Data as of Oct 28, 2026.
IGSB vs MBB: Differences, Returns & Fees
On Aug 31, 2026 IGSB's duration was 2.7 years and MBB's 5.7; both charge 0.04%.
askIQ about this page
askIQ about IGSB and MBB
Net assets on Oct 28, 2026: $23.7bn for iShares 1-5 Year Investment Grade Corporate Bond ETF and $35.5bn for iShares MBS ETF.
Pair scorecard
Both cost 0.04% a year; their one-year returns differ by 2.1 points; MBB is 1.5 times larger.
Points (pts) are percentage points.
| Measure | IGSB | MBB |
|---|---|---|
| Return | ||
| Total return, 1 year | +1.3% | −0.8% |
| Benchmark | ||
| What it tracks | ICE BofA 1-5 Year US Corporate Index | Bloomberg U.S. MBS Index |
| Cost and size | ||
| Expense ratio | 0.04% | 0.04% |
| Net assets | $23.7bn | $35.5bn |
| Holdings | ||
| Holdings in common | 0% | |
Holdings in common uses holdings dated Aug 31, 2026. Method
Risk and return
Mar 23, 2007 to Oct 23, 2026 · 1,022 weekly returnsIGSB returned slightly more: +69.6% to +63.4%. MBB swung slightly less: 4.2% to 4.3%. IGSB fell less at its worst: −11.6% to −17.4%.
Full scorecard
9 measures, with how each is measured Open ↓
| Measure | IGSB | MBB | Edge | How it is measured |
|---|---|---|---|---|
| Return | ||||
| Total return | +69.6% | +63.4% | IGSB (slight) | Price change plus distributions, reinvested. |
| Annualized | +2.7% | +2.5% | IGSB (slight) | Total return as a yearly rate. |
| Price return | +2.0% | −9.6% | IGSB | Price change alone, distributions left out. |
| Risk | ||||
| Volatility | 4.3% | 4.2% | MBB (slight) | Spread of weekly returns, annualized. Lower is steadier. |
| Downside deviation | 3.3% | 2.9% | MBB | Like volatility, counting only weeks below the Treasury bill rate. |
| Max drawdown | −11.6% | −17.4% | IGSB | Deepest fall from a high to the low after it. |
| Risk-adjusted | ||||
| Sharpe | 0.28 | 0.24 | IGSB | Return above Treasury bills per unit of volatility. |
| Sortino | 0.37 | 0.35 | IGSB (slight) | Return above Treasury bills per unit of downside deviation. |
| Calmar | 0.24 | 0.15 | IGSB | Annualized return divided by the max drawdown. |
Computed by ETFIQ from Tiingo daily prices and ETFIQ's distribution records, 1,022 weekly returns. Cash rate: the 13-week Treasury bill.
What they share
By the books each fund has filed, IGSB and MBB hold 0% of their money in the same securities at the same weight. Holdings dated Aug 31, 2026.
half
0% in common
Only in one fund ↓
Side by side
IGSB and MBB on the fields both publish, as of Oct 28, 2026. Source: ETFIQ.
IGSB and MBB do different jobs. What does each one do in a portfolio?
- What each follows. IGSB follows ICE BofA 1-5 Year US Corporate Index and MBB follows Bloomberg U.S. MBS Index.
- Holdings in common. 0% of the weight is in the same securities (holdings dated Aug 31, 2026).
- One-year total return. Over 1 year to Oct 28, 2026 IGSB returned +1.3% and MBB −0.8% with distributions reinvested, a gap of 2.1 points.
Data as of Oct 28, 2026.
The two-page PDF for this pair is coming. Save the comparison to follow its changes. Free. It needs an email sign-in, once.
IGSB
IGSB tracks an index of 1-5 Year Investment Grade Corporate Bond. Over the year to Oct 28, 2026 it returned +1.3% with distributions reinvested. The prospectus expense ratio is 0.04% a year.
MBB
MBB tracks an index of mortgage-backed securities. Over the year to Oct 28, 2026 it returned −0.8% with distributions reinvested, against −1.1% for its benchmark, the Bloomberg U.S. MBS Index.
Questions people ask
Links are sources, not endorsements. A comparison is not a recommendation.
How this is computed
Overlap adds up the smaller of the two weights for each security both funds hold.
Cite this pageCitation, APA and Markdown
ETFIQ, IGSB against MBB, data as of Oct 28, 2026. https://etfiq.com/compare/any/igsb-vs-mbb
ETFIQ. (Oct 28, 2026). IGSB against MBB. Retrieved from https://etfiq.com/compare/any/igsb-vs-mbb
[IGSB against MBB (ETFIQ, Oct 28, 2026)](https://etfiq.com/compare/any/igsb-vs-mbb)
Free to use with attribution for data ETFIQ computes; issuer data stays under its owner's terms.