Blackrock Muniholdings Investment Quality Fund (MFL) NPORT-P BlackRock MuniHoldings Investment Quality Fund (Nov 2019 report)

Schedule of Investments  (unaudited) November 30, 2019 BlackRock MuniHoldings Investment Quality Fund (MFL) (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Municipal Bonds — 128.0%
Alabama — 1.6%
City of Selma Alabama IDB, RB, Gulf Opportunity Zone, International Paper Co. Project, Series A, 5.38%, 12/01/35	$	1,745	$	1,851,585
Homewood Educational Building Authority, Refunding RB, Samford University, Series A(a):
4.00%, 12/01/34		1,100		1,224,091
4.00%, 12/01/36		1,200		1,324,368
4.00%, 12/01/38		2,465		2,703,291
4.00%, 12/01/39		1,700		1,859,783
				8,963,118
Arizona — 2.6%
Arizona IDA, RB(b):
Leman Academy of Excellence-East Tucson And Central Tucson Projects, Series A, 5.00%, 07/01/39		855		888,131
Leman Academy of Excellence-East Tucson And Central Tucson Projects, Series A, 5.00%, 07/01/49		965		993,468
Leman Academy of Excellence-East Tucson And Central Tucson Projects, Series A, 5.00%, 07/01/54		745		764,355
Odyssey Preparatory Academy Project, 4.38%, 07/01/39		1,015		1,015,913
County of Maricopa Arizona IDA, Refunding RB, Banner Health Obligation Group, 5.00%, 01/01/38		3,000		3,549,210
County of Maricopa IDA, Refunding RB, Legacy Traditional Schools Project(a)(b):
5.00%, 07/01/39		360		401,987
5.00%, 07/01/49		510		562,550
5.00%, 07/01/54		320		350,586
County of Pima Arizona IDA, Refunding RB, American Leadership Academy Project, 5.00%, 06/15/52(b)		825		866,861
Salt River Project Agricultural Improvement & Power District, RB, Salt River Project Electric System, 4.00%, 01/01/41		2,000		2,298,620

Security	Par (000)		Value
Arizona (continued)
University of Arizona, Refunding RB, Series A, 5.00%, 06/01/40	$	2,300	$	2,685,342
				14,377,023
California — 14.7%
California Health Facilities Financing Authority, RB, Sutter Health, Series B, 6.00%, 08/15/20(c)		5,370		5,557,144
City & County of San Francisco California Airports Commission, Refunding ARB, AMT, Series A:
2nd, 5.50%, 05/01/28		3,330		3,770,825
2nd, 5.25%, 05/01/33		6,370		7,159,753
5.00%, 05/01/44		3,430		3,836,969
City of Los Angeles California Department of Airports, ARB,Sub-Series A, AMT, 5.00%, 05/15/42		1,750		2,074,048
City of Manteca California Financing Authority, RB, Manteca Sewer (AGC), 5.75%, 12/01/36		3,285		3,296,038
City of San Jose California, Refunding ARB, Norman Y Mineta San Jose International Airport SJC, SeriesA-1, AMT, 5.75%, 03/01/34		4,450		4,677,573
County of Sacramento California Airport System Revenue, Refunding RB, AMT, Series C, 5.00%, 07/01/39		3,410		4,122,417
Kern Community College District, GO, Safety, Repair & Improvement, Series C, 5.50%, 11/01/23(c)		4,365		5,123,331
Regents of the University of California Medical Center Pooled Revenue, Refunding RB, Series J, 5.25%, 05/15/38		2,705		3,043,098
State of California, GO, Various Purposes (AGC), 5.50%, 11/01/39		11,410		11,444,915
State of California Public Works Board, LRB, Various Capital Projects, Series I:
5.50%, 11/01/30		4,500		5,242,905
5.50%, 11/01/33		2,000		2,322,000
State of California Public Works Board, RB, Department of Corrections & Rehabilitation, Series F, 5.25%, 09/01/33		3,240		3,697,585
State of California University, Refunding RB, Systemwide, Series A, 5.00%, 11/01/42		3,500		4,254,040

1

Schedule of Investments  (unaudited) (continued) November 30, 2019 BlackRock MuniHoldings Investment Quality Fund (MFL) (Percentages shown are based on Net Assets)

Security	Par (000)		Value
California (continued)
University of California, Refunding RB, Series AR, 5.00%, 05/15/38	$	10,000	$	12,023,700
				81,646,341
Colorado — 2.6%
City & County of Denver Colorado Airport System Revenue, ARB, Series A, AMT:
5.50%, 11/15/28		2,700		3,098,385
5.50%, 11/15/30		1,040		1,190,114
5.50%, 11/15/31		1,250		1,428,412
City & County of Denver Colorado Airport System Revenue, Refunding ARB, AMT, Series A, 5.00%, 12/01/43		7,500		8,977,950
				14,694,861
Connecticut — 0.1%
Connecticut State Health & Educational Facilities Authority, RB, Mary Wade Home Issue, SeriesA-1, 5.00%, 10/01/54(b)		415		450,400
Florida — 9.2%
County of Hillsborough Florida Aviation Authority, Refunding ARB, Tampa International Airport, Series A, AMT:
5.50%, 10/01/29		5,360		6,136,771
5.25%, 10/01/30		3,255		3,691,691
County of Lee Florida, Refunding ARB, Series A, AMT, 5.38%, 10/01/32		7,100		7,548,578
County of Lee Florida HFA, RB, S/F Housing, Multi-County Program, SeriesA-2, AMT (Ginnie Mae, Fannie Mae & Freddie Mac), 6.00%, 09/01/40		240		245,505
County of Manatee Florida HFA, RB, S/F Housing, Series A, AMT (Ginnie Mae, Fannie Mae & Freddie Mac), 5.90%, 09/01/40		110		112,516
County of Miami-Dade Florida, RB, Seaport Department:
Series A, 5.38%, 10/01/33		3,145		3,564,040
Series B, AMT, 6.25%, 10/01/38		1,405		1,614,598
Series B, AMT, 6.00%, 10/01/42		1,885		2,158,117
County of Miami-Dade Florida, Refunding RB, Water & Sewer System, Series B, 5.25%, 10/01/23(c)		2,870		3,309,426
County of Miami-Dade Florida Aviation, Refunding ARB, Series A, AMT, 5.00%, 10/01/22(c)		5,465		6,010,571
County of Miami-Dade Florida Aviation Revenue, Refunding RB, AMT, Series A, 4.00%, 10/01/44		8,000		8,790,240

Security	Par (000)		Value
Florida (continued)
County of Miami-Dade Florida Water & Sewer System Revenue, Refunding RB, Series B, 4.00%, 10/01/44	$	4,000	$	4,481,360
Reedy Creek Florida Improvement District, GO, Series A, 5.25%, 06/01/32		3,225		3,639,058
				51,302,471
Hawaii — 2.0%
State of Hawaii Airports System, ARB, Series A, AMT, 5.00%, 07/01/45		5,985		6,799,618
State of Hawaii Airports System, COP, AMT:
5.25%, 08/01/25		1,350		1,522,935
5.25%, 08/01/26		2,500		2,816,650
				11,139,203
Idaho — 2.0%
Idaho Health Facilities Authority, RB, Trinity Health Credit Group, 4.00%, 12/01/43		10,000		11,061,100
Illinois — 19.1%
Chicago Board of Education, GO, Refunding, Series A:
CAB, 0.00%, 12/01/25(d)		395		333,368
5.00%, 12/01/29		1,045		1,249,496
5.00%, 12/01/30		1,245		1,483,953
City of Chicago Illinois Midway International Airport, Refunding ARB, 2nd Lien, Series A, AMT:
5.50%, 01/01/30		6,500		7,223,320
5.50%, 01/01/32		6,275		6,957,783
City of Chicago Illinois Midway International Airport, Refunding GARB, 2nd Lien, Series A, AMT, 5.00%, 01/01/41		8,020		8,841,488
City of Chicago Illinois O’Hare International Airport, GARB:
3rd Lien, Series A, 5.75%, 01/01/39		1,185		1,236,026
3rd Lien, Series C, 6.50%, 01/01/21(c)		16,800		17,761,296
Senior Lien, Series D, 5.25%, 01/01/42		2,630		3,143,218
City of Chicago Illinois O’Hare International Airport, Refunding RB, Senior Lien, Series B, 5.00%, 01/01/35		4,300		5,120,956
City of Chicago Illinois Transit Authority, RB, Sales Tax Receipts, 5.25%, 12/01/40		10,960		11,571,239

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Schedule of Investments  (unaudited) (continued) November 30, 2019 BlackRock MuniHoldings Investment Quality Fund (MFL) (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Illinois (continued)
City of Chicago Illinois Transit Authority, Refunding RB, Federal Transit Administration, Section 5309 (AGM), 5.00%, 06/01/28	$	7,735	$	7,883,744
Illinois Finance Authority, RB, Carle Foundation, Series A, 6.00%, 08/15/41		4,000		4,270,400
Railsplitter Tobacco Settlement Authority, RB(c):
5.50%, 06/01/21		4,365		4,646,150
6.00%, 06/01/21		1,245		1,333,968
State of Illinois, GO:
Rebuild Illinois Program, Series B, 5.00%, 11/01/32		10,000		11,650,500
Series A, 5.00%, 11/01/26		10,000		11,530,100
				106,237,005
Indiana — 0.7%
Bloomington Redevelopment District, Tax Allocation Bonds, Series B, 5.00%, 02/01/40		2,205		2,596,873
State of Indiana Finance Authority, RB, Private Activity Bond, Ohio River Bridges, Series A, AMT, 5.00%, 07/01/40		1,240		1,350,980
				3,947,853
Kansas — 0.9%
County of Wyandotte Kansas Unified School District, GO, Series A, 5.50%, 09/01/47		4,000		4,843,280
Kentucky — 2.0%
Kentucky Public Energy Authority, RB, Gas Supply, SeriesC-1, 4.00%, 12/01/49(e)		10,000		11,039,000
Massachusetts — 7.9%
Collegiate Charter School of Lowell, RB, 5.00%, 06/15/49(a)		2,430		2,589,845
Commonwealth of Massachusetts, GO, Series G, 4.00%, 09/01/42		22,535		24,814,415
Massachusetts Development Finance Agency, Refunding RB, Partners Healthcare System, 5.00%, 07/01/41		4,710		5,573,673
Massachusetts Educational Financing Authority, RB, Education Loan, Issue I, AMT, 5.00%, 01/01/27		1,000		1,146,750
Massachusetts Housing Finance Agency, Refunding RB, Series G, 3.45%, 12/01/30		3,100		3,311,668

Security	Par (000)		Value
Massachusetts (continued)
Massachusetts School Building Authority, RB, Sub Series B, 4.00%, 02/15/42	$	6,200	$	6,649,376
				44,085,727
Michigan — 1.2%
City of Detroit Michigan Water Supply System Revenue, RB, 2nd Lien, Series B (AGM), 6.25%, 07/01/36		10		10,036
Michigan Finance Authority, Refunding RB, Henry Ford Health System:
4.00%, 11/15/46		5,470		5,877,022
5.00%, 11/15/41		525		617,967
				6,505,025
Mississippi — 2.7%
Mississippi Development Bank, RB, Jackson Water & Sewer System Project (AGM):
6.88%, 12/01/40		6,405		7,623,551
Special Obligation, 6.75%, 12/01/31		3,775		4,479,943
Special Obligation, 6.75%, 12/01/33		2,350		2,779,228
				14,882,722
Nevada — 2.0%
County of Clark Nevada, ARB, Las Vegas-McCarran International Airport, Series A (AGM), 5.25%, 07/01/39		11,175		11,210,313
New Jersey — 11.3%
New Jersey EDA, RB, Goethals Bridge Replacement Project, AMT, Private Activity Bond:
5.38%, 01/01/43		7,000		7,838,320
(AGM), 5.00%, 01/01/31		2,425		2,713,817
New Jersey EDA, Refunding RB, Series B, 5.50%, 06/15/30		4,080		4,901,386
New Jersey Higher Education Student Assistance Authority, Refunding RB, Series 1, AMT, 5.75%, 12/01/28		1,880		2,002,012
New Jersey Transportation Trust Fund Authority, RB:
Transportation Program Bonds, Series S, 5.25%, 06/15/43		10,000		11,664,400
Transportation System, Series AA, 5.50%, 06/15/39		8,175		9,042,449
New Jersey Transportation Trust Fund Authority, Refunding RB, Transportation System, Series A, 4.25%, 12/15/38		5,745		6,172,026
New Jersey Turnpike Authority, Refunding RB, Series A, 5.00%, 01/01/34		1,685		1,987,862

3

Schedule of Investments  (unaudited) (continued) November 30, 2019 BlackRock MuniHoldings Investment Quality Fund (MFL) (Percentages shown are based on Net Assets)

Security	Par (000)		Value
New Jersey (continued)
Tobacco Settlement Financing Corp., Refunding RB,Sub-Series B, 5.00%, 06/01/46	$	15,000	$	16,579,050
				62,901,322
New Mexico — 0.1%
City of Santa Fe New Mexico, RB, EL Castillo Retirement Residences Project, Series A, 5.00%, 05/15/39		310		346,785
New York — 9.7%
City of New York, GO,Sub-SeriesF-1, 5.00%, 04/01/40		4,850		5,921,704
Hudson Yards Infrastructure Corp., Refunding RB, Series A, 4.00%, 02/15/44		10,000		11,026,800
Metropolitan Transportation Authority, RB, SeriesA-1, 5.25%, 11/15/39		4,490		5,057,581
Metropolitan Transportation Authority, Refunding RB, Series B, 5.00%, 11/15/37		6,140		7,233,104
New York City Transitional Finance Authority Future Tax Secured Revenue, RB, Subordinate, Series C, 4.00%, 05/01/43		5,000		5,563,000
New York City Water & Sewer System, RB, 2nd General Resolution:
5.38%, 12/15/20(c)		2,300		2,402,695
5.38%, 06/15/43		1,175		1,220,802
Port Authority of New York & New Jersey, Refunding ARB, Consolidated, 166th Series, 5.25%, 07/15/36		10,000		10,423,400
Triborough Bridge & Tunnel Authority, Refunding RB, Series B, 5.00%, 11/15/38		4,400		5,339,840
				54,188,926
Ohio — 4.3%
Buckeye Tobacco Settlement Financing Authority, RB, Asset-Backed, Senior Turbo Term, SeriesA-2, 5.88%, 06/01/47		4,650		4,659,904
State of Ohio, RB, Cleveland Clinic Health System Obligated Group, 4.00%, 01/01/41		7,285		8,148,928
State of Ohio, Refunding RB, Cleveland Clinic Health, Series A:
4.00%, 01/01/28(c)		25		29,975
4.00%, 01/01/43		2,475		2,717,303
State of Ohio Turnpike Commission, RB, Junior Lien, Infrastructure Projects, SeriesA-1:
5.25%, 02/15/31		5,145		5,763,429

Security	Par (000)		Value
Ohio (continued)
5.25%, 02/15/32	$	2,250	$	2,518,560
				23,838,099
Pennsylvania — 5.8%
Pennsylvania Turnpike Commission, RB:
Series A, 5.25%, 12/01/44		5,000		6,227,800
Sub-Series A, 5.50%, 12/01/46		18,570		22,746,393
Township of Bristol Pennsylvania School District, GO, 5.25%, 06/01/37		3,000		3,309,840
				32,284,033
Puerto Rico — 3.6%
Puerto Rico Sales Tax Financing Corp. Sales Tax Revenue, RB, Restructured:
CAB, SeriesA-1, 0.00%, 07/01/46(d)		574		152,168
SeriesA-1, 4.75%, 07/01/53		2,944		3,039,827
SeriesA-1, 5.00%, 07/01/58		3,926		4,126,736
SeriesA-2, 4.33%, 07/01/40		10,137		10,254,082
SeriesA-2, 4.78%, 07/01/58		875		902,300
SeriesB-1, 4.75%, 07/01/53		749		773,170
SeriesB-2, 4.78%, 07/01/58		726		747,374
				19,995,657
South Carolina — 5.8%
County of Charleston South Carolina, RB, Special Source, 5.25%, 12/01/38		6,735		7,670,020
County of Charleston South Carolina Airport District, ARB, Series A, AMT:
5.25%, 07/01/25		4,490		5,062,430
5.50%, 07/01/38		3,000		3,358,080
6.00%, 07/01/38		5,270		5,989,513
5.50%, 07/01/41		4,170		4,652,553
South Carolina Jobs-Economic Development Authority, Refunding RB, Prisma Health Obligated Group, Series A, 5.00%, 05/01/37		4,480		5,371,744
				32,104,340
South Dakota — 0.2%
South Dakota Housing Development Authority, RB, S/F Housing, Series B, 4.05%, 11/01/38		910		989,115
Texas — 12.1%
City of Beaumont Texas, GO, Certificates of Obligation, 5.25%, 03/01/37		4,190		4,659,238

4

Schedule of Investments  (unaudited) (continued) November 30, 2019 BlackRock MuniHoldings Investment Quality Fund (MFL) (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Texas (continued)
Dallas-Fort Worth Texas International Airport, ARB, Joint Improvement, AMT:
Series A, 5.00%, 11/01/20(c)	$	5,580	$	5,762,745
Series H, 5.00%, 11/01/37		4,575		4,829,827
Lower Colorado River Authority, Refunding RB, 5.50%, 05/15/33		3,735		4,230,000
North Texas Tollway Authority, Refunding RB, 1st Tier (AGM), 6.00%, 01/01/21(c)		5,555		5,842,527
Red River Texas Education Financing Corp., RB, Texas Christian University Project, 5.25%, 03/15/38		7,170		7,973,542
State of Texas, GO:
Transportation Commission Highway Improvement, 5.00%, 04/01/43		15,550		18,321,476
Water Financial Assistance, Series D, 5.00%, 05/15/40		4,000		4,666,520
Texas Water Development Board, RB:
State Water Implementation Fund, Series B, 4.00%, 10/15/43		5,000		5,615,850
State Water Implementation Revenue, 5.25%, 10/15/46		4,780		5,770,225
				67,671,950
Utah — 2.5%
County of Utah, RB, IHC Health Services, Inc., Series B, 5.00%, 05/15/46		7,500		8,810,250
Utah Charter School Finance Authority, RB, Wallace Stegner Academy Project, Series A, 5.00%, 06/15/49(b)		320		336,160
Utah State University, RB, Series B (AGM), 4.00%, 12/01/45		4,390		4,804,987
				13,951,397
Virginia — 0.3%
City of Lexington Virginia IDA, RB, Washington & Lee University, 5.00%, 01/01/43		1,750		1,868,318
Washington — 0.7%
State of Washington, GO, Series C, 5.00%, 02/01/41		2,500		3,043,850

Security	Par (000)		Value
Washington (continued)
Washington State Housing Finance Commission, RB, Transforming Age Project, Series A, 5.00%, 01/01/55(b)	$	875	$	951,265
				3,995,115
Wisconsin — 0.3%
Public Finance Authority, RB, American Preparatory Academy - Las Vegas Project, Class A(a)(b):
5.00%, 07/15/39		165		180,531
5.00%, 07/15/49		630		680,419
5.00%, 07/15/54		300		322,332
Public Finance Authority, Refunding RB, Penick Village Obligation Group, 5.00%, 09/01/49(b)		520		560,394
				1,743,676
Total Municipal Bonds — 128.0% (Cost — $670,746,286)				712,264,175
Municipal Bonds Transferred to Tender Option Bond Trusts(f)
Alabama — 8.3%
City of Birmingham Alabama Special Care Facilities Financing Authority, Refunding RB, Ascension Senior Credit Group:
Series B, 5.00%, 11/15/46		27,798		32,424,886
Series C, 5.00%, 11/15/46		11,920		13,895,501
				46,320,387
Massachusetts — 4.5%
Commonwealth of Massachusetts, GOL, Consolidated Loan, Series E, 5.25%, 09/01/43		20,000		25,020,200
Michigan — 4.0%
Michigan Finance Authority, Refunding RB, Trinity Health Credit Group, Series A, 4.00%, 12/01/40		10,100		11,160,197

5

Schedule of Investments  (unaudited) (continued) November 30, 2019 BlackRock MuniHoldings Investment Quality Fund (MFL) (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Michigan (continued)
Michigan Finance Authority, RB, Mclaren Health Care, Series A, 4.00%, 02/15/44	$	10,000	$	11,040,500
				22,200,697
Nevada — 2.0%
County of Clark Nevada, GOL, Las Vagas Convention and Visitor, 4.00%, 07/01/47		10,000		10,976,000
New Jersey — 0.6%
New Jersey Transportation Trust Fund Authority, RB, Transportation System, Series B, 5.25%, 06/15/36		2,961		3,104,454
New York — 14.6%
City of New York Transitional Finance Authority, RB, Series,S-1, 5.00%, 07/15/43		11,825		14,468,714
Hudson Yards Infrastructure Corp., RB, Senior-Fiscal 2012(g):
5.75%, 02/15/21(c)		5,726		6,027,139
5.75%, 02/15/47		3,523		3,707,714
Hudson Yards Infrastructure Corp., Refunding RB, Series A, 4.00%, 02/15/44		30,165		33,262,333
New York Liberty Development Corp., ARB, 1 World Trade Center Port Authority Consolidated Bonds, 5.25%, 12/15/43		13,950		15,037,542

Security	Par (000)		Value
New York (continued)
New York Liberty Development Corp., Refunding RB, 4 World Trade Center Project, 5.75%, 11/15/51(g)	$	8,200	$	8,866,406
				81,369,848
Pennsylvania — 1.9%
Geisinger Authority Pennsylvania, Refunding RB, Geisinger Health System, Series A, 4.00%, 06/01/41		10,000		10,631,000
Texas — 1.9%
North Texas Tollway Authority, RB, Special Projects System, Series A, 5.50%, 09/01/21(c)		9,640		10,354,999
Total Municipal Bonds Transferred to Tender Option Bond Trusts — 37.8% (Cost — $200,321,185)				209,977,585
Total Long-Term Investments — 165.8% (Cost — $871,067,471)				922,241,760
	Shares
Short-Term Securities — 1.2%
BlackRock Liquidity Funds, MuniCash, Institutional Class, 0.95.%(h)(i)		6,697,523		6,698,193
Total Short-Term Securities — 1.2% (Cost — $6,698,193)				6,698,193
Total Investments — 167.0% (Cost — $877,765,664)				928,939,953
Liabilities in Excess of Other Assets — (0.3)%				(2,143,320	)
Liability for TOB Trust Certificates, Including Interest Expense and Fees Payable — (17.3)%				(96,228,162	)
VRDP Shares, at Liquidation Value, Net of Deferred Offering Costs — (49.4)%				(274,234,307	)
Net Assets Applicable to Common Shares — 100.0%			$	556,334,164

^(a)  When-issued security.

^(b)  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.

^(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)  Zero-coupon bond.

^(e)  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.

^(f)  Represent bonds transferred to a TOB Trust in exchange of cash and residual certificates received by the Trust. 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 Trust could ultimately be required to pay under the agreements, which expire between August 15, 2020 to May 15, 2021, is $9,235,612.

^(h)  Annualized7-day yield as of period end.

6

Schedule of Investments  (unaudited) (continued) November 30, 2019 BlackRock MuniHoldings Investment Quality Fund (MFL)

⁽ⁱ⁾  During the period ended November 30, 2019, investments in issuers considered to be an affiliate/affiliates of the Trust for purposes of Section 2(a)(3) of the Investment Company Act of 1940, as amended, were as follows:

Affiliate	Shares Held at 08/31/19		Net Activity		Shares Held at 11/30/19		Value at 11/30/19		Income		Net Realized Gain (Loss) (a)			Change in Unrealized Appreciation (Depreciation)
BlackRock Liquidity Funds, MuniCash, Institutional Class		3,255,767		3,441,756		6,697,523	$	6,698,193	$	13,629	$	(569	)	$	5

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

Portfolio Abbreviations

AGC — Assured Guarantee Corp.

AGM — Assured Guaranty Municipal Corp.

AMT — Alternative Minimum Tax (subject to)

ARB — Airport Revenue Bonds

CAB — Capital Appreciation Bonds

COP — Certificates of Participation

EDA — Economic Development Authority

GO — General Obligation Bonds

HFA — Housing Finance Agency

IDA — Industrial Development Authority

IDB — Industrial Development Board

LRB — Lease Revenue Bonds

RB — Revenue Bonds

S/F — Single-Family

Derivative Financial Instruments Outstanding as of Period End

Futures Contracts

Description	Number of Contracts		Expiration Date		Notional Amount (000)		Value/ Unrealized Appreciation (Depreciation)
Short Contracts
10-Year U.S. Treasury Note		99		03/20/20	$	12,807	$	14,546
Long U.S. Treasury Bond		177		03/20/20		28,137		62,436
5-Year U.S. Treasury Note		77		03/31/20		9,161		5,778
							$	82,760

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Schedule of Investments  (unaudited) (continued) November 30, 2019 BlackRock MuniHoldings Investment Quality Fund (MFL)

Fair Value Hierarchy as of Period End

Various inputs are used in determining the fair value of investments and derivative 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 the Trust 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 and derivative 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 investments and derivative financial instruments 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 Trust’s policy regarding valuation of investments and derivative financial instruments, refer to the Trust’s most recent financial statements as contained in its annual report.

The following tables summarize the Trust’s investments and derivative financial instruments categorized in the disclosure hierarchy:

	Level 1		Level 2		Level 3		Total
Assets:
Investments:
Long-Term Investments(a)	$	—	$	922,241,760	$	—	$	922,241,760
Short-Term Securities		6,698,193		—		—		6,698,193
Total	$	6,698,193	$	922,241,760	$	—	$	928,939,953
Derivative Financial Instruments(b)
Assets:
Interest rate contracts	$	82,760	$	—	$	—	$	82,760

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

^(b)  Derivative financial instruments are futures contracts. Futures contracts are valued at the unrealized appreciation (depreciation) on the instrument.

The Trust 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	$	—	$	(95,978,045	)	$	—	$	(95,978,045	)
VRDP Shares at Liquidation Value		—		(274,600,000	)		—		(274,600,000	)
	$	—	$	(370,578,045	)	$	—	$	(370,578,045	)

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