Get the weekly note

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

ETFIQetfiq.com · independent ETF data

GOVT vs MBB: how they differ

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

iShares U.S. Treasury Bond ETF and iShares MBS ETF.

What they hold in common

By the books each fund has filed, GOVT 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 GOVTOnly in MBB
United States of America 5.31%Freddie Mac 1.07%
United States of America 2.96%Government National Mortgage Association 0.97%
United States of America 2.63%UMBS, TBA 0.85%
United States of America 2.09%Government National Mortgage Association 0.69%
United States of America 1.61%UMBS, TBA 0.66%
United States of America 1.57%Government National Mortgage Association 0.56%
United States of America 1.53%Government National Mortgage Association 0.55%
United States of America 1.51%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 Apr 30, 2026 and May 31, 2026.

GOVT and MBB on the fields both publish, as of Sep 12, 2026. Source: ETFIQ.
GOVT
iShares U.S. Treasury Bond ETF
MBB
iShares MBS ETF
Where it sitsCore index fundCore index fund
IssueriSharesiShares
What it isU.S. Treasury BondMbs
Total return, 1 year−1.0%−0.1%
S&P 500 over the same days+17.5%+17.5%
Gap to the S&P 500−18.5 pts−17.6 pts
Expense ratio0.05%0.04%
Holdings22311144

GOVT in plain words

GOVT is a bond fund tracking the U.S. Treasury Bond. Over the year to Sep 11, 2026 it returned −1.0% with distributions reinvested, against +17.5% for the S&P 500 and +23.0% for the Nasdaq-100. The prospectus expense ratio is 0.05% a year. It sat 8.4% below its high of Aug 4, 2020 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, GOVT or MBB?
In the year to Sep 12, 2026, with distributions reinvested, GOVT returned −1.0% and MBB returned −0.1%, so MBB returned more. One year is one year; the longer windows are in the table.
Which is cheaper, GOVT or MBB?
GOVT charges 0.05% a year and MBB charges 0.04%, so MBB is cheaper. Fees come from each fund's prospectus.

Other comparisons

Where to next

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.

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

A comparison is not a recommendation. Standards and sources