iSharesGovernment Mortgage-Backed BondMBB · Nasdaq

iShares MBS ETF (MBB)

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Price: $91.38; —11 Sept 2026
Assets: $39.6B; Total net assets
Expense ratio: 0.04%; Category 0.82%
Yield: 4.34%; Trailing distributions

1Y return: -0.1%-0.6%; Category 0.5%
3Y CAGR: 4.4%0.0%; Category 4.4%
5Y CAGR: -0.1%-0.2%; Category 0.1%

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iShares MBS ETF

Calendar-year returns

Fund only: no comparison series covers this fund's history.

Risk statistics

Five years of daily closes. Risk-free rate 4% a year.

Standard deviation: —
Maximum drawdown: —
Sharpe ratio: —
Sortino ratio: —
Beta: —
Alpha: —
R²: —
Information ratio: —
Upside capture: —
Downside capture: —
Tracking error: —

Trailing returns compared with benchmark
Period	1M	3M	6M	YTD	1Y	3YCAGR	5YCAGR	10YCAGR	LaunchCAGR
ETF	-1.6%	-2.1%	-1.6%	-1.3%	-0.1%	+4.4%	-0.1%	+1.0%	+2.5%
Government Mortgage-Backed Bond average	-1.4%	-1.8%	-1.3%	-0.8%	0.5%	4.4%	0.1%	1.1%	2.1%
Difference	-0.2%	-0.3%	-0.3%	-0.4%	-0.6%	0.0%	-0.2%	0.0%	+0.5%

Holdings

The 1 largest positions make up 7.6% of the fund.

Top holdings

Largest holdings by weight
Ticker	Holding	Weight
BISXX	BlackRock Cash Funds Instl SL Agency	7.60%

Credit quality

Share of the bonds by rating.

AA100.0%

Asset mix

Bonds92.7%
Cash7.3%

ETF details

Issuer: iShares
Category: Fixed Income · Government Mortgage-Backed Bond
Ticker: MBB
Exchange: Nasdaq
Inception: 13 Mar 2007 (19.5 years)
Structure: Exchange Traded Fund
Expense ratio: 0.04% (category 0.82%)
Holdings turnover: 153% (category 321%)
Distribution yield: 4.34%
Beta, 3 years: 1.14
Total net assets: $39.6B
Average duration: 3.74 years
Average maturity: 9.08 years

Prices and returns as of 11 Sept 2026; total return with distributions reinvested, before brokerage and taxes. Not investment advice.

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