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

In the year to Oct 28, 2026, with distributions reinvested, MBB returned −0.8% and SPY +13.6%.

Which is cheaper, MBB or SPY?

MBB is cheaper, by 0.05 percentage points a year. That is about $5 on $10,000 held for a year. Fees come from each fund's prospectus.

Data as of Oct 28, 2026.

Across categories

MBB vs SPY: Differences, Returns & Fees

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Over the year to Oct 28, 2026, MBB returned −0.8% to SPY's +13.6%; 0% of their weight is in the same names.

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Net assets: $35.5bn on Oct 28, 2026 for iShares MBS ETF, and $814.8bn on Oct 27, 2026 for SPDR S&P 500 ETF Trust.

MBB on its own →SPY on its own →

At a glance

−0.8%

MBB total return, 1 year

+13.6%

SPY total return, 1 year

0.04%

MBB expense ratio

0.09%

SPY expense ratio

Pair scorecard

MBB costs 0.05 points a year less; their one-year returns differ by 14.4 points; SPY is far larger, $810.0bn against $35.6bn.

MBB vs SPY: Differences, Returns & Fees
Measure	MBB	SPY
Return
Measure	MBB	SPY
Total return, 1 year	−0.8%	+13.6%
Benchmark
Measure	MBB	SPY
What it tracks	Bloomberg U.S. MBS Index	S&P 500 Index
Cost and size
Measure	MBB	SPY
Expense ratio	0.04%	0.09%
Net assets, as of Oct 26, 2026	$35.6bn	$810.0bn
Holdings
Measure	MBB	SPY
Holdings in common	0%
In the S&P 500, by weight		100%
Top ten holdings, share of the fund		38.1%

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

What they share

By the books each fund has filed, MBB and SPY 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 MBB SPY

Only in one fund ↓

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%

Only in SPY

NVIDIA CORP 7.92%

APPLE INC 7.61%

MICROSOFT CORP 5.93%

AMAZON.COM INC 3.73%

ALPHABET INC CL A 2.83%

BROADCOM INC 2.45%

ALPHABET INC CL C 2.26%

META PLATFORMS INC CLASS A 2.06%

Check overlap with more funds →

Side by side

MBB iShares MBS ETF SPY SPDR S&P 500 ETF Trust

Where it sits Bond ETF Stock ETF

Issuer iShares State Street

What it is Tracks an index of mortgage-backed securities Tracks the S&P 500

Total return, 1 year −0.8% +13.6%

Its benchmark over the same days −1.1% (SPMB) +13.7% (VOO)

Gap to its benchmark +0.3 pts vs SPMB −0.1 pts vs VOO

Expense ratio 0.04% 0.09%

Holdings 10813 504

Net assets, MBB as of Oct 28, 2026 and SPY as of Oct 27, 2026 $35.5bn $814.8bn

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

Alert

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.

SPY

SPY tracks the S&P 500. Over the year to Oct 28, 2026 it returned +13.6% with distributions reinvested, against +13.7% for its benchmark, the S&P 500 Index. The prospectus expense ratio is 0.09% a year. By its holdings published by its issuer for Oct 27, 2026, 100% of the fund by weight is stocks the S&P 500 also holds, across 504 positions, with the top ten at 38.1%.

Questions people ask

Which returned more over the last year, MBB or SPY?: In the year to Oct 28, 2026, with distributions reinvested, MBB returned −0.8% and SPY +13.6%.
Which is cheaper, MBB or SPY?: MBB is cheaper, by 0.05 percentage points a year. That is about $5 on $10,000 held for a year. Fees come from each fund's prospectus.

Other comparisons

IVV vs MBB MBB vs VTI MBB vs VOO MBB vs SPYM SPY vs TLT BIL vs SPY PULS vs SPY SPY vs USFR

Where to next

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

Sources and dates

MBB filings on SEC EDGAR ↗

MBB prospectus with the expense ratio (SEC) ↗

iShares page for MBB ↗

SPY filings on SEC EDGAR ↗

State Street website ↗

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 SPY, data as of Oct 28, 2026. https://etfiq.com/compare/any/mbb-vs-spy

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