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Data as of Sep 12, 2026. Both funds on the fields they both publish, from the same sources.

ETFIQetfiq.com · independent ETF data

IWF vs MBB: how they differ

IWF and MBB hold 0% of their weight in the same names, and IWF returned more over the year.

iShares Russell 1000 Growth ETF and iShares MBS ETF.

What they hold in common

By the books each fund has filed, IWF and MBB hold 0% of their money in the same securities at the same weight.

Largest positions each one holds and the other does not
Only in IWFOnly in MBB
NVIDIA CORPORATION 13.85%Freddie Mac 1.07%
APPLE INC. 6.72%Government National Mortgage Association 0.97%
ALPHABET INC. 6.18%UMBS, TBA 0.85%
BROADCOM INC. 5.21%Government National Mortgage Association 0.69%
ALPHABET INC. 4.98%UMBS, TBA 0.66%
MICROSOFT CORPORATION 4.11%Government National Mortgage Association 0.56%
MICRON TECHNOLOGY, INC. 3.86%Government National Mortgage Association 0.55%
TESLA, INC. 3.65%Government National Mortgage Association 0.54%

Weight overlap is an ETFIQ calculation: for every security both funds hold, the smaller of the two weights, summed. Above 50%, holding both is close to holding one of them twice. Holdings dated Jun 30, 2026 and May 31, 2026.

IWF and MBB on the fields both publish, as of Sep 12, 2026. Source: ETFIQ.
IWF
iShares Russell 1000 Growth ETF
MBB
iShares MBS ETF
Where it sitsCore index fundCore index fund
IssueriSharesiShares
What it isRussell 1000 growthMbs
Total return, 1 year+7.0%−0.1%
S&P 500 over the same days+17.5%+17.5%
Gap to the S&P 500−10.5 pts−17.6 pts
Expense ratio0.18%0.04%
Holdings36811144

IWF in plain words

IWF is an index equity fund tracking the Russell 1000 growth. Over the year to Sep 11, 2026 it returned +7.0% with distributions reinvested, against +17.5% for the S&P 500 and +23.0% for the Nasdaq-100. The prospectus expense ratio is 0.18% a year. By its holdings filed for Jun 30, 2026, 94% of the fund by weight is stocks the S&P 500 also holds, across 368 positions, with the top ten at 54.4%. It sat 5.0% below its high of Jun 1, 2026 on Sep 11, 2026.

MBB in plain words

MBB is a bond fund tracking the Mbs. Over the year to Sep 11, 2026 it returned −0.1% with distributions reinvested, against +17.5% for the S&P 500 and +23.0% for the Nasdaq-100. The prospectus expense ratio is 0.04% a year. It sat 3.3% below its high of Feb 27, 2026 on Sep 11, 2026.

Questions people ask

Which returned more over the last year, IWF or MBB?
In the year to Sep 12, 2026, with distributions reinvested, IWF returned +7.0% and MBB returned −0.1%, so IWF returned more. One year is one year; the longer windows are in the table.
Which is cheaper, IWF or MBB?
IWF charges 0.18% a year and MBB charges 0.04%, so MBB is cheaper. Fees come from each fund's prospectus.

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Where these figures came from

ETFIQ links to the documents behind every figure. It is not affiliated with any issuer, and a link is not an endorsement.

IWF against MBB, ETFIQ, data as of Sep 12, 2026. Every figure is arithmetic on a named public source; the method is at etfiq.com/methodology. A comparison is not a recommendation.

Cite this page. ETFIQ, IWF against MBB, data as of Sep 12, 2026. https://etfiq.com/compare/any/IWF-MBB Free to use with attribution; the underlying files are at Open data.

A comparison is not a recommendation. Standards and sources