Schedule of Investments  (unaudited) October 31, 2021 BlackRock Future Health ETF (Percentages shown are based on Net Assets)

Security	Shares		Value
Common Stocks
Biotechnology — 33.3%
Acceleron Pharma Inc.(a)		946	$	164,774
Acumen Pharmaceuticals Inc.(a)		502		7,053
Agios Pharmaceuticals Inc.(a)		1,192		56,024
Allakos Inc.(a)(b)		563		56,627
Alnylam Pharmaceuticals Inc.(a)		695		110,894
ALX Oncology Holdings Inc.(a)		175		9,807
Ambrx Biopharma Inc., ADR(a)		322		4,057
Annexon Inc.(a)		460		7,503
Apellis Pharmaceuticals Inc.(a)		461		14,171
Applied Molecular Transport Inc.(a)		416		9,368
Arcus Biosciences Inc.(a)		389		13,008
Arcutis Biotherapeutics Inc.(a)		1,267		26,835
Arena Pharmaceuticals Inc.(a)		546		31,335
Argenx SE, ADR(a)(b)		325		98,137
Arrowhead Pharmaceuticals Inc.(a)		230		14,679
Beam Therapeutics Inc.(a)		87		7,723
BioAtla Inc.(a)		350		10,231
Biohaven Pharmaceutical Holding Co. Ltd.(a)		278		39,565
BioMarin Pharmaceutical Inc.(a)		743		58,868
Blueprint Medicines Corp.(a)		482		54,220
Bridgebio Pharma Inc.(a)		561		27,702
C4 Therapeutics Inc.(a)		854		37,935
Connect Biopharma Holdings Ltd.(a)		159		2,519
Cytokinetics Inc.(a)(b)		698		24,367
Decibel Therapeutics Inc.(a)		353		2,863
Deciphera Pharmaceuticals Inc.(a)		407		13,590
Design Therapeutics Inc.(a)		183		2,869
Dicerna Pharmaceuticals Inc.(a)		1,086		22,600
Enanta Pharmaceuticals Inc.(a)		363		31,164
Fate Therapeutics Inc.(a)		123		6,617
Genmab A/S(a)		387		173,860
Genmab A/S, ADR(a)(b)		1,730		77,227
Gritstone bio Inc.(a)		715		7,858
Horizon Therapeutics PLC(a)		567		67,989
Icosavax Inc.(a)		1,548		40,496
Ideaya Biosciences Inc.(a)		804		17,238
Imago Biosciences Inc.(a)		310		8,252
Immuneering Corp., Class A(a)		168		4,553
Immunocore Holdings PLC(a)		150		5,778
Iovance Biotherapeutics Inc.(a)		526		12,787
Kadmon Holdings Inc.(a)		5,670		53,581
Karuna Therapeutics Inc.(a)		201		28,216
Keros Therapeutics Inc.(a)		573		23,906
Kinnate Biopharma Inc.(a)(b)		633		15,046
Kodiak Sciences Inc.(a)		207		24,238
Krystal Biotech Inc.(a)		67		3,356
Kymera Therapeutics Inc.(a)		681		40,097
Mirati Therapeutics Inc.(a)		227		42,908
Monte Rosa Therapeutics Inc.(a)(b)		344		8,067
Morphic Holding Inc.(a)		239		13,743
Natera Inc.(a)		1,196		137,026
Neurocrine Biosciences Inc.(a)		210		22,136
Olema Pharmaceuticals Inc.(a)		573		15,471
Omega Therapeutics Inc.(a)(b)		276		8,109
Prometheus Biosciences Inc.(a)		710		22,621
Prothena Corp. PLC(a)		910		50,368
RAPT Therapeutics Inc.(a)		473		14,937
REVOLUTION Medicines Inc.(a)		609		17,923

Security	Shares		Value
Biotechnology (continued)
Sarepta Therapeutics Inc.(a)		489	$	38,695
Seagen Inc.(a)		1,252		220,765
Sigilon Therapeutics Inc.(a)		722		3,892
Talaris Therapeutics Inc.(a)		287		4,847
Taysha Gene Therapies Inc.(a)		449		7,022
Tenaya Therapeutics Inc.(a)		354		9,101
TScan Therapeutics Inc., NVS(a)		1,378		12,071
Twist Bioscience Corp.(a)		54		6,415
United Therapeutics Corp.(a)		161		30,712
Vertex Pharmaceuticals Inc.(a)		192		35,507
Zai Lab Ltd., ADR(a)		256		26,726
Zentalis Pharmaceuticals Inc.(a)		616		49,551
				2,370,196
Diversified Financial Services — 1.4%
DA32 Life Science Tech Acquisition Corp., Class A, NVS(a)		3,181		31,174
Eucrates Biomedical Acquisition Corp.(a)		1,857		18,161
Health Assurance Acquisition Corp., Class A(a)		2,816		27,681
Helix Acquisition Corp., Class A(a)(b)		445		4,450
MedTech Acquisition Corp./NY, Class A(a)		1,908		18,985
				100,451
Electronic Equipment, Instruments & Components — 0.3%
908 Devices Inc.(a)(b)		648		21,319
Health Care Equipment & Supplies — 29.2%
ABIOMED Inc.(a)		424		140,785
Alcon Inc.(b)		2,110		175,889
ConvaTec Group PLC(c)		11,764		34,421
Cooper Companies Inc. (The)		285		118,822
Demant A/S(a)		1,120		54,295
DENTSPLY SIRONA Inc.		1,627		93,081
Dexcom Inc.(a)		139		86,626
Edwards Lifesciences Corp.(a)		759		90,943
Globus Medical Inc., Class A(a)		230		17,749
Hill-Rom Holdings Inc.		393		60,876
Insulet Corp.(a)		385		119,358
Intuitive Surgical Inc.(a)		602		217,400
Masimo Corp.(a)		505		143,188
Novocure Ltd.(a)		55		5,641
Nyxoah SA, NVS(a)		1,368		34,268
Penumbra Inc.(a)		147		40,653
Pulmonx Corp.(a)		245		9,538
ResMed Inc.		456		119,887
SI-BONE Inc.(a)		368		8,298
Sonova Holding AG, Registered		194		80,388
STERIS PLC		374		87,419
Straumann Holding AG, Registered		20		41,634
Tandem Diabetes Care Inc.(a)		372		50,715
Teleflex Inc.		389		138,850
Zimmer Biomet Holdings Inc.		789		112,922
				2,083,646
Health Care Providers & Services — 5.7%
Addus HomeCare Corp.(a)		111		10,378
Agilon Health Inc.(a)(b)		634		15,533
Alignment Healthcare Inc.(a)		780		15,491
Amplifon SpA		1,748		88,953
Centene Corp.(a)		963		68,604
Encompass Health Corp.		1,040		66,102
Guardant Health Inc.(a)		329		38,424
Innovage Holding Corp.(a)		182		1,205

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Schedule of Investments  (unaudited) (continued) October 31, 2021 BlackRock Future Health ETF (Percentages shown are based on Net Assets)

Security	Shares		Value
Health Care Providers & Services (continued)
Privia Health Group Inc.(a)		297	$	7,633
Quest Diagnostics Inc.		477		70,014
Rede D’Or Sao Luiz SA(c)		2,099		21,943
				404,280
Health Care Technology — 0.3%
Definitive Healthcare Corp.(a)(b)		322		12,925
Sophia Genetics SA, NVS(a)		619		8,784
				21,709
Life Sciences Tools & Services — 18.0%
Avantor Inc.(a)		4,583		185,061
Bruker Corp.		921		73,956
Charles River Laboratories International Inc.(a)		245		109,927
Cytek Biosciences Inc.(a)		1,786		40,739
ICON PLC(a)(b)		800		229,416
Illumina Inc.(a)		163		67,655
IQVIA Holdings Inc.(a)		391		102,215
IsoPlexis Corp, NVS(a)		360		4,590
Lonza Group AG, Registered		96		78,893
Olink Holding AB, ADR(a)(b)		63		2,026
QIAGEN NV(a)		2,354		131,259
Rapid Micro Biosystems Inc., Cass A(a)		241		4,914
Sotera Health Co.(a)		2,797		69,086
Thermo Fisher Scientific Inc.		210		132,945
Wuxi Biologics Cayman Inc., New(a)(c)		3,500		53,014
				1,285,696
Pharmaceuticals — 4.9%
Astellas Pharma Inc.		4,700		79,236
Daiichi Sankyo Co. Ltd.		4,700		118,592
Merck KGaA		214		50,574
Nektar Therapeutics(a)		890		13,492
UCB SA		749		89,525
				351,419
Total Common Stocks — 93.1% (Cost: $5,466,805)				6,638,716

Security	Shares		Value
Warrants
Diversified Financial Services — 0.0%
Eucrates Biomedical Acquisition Corp., (Expires 12/14/25)(a)		619	$	526
Health Assurance Acquisition Corp., (Expires 11/12/25)(a)		704		676
MedTech Acquisition Corp./NY, (Expires 12/18/25)(a)		636		617
				1,819
Total Warrants — 0.0% (Cost: $4,671)				1,819
Short-Term Investments
Money Market Funds — 16.1%
BlackRock Cash Funds: Institutional, SL Agency Shares, 0.05%(d)(e)(f)		606,058		606,361
BlackRock Cash Funds: Treasury, SL Agency Shares, 0.00%(d)(e)		540,000		540,000
				1,146,361
Total Short-Term Investments — 16.1% (Cost: $1,146,361)				1,146,361
Total Investments in Securities — 109.2% (Cost: $6,617,837)				7,786,896
Other Assets, Less Liabilities — (9.2)%				(655,726	)
Net Assets — 100.0%			$	7,131,170

^(a)  Non-income producing security.

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

^(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.

^(f)  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 October 31, 2021 for purposes of Section 2(a)(3) of the Investment Company Act of 1940, as amended, were as follows:

Affiliated Issuer	Value at 07/31/21		Purchases at Cost			Proceeds from Sales		Net Realized Gain (Loss)		Change in Unrealized Appreciation (Depreciation)		Value at 10/31/21		Shares Held at 10/31/21		Income			Capital Gain Distributions from Underlying Funds
BlackRock Cash Funds: Institutional, SL Agency Shares	$	185,281	$	421,080	(a)	$	—	$	—	$	—	$	606,361		606,058	$	316	(b)	$	—
BlackRock Cash Funds: Treasury, SL Agency Shares		430,000		110,000	(a)		—		—		—		540,000		540,000		4			—
								$	—	$	—	$	1,146,361			$	320		$	—

^(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.

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Schedule of Investments  (unaudited) (continued) October 31, 2021 BlackRock Future Health ETF

Fair Value Measurements

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 BlackRock Global Valuation Methodologies Committee’s (the “Global 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 Global 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
Investments
Assets
Common Stocks	$	5,729,752	$	908,964	$	—	$	6,638,716
Warrants		1,819		—		—		1,819
Money Market Funds		1,146,361		—		—		1,146,361
	$	6,877,932	$	908,964	$	—	$	7,786,896

Portfolio Abbreviations - Equity
ADR	American Depositary Receipt
NVS	Non-Voting Shares

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