Data as of Oct 28, 2026.
IBB vs IWM: Differences, Returns & Fees
Over the year to Oct 28, 2026, IBB returned +37.5% to IWM's +14.1%, and IWM charges 0.19% to IBB's 0.44%.
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Net assets on Oct 27, 2026: $11.0bn for iShares Biotechnology ETF and $75.5bn for iShares Russell 2000 ETF.
Pair scorecard
IWM costs 0.25 points a year less; their one-year returns differ by 23.4 points; IWM is 6.9 times larger.
| Measure | IBB | IWM |
|---|---|---|
| Return | ||
| Total return, 1 year | +37.5% | +14.1% |
| Drawdown | ||
| Below its high | 7.6%, high on Aug 14, 2026 | |
| Benchmark | ||
| What it tracks | Biotech | Russell 2000 Index |
| Cost and size | ||
| Expense ratio | 0.44% | 0.19% |
| Net assets, as of Oct 27, 2026 | $11.0bn | $75.5bn |
| Active share vs the S&P 500 | 99% | |
| Holdings | ||
| Holdings in common | 10% | |
| Top ten holdings, share of the fund | 50% | 3.3% |
Holdings in common uses holdings dated Oct 27, 2026. Method
Risk and return
Feb 23, 2001 to Oct 23, 2026 · 1,339 weekly returnsIWM returned more: +706.8% to +586.4%. IWM swung slightly less: 22.4% to 24.3%. IWM fell slightly less at its worst: −57.7% to −59.2%.
Full scorecard
9 measures, with how each is measured Open ↓
| Measure | IBB | IWM | Edge | How it is measured |
|---|---|---|---|---|
| Return | ||||
| Total return | +586.4% | +706.8% | IWM | Price change plus distributions, reinvested. |
| Annualized | +7.8% | +8.4% | IWM (slight) | Total return as a yearly rate. |
| Price return | +557.1% | +479.3% | IBB | Price change alone, distributions left out. |
| Risk | ||||
| Volatility | 24.3% | 22.4% | IWM (slight) | Spread of weekly returns, annualized. Lower is steadier. |
| Downside deviation | 17.2% | 15.7% | IWM (slight) | Like volatility, counting only weeks below the Treasury bill rate. |
| Max drawdown | −59.2% | −57.7% | IWM (slight) | Deepest fall from a high to the low after it. |
| Risk-adjusted | ||||
| Sharpe | 0.36 | 0.40 | IWM (slight) | Return above Treasury bills per unit of volatility. |
| Sortino | 0.50 | 0.56 | IWM | Return above Treasury bills per unit of downside deviation. |
| Calmar | 0.13 | 0.15 | IWM | Annualized return divided by the max drawdown. |
Computed by ETFIQ from Tiingo daily prices and ETFIQ's distribution records, 1,339 weekly returns. Cash rate: the 13-week Treasury bill.
What they share
By the books each fund has filed, IBB and IWM hold 10% of their money in the same securities at the same weight. Holdings dated Oct 27, 2026.
half
10% in common
Only in one fund ↓
Side by side
IBB and IWM on the fields both publish, as of Oct 28, 2026. Source: ETFIQ.
IBB and IWM do different jobs. What does each one do in a portfolio?
- What each follows. IBB follows Biotech and IWM follows Russell 2000 Index.
- Holdings in common. 10% of the weight is in the same securities (holdings dated Oct 27, 2026).
- One-year total return. Over 1 year to Oct 28, 2026 IBB returned +37.5% and IWM +14.1% with distributions reinvested, a gap of 23.4 points.
Data as of Oct 28, 2026.
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IBB
By weight, 40% of IBB's portfolio is stocks that are also in the S&P 500; its active share against the S&P 500 is 99%. The top ten holdings are 50% of the fund across 245 positions, as published by its issuer for Oct 27, 2026. Over the year to Oct 28, 2026 the fund returned +37.5% with distributions reinvested.
IWM
IWM tracks the Russell 2000. Over the year to Oct 28, 2026 it returned +14.1% with distributions reinvested, against +14.3% for its benchmark, the Russell 2000 Index. The prospectus expense ratio is 0.19% a year. By its holdings published by its issuer for Oct 27, 2026, 0% of the fund by weight is stocks the S&P 500 also holds, across 1,977 positions, with the top ten at 3.3%. It sat 7.6% below its high of Aug 14, 2026 on Oct 28, 2026.
Questions people ask
- Are IBB and IWM in the same category?
- IBB is a thematic ETF and IWM is a stock ETF, so they do different jobs. The table compares what both publish: return, cost and holdings.
- Which returned more over the last year, IBB or IWM?
- In the year to Oct 28, 2026, with distributions reinvested, IBB returned +37.5% and IWM +14.1%.
- Which is cheaper, IBB or IWM?
- IWM is cheaper, by 0.25 percentage points a year. That is about $25 on $10,000 held for a year. Fees come from each fund's prospectus.
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.
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ETFIQ, IBB against IWM, data as of Oct 28, 2026. https://etfiq.com/compare/any/ibb-vs-iwm
ETFIQ. (Oct 28, 2026). IBB against IWM. Retrieved from https://etfiq.com/compare/any/ibb-vs-iwm
[IBB against IWM (ETFIQ, Oct 28, 2026)](https://etfiq.com/compare/any/ibb-vs-iwm)
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