GNMA vs MBB
iShares GNMA Bond ETF against iShares MBS ETF: cost, size, returns, what they hold and how much of it is the same.
Overlap by weight
16%
301 shared positions
Fee gap
6 bp
MBB is cheaper
1-year return gap
0.2 pts
MBB is ahead
Larger fund
MBB
$35.2B
Side by side
| GNMA | MBB | |
|---|---|---|
| Fund | iShares GNMA Bond ETF | iShares MBS ETF |
| Issuer | iShares | iShares |
| Category | Mortgage & Securitized | Mortgage & Securitized |
| Expense ratio | 0.10% | 0.04% |
| Assets | $416M | $35.2B |
| Average daily dollar volume | $2.6M | $690M |
| Listed | Feb 14, 2012 | Mar 13, 2007 |
| FrenzyCap score | 72 | 98 |
| 1-month return | −1.0% | −1.0% |
| 3-month return | −2.8% | −2.5% |
| Year to date | −5.1% | −4.9% |
| 1-year return | −5.8% | −5.7% |
| 30-day volatility | 6.8% | 6.7% |
| Worst drawdown, 1 year | −8.2% | −8.1% |
| Trailing 12-month yield | 4.45% | 4.50% |
| Holdings | 358 | 10,818 |
| Top 10 weight | 19.3% | 6.0% |
| Look-through P/E | — | — |
| Holdings vs fair value | — | — |
| Holdings above 200-day average | — | — |
| Net flow, latest 3 reported months | +$18M thru Jul 2026 | −$179M thru May 2026 |
| 30-day implied volatility | — | 7.8% |
| Holdings as of | as of Oct 20, 2026issuer data | as of Oct 20, 2026issuer data |
Returns are price returns and exclude distributions. Flows are each fund's own latest reported months and may not cover the same period.
Largest shared holdings
85% of GNMA · 17% of MBB| Holding | GNMA | MBB |
|---|---|---|
| GNMA2 30YR TBA, due Nov 19, 2026 | 1.05% | 0.62% |
| GNMA2 30YR, due Nov 20, 2054 | 1.67% | 0.59% |
| GNMA2 30YR, due Oct 20, 2051 | 0.62% | 0.54% |
| GNMA2 30YR, due Dec 20, 2051 | 1.93% | 0.53% |
| GNMA2 30YR TBA(REG C), due Nov 19, 2026 | 1.03% | 0.53% |
| GNMA2 30YR, due Jul 20, 2051 | 1.64% | 0.52% |
| GNMA2 30YR, due Apr 20, 2056 | 0.83% | 0.43% |
| GNMA2 30YR, due Sep 20, 2053 | 0.54% | 0.41% |
| GNMA2 30YR, due Sep 20, 2055 | 1.08% | 0.40% |
| GNMA2 30YR, due May 20, 2051 | 1.41% | 0.35% |
| GNMA2 30YR, due Jan 20, 2052 | 1.30% | 0.33% |
| GNMA2 30YR, due May 20, 2056 | 0.70% | 0.32% |
| GNMA2 30YR, due Aug 20, 2051 | 1.42% | 0.30% |
| GNMA2 30YR TBA(REG C), due Nov 19, 2026 | 0.73% | 0.28% |
| GNMA2 30YR, due Dec 20, 2051 | 0.61% | 0.28% |
| GNMA2 30YR, due Jul 20, 2054 | 0.70% | 0.26% |
| GNMA2 30YR, due Dec 20, 2054 | 0.93% | 0.25% |
| GNMA2 30YR, due Apr 20, 2052 | 1.25% | 0.23% |
| GNMA2 30YR, due Sep 20, 2051 | 1.05% | 0.22% |
| GNMA2 30YR, due Dec 20, 2050 | 0.20% | 0.28% |
| GNMA2 30YR, due Aug 20, 2054 | 0.89% | 0.18% |
| GNMA2 30YR TBA(REG C), due Nov 19, 2026 | 0.17% | 0.22% |
| GNMA2 30YR, due Feb 20, 2051 | 2.63% | 0.16% |
| GNMA II 30YR, due Jul 20, 2053 | 0.78% | 0.16% |
| GNMA2 30YR, due Jan 20, 2051 | 0.48% | 0.15% |
Sector mix of the stock holdings
No sector breakdown: these funds hold few classified stocks.
More: full overlap table · GNMA holdings · MBB holdings
Fund data comes from each fund's SEC filings and issuer disclosures and is shown with the date it is as of. SEC portfolio and flow filings become public about 60 days after the period they cover. Nothing here is investment advice; see Terms.