therapeutics Inc.(a)		59		11,708
Keros Therapeutics Inc.(a)		343		15,214
Kinnate Biopharma Inc.(a)		553		1,399
Krystal Biotech Inc.(a)		74		6,216
Legend Biotech Corp., ADR(a)		567		38,959
MacroGenics Inc.(a)		520		3,583
Merus NV(a)		995		19,084
Mirati Therapeutics Inc.(a)		500		22,155
Monte Rosa Therapeutics Inc.(a)		344		1,562
MoonLake Immunotherapeutics, NVS(a)		315		6,710
Morphic Holding Inc.(a)		315		14,887
MorphoSys AG(a)		145		3,046
Neurocrine Biosciences Inc.(a)		542		54,764
Nuvalent Inc., Class A(a)		413		14,616
PMV Pharmaceuticals Inc.(a)		723		3,333
Prime Medicine Inc., NVS(a)(b)		1,056		14,541
Prometheus Biosciences Inc.(a)		223		43,251

Security	Shares		Value
Biotechnology (continued)
Protagonist Therapeutics Inc.(a)		1,170	$	26,442
Prothena Corp. PLC(a)		320		16,838
PTC Therapeutics Inc.(a)(b)		550		30,327
Regeneron Pharmaceuticals Inc.(a)		120		96,215
Relay Therapeutics Inc.(a)		95		1,080
REVOLUTION Medicines Inc.(a)		931		21,869
Rhythm Pharmaceuticals Inc.(a)(b)		1,725		34,793
Rocket Pharmaceuticals Inc.(a)		684		12,257
Sage Therapeutics Inc.(a)(b)		805		39,324
Sarepta Therapeutics Inc.(a)		311		38,181
Seagen Inc.(a)		274		54,800
Sigilon Therapeutics Inc.(a)		722		498
Swedish Orphan Biovitrum AB(a)		650		15,818
Tenaya Therapeutics Inc.(a)		354		1,882
TScan Therapeutics Inc.(a)(b)		1,378		3,142
Twist Bioscience Corp.(a)(b)		447		5,579
Ultragenyx Pharmaceutical Inc.(a)		222		9,695
United Therapeutics Corp.(a)		161		37,051
Vaxcyte Inc.(a)		122		5,225
Vertex Pharmaceuticals Inc.(a)		481		163,891
Viking Therapeutics Inc.(a)		650		13,851
Viridian Therapeutics Inc.(a)		231		6,475
				2,023,153
Financial Services — 0.6%
DA32 Life Science Tech Acquisition Corp., Class A(a)		3,181		32,414
Electronic Equipment, Instruments & Components — 0.1%
908 Devices Inc.(a)		648		4,381
Health Care Equipment & Supplies — 35.2%
Abiomed Inc., CVR(c)		246		694
Alcon Inc.		2,110		152,933
Align Technology Inc.(a)		162		52,699
Bausch + Lomb Corp.(a)(b)		1,238		21,616
Baxter International Inc		1,015		48,395
Becton Dickinson and Co.		225		59,470
Boston Scientific Corp.(a)		3,048		158,862
CONMED Corp.		270		33,904
ConvaTec Group PLC(d)		11,764		32,522
Cooper Companies Inc. (The)		312		119,012
Dexcom Inc.(a)		1,131		137,236
Glaukos Corp.(a)		298		14,158
Heska Corp.(a)		140		16,402
Hologic Inc.(a)(b)		1,038		89,278
Inspire Medical Systems Inc.(a)(b)		135		36,130
Insulet Corp.(a)		317		100,819
Intuitive Surgical Inc.(a)		373		112,355
iRhythm Technologies Inc.(a)		275		36,135
Masimo Corp.(a)		570		107,810
Novocure Ltd.(a)(b)		577		38,024
Nyxoah SA(a)(b)		1,368		11,053
Omnicell Inc.(a)		339		20,601
Penumbra Inc.(a)		306		86,941
Pulmonx Corp.(a)		879		10,328
ResMed Inc.		569		137,106
Shockwave Medical Inc.(a)(b)		139		40,332
SI-BONE Inc.(a)		448		9,901
STAAR Surgical Co.(a)		188		13,248
STERIS PLC		465		87,676
Straumann Holding AG		300		45,135
Stryker Corp.		455		136,341

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Schedule of Investments  (unaudited) (continued) April 30, 2023 BlackRock Future Health ETF (Percentages shown are based on Net Assets)

Security	Shares		Value
Health Care Equipment & Supplies (continued)
Tandem Diabetes Care Inc.(a)		1,023	$	40,490
Zimmer Biomet Holdings Inc.		340		47,070
				2,054,676
Health Care Providers & Services — 3.6%
Amedisys Inc.(a)		228		18,308
AmerisourceBergen Corp.		804		134,147
Encompass Health Corp.		310		19,887
Guardant Health Inc.(a)		561		12,656
R1 RCM Inc.(a)(b)		1,644		25,630
				210,628
Health Care Technology — 0.1%
Sophia Genetics SA(a)(b)		619		2,996
Life Sciences Tools & Services — 15.4%
10X Genomics Inc., Class A(a)		537		28,155
Avantor Inc.(a)		1,805		35,161
Bio-Rad Laboratories Inc., Class A(a)		55		24,793
Bio-Techne Corp.		747		59,670
Bruker Corp.		523		41,385
Gerresheimer AG		660		71,919
IQVIA Holdings Inc.(a)		380		71,527
Mettler-Toledo International Inc.(a)		93		138,710
Pacific Biosciences of California Inc.(a)(b)		1,170		12,402
QIAGEN NV(a)		1,720		76,729
Repligen Corp.(a)		380		57,619
Thermo Fisher Scientific Inc.		78		43,282
Waters Corp.(a)		266		79,896
West Pharmaceutical Services Inc.		377		136,188
Wuxi Biologics Cayman Inc.(a)(d)		3,000		17,889
				895,325
Personal Care Products — 0.2%
Haleon PLC, ADR, NVS(b)		1,213		10,759
Pharmaceuticals — 5.3%
Arvinas Inc.(a)		641		16,801
Catalent Inc.(a)		928		46,511
Merck & Co. Inc.		402		46,419
Novo Nordisk A/S, Class B		175		29,112
Pliant Therapeutics Inc.(a)		367		10,368
Reata Pharmaceuticals Inc., Class A(a)		103		10,183
Structure Therapeutics Inc.(a)		447		11,197
UCB SA		969		90,076

Security	Shares		Value
Pharmaceuticals (continued)
Ventyx Biosciences Inc.(a)		80	$	3,008
Zoetis Inc.		273		47,988
				311,663
Total Common Stocks — 95.2% (Cost: $5,432,006)				5,545,995
Preferred Stocks
Life Sciences Tools & Services — 0.6%
Sartorius AG, Preference Shares, NVS		95		36,925
Total Preferred Stocks — 0.6% (Cost: $43,183)				36,925
Total Long-Term Investments — 95.8% (Cost: $5,475,189)				5,582,920
Short-Term Securities
Money Market Funds — 13.1%
BlackRock Cash Funds: Institutional, SL Agency Shares, 5.02%(e)(f)(g)		545,699		545,863
BlackRock Cash Funds: Treasury, SL Agency Shares, 4.75%(e)(f)		220,000		220,000
Total Short-Term Securities — 13.1% (Cost: $765,791)				765,863
Total Investments — 108.9% (Cost: $6,240,980)				6,348,783
Liabilities in Excess of Other Assets — (8.9)%				(519,403	)
Net Assets — 100.0%			$	5,829,380

^(a) Non-income producing security.

^(b) All or a portion of this security is on loan.

^(c) Security is valued using significant unobservable inputs and is classified as Level 3 in the fair value hierarchy.

^(d) 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.

^(e) Affiliate of the Fund.

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

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

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Schedule of Investments  (unaudited) (continued) April 30, 2023 BlackRock Future Health ETF

Affiliates

Investments in issuers considered to be affiliate(s) of the Fund during the period endedApril 30, 2023 for purposes of Section 2(a)(3) of the Investment CompanyAct of 1940, as amended, were as follows:

Affiliated Issuer	Value at 07/31/22		Purchases at Cost			Proceeds from Sale		Net Realized Gain (Loss)		Change in Unrealized Appreciation (Depreciation)		Value at 04/30/23		Shares Held at 04/30/23		Income			Capital Gain Distributions from Underlying Funds
BlackRock Cash Funds: Institutional, SL Agency Shares	$	133,820	$	411,950	(a)	$	—	$	47	$	46	$	545,863		545,699	$	2,555	(b)	$	—
BlackRock Cash Funds: Treasury, SL Agency Shares		180,000		40,000	(a)		—		—		—		220,000		220,000		4,880			—
								$	47	$	46	$	765,863			$	7,435		$	—

^(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.

Forward Foreign Currency Exchange Contracts

Currency Purchased		Currency Sold			Counterparty	Settlement Date		Unrealized Appreciation (Depreciation)
CHF	121,500		USD	134,687	Bank of America N.A.		06/15/23	$	1,913
DKK	220,000		USD	31,901	BNP Paribas SA		06/15/23		717
EUR	94,000		USD	101,392	BNP Paribas SA		06/15/23		2,441
GBP	20,000		USD	24,410	BNP Paribas SA		06/15/23		748
									5,819
AUD	90,200		USD	60,316	BNP Paribas SA		06/15/23		(519	)
JPY	5,745,000		USD	43,714	Bank of America N.A.		06/15/23		(1,266	)
JPY	6,839,000		USD	52,022	BNP Paribas SA		06/15/23		(1,491	)
USD	32,376		DKK	220,000	Imperial Bank of Canada		06/15/23		(242	)
									(3,518	)
									$2,301

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.

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Schedule of Investments  (unaudited) (continued) April 30, 2023 BlackRock Future Health ETF

Fair Value Hierarchy as of Period End (continued)

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
Common Stocks	$	5,199,488	$	345,813		$	694	$	5,545,995
Preferred Stocks		—		36,925			—		36,925
Short-Term Securities
Money Market Funds		765,863		—			—		765,863
	$	5,965,351	$	382,738		$	694	$	6,348,783
Derivative Financial Instruments
Assets
Foreign Currency Exchange Contracts	$	—	$	5,819		$	—	$	5,819
Liabilities
Foreign Currency Exchange Contracts		—		(3,518	)		—		(3,518	)
	$	—	$	2,301		$	—		2,301

Portfolio Abbreviation
ADR	American Depositary Receipt
NVS	Non-Voting Shares
Currency Abbreviations
AUD	Australian Dollar	GBP	British Pound
CHF	Swiss Franc	JPY	Japanese Yen
DKK	Danish Krone	USD	United States Dollar
EUR	Euro

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