Which returned more over the last year, MBB or MUB?

In the year to Oct 28, 2026, with distributions reinvested, MBB returned −0.8% and MUB −0.4%.

Which is cheaper, MBB or MUB?

MBB is cheaper, by 0.01 percentage points a year. That is about $1 on $10,000 held for a year. Fees come from each fund's prospectus.

Data as of Oct 28, 2026.

Across categories

MBB vs MUB: Differences, Returns & Fees

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On Aug 31, 2026 MBB's duration was 5.7 years and MUB's 7.0; MBB charges 0.04% to MUB's 0.05%.

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Net assets: $35.5bn on Oct 28, 2026 for iShares MBS ETF, and $54.1bn on Oct 27, 2026 for iShares National Muni Bond ETF.

MBB on its own →MUB on its own →

At a glance

−0.8%

MBB total return, 1 year

−0.4%

MUB total return, 1 year

0.04%

MBB expense ratio

0.05%

MUB expense ratio

Pair scorecard

MBB costs 0.01 points a year less; their one-year returns differ by 0.4 points; MUB is 1.5 times larger.

MBB vs MUB: Differences, Returns & Fees
Measure	MBB	MUB
Return
Measure	MBB	MUB
Total return, 1 year	−0.8%	−0.4%
Benchmark
Measure	MBB	MUB
What it tracks	Bloomberg U.S. MBS Index	ICE AMT-Free US National Municipal Index
Cost and size
Measure	MBB	MUB
Expense ratio	0.04%	0.05%
Net assets, as of Oct 26, 2026	$35.6bn	$54.1bn
Holdings
Measure	MBB	MUB
Holdings in common	0%

Holdings in common uses holdings dated Aug 31, 2026. Method

Risk and return

Sep 21, 2007 to Oct 23, 2026 · 996 weekly returns

MBB MUB

Return

Total return edge MUB +60.8% +76.1%

Annualized edge MUB +2.5% +3.0%

Price return edge MUB −8.9% +3.4%

Risk

Volatility edge MBB 4.2% 6.5%

Max drawdown edge MUB −17.4% −12.4%

Risk-adjusted

Sharpe edge Tie 0.26 0.26

Sortino edge MBB (slight) 0.37 0.36

Calmar edge MUB 0.14 0.24

Reading

MUB returned more: +76.1% to +60.8%. MBB swung less: 4.2% to 6.5%. MUB fell less at its worst: −12.4% to −17.4%.

Full scorecard

9 measures, with how each is measured Open ↓

Risk and return: MBB vs MUB: Differences, Returns & Fees
Measure	MBB	MUB	Edge	How it is measured
Return
Total return	+60.8%	+76.1%	MUB	Price change plus distributions, reinvested.
Annualized	+2.5%	+3.0%	MUB	Total return as a yearly rate.
Price return	−8.9%	+3.4%	MUB	Price change alone, distributions left out.
Risk
Volatility	4.2%	6.5%	MBB	Spread of weekly returns, annualized. Lower is steadier.
Downside deviation	2.9%	4.7%	MBB	Like volatility, counting only weeks below the Treasury bill rate.
Max drawdown	−17.4%	−12.4%	MUB	Deepest fall from a high to the low after it.
Risk-adjusted
Sharpe	0.26	0.26	Tie	Return above Treasury bills per unit of volatility.
Sortino	0.37	0.36	MBB (slight)	Return above Treasury bills per unit of downside deviation.
Calmar	0.14	0.24	MUB	Annualized return divided by the max drawdown.

Computed by ETFIQ from Tiingo daily prices and ETFIQ's distribution records, 996 weekly returns. Cash rate: the 13-week Treasury bill.

What they share

By the books each fund has filed, MBB and MUB hold 0% of their money in the same securities at the same weight. Holdings dated Aug 31, 2026.

50%

0 half 100%

half

0% in common

Positions both hold · largest shared weight first MBB MUB

Only in one fund ↓

Only in MBB

Ginnie Mae, due Sep 1, 2056 1.05%

Freddie Mac Pool, due May 1, 2051 0.98%

Uniform Mortgage-Backed Security, TBA, due Sep 1, 2056 0.85%

Uniform Mortgage-Backed Security, TBA, due Sep 1, 2056 0.70%

Ginnie Mae, due Sep 1, 2056 0.53%

Ginnie Mae II Pool, due Nov 20, 2054 0.51%

Ginnie Mae II Pool, due Oct 20, 2051 0.51%

Ginnie Mae II Pool, due Dec 20, 2051 0.50%

Only in MUB

Board of Regents of the University of Texas System, Series 2025B, due Aug 15, 2036 0.18%

San Antonio Water System, Series 2025D, due May 1, 2055 0.15%

New York State Thruway Authority, Series 2022A, due Mar 15, 2048 0.15%

New York State Dormitory Authority, Series 2019D, due Feb 15, 2047 0.13%

Northwest Independent School District, Series 2025, due Feb 15, 2055 0.12%

Houston Higher Education Finance Corp., Series 2024, due May 15, 2034 0.12%

State of New Jersey, Series 2020A, due Jun 1, 2028 0.12%

Ohio State University (The), Series 2026A, due Jun 1, 2035 0.12%

Check overlap with more funds →

Side by side

MBB iShares MBS ETF MUB iShares National Muni Bond ETF

Where it sits Bond ETF Bond ETF

Issuer iShares iShares

What it is Tracks an index of mortgage-backed securities Tracks an index of National Muni Bond

Total return, 1 year −0.8% −0.4%

Its benchmark over the same days −1.1% (SPMB) not measured

Gap to its benchmark +0.3 pts vs SPMB not measured

Expense ratio 0.04% 0.05%

Holdings 10813 7873

Net assets, MBB as of Oct 28, 2026 and MUB as of Oct 27, 2026 $35.5bn $54.1bn

MBB and MUB on the fields both publish, as of Oct 28, 2026. Source: ETFIQ.

Client brief · page 1 of 2 Report BR-52C8800506

MBB and MUB do different jobs. What does each one do in a portfolio?

What each follows. MBB follows Bloomberg U.S. MBS Index and MUB follows ICE AMT-Free US National Municipal Index.
Holdings in common. 0% of the weight is in the same securities (holdings dated Aug 31, 2026).
One-year total return (similar). Over 1 year to Oct 28, 2026 MBB returned −0.8% and MUB −0.4% with distributions reinvested, a gap of 0.4 points.

Data as of Oct 28, 2026.

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About each fund

MBB

MBB tracks an index of mortgage-backed securities. Over the year to Oct 28, 2026 it returned −0.8% with distributions reinvested, against −1.1% for its benchmark, the Bloomberg U.S. MBS Index. The prospectus expense ratio is 0.04% a year.

MUB

MUB tracks an index of National Muni Bond. Over the year to Oct 28, 2026 it returned −0.4% with distributions reinvested. The prospectus expense ratio is 0.05% a year.

Questions people ask

Which returned more over the last year, MBB or MUB?: In the year to Oct 28, 2026, with distributions reinvested, MBB returned −0.8% and MUB −0.4%.
Which is cheaper, MBB or MUB?: MBB is cheaper, by 0.01 percentage points a year. That is about $1 on $10,000 held for a year. Fees come from each fund's prospectus.

Other comparisons

MBB vs VTEB HYMB vs MBB MBB vs SGOV BINC vs MBB MUB vs TLT BIL vs MUB IGSB vs MUB MUB vs SHV

Where to next

MBB on its own →MUB on its own →Hold both: look the portfolio through →Rankings →MBB dividend history →MBB holdings →MUB dividend history →MUB holdings →Standards and sources →

Sources and dates

MBB and MUB filings on SEC EDGAR ↗

MBB and MUB prospectus with the expense ratio (SEC) ↗

iShares page for MBB ↗

iShares page for MUB ↗

Links are sources, not endorsements. A comparison is not a recommendation.

How this is computed

Overlap adds up the smaller of the two weights for each security both funds hold.

Cite this pageCitation, APA and Markdown

ETFIQ, MBB against MUB, data as of Oct 28, 2026. https://etfiq.com/compare/any/mbb-vs-mub

Open data →

Free to use with attribution for data ETFIQ computes; issuer data stays under its owner's terms.