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

In the year to Sep 13, 2026, with distributions reinvested, MBB returned −0.1% and XBI returned +64.0%, so XBI returned more. One year is one year; the longer windows are in the table.

Which is cheaper, MBB or XBI?

MBB charges 0.04% a year and XBI charges 0.35%, so MBB is cheaper. Fees come from each fund's prospectus.

Data as of Sep 13, 2026. Both funds on the fields they both publish, from the same sources.

ETFIQetfiq.com · independent ETF data

MBB vs XBI: how they differ

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

iShares MBS ETF and State Street(R) SPDR(R) S&P(R) Biotech ETF.

What they hold in common

By the books each fund has filed, MBB and XBI 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 MBB	Only in XBI
BLACKROCK CASH CL INST SL AGENCY 7.26%	MODERNA INC 2.87%
GNMA2 SF 30YR 0.09%	TWIST BIOSCIENCE CORP 1.81%
GNMA II 30YR SF - JUMBO-CONFORMING 0.08%	HALOZYME THERAPEUTICS INC 1.47%
GNMA2 SINGLE FAMILY 30YR 0.04%	NATERA INC 1.46%
GNMA II 30YR 0.03%	KYMERA THERAPEUTICS INC 1.45%
GNMA2 30YR TBA(REG C) 0.03%	TRAVERE THERAPEUTICS INC 1.40%
UMBS 15YR TBA(REG B) 0.03%	ROIVANT SCIENCES LTD 1.39%
FNMA 30YR UMBS MEGA REMIC SUPER 0.02%	ORUKA THERAPEUTICS INC 1.38%

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 Sep 10, 2026.

MBB and XBI on the fields both publish, as of Sep 13, 2026. Source: ETFIQ.
	MBB iShares MBS ETF	XBI State Street(R) SPDR(R) S&P(R) Biotech ETF
Where it sits	Core index fund	Core index fund
Issuer	iShares	State Street
What it is	Mbs	SPDR S&P Biotech
Total return, 1 year	−0.1%	+64.0%
S&P 500 over the same days	+17.5%	+17.5%
Gap to the S&P 500	−17.6 pts	+46.5 pts
Expense ratio	0.04%	0.35%
Holdings	2599	154

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.

XBI in plain words

XBI is an index equity fund tracking the SPDR S&P Biotech. Over the year to Sep 11, 2026 it returned +64.0% with distributions reinvested, against +17.5% for the S&P 500 and +23.0% for the Nasdaq-100. The prospectus expense ratio is 0.35% a year. By its holdings filed for Sep 10, 2026, 8% of the fund by weight is stocks the S&P 500 also holds, across 154 positions, with the top ten at 15.9%. It sat 9.6% below its high of Feb 8, 2021 on Sep 11, 2026.

Questions people ask

Which returned more over the last year, MBB or XBI?: In the year to Sep 13, 2026, with distributions reinvested, MBB returned −0.1% and XBI returned +64.0%, so XBI returned more. One year is one year; the longer windows are in the table.
Which is cheaper, MBB or XBI?: MBB charges 0.04% a year and XBI charges 0.35%, 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.

MBB against XBI, ETFIQ, data as of Sep 13, 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, MBB against XBI, data as of Sep 13, 2026. https://etfiq.com/compare/any/mbb-vs-xbi Free to use with attribution; the underlying files are at Open data.

A comparison is not a recommendation. Standards and sources