Schedule of Investments  (unaudited) April 30, 2020 BlackRock MuniYield Investment Fund (MYF) (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Municipal Bonds — 109.3%
Alabama — 0.3%
City of Selma Alabama IDB, RB, Gulf Opportunity Zone, International Paper Co. Project, Series A, 5.38%,12/01/35	$	545	$	561,410
Arizona — 2.6%
Arizona IDA, Refunding RB, Basis Schools, Inc. Projects, Series A, 5.38%, 07/01/50(a)		1,645		1,499,056
City of Phoenix Arizona IDA, RB, Legacy Traditional Schools Projects, Series A, 5.00%, 07/01/46(a)		1,070		976,418
City of Phoenix Civic Improvement Corp., ARB, Junior Lien Airport Revenue Bonds, 3.00%, 07/01/49		1,500		1,356,930
County of Maricopa Arizona IDA, Refunding RB, Honorhealth, Series A, 4.13%, 09/01/38		550		579,441
Salt Verde Financial Corp., RB, Senior, 5.00%, 12/01/32		155		188,571
				4,600,416
Arkansas — 0.6%
Arkansas Development Finance Authority, RB, Big River Steel Project, AMT, 4.50%, 09/01/49(a)		1,210		1,033,279
California — 10.3%
ABC Unified School District, GO, (FGIC), 0.00%, 08/01/34(b)		1,215		785,874
Alvord Unified School District, GO, Refunding Series B, 0.00%, 08/01/41(b)		1,175		548,749
California Municipal Finance Authority, Refunding RB, Community Medical Centers, Series A, 5.00%, 02/01/42		145		161,565
California Statewide Communities Development Authority, RB, Series A(a):
Lancer Educational student Housing Project, 5.00%, 06/01/46		1,680		1,525,272
Loma Linda University Medical Center, 5.00%, 12/01/46		290		283,727
California Statewide Communities Development Authority, Refunding RB, Lancer Educational student Housing Project, Series A, 5.00%, 06/01/36(a)		1,360		1,310,700
City & County of San Francisco California Airports Commission, Refunding ARB, 2nd Series A, AMT:
5.50%, 05/01/28		1,065		1,169,540

Security	Par (000)		Value
California (continued)
5.25%, 05/01/33	$	830	$	895,155
City of San Jose California, Refunding ARB, Norman Y Mineta San Jose International Airport SJC, Series A-1, AMT, 5.50%, 03/01/30		1,500		1,542,000
Golden State Tobacco Securitization Corp., Refunding RB, Series A-2, 5.00%, 06/01/47		655		639,005
Kern Community College District, GO, Safety, Repair & Improvement, Series C, 5.50%, 11/01/23(c)		1,620		1,870,906
Regents of the University of California Medical Center Pooled Revenue, Refunding RB, Series J:
5.25%, 05/15/23(c)		2,905		3,276,085
5.25%, 05/15/38		825		910,891
State of California, GO, Various Purposes, 6.00%, 03/01/33		850		852,941
State of California Public Works Board, LRB, Various Capital Projects, Series I, 5.50%, 11/01/31		1,000		1,135,980
State of California Public Works Board, RB, Department of Corrections & Rehabilitation, Series F, 5.25%, 09/01/33		835		932,611
Township of Washington California Health Care District, GO, Election of 2004, Series B, 5.50%, 08/01/40		625		717,250
				18,558,251
Colorado — 2.5%
Centerra Metropolitan District No. 1, Tax Allocation Bonds, 5.00%, 12/01/47(a)		345		287,440
City & County of Denver Colorado, RB, Capital Appreciation Bonds, Series A-2, 0.00%, 08/01/37(b)		1,760		938,502
City & County of Denver Colorado Airport System Revenue, ARB, Series A, AMT:
5.50%, 11/15/28		1,000		1,109,780
5.50%, 11/15/30		330		365,554
5.50%, 11/15/31		400		442,772
Colorado Health Facilities Authority, Refunding RB:
Commonspirit Health, Series A-2, 3.25%, 08/01/49		1,195		1,002,223

1

Schedule of Investments  (unaudited) (continued) April 30, 2020 BlackRock MuniYield Investment Fund (MYF) (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Colorado (continued)
Frasier Meadows Retirement Community Project, Series A, 5.25%, 05/15/37	$	290	$	270,814
				4,417,085
Connecticut — 1.4%
Connecticut Housing Finance Authority, Refunding RB, S/F Housing:
Sub-Series A-1, 3.85%, 11/15/43		1,545		1,580,921
Series A-1, 3.80%, 11/15/39		995		1,026,213
				2,607,134
Delaware — 1.2%
County of Sussex Delaware, RB, NRG Energy, Inc., Indian River Power LLC Project, 6.00%, 10/01/40		500		505,745
Delaware State Health Facilities Authority, RB, Beebe Medical Center Project, 5.00%, 06/01/48		1,605		1,737,589
				2,243,334
District of Columbia — 0.3%
Metropolitan Washington Airports Authority Dulles Toll Road Revenue, Refunding RB, Subordinate, Dulles Metrorail and Capital Improvement Projects, Series B, 4.00%, 10/01/49		530		501,698
Florida — 8.1%
Broward County FL Airport System Revenue, RB, AMT, Series A, 5.00%, 10/01/49		300		329,295
County of Broward Florida Airport System Revenue, ARB, Series A, AMT, 5.00%, 10/01/45		1,005		1,072,285
County of Hillsborough Florida Aviation Authority, Refunding ARB, Tampa International Airport, Series A, AMT, 5.50%, 10/01/29		1,995		2,183,647
County of Lee Florida, Refunding ARB, Series A, AMT, 5.38%, 10/01/32		2,000		2,073,420
County of Lee Florida HFA, RB, S/F Housing, Multi-County Program, Series A-2, AMT (Ginnie Mae, Fannie Mae & Freddie Mac), 6.00%, 09/01/40		80		81,842
County of Manatee Florida HFA, RB, S/F Housing, Series A, AMT (Ginnie Mae, Fannie Mae & Freddie Mac), 5.90%, 09/01/40		80		81,837

Security	Par (000)		Value
Florida (continued)
County of Miami-Dade Florida, RB, Seaport Department:
Series A, 5.38%, 10/01/33	$	1,170	$	1,287,644
Series B, AMT, 6.25%, 10/01/38		525		585,475
Series B, AMT, 6.00%, 10/01/42		700		775,516
County of Miami-Dade Florida Aviation, Refunding ARB, Series A, AMT, 5.00%, 10/01/22(c)		2,440		2,664,382
County of Osceola FL Transportation Revenue, Refunding RB, Series A-2(b):
0.00%, 10/01/38		1,000		535,790
0.00%, 10/01/41		555		231,085
0.00%, 10/01/42		410		163,656
0.00%, 10/01/43		370		141,414
0.00%, 10/01/44		380		139,198
0.00%, 10/01/45		1,315		461,328
Lakewood Ranch Stewardship District, Special Assessment Bonds, Lakewood National & Polo Run Projects:
5.25%, 05/01/37		240		248,057
5.38%, 05/01/47		260		267,940
Reedy Creek Florida Improvement District, GO, Series A, 5.25%, 06/01/23(c)		1,200		1,355,148
				14,678,959
Georgia — 2.6%
Main Street Natural Gas, Inc., RB, Series A:
5.00%, 05/15/37		1,475		1,681,353
5.00%, 05/15/38		910		1,030,448
5.00%, 05/15/49		1,080		1,254,042
Municipal Electric Authority of Georgia, RB, Plant Vogtle Units 3 & 4 Project:
4.00%, 01/01/49		280		269,396
5.00%, 01/01/56		385		406,094
				4,641,333
Hawaii — 0.6%
State of Hawaii Airports System, COP, AMT:
5.25%, 08/01/25		485		528,223
5.25%, 08/01/26		525		570,539
				1,098,762
Illinois — 13.3%
Chicago Board of Education, GO, Series C:
Dedicated Revenues, Series H, 5.00%, 12/01/36		295		284,362
Project, 5.25%, 12/01/35		970		960,853

2

Schedule of Investments  (unaudited) (continued) April 30, 2020 BlackRock MuniYield Investment Fund (MYF) (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Illinois (continued)
Chicago Board of Education, GO, Refunding:
Dedicated Revenues, Series D, 5.00%, 12/01/25	$	530	$	540,944
Dedicated Revenues, Series G, 5.00%, 12/01/34		290		279,946
5.00%, 12/01/25		415		423,570
Chicago Board of Education, GO:
,5.00%, 12/01/46		345		310,538
,5.00%, 12/01/46		885		765,454
City of Chicago Illinois Midway International Airport, Refunding GARB, 2nd Lien, Series A, AMT, 5.00%, 01/01/41		1,000		1,043,700
City of Chicago Illinois O’Hare International Airport, GARB, 3rd Lien, Series C, 6.50%, 01/01/21(c)		2,065		2,142,128
City of Chicago Illinois Transit Authority, RB, Sales Tax Receipts:
5.25%, 12/01/36		1,000		1,053,840
5.25%, 12/01/40		1,000		1,051,470
County of Cook Illinois Community College District No. 508, GO, City College of Chicago:
5.50%, 12/01/38		1,000		1,013,440
5.25%, 12/01/43		1,500		1,498,020
Illinois Finance Authority, RB, Carle Foundation, Series A, 6.00%, 08/15/41		4,000		4,189,000
Metropolitan Pier & Exposition Authority, RB:
Mccormick Place Expansion (BAM), 0.00%, 12/15/56(b)		2,965		529,756
McCormick Place Expansion Project Bonds, Series A, 5.00%, 06/15/57		1,215		1,081,982
Metropolitan Pier & Exposition Authority, Refunding RB:
Mccormick Place Expansion (BAM), 0.00%, 12/15/54(b)		4,140		823,280
McCormick Place Expansion Project, 4.00%, 06/15/50		315		262,304
Railsplitter Tobacco Settlement Authority, RB(c):
5.50%, 06/01/21		1,370		1,438,322
6.00%, 06/01/21		390		411,563
State of Illinois, GO:
5.25%, 02/01/32		2,200		2,118,534
5.50%, 07/01/33		1,000		972,770
5.50%, 07/01/38		415		391,997
Series D, 5.00%, 11/01/28		440		428,547
				24,016,320

Security	Par (000)		Value
Indiana — 2.1%
City of Valparaiso Indiana, RB, Exempt Facilities, Pratt Paper LLC Project, AMT, 6.75%, 01/01/34	$	1,350	$	1,412,586
County of Allen Indiana, RB, StoryPoint Fort Wayne Project, Series A-1(a):
6.63%, 01/15/34		170		168,059
6.75%, 01/15/43		355		339,834
6.88%, 01/15/52		515		487,236
Indiana Finance Authority, Refunding RB, Marquette Project, 4.75%, 03/01/32		700		683,760
Town of Chesterton Indiana, RB, StoryPoint Chesterton Project, Series A-1, 6.38%, 01/15/51(a)		720		639,022
				3,730,497
Iowa — 2.1%
Iowa Finance Authority, Refunding RB, Iowa Fertilizer Co. Project:
Series B, 5.25%, 12/01/50(d)		1,255		1,196,592
Midwestern Disaster Area, 5.25%, 12/01/25		865		860,736
Iowa Student Loan Liquidity Corp., Refunding RB, AMT, Series B, 3.00%, 12/01/39		1,885		1,774,049
				3,831,377
Kansas — 0.3%
City of Lenexa Kansas, Refunding RB, Lakeview Village, Inc., Series A, 5.00%, 05/15/43		655		581,077
Louisiana — 3.4%
Lake Charles Louisiana Harbor & Terminal District, RB, Series B, AMT (AGM), 5.50%, 01/01/29		1,500		1,679,505
Louisiana Local Government Environmental Facilities & Community Development Authority, RB, Westlake Chemical Corp. Project, Series A-1, 6.50%, 11/01/35		1,420		1,437,849
Louisiana Public Facilities Authority, Refunding RB, Ochsner Clinic Foundation Project, 5.00%, 05/15/47		1,895		1,996,193

3

Schedule of Investments  (unaudited) (continued) April 30, 2020 BlackRock MuniYield Investment Fund (MYF) (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Louisiana (continued)
Tobacco Settlement Financing Corp., Refunding RB, Asset-Backed, Series A, 5.50%, 05/15/29	$	965	$	965,869
				6,079,416
Maine — 0.7%
Maine Health & Higher Educational Facilities Authority, RB, Maine General Medical Center, 7.50%, 07/01/32		765		794,284
State of Maine Housing Authority, RB, M/F Housing, Series E, 4.25%, 11/15/43		420		452,172
				1,246,456
Maryland — 1.3%
City of Baltimore Maryland, Refunding RB, East Baltimore Research Park, Series A, 4.50%, 09/01/33		185		173,867
County of Montgomery Housing Opportunites Commission, Refunding RB, S/F Housing, Series C, AMT, 3.30%, 07/01/39		2,200		2,217,644
				2,391,511
Massachusetts — 2.7%
Massachusetts Development Finance Agency, Refunding RB:
Atrius Health Issue, Series A, 4.00%, 06/01/49		170		170,485
Suffolk University, 4.00%, 07/01/39		2,045		2,070,971
Massachusetts Educational Financing Authority, RB, Subordinate Education Loan Revenue Bonds, AMT, 3.75%, 07/01/47		2,135		2,056,197
Massachusetts HFA, Refunding RB, Series C, AMT, 5.35%, 12/01/42		545		545,654
				4,843,307
Michigan — 2.4%
Eastern Michigan University, RB, Series A, 4.00%, 03/01/47		1,455		1,474,119
Michigan Finance Authority, Refunding RB, Henry Ford Health System, 4.00%, 11/15/46		645		619,761
Michigan Strategic Fund, RB, I-75 Improvement Projects, AMT, 5.00%, 06/30/48		570		573,996
State of Michigan HDA, RB, S/F Housing, Series C, 4.13%, 12/01/38		860		923,941
State of Michigan Housing Development Authority, RB:
M/F Housing, Series A-1, 3.35%, 10/01/49		420		422,705

Security	Par (000)		Value
Michigan (continued)
S/F Housing, Series A, 4.00%, 06/01/49	$	310	$	328,826
				4,343,348
Montana — 0.1%
City of Kalispell Montana, Refunding RB, Immanuel Lutheran Corporation Project, Series A, 5.25%, 05/15/37		170		154,290
Nevada — 1.0%
Las Vegas Convention & Visitors Authority, RB, Series B, 4.00%, 07/01/49		2,000		1,802,200
New Hampshire — 0.6%
New Hampshire Housing Finance Authority, RB, M/F Housing, Cimarron, Whittier Falls & Marshall (FHA), 4.00%, 07/01/52		1,000		1,036,690
New Jersey — 4.7%
New Jersey EDA, RB, Private Activity Bond, Goethals Bridge Replacement Project, AMT (AGM), 5.00%, 01/01/31		900		980,631
New Jersey Transportation Trust Fund Authority, RB, Series AA:
Transportation Program Bonds, 4.13%, 06/15/39		1,210		1,089,811
Transportation System, 5.50%, 06/15/39		2,475		2,505,121
New Jersey Transportation Trust Fund Authority, Refunding RB, Transportation System, Series A, 5.00%, 12/15/36		180		177,831
Tobacco Settlement Financing Corp., Refunding RB, Sub-Series B, 5.00%, 06/01/46		3,610		3,629,205
				8,382,599
New York — 5.4%
City of New York Water & Sewer System, RB, 2nd General Resolution Revenue Bonds, 3.00%, 06/15/50		3,000		2,767,800
Counties of New York Tobacco Trust IV, Refunding RB, Settlement Pass-Through Turbo, Series A, 6.25%, 06/01/41(a)		1,100		1,097,250
Metropolitan Transportation Authority, Refunding RB, Sereis C-1, 5.00%, 11/15/56		3,010		3,077,063

4

Schedule of Investments  (unaudited) (continued) April 30, 2020 BlackRock MuniYield Investment Fund (MYF) (Percentages shown are based on Net Assets)

Security	Par (000)		Value
New York (continued)
New York Transportation Development Corp., ARB, LaGuardia Airport Terminal B Redevelopment Project, Series A, AMT, 5.25%, 01/01/50	$	475	$	484,263
State of New York Power Authority, Refunding RB, Series A, 4.00%, 11/15/60(e)		1,735		1,829,401
State of New York Thruway Authority, Refunding RB, Subordinate, Series B, 4.00%, 01/01/50		510		523,642
				9,779,419
North Carolina — 0.4%
North Carolina Medical Care Commission, RB, Novant Health Obligated Group, 4.00%, 11/01/52		445		463,089
North Carolina Turnpike Authority, RB, Senior Lien, Triangle Express Way System:
4.00%, 01/01/55		105		93,984
(AGM), 4.00%, 01/01/55		100		102,117
				659,190
Ohio — 2.9%
Buckeye Tobacco Settlement Financing Authority, Refunding RB, Senior, Class 2, Series B-2, 5.00%, 06/01/55		1,895		1,676,468
County of Montgomery Ohio, Refunding RB, Premier Health Partners Obligated Group, 4.00%, 11/15/42		715		600,157
Ohio Air Quality Development Authority, RB, AMG Vanadium Project, AMT, 5.00%, 07/01/49(a)		460		417,928
Ohio Housing Finance Agency, RB, S/F Housing, Series A (Ginnie Mae, Fannie Mae & Freddie Mac), 4.00%, 09/01/48		295		305,467
State of Ohio, Refunding RB, Series A, 4.00%, 01/15/50		1,055		1,077,788
State of Ohio Turnpike Commission, RB, Junior Lien, Infrastructure Projects, Series A-1, 5.25%, 02/15/31		1,000		1,077,070
				5,154,878
Oklahoma — 0.9%
City of Oklahoma Turnpike Authority, RB, Series A, 4.00%, 01/01/48		325		351,514
County of Tulsa Oklahoma Industrial Authority, Refunding RB, Montereau, Inc. Project, 5.25%, 11/15/37		450		443,020

Security	Par (000)		Value
Oklahoma (continued)
Oklahoma Development Finance Authority, RB, OU Medicine Project, Series B, 5.25%, 08/15/48	$	760	$	782,025
				1,576,559
Oregon — 0.1%
State of Oregon Housing & Community Services Department, RB, S/F Housing, Mortgage Program, Series C, 3.95%, 07/01/43		245		255,981
Pennsylvania — 6.9%
Allentown Neighborhood Improvement Zone Development Authority, RB, City Center Project, 5.00%, 05/01/42(a)		585		562,361
County of Berks IDA, Refunding RB, Tower Health Projects, 5.00%, 11/01/50		915		908,375
County of Bucks IDA, RB, St. Luke’s University Health Network Project, 4.00%, 08/15/50		1,430		1,430,501
County of Montgomery Higher Education & Health Authority, Refunding RB, Thomas Jefferson University, Series A, 4.00%, 09/01/49		560		563,388
Pennsylvania Economic Development Financing Authority, RB, Series A-1, 4.00%, 04/15/50		525		532,124
Pennsylvania Economic Development Financing Authority, Refunding RB, National Gypsum Co., AMT, 5.50%, 11/01/44		1,000		858,120
Pennsylvania Higher Education Assistance Agency, RB, AMT, Series B, 3.00%, 06/01/47		105		87,839
Pennsylvania Higher Educational Facilities Authority, RB, University of Pennsylvania Health System Obligation, 4.00%, 08/15/44		1,000		1,057,120
Pennsylvania Housing Finance Agency, Refunding RB, S/F Housing Mortgage, Series 119, 3.50%, 10/01/36		1,490		1,537,799
Pennsylvania Turnpike Commission, RB, Series A:
5.63%, 12/01/20(c)		1,470		1,510,410
5.63%, 12/01/20(c)		545		559,982
Subordinate, 4.00%, 12/01/49		1,215		1,244,184

5

Schedule of Investments  (unaudited) (continued) April 30, 2020 BlackRock MuniYield Investment Fund (MYF) (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Pennsylvania (continued)
Township of Bristol Pennsylvania School District, GO, 5.25%, 06/01/37	$	1,500	$	1,666,275
				12,518,478
Puerto Rico — 5.3%
Children’s Trust Fund, Refunding RB, Tobacco Settlement Asset-Backed Bonds:
5.50%, 05/15/39		430		430,340
5.63%, 05/15/43		445		438,369
Commonwealth of Puerto Rico Aqueduct & Sewer Authority, RB, Senior Lien, Series A, 5.00%, 07/01/33		1,280		1,215,808
Commonwealth of Puerto Rico Aqueduct & Sewer Authority, Refunding RB, Senior Lien, Series A:
6.00%, 07/01/38		465		461,150
6.00%, 07/01/44		840		839,849
Puerto Rico Sales Tax Financing Corp. Sales Tax Revenue, RB, Restructured:
Series A-1, 4.75%, 07/01/53		991		892,722
Series A-1, 5.00%, 07/01/58		4,612		4,307,700
Series A-2, 4.33%, 07/01/40		364		325,088
Series A-2, 4.78%, 07/01/58		136		122,426
Series B-1, 4.75%, 07/01/53		252		227,123
Series B-2, 4.78%, 07/01/58		244		217,521
				9,478,096
Rhode Island — 3.0%
Rhode Island Turnpike & Bridge Authority, RB, Series A:
3.00%, 10/01/38		375		375,626
3.00%, 10/01/39		535		535,080
Tobacco Settlement Financing Corp., Refunding RB:
Series A, 5.00%, 06/01/35		525		552,631
Series B, 4.50%, 06/01/45		3,950		4,026,433
				5,489,770
South Carolina — 5.7%
County of Charleston South Carolina, RB, Special Source, 5.25%, 12/01/38		2,505		2,837,639
County of Charleston South Carolina Airport District, ARB, Series A, AMT:
6.00%, 07/01/38		1,955		2,156,971
5.50%, 07/01/41		1,000		1,070,820
South Carolina Jobs EDA, Refunding RB, Prisma Health Obligated Group, Series A, 4.25%, 05/01/48		1,685		1,702,423
State of South Carolina Ports Authority, ARB, AMT, 5.00%, 07/01/55		820		889,995

Security	Par (000)		Value
South Carolina (continued)
State of South Carolina Ports Authority, RB, AMT, 5.25%, 07/01/25(c)	$	1,280	$	1,525,658
				10,183,506
Tennessee — 0.8%
Greeneville Health & Educational Facilities Board, Refunding RB, Ballad Health Obligation Group, Series A, 4.00%, 07/01/40		1,500		1,444,770
Texas — 6.6%
Brazos Higher Education Authority, Inc., RB, Subordinate, Student Loan Program, Series 1B (AMT), 3.00%, 04/01/40		70		59,233
Central Texas Regional Mobility Authority, Refunding RB, Senior Lien, 6.00%, 01/01/21(c)		2,600		2,690,402
City of Houston Texas Airport System Revenue, Refunding RB, Special Facilities, Continental Airlines, Inc., Series A, AMT, 6.63%, 07/15/38		250		252,685
Dallas-Fort Worth Texas International Airport, ARB, Joint Improvement, Series H, AMT, 5.00%, 11/01/37		1,535		1,580,052
North Texas Tollway Authority, Refunding RB, 4.25%, 01/01/49		720		778,594
Red River Texas Education Financing Corp., RB, Texas Christian University Project, 5.25%, 03/15/23(c)		710		796,592
Texas Department of Housing & Community Affairs, RB, S/F Housing Mortgage, Series A (Ginnie Mae), 4.25%, 09/01/43		230		245,803
Texas Private Activity Bond Surface Transportation Corp., RB, Segment 3C Project, AMT, 5.00%, 06/30/58		1,795		1,857,125
Texas Transportation Commission, RB, First Tier Toll Revenue(b):
CAB, 0.00%, 08/01/41		1,950		717,775
0.00%, 08/01/35		310		157,886
0.00%, 08/01/36		170		82,239
0.00%, 08/01/37		225		103,304
0.00%, 08/01/38		810		351,961
0.00%, 08/01/44		1,010		315,797
0.00%, 08/01/45		1,775		526,802
University of Texas System, Refunding RB, Series A, 3.50%, 08/15/50		1,060		1,318,746
				11,834,996
Virginia — 3.8%
City of Lexington Virginia IDA, RB, Washington & Lee University, 5.00%, 01/01/22(c)		560		599,194

6

Schedule of Investments  (unaudited) (continued) April 30, 2020 BlackRock MuniYield Investment Fund (MYF) (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Virginia (continued)
Tobacco Settlement Financing Corp., Refunding RB, Senior Series B-1, 5.00%, 06/01/47	$	1,395	$	1,321,763
Virginia Housing Development Authority, RB:
M/F, Rental Housing, Series D, 3.90%, 10/01/48		1,570		1,645,815
Series E, 3.15%, 12/01/49		1,070		1,040,372
Virginia Small Business Financing Authority, RB, AMT:
Covanta Project, 5.00%, 01/01/48(a)(d)		585		547,695
Senior Lien, Elizabeth River Crossings OpCo LLC Project, 6.00%, 01/01/37		1,715		1,767,873
				6,922,712
West Virginia — 1.1%
West Virginia Hospital Finance Authority, RB, Improvement, West Virginia University Health System Obligated Group, Series A, 4.00%, 06/01/51		1,940		1,980,022
Wisconsin — 1.2%
Public Finance Authority, Refunding RB, Mery’s Wood at Marylhurst Projects, 5.25%, 05/15/52(a)		1,015		963,976
Wisconsin Housing & Economic Development Authority, RB, M/F Housing, Series A:
4.45%, 05/01/57		660		710,721
3.15%, 11/01/44		520		523,967
				2,198,664
Total Municipal Bonds — 109.3% (Cost — $195,187,832)				196,857,790
Municipal Bonds Transferred to Tender Option Bond Trusts — 52.6%(f)
Arizona — 0.6%
County of Maricopa Industrial Development Authority, RB, Banner Health, Series A, 4.00%, 01/01/41		1,065		1,129,667
California — 8.8%
Bay Area Toll Authority, Refunding RB, San Francisco Bay Area Toll Bridge, 4.00%, 04/01/42(g)		1,998		2,137,631
Grossmont California Union High School District, GO, Election of 2008, Series B, 5.00%, 08/01/20(c)		6,000		6,061,080

Security	Par (000)		Value
California (continued)
Los Angeles Community College District California, GO, Election of 2008, Series C, 5.25%, 08/01/20(c)(g)	$	5,251	$	5,309,097
Sacramento Area Flood Control Agency, Refunding, Consolidated Capital Assessment District No. 2 Bonds, 5.00%, 10/01/47		1,980		2,285,801
				15,793,609
District of Columbia — 0.4%
District of Columbia Housing Finance Agency, RB, M/F Housing, Series B-2 (FHA), 4.10%, 09/01/39		610		662,613
Florida — 5.7%
City of South Miami Health Facilities Authority, Inc., Refunding RB, Baptist Health South Florida, 5.00%, 08/15/47		1,575		1,727,743
City of Tampa Florida, RB, Baycare Health System, Series A, 4.00%, 11/15/46		1,918		2,021,247
County of Broward Florida Airport Facilities Revenue, ARB, Senior Bond, Series B, AMT, 4.00%, 09/01/49		2,660		2,654,334
Greater Orlando Aviation Authority, ARB, Series A, AMT, 4.00%, 10/01/49(g)		3,858		3,914,083
				10,317,407
Georgia — 2.5%
Georgia Housing & Finance Authority, Refunding RB, S/F Mortgage Bonds, Series A:
3.70%, 06/01/49		2,696		2,775,472
3.60%, 12/01/44		1,615		1,666,407
				4,441,879
Illinois — 0.5%
Illinois Finance Authority, Refunding RB, Presence Health Network, Series C:
4.00%, 02/15/27(c)		2		2,413

7

Schedule of Investments  (unaudited) (continued) April 30, 2020 BlackRock MuniYield Investment Fund (MYF) (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Illinois (continued)
4.00%, 02/15/41	$	912	$	962,142
				964,555
Maine — 0.3%
State of Maine Housing Authority, RB, M/F Housing, Series E, 4.15%, 11/15/38		563		606,776
Maryland — 2.0%
City of Baltimore Maryland, RB, Water Projects, Series A, 4.00%, 07/01/49		3,378		3,618,691
Michigan — 4.3%
Michigan Finance Authority, RB, Multi Model- McLaren Health Care, 4.00%, 02/15/47		1,964		2,030,460
Michigan State Building Authority, Refunding RB, Facilities Program, Series I, 4.00%, 04/15/54		2,524		2,752,067
State of Michigan Housing Development Authority, RB, M/F Housing, Series A, 4.05%, 10/01/48		2,756		2,917,097
				7,699,624
Nebraska — 0.7%
Nebraska Investment Finance Authority, RB, S/F Housing, Series A (Ginnie Mae, Fannie Mae & Freddie Mac), 3.70%, 03/01/47		1,206		1,264,295
Nevada — 5.2%
County of Clark Nevada, GO, Stadium Improvement, Series A, 5.00%, 05/01/48		2,740		3,138,038
Las Vegas Valley Water District, GO, Refunding, Series C, 5.00%, 06/01/28		6,070		6,312,133
				9,450,171
New Jersey — 0.6%
New Jersey Transportation Trust Fund Authority, RB, Transportation System, Series B, 5.25%, 06/15/36		1,000		1,002,181
New York — 10.4%
City of New York Housing Development Corp., Refunding RB, Sustainable Neighborhood Bonds, Series A, 4.15%, 11/01/38		1,280		1,368,192
City of New York Municipal Water Finance Authority, Refunding RB:
Series FF, 5.00%, 06/15/45		3,859		4,116,903

Security	Par (000)		Value
New York (continued)
Water & Sewer System, 2nd General Resolution, Series BB, 5.25%, 12/15/21(c)	$	4,408	$	4,726,584
Hudson Yards Infrastructure Corp., RB, Senior-Fiscal 2012(g):
5.75%, 02/15/21(c)		799		826,756
5.75%, 02/15/47		491		508,596
New York Liberty Development Corp., ARB, 1 World Trade Center Port Authority Consolidated Bonds, 5.25%, 12/15/43		4,365		4,577,229
New York Liberty Development Corp., Refunding RB, 4 World Trade Center Project, 5.75%, 11/15/51(g)		2,560		2,670,149
				18,794,409
Pennsylvania — 2.0%
Commonwealth of Pennsylvania, GO, 1st Series, 4.00%, 03/01/36(g)		1,769		1,952,820
Pennsylvania Turnpike Commission, RB, Subordinate, Series A, 5.50%, 12/01/42		1,514		1,702,406
				3,655,226
Rhode Island — 1.2%
Rhode Island Housing & Mortgage Finance Corp., Refunding RB, S/F Housing, Home Ownership Opportunity Bonds, Series 69-B (Ginnie Mae, Fannie Mae & Freddie Mac):
3.55%, 10/01/33		1,440		1,530,389
3.95%, 10/01/43		514		585,036
				2,115,425
South Carolina — 1.3%
South Carolina Ports Authority, ARB, Series B, AMT, 4.00%, 07/01/49(g)		2,235		2,275,029
Texas — 4.2%
County of Hidalgo Texas, GOL, Certificates of Obligation, Series A, 4.00%, 08/15/43		2,703		2,969,757
North Texas Tollway Authority, RB, Special Projects System, Series A, 5.50%, 09/01/21(c)		3,480		3,698,753
Texas Department of Housing & Community Affairs, RB, S/F Housing, Series A (Ginnie Mae):
3.63%, 09/01/44		495		531,905

8

Schedule of Investments  (unaudited) (continued) April 30, 2020 BlackRock MuniYield Investment Fund (MYF) (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Texas (continued)
3.75%, 09/01/49	$	271	$	291,620
				7,492,035
Washington — 0.9%
Washington Health Care Facilities Authority, Refunding RB, Multicare Health System, Series B, 4.13%, 08/15/43		1,641		1,711,403
Wisconsin — 1.0%
Wisconsin Housing & Economic Development Authority, RB, M/F Housing, Series A, 4.30%, 11/01/53		1,605		1,718,185

Security	Value
Total Municipal Bonds Transferred to Tender Option Bond Trusts — 52.6% (Cost — $92,870,165)	$	94,713,180
Total Long-Term Investments — 161.9% (Cost — $288,057,997)		291,570,970
Total Investments — 161.9% (Cost — $288,057,997)		291,570,970
Other Assets Less Liabilities — 2.0%		3,443,937
Liability for TOB Trust Certificates, Including Interest Expense and Fees Payable — (31.0)%		(55,800,355	)
VRDP Shares, at Liquidation Value, Net of Deferred Offering Costs — (32.9)%		(59,158,449	)
Net Assets Applicable to Common Shares — 100.0%	$	180,056,103

^(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)  Zero-coupon bond.

^(c)  U.S. Government securities held in escrow, are used to pay interest on this security as well as to retire the bond in full at the date indicated, typically at a premium to par.

^(d)  Variable or floating rate security, which interest rate adjusts periodically based on changes in current interest rates and prepayments on the underlying pool of assets. Rate shown is the rate in effect as of period end.

^(e)  When-issued security.

^(f)  Represent bonds transferred to a TOB Trust in exchange of cash and residual certificates received by the Fund. These bonds serve as collateral in a secured borrowing.

^(g)  All or a portion of the security is subject to a recourse agreement. The aggregate maximum potential amount the Fund could ultimately be required to pay under the agreements, which expire between August 15, 2020 to August 1, 2039, is $11,759,292.

Investments in issuers considered to be an affiliate/affiliates of the Fund during the period ended April 30, 2020 for purposes of Section 2(a)(3) of the Investment Company Act of 1940, as amended, were as follows:

Affiliated Issuer	Shares Held at 07/31/19		Shares Purchased		Shares Sold			Shares Held at 04/30/20		Value at 04/30/20		Income		Net Realized Gain (Loss) (a)		Change in Unrealized Appreciation (Depreciation)
BlackRock Liquidity Funds, MuniCash, Institutional Class(b)		382,946		—		(382,946	)(c)		—	$	—	$	8,701	$	2,141	$	—

^(a)  Includes net capital gain distributions, if applicable.

^(b)  As of period end, the entity is no longer held by the Fund.

^(c)  Represents net shares purchased (sold).

9

Schedule of Investments  (unaudited) (continued) April 30, 2020 BlackRock MuniYield Investment Fund (MYF)

Portfolio Abbreviations

AGM — Assured Guaranty Municipal Corp.

AMT — Alternative Minimum Tax (subject to)

ARB — Airport Revenue Bonds

BAM — Build America Mutual Assurance Co.

CAB — Capital Appreciation Bonds

COP — Certificates of Participation

EDA — Economic Development Authority

FHA — Federal Housing Administration

GARB — General Airport Revenue Bonds

GO — General Obligation Bonds

HDA — Housing Development Authority

HFA — Housing Finance Agency

IDA — Industrial Development Authority

IDB — Industrial Development Board

LRB — Lease Revenue Bonds

M/F — Multi-Family

RB — Revenue Bonds

S/F — Single-Family

Fair Value Hierarchy as of Period End

Various inputs are used in determining the fair value of investments. 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 the 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)

• 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 investments)

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 investments is based on the pricing transparency of the investments 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 investments, refer to the Fund’s most recent financial statements as contained in its semi-annual report.

10

Schedule of Investments  (unaudited) (continued) April 30, 2020 BlackRock MuniYield Investment Fund (MYF)

Fair Value Hierarchy as of Period End (continued)

The following tables summarize the Fund’s investments categorized in the disclosure hierarchy:

	Level 1		Level 2		Level 3		Total
Assets:
Investments:
Long-Term Investments (a)	$	—	$	291,570,970	$	—	$	291,570,970

^(a)  See above Schedule of Investments for values in state or political division.

The Fund may hold assets and/or liabilities in which the fair value approximates the carrying amount for financial reporting purposes. As of period end, such assets and/or liabilities are categorized within the disclosure hierarchy as follows:

	Level 1		Level 2			Level 3		Total
Liabilities:
TOB Trust Certificates	$	—	$	(55,572,504	)	$	—	$	(55,572,504	)
VRDP Shares at Liquidation Value		—		(59,400,000	)		—		(59,400,000	)
	$	—	$	(114,972,504	)	$	—	$	(114,972,504	)

11