iShares MBS ETF
$89.97+0.14 (+0.16%)
- 0.04%
- $35.6B
- −1.6%
- 4.53%
- 3.6M sh
- $89.80
- low $88.58high $96.97
The ETF.net MBB Grade
A
Score 70 out of 100
- 3 of 25
Score 70 of 100 falls in the A band. A is 70 or higher, B 55 to under 70, C 40 to under 55, D 25 to under 40, F under 25.
Cost
The fund’s net expense ratio, ranked against its category.A94 out of 100Rank 1 of 25Mission
Whether the fund did what it promised, tested against its stated mandate.C53 out of 100Rank 8 of 20Risk
How the fund held up when markets fell: downside volatility, drawdowns and tail loss.D31 out of 100Rank 21 of 25Tradability
How easy the fund is to trade: daily volume, and how far its price strays from net asset value.A84 out of 100Rank 2 of 25Holdings
How concentrated the fund is, and how complete and current its disclosed holdings are.A78 out of 100Rank 6 of 25Durability
Whether the fund is likely to stay open, judged by its age, its assets and its issuer’s assets.A92 out of 100Rank 1 of 25
Our read on MBB
ALaunched in 2007, MBB is the plain-vanilla way to own U.S. agency mortgage bonds: one of the biggest and busiest funds in a small niche, tracking the Bloomberg U.S. MBS Index for four basis points.
The fund seeks to track an index composed of U.S. agency mortgage-backed securities.
Why people hold it
- Four basis points to rent the entire agency mortgage market, against a category median near 0.35%. In low-coupon bond land, that gap compounds quietly.
- Scale is the real feature: one of the largest and most actively traded funds in the mortgage-bond category, which generally shows up as tighter spreads.
- Pays monthly, and the mandate stays narrow: an index of U.S. agency mortgage-backed securities, nothing exotic bolted on.
- Among the stronger builds in a thin peer group of mortgage-bond ETFs, on the combination of cost, trading friction and issuer staying power.
Worth knowing
- This is one slice of the bond market. Agency mortgage paper only, with no Treasuries or corporates alongside it.
- Mortgage bonds cut both ways with rates: borrowers refinance when yields fall and sit tight when they rise, so the portfolio's duration shifts underneath you.
- On price it's a photo finish: SPMB tracks the same index at the same 0.04%, and VMBS runs a basis point cheaper.
MBB Holdings
- Bonds
- 10,844
- 10%
- BlackRock Cash Class Inst Sl Agency
Geography
- United States100.00%
MBB Performance
Shows how $10,000 changes over the selected period, with cash distributions reinvested at the closing price on each ex-dividend date.
MBB$9,844
Returns run to the Oct 12, 2026 close, with cash distributions reinvested. Each period starts on the same date that many months or years earlier. Periods over one year show the average yearly return.
| Period | MBB |
|---|---|
| Year to date | −2.5% |
| 1 month | −1.3% |
| 3 months | −3.1% |
| 1 year | −1.6% |
| 3 years | +5.1% |
| 5 years | −0.2% |
| 10 years | +0.9% |
Calendar-year total return with cash distributions hypothetically reinvested at the ex-dividend date’s closing price. The current year shows year to date.
| Year | Return bar | MBB |
|---|---|---|
| 2026 YTD | −2.5% | |
| 2025 | +8.4% | |
| 2024 | +1.3% | |
| 2023 | +5.0% | |
| 2022 | −11.7% | |
| 2021 | −1.6% | |
| 2020 | +4.1% |
MBB in the news
MBB Dividends
- 4.53%
- $4.07
- $0.37 per share
- Monthly
Distribution history
MBB Risk
- 6.4%
How it’s calculated: standard deviation
The sample standard deviation of monthly total returns, multiplied by the square root of 12.
Uses up to 36 complete months, with at least 12 required. Total returns include reinvested distributions.
- 0.01
How it’s calculated: Sharpe ratio
Subtract each month’s Treasury-bill return from the fund’s monthly total return.
Divide the average of those excess returns by their sample standard deviation, then multiply by the square root of 12.
Uses up to 36 complete months, with at least 12 required. Each month uses the Treasury yield quoted at the end of the previous month.
- −16.8%
How it’s calculated: maximum drawdown
The largest percentage decline from an earlier peak, using total returns with reinvested distributions.
Uses up to five years through the last close, with at least 12 months required.
- 1.14
How it’s calculated: beta
The beta figure is supplied by FMP. The comparison index depends on the fund’s broad asset class.
MBB Cost
0.04%
MBB0.04%
- The middle half of Mortgage-Backed Securities funds
- Median 0.36%
2 of the 24 Mortgage-Backed Securities funds charge less.
Other funds in Mortgage-Backed Securities
- BSMBSSchwab Strategic Trust - Schwab Mortgage-Backed Securities ETFExpense ratio 0.03%1 year return −1.6%
- ASPMBState Street SPDR Portfolio Mortgage Backed Bond ETFExpense ratio 0.04%1 year return −1.9%
- BVMBSVanguard Mortgage-Backed Securities ETFExpense ratio 0.03%1 year return −1.2%
- BJMTGJPMorgan Mortgage-Backed Securities ETFExpense ratio 0.37%1 year return −1.2%
- BMBSDNorthern Trust Disciplined Duration MBS ETFExpense ratio 0.21%1 year return −0.7%