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

In the year to Oct 28, 2026, with distributions reinvested, IWM returned +14.1% and MBB −0.8%.

Which is cheaper, IWM or MBB?

MBB is cheaper, by 0.15 percentage points a year. That is about $15 on $10,000 held for a year. Fees come from each fund's prospectus.

Data as of Oct 28, 2026.

Across categories

IWM vs MBB: Differences, Returns & Fees

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Over the year to Oct 28, 2026, IWM returned +14.1% to MBB's −0.8%; 0% of their weight is in the same names.

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Net assets: $75.5bn on Oct 27, 2026 for iShares Russell 2000 ETF, and $35.5bn on Oct 28, 2026 for iShares MBS ETF.

IWM on its own →MBB on its own →

At a glance

+14.1%

IWM total return, 1 year

−0.8%

MBB total return, 1 year

0.19%

IWM expense ratio

0.04%

MBB expense ratio

Pair scorecard

MBB costs 0.15 points a year less; their one-year returns differ by 14.9 points; IWM is 2.1 times larger.

IWM vs MBB: Differences, Returns & Fees
Measure	IWM	MBB
Return
Measure	IWM	MBB
Total return, 1 year	+14.1%	−0.8%
Drawdown
Measure	IWM	MBB
Below its high	7.6%, high on Aug 14, 2026
Benchmark
Measure	IWM	MBB
What it tracks	Russell 2000 Index	Bloomberg U.S. MBS Index
Cost and size
Measure	IWM	MBB
Expense ratio	0.19%	0.04%
Net assets, as of Oct 26, 2026	$74.6bn	$35.6bn
Holdings
Measure	IWM	MBB
Holdings in common	0%
In the S&P 500, by weight	0%
Top ten holdings, share of the fund	3.3%

Holdings in common uses holdings dated Oct 27, 2026. Method

What they share

By the books each fund has filed, IWM and MBB hold 0% of their money in the same securities at the same weight. Holdings dated Oct 27, 2026.

50%

0 half 100%

half

0% in common

Positions both hold · largest shared weight first IWM MBB

Only in one fund ↓

Only in IWM

JFROG 0.37%

GLAUKOS 0.35%

TWIST BIOSCIENCE 0.35%

MOOG INC CLASS A 0.34%

BRIGHTSPRING HEALTH SERVICES INC 0.33%

UMB FINANCIAL 0.33%

SM ENERGY 0.32%

10X GENOMICS CLASS A 0.31%

Only in MBB

BLACKROCK CASH CL INST SL AGENCY 5.45%

FHLMC 30YR UMBS SUPER 1.05%

UMBS 30YR TBA(REG A) 0.60%

GNMA2 30YR 0.59%

GNMA2 30YR 0.54%

FNMA 30YR UMBS 0.53%

GNMA2 30YR 0.53%

GNMA2 30YR 0.52%

Check overlap with more funds →

Side by side

IWM iShares Russell 2000 ETF MBB iShares MBS ETF

Where it sits Stock ETF Bond ETF

Issuer iShares iShares

What it is Tracks the Russell 2000 Tracks an index of mortgage-backed securities

Total return, 1 year +14.1% −0.8%

Its benchmark over the same days +14.3% (VTWO) −1.1% (SPMB)

Gap to its benchmark −0.2 pts vs VTWO +0.3 pts vs SPMB

Expense ratio 0.19% 0.04%

Holdings 1977 10813

Net assets, IWM as of Oct 27, 2026 and MBB as of Oct 28, 2026 $75.5bn $35.5bn

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

Alert

About each fund

IWM

IWM tracks the Russell 2000. Over the year to Oct 28, 2026 it returned +14.1% with distributions reinvested, against +14.3% for its benchmark, the Russell 2000 Index. The prospectus expense ratio is 0.19% a year. By its holdings published by its issuer for Oct 27, 2026, 0% of the fund by weight is stocks the S&P 500 also holds, across 1,977 positions, with the top ten at 3.3%. It sat 7.6% below its high of Aug 14, 2026 on Oct 28, 2026.

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.

Questions people ask

Which returned more over the last year, IWM or MBB?: In the year to Oct 28, 2026, with distributions reinvested, IWM returned +14.1% and MBB −0.8%.
Which is cheaper, IWM or MBB?: MBB is cheaper, by 0.15 percentage points a year. That is about $15 on $10,000 held for a year. Fees come from each fund's prospectus.

Other comparisons

IWM vs LQD IWM vs TLT BIL vs IWM IGSB vs IWM MBB vs VB MBB vs VTWO IJR vs MBB IJT vs MBB

Where to next

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

Sources and dates

IWM and MBB filings on SEC EDGAR ↗

IWM prospectus with the expense ratio (SEC) ↗

iShares page for IWM ↗

MBB prospectus with the expense ratio (SEC) ↗

iShares page for MBB ↗

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

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