MUB's largest holdings are BlackRock Liquidity Funds MuniCash, Board of Regents of the University of Texas System, San Antonio Water System, Northwest Independent School District, New York State Thruway Authority. The full top list is on this page.

How concentrated is MUB?

The top 10 holdings are 4.3% of the fund, across 7,472 positions.

The total expense ratio on record is 0.05%. That is cheaper than 92% of the 865 US-listed bond funds we track.

US-listed · United States

MUB

The Fund seeks to track the investment results of an index composed of investment-grade U.S. municipal bonds.

iShares National Muni Bond ETF

US4642884146 · BlackRock (iShares)

7,472 holdings as of 2026-10-12 · top 10 = 4.3% · TER 0.05%

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Concentration

Well diversifiedtop 10 = 4.3%

diversifiedconcentrated

GROWTH · PRICE DEVELOPMENTrebased to 0%

Holdings

7,472

as of 2026-10-12

Top 10

4.3%

TER

0.05%

cheaper than 92% of peers

Net assets

US$49.5B

reported in USD

Largest

3.0%

P / E

–

Sections

Holdings as of 2026-10-12.

01Overview

the fund's regulatory facts

Fund currency

USD

Domicile

United States

Volatility 1Y

3.8%

Tracked index

ICE AMT-Free US National Municipal Index

How it tracks

Index, sampling

02Performance

market price return · as of 2026-10-27

+2.7%

-2.0%

-3.2%

YTD

-3.0%

-3.5%

Trackingfund minus ICE AMT-Free US National Municipal Index · annualised

1Y return gap

+0.05 pp/yr

3Y return gap

-0.13 pp/yr

5Y return gap

-0.03 pp/yr

3Y tracking error

0.11%

A positive return gap means the fund finished ahead of the index over that window. The 3Y tracking error shows how variable that monthly gap was; lower means steadier tracking. MethodologyReturn gap and tracking errorReturn gap is the fund's return minus its index over the same months, converted to a yearly rate. Tracking error is the annualised standard deviation of those monthly fund-minus-index returns. Both lines come from the manager's own chart, in the same currency and the exact index variant the fund tracks. We use month-end values so different intraday valuation times are not mistaken for tracking error.. Not investment advice.

03Holdings

50 largest · as of 2026-10-12

#	Company	Identifier	Weight
1	BlackRock Liquidity Funds MuniCash US	MCSXX	3.1
2	Board of Regents of the University of Texas System US	US91514ANG66	0.2
3	San Antonio Water System US	US79642GTU66	0.1
4	Northwest Independent School District US	US667826HG94	0.1
5	New York State Thruway Authority US	US650028ZA41	0.1
6	OKLAHOMA TURNPIKE AUTHORITY US	US679111D279	0.1
7	Triborough Bridge & Tunnel Authority US	US89602RKE44	0.1
8	New Jersey (State of) US	US646039YM35	0.1
9	WILLIAM MARSH RICE UNIV US	HOUHGR	0.1
10	Ohio State University/The US	OHSHGR	0.1
11	Washington (State of) (Bid Group 2) US	US93974EVY93	0.1
12	State of California US	US13063D7Q50	0.1
13	New York State Dormitory Authority US	NYSHGR	0.1
14	Triborough Bridge & Tunnel Authority US	US89602RPH20	0.1
15	NEW YORK CITY TRANSITIONAL FIN AUT US	NYCGEN	0.1
16	ILLINOIS ST US	ILS	0.1
17	County of King WA Sewer Revenue US	US495290ET12	0.1
18	City of Houston TX Combined Utility System Revenue US	US44244CN944	0.1
19	City of Seattle US	US812643ZK32	0.1
20	Triborough Bridge & Tunnel Authority US	US89602HAB33	0.1
21	New Jersey Educational Facilities Authority US	US646067KD94	0.1
22	Chicago Transit Authority Sales Tax Receipts Fund US	US16772PEP71	0.1
23	California Educational Facilities Authority US	US130179YE89	0.1
24	Commonwealth of Massachusetts US	US57582R8A79	0.1
25	State of California US	US13063D4Q87	0.1
26	DIST OF COLUMBIA UNIV REVENUE US	US25484JDJ60	0.1
27	City of Los Angeles Department of Airports US	US5444456K08	0.1
28	New York City Municipal Water Finance Authority US	US64972GH724	0.1
29	HOUSTON TEX UTIL SYS REV US	US442435XN88	0.1
30	ALABAMA TOLL RD BRDG & TUNL AU US	US01065CAK99	0.1
31	Commonwealth of Massachusetts US	US57582R2F21	0.1
32	City of New York US	US64966SPY62	0.1
33	New York State Dormitory Authority US	US65000BW384	0.1
34	METROPOLITAN ATLANTA RAPID TRA US	US591746EE80	0.1
35	Washoe County School District US	US940859BX82	0.1
36	Los Angeles Unified School District US	US544647HR40	0.1
37	City of Chicago IL US	US167486T338	0.1
38	Ohio Water Development Authority US	US67766WQ212	0.1
39	CALIFORNIA ST US	US13063EEV48	0.1
40	New York (State of) Thruway Authority US	US650028ZU05	0.1
41	Pennsylvania Turnpike Commission US	US7092248P76	0.1
42	Triborough Bridge & Tunnel Authority US	US89602HGZ47	0.1
43	State of California US	US13063D5R51	0.1
44	NEW JERSEY ST TRANSPRTN TRUST US	US646136EV97	0.1
45	New York City Municipal Water Finance Authority US	US64972GPZ18	0.1
46	San Diego Unified School District US	US797356BY75	0.1
47	Los Angeles Unified School District US	US544647BX71	0.1
48	University of California US	US91412HPR83	0.1
49	Long Island Power Authority US	US542691LG38	0.1
50	Metropolitan Government of Nashville & Davidson County US	US592112XP62	0.1

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04Exposure

Equity 3.1%Bonds 95.1%Cash 1.8%

By country

USUnited States97.7%

CurrencyUSD 97.7%

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