MBB iShares MBS ETF
Quote as of Oct 09, 2026 20:00 UTC · Market data delayed approximately 15–20 minutes unless otherwise indicated.
| Previous Close | 89.73 | Day Range | 89.40 – 89.79 |
| 52-Week Range | 88.58 – 96.97 | Volume | 3.82M |
| Avg Volume | 3.62M | AUM | $35.65B (Oct 10, 2026) |
| Expense Ratio | 0.04% | Yield (TTM) | 4.53% |
| NAV | 89.90 | Premium/Discount | -0.12% indicative |
| Inception | Mar 13, 2007 | Holdings | 10858 |
| Issuer | iShares | Exchange | NASDAQ |
| Category | Bonds | Index Tracked | Not stated in source data |
| CUSIP | 464288588 | ISIN | US4642885887 |
| Management | Not stated in source data | ||
About this ETF
The iShares MBS ETF, known by its symbol MBB, is structured to mirror the financial performance of a specific index. This index is made up of premium, mortgage-backed pass-through securities that have been either provided or secured by agencies of the United States government.
Description from the fund data provider · profile as of Oct 10, 2026.
Price Chart
Daily closing prices (price return, not total return). Comparison lines are normalized to percent change from the range start. Source: Financial Modeling Prep.
Performance
| 1M | 3M | 6M | YTD | 1Y | 3Y* | 5Y* | 10Y* | Incep.* | |
|---|---|---|---|---|---|---|---|---|---|
| Price return | -2.63% | -4.19% | -5.45% | -5.70% | -5.40% | +0.57% | -3.59% | -1.97% | -0.59% |
| Total return | -2.63% | -3.84% | -4.10% | -3.35% | -2.01% | +4.42% | -0.51% | +0.67% | +2.33% |
* Annualized. Total return uses the dividend-adjusted price series (distributions reinvested); price return uses unadjusted closes. Performance through Oct 09, 2026. Past performance does not guarantee future results.
Fees
| Net expense ratio | 0.04% | Annual cost of a $10,000 investment | $4.00 |
Illustrative calculation only: expense ratio × $10,000. It excludes trading costs, bid/ask spreads, taxes and changes in investment value. Gross vs. net expense details and any fee waivers are in the prospectus.
Holdings
Holdings as of Oct 10, 2026 · portfolio reporting date from the data provider; holdings are not live positions. 3000 rows in database.
| # | Holding | Ticker | Weight | Shares | Market Value |
|---|---|---|---|---|---|
| 1 | BLACKROCK CASH CL INST SL AGENCY | — | 4.69% | 0 | $1.67B |
| 2 | FHLMC 30YR UMBS SUPER 2.00% 05/01/2051 | — | 1.03% | 0 | $367.0M |
| 3 | GNMA2 30YR TBA(REG C) 6.00% 10/20/2026 | — | 0.68% | 0 | $241.0M |
| 4 | UMBS 30YR TBA(REG A) 5.50% 11/12/2026 | — | 0.59% | 0 | $211.3M |
| 5 | GNMA2 30YR 5.00% 11/20/2054 | — | 0.58% | 0 | $206.7M |
| 6 | GNMA2 30YR TBA(REG C) 5.50% 10/20/2026 | — | 0.57% | 0 | $203.2M |
| 7 | GNMA2 30YR 2.00% 10/20/2051 | — | 0.53% | 0 | $188.9M |
| 8 | GNMA2 30YR 2.00% 12/20/2051 | — | 0.52% | 0 | $185.6M |
| 9 | FNMA 30YR UMBS 2.00% 12/01/2051 | — | 0.52% | 0 | $183.7M |
| 10 | GNMA2 30YR 2.50% 07/20/2051 | — | 0.51% | 0 | $180.4M |
| 11 | FHLMC 30YR UMBS SUPER 2.00% 04/01/2051 | — | 0.49% | 0 | $176.2M |
| 12 | FNMA 30YR UMBS 2.00% 11/01/2051 | — | 0.44% | 0 | $155.9M |
| 13 | GNMA2 30YR 5.00% 04/20/2056 | — | 0.43% | 0 | $151.6M |
| 14 | GNMA2 30YR 5.50% 09/20/2053 | — | 0.40% | 0 | $141.8M |
| 15 | GNMA2 30YR 5.50% 09/20/2055 | — | 0.39% | 0 | $139.7M |
| 16 | GNMA2 30YR 2.50% 05/20/2051 | — | 0.35% | 0 | $123.5M |
| 17 | UMBS 30YR TBA(REG A) 5.00% 11/12/2026 | — | 0.35% | 0 | $123.4M |
| 18 | FNMA 30YR UMBS SUPER 2.00% 04/01/2052 | — | 0.32% | 0 | $115.0M |
| 19 | FNMA 30YR UMBS 2.00% 03/01/2051 | — | 0.32% | 0 | $114.6M |
| 20 | GNMA2 30YR 2.00% 01/20/2052 | — | 0.32% | 0 | $113.8M |
| 21 | GNMA2 30YR 5.00% 05/20/2056 | — | 0.31% | 0 | $111.8M |
| 22 | FNMA 30YR UMBS 2.00% 10/01/2051 | — | 0.31% | 0 | $110.0M |
| 23 | GNMA2 30YR 2.50% 08/20/2051 | — | 0.30% | 0 | $105.4M |
| 24 | FNMA 30YR UMBS 2.00% 04/01/2051 | — | 0.29% | 0 | $103.9M |
| 25 | FNMA 30YR UMBS 5.50% 09/01/2056 | — | 0.27% | 0 | $97.7M |
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Geographic Exposure
Country weights as reported by the data provider. Developed/emerging/frontier labels follow the classification on the Methodology page. Currency hedged: No hedging indicated in the fund name.
Distributions
| Yield (TTM) | 4.53% | Paid (last 12 months) | $4.0701 |
| Frequency | Monthly | SEC yield | Not provided by our data source; see the issuer page |
| Last ex-date | Oct 01, 2026 | Last payment | $0.3662 (Oct 06, 2026) |
| Growth 1Y | +4.53% | Growth 3Y / 5Y (ann.) | +10.30% / +21.73% |
| Ex-date | Record | Pay date | Amount |
|---|---|---|---|
| Oct 01, 2026 | Oct 01, 2026 | Oct 06, 2026 | $0.3662 |
| Sep 01, 2026 | Sep 01, 2026 | Sep 04, 2026 | $0.3388 |
| Aug 03, 2026 | Aug 03, 2026 | Aug 06, 2026 | $0.3413 |
| Jul 01, 2026 | Jul 01, 2026 | Jul 07, 2026 | $0.3373 |
| Jun 01, 2026 | Jun 01, 2026 | Jun 04, 2026 | $0.3334 |
| May 01, 2026 | May 01, 2026 | May 06, 2026 | $0.3347 |
| Apr 01, 2026 | Apr 01, 2026 | Apr 07, 2026 | $0.3330 |
| Mar 02, 2026 | Mar 02, 2026 | Mar 05, 2026 | $0.3278 |
| Feb 02, 2026 | Feb 02, 2026 | Feb 05, 2026 | $0.3347 |
| Dec 19, 2025 | Dec 19, 2025 | Dec 24, 2025 | $0.3341 |
| Dec 01, 2025 | Dec 01, 2025 | Dec 04, 2025 | $0.3469 |
| Nov 03, 2025 | Nov 03, 2025 | Nov 06, 2025 | $0.3420 |
Trailing distribution yield = last 12 months of cash ÷ current price. It is NOT the SEC 30-day yield and distributions are not guaranteed to continue. The difference explained →
Risk Statistics
| Volatility 1Y / 3Y | 4.78% / 5.96% | Sharpe 1Y / 3Y | -1.33 / 0.078 |
| Max drawdown 1Y / 3Y | -6.10% / -6.10% | Sortino 1Y | -1.75 |
| Beta vs S&P 500 (3Y) | 0.077 | Correlation vs S&P 500 (1Y) | 0.396 |
| Downside deviation 1Y | 3.62% | Risk-free rate used | 4.05% (3M T-bill, FRED) |
Computed by ETF Explorer from daily dividend-adjusted closes; volatility and drawdown are annualized/period figures; S&P 500 exposure proxied by SPY. As of Oct 11, 2026. Formulas →
Liquidity
| Volume today | 3.82M | Average volume | 3.62M |
| AUM | $35.65B | Premium/Discount | -0.12% |
| Bid/Ask spread | Not provided by our data source. Check your broker's quote screen; spreads are widest at the open and close. | ||
Premium/discount compares the delayed market price with the last reported NAV: an indicative figure, not the official closing premium/discount. How ETF liquidity works →
Fund Flows (estimated)
| Period | Est. net flow | % of starting AUM | AUM start → end |
|---|---|---|---|
| 1 Day | $244.5M | +0.69% | $35.41B → $35.65B |
| 1 Month | -$2.66B | -6.83% | $39.00B → $35.65B |
| 1 Week | -$1.13B | -3.09% | $36.55B → $35.65B |
ETF Explorer estimate: change in reported AUM minus the market-move effect, from our own daily snapshots. Not official issuer creation/redemption data.
Official Fund Resources
External links open the issuer's site or SEC EDGAR in a new tab. The prospectus and official documents are always the authoritative source; review them before investing.
Latest News for MBB
Guided help: AUM is fund size. The expense ratio is the yearly cost baked into returns. NAV is the value of what the fund owns per share; the market price can sit slightly above (premium) or below (discount) it. Total return assumes distributions were reinvested. Every dataset shows its own as-of date because holdings, assets and quotes update on different schedules.