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MBBvsSPMBETF Comparison

ETF 1

MBB

iShares MBS ETF

This fund is part of

MBS & ABS

+0%

Full MBB fund page

VS

ETF 2

SPMB

State Street SPDR Portfolio Mortgage Backed Bond ETF

This fund is part of

MBS & ABS

+0%

Full SPMB fund page

The ETFs iShares MBS ETF (MBB) and State Street SPDR Portfolio Mortgage Backed Bond ETF (SPMB) track the Bloomberg U.S. MBS Total Return Index - USD and belong to the same industry segment: MBS & ABS. MBB's top 3 sector exposures are Other sectors, Government agencies and Other financial institutions. In contrast, SPMB's top sector exposures are Other sectors, Government agencies Both MBB and SPMB have the same Total Expense Ratio (TER) of 0.04%. MBB is up 0.66% year-to-date (YTD) with -$180M in YTD flows. SPMB performs better with 0.69% YTD performance, and +$268M in YTD flows. Run a side-by-side ETF comparison of MBB and SPMB below, and assess how they stack up in performance, liquidity, risk, exposure, holdings, and more, helping you select the best ETF for your investments.

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MBB vs SPMB performance and flow charts

Performance

Cumulative Flows

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Daily, global ETF data for advanced analysis or integration into apps (API), from our partner Trackinsight.

Data Services

Historic performance and flows

Data as of 04/02/2026

		1M	3M	YTD	1Y	3Y	5Y
Perf.	MBB SPMB	-1.01%-0.99%	+0.82%+0.85%	+0.66%+0.69%	+5.76%+5.78%	+12.51%+12.53%	+2.15%+1.84%
Flows	MBB SPMB	-$285M+$81M	-$180M+$268M	-$180M+$268M	+$1.33B+$857M	+$12.17B+$2.60B	+$14.73B+$3.92B

Volatility and drawdown

		3M	1Y	3Y	5Y
Volatility	MBB SPMB	+4.56%+4.58%	+4.70%+4.74%	+6.22%+6.33%	+6.46%+6.59%
Max drawdown	MBB SPMB	-2.55%-2.61%	-2.84%-2.86%	-8.73%-8.74%	-17.39%-17.60%
Max drawdown duration	MBB SPMB	32d32d	80d80d	252d252d	1535d1540d

Trading data

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	MBB	SPMB
Last sale 4/6/2026 at 1:30 PM	$94.66	$22.33
Previous close 04/02/2026	$94.86	$22.38
Consolidated volume 04/02/2026
Average volume 30 days
Average discount or premium 30 days
Average Bid/Ask spread 30 days

Replication quality

Data as of March 31, 2026

1-year trailing difference

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	MBB	SPMB
Tracking error
Tracking difference
1 year cumulative return difference
Best
Worst
Daily return difference
Average
Worst

Main metrics

Last update 4/6/2026 at 1:30 PM

Live

Closed

	MBB	SPMB
Last price	$94.66	$22.33
1D performance	-0.21%	-0.22%
AuM	$38.71 B	$6.90 B
E/R	0.04%	0.04%

Characteristics

	MBB	SPMB
Management strategy	Passive	Passive
Provider	iShares	SPDR
Benchmark	Bloomberg U.S. MBS Index	Bloomberg U.S. MBS Index
N° of holdings	1189	509
Asset class	Bonds	Bonds
Trailing 12m distribution yield	Join	Join
Inception date	March 13, 2007	January 15, 2009
ESG	No	No

More MBB data on Trackinsight

More SPMB data on Trackinsight

Exposure

Countries

MBB

USA

104.53%

Other

-4.53%

SPMB

USA

99.27%

Other

0.73%

Sectors

MBB

Other sectors

20.01%

Other

79.99%

SPMB

Other sectors

28.93%

Other

71.07%

Diversification

MBB

Total weight of top 15 holdings out of 15

14%

SPMB

Total weight of top 15 holdings out of 15

9.93%

Top 15 holdings

Data as of February 28, 2026

MBB

US0669225197

5.91%

FR SD8146, 2% 1may2051, USD (ABS)

1.07%

US21H0526374

1.01%

US01F0506356

0.57%

G2 MA7648, 2% 20oct2051, USD (ABS)

0.56%

US36179WTX64

0.55%

FN MA4492, 2% 1dec2051, USD (ABS)

0.53%

US21H0506319

0.53%

FR SD8140, 2% 1apr2051, USD (ABS)

0.51%

US01F0526313

0.50%

US36179WJR07

0.47%

US21H0606309

0.46%

FN MA4465, 2% 1nov2051, USD (ABS)

0.45%

US3140XLE460

0.45%

US3618N5A332

0.43%

SPMB

US01F0506356

1.28%

US3142J6BK85

0.94%

FN MA4547, 2% 1feb2052, USD (ABS)

0.85%

US01F0226344

0.75%

US3618N5PJ27

0.66%

US3132DWMY65

0.62%

US01F0206387

0.60%

US21H0506319

0.59%

US01F0326334

0.58%

US01F0526313

0.58%

FN MA4701, 4.5% 1aug2052, USD (ABS)

0.56%

US3132DWKV45

0.50%

FN FS2040, 2% 1feb2052, USD (ABS)

0.48%

FR SD8193, 2% 1feb2052, USD (ABS)

0.47%

US3132DWMB62

0.47%

Frequently asked questions about MBB and SPMB

How have the MBB and SPMB ETFs performed in 2026?

As of April 2, 2026, MBB is up 0.66% year-to-date (YTD), while SPMB has returned 0.69%. That puts SPMB better performer ahead so far this year.

Which ETF is attracting more investor money: MBB or SPMB?

Year-to-date, the MBB ETF saw -$180M in flows, compared to +$268M for SPMB.

Which ETF is more volatile: MBB or SPMB?

Over the past year, MBB had a volatility of 4.7%, while SPMB experienced 4.74%.

Which ETF is bigger: MBB or SPMB?

As of April 2, 2026, MBB holds $38.71 B in assets under management (AUM), while SPMB manages $6.90 B.

What sectors do the MBB and SPMB ETFs invest in?

MBB leans toward sectors like Other sectors. Meanwhile, SPMB focuses on Other sectors.

What are the top holdings of the MBB ETF and SPMB ETF?

MBB top holdings include US0669225197, FR SD8146, 2% 1may2051, USD (ABS) and US21H0526374. SPMB holds in its top three: US01F0506356, US3142J6BK85 and FN MA4547, 2% 1feb2052, USD (ABS).

Which ETF is more diversified: MBB or SPMB?

MBB holds 9368 securities with 14% of its assets in the top 15. SPMB has 2639 securities and a top 15 weight of 9.93%.

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MBB

MBBvsSPMBETF Comparison

iShares MBS ETF

State Street SPDR Portfolio Mortgage Backed Bond ETF

MBB vs SPMB performance and flow charts

Performance

Cumulative Flows

Get all the metrics on this page, and more, through a reliable ETF data feed

Countries

Sectors

Diversification

Top 15 holdings

How have the MBB and SPMB ETFs performed in 2026?

As of April 2, 2026, MBB is up 0.66% year-to-date (YTD), while SPMB has returned 0.69%. That puts SPMB better performer ahead so far this year.

Which ETF is attracting more investor money: MBB or SPMB?

Year-to-date, the MBB ETF saw -$180M in flows, compared to +$268M for SPMB.

Which ETF is more volatile: MBB or SPMB?

Over the past year, MBB had a volatility of 4.7%, while SPMB experienced 4.74%.

Which ETF is bigger: MBB or SPMB?

As of April 2, 2026, MBB holds $38.71 B in assets under management (AUM), while SPMB manages $6.90 B.

What sectors do the MBB and SPMB ETFs invest in?

MBB leans toward sectors like Other sectors. Meanwhile, SPMB focuses on Other sectors.

What are the top holdings of the MBB ETF and SPMB ETF?

MBB top holdings include US0669225197, FR SD8146, 2% 1may2051, USD (ABS) and US21H0526374. SPMB holds in its top three: US01F0506356, US3142J6BK85 and FN MA4547, 2% 1feb2052, USD (ABS).

Which ETF is more diversified: MBB or SPMB?

MBB holds 9368 securities with 14% of its assets in the top 15. SPMB has 2639 securities and a top 15 weight of 9.93%.

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