Data as of Oct 28, 2026.
IWM vs IWO: Differences, Returns & Fees
Over the year to Oct 28, 2026, IWM returned +14.1% to IWO's +7.9%; 55% of their weight is in the same names.
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Net assets on Oct 27, 2026: $75.5bn for iShares Russell 2000 ETF and $14.0bn for iShares Russell 2000 Growth ETF.
Pair scorecard
IWM costs 0.05 points a year less; their one-year returns differ by 6.2 points; IWM is 5.4 times larger.
| Measure | IWM | IWO |
|---|---|---|
| Return | ||
| Total return, 1 year | +14.1% | +7.9% |
| Drawdown | ||
| Below its high | 7.6%, high on Aug 14, 2026 | 9.9%, high on Aug 14, 2026 |
| Benchmark | ||
| What it tracks | Russell 2000 Index | Russell 2000 Growth Index |
| Cost and size | ||
| Expense ratio | 0.19% | 0.24% |
| Net assets, as of Oct 27, 2026 | $75.5bn | $14.0bn |
| Holdings | ||
| Holdings in common | 55% | |
| Top ten holdings, share of the fund | 3.3% | 6.4% |
Holdings in common uses holdings dated Oct 27, 2026. Method
Risk and return
Aug 4, 2000 to Oct 23, 2026 · 1,368 weekly returnsEach against its own benchmark: IWM against VTWO, Oct 1, 2010 to Oct 23, 2026; IWO against VTWG, Oct 1, 2010 to Oct 23, 2026.
IWM returned more: +671.2% to +433.5%. IWM swung slightly less: 22.3% to 23.8%. IWM and IWO fell about the same at their worst: −57.7% and −58.2%.
Full scorecard
19 measures, with how each is measured Open ↓
| Measure | IWM | IWO | Edge | How it is measured |
|---|---|---|---|---|
| Return | ||||
| Total return | +671.2% | +433.5% | IWM | Price change plus distributions, reinvested. |
| Annualized | +8.1% | +6.6% | IWM | Total return as a yearly rate. |
| Price return | +449.3% | +350.2% | IWM | Price change alone, distributions left out. |
| Risk | ||||
| Volatility | 22.3% | 23.8% | IWM (slight) | Spread of weekly returns, annualized. Lower is steadier. |
| Downside deviation | 15.7% | 16.9% | IWM (slight) | Like volatility, counting only weeks below the Treasury bill rate. |
| Max drawdown | −57.7% | −58.2% | Tie | Deepest fall from a high to the low after it. |
| Upside capture | 101.0% | 100.2% | Share of its benchmark's rise caught in the weeks it rose. | |
| Downside capture | 100.5% | 100.1% | Share of its benchmark's fall taken in the weeks it fell. Lower is better. | |
| Beta | 1.01 | 1.00 | Not an edge | How far it moves for each 1% its benchmark moves. |
| R squared | 1.00 | 1.00 | Not an edge | Share of its weekly moves its benchmark explains. |
| Risk-adjusted | ||||
| Sharpe | 0.38 | 0.31 | IWM | Return above Treasury bills per unit of volatility. |
| Sortino | 0.54 | 0.44 | IWM | Return above Treasury bills per unit of downside deviation. |
| Treynor | 0.106 | 0.111 | Return above Treasury bills per unit of beta. | |
| Calmar | 0.14 | 0.11 | IWM | Annualized return divided by the max drawdown. |
| Against the benchmark | ||||
| Benchmark | VTWO | VTWG | The ETF each fund is measured against. | |
| Alpha | −0.1% a year | 0.0% a year | Not significant | Yearly return beyond what its beta to the benchmark predicts. |
| Alpha t-stat | −0.36 | 0.06 | Not an edge | How sure the alpha is. Below 2, it could be chance. |
| Alpha range | −0.6% to +0.4% | −0.7% to +0.7% | Includes zero | The 95% range for the yearly alpha. |
| Information ratio | −0.02 | 0.01 | Return against its benchmark per unit of tracking error. | |
| Tracking error | 1.0% | 1.5% | Not an edge | How far weekly returns stray from the benchmark, annualized. |
Computed by ETFIQ from Tiingo daily prices and ETFIQ's distribution records, 1,368 weekly returns. Cash rate: the 13-week Treasury bill.
What they share
By the books each fund has filed, IWM and IWO hold 55% of their money in the same securities at the same weight. Holdings dated Oct 27, 2026.
half
55% in common
Only in one fund ↓
Side by side
IWM and IWO on the fields both publish, as of Oct 28, 2026. Source: ETFIQ.
IWM and IWO do different jobs. What does each one do in a portfolio?
- What each follows. IWM follows Russell 2000 Index and IWO follows Russell 2000 Growth Index.
- One-year total return. Over 1 year to Oct 28, 2026 IWM returned +14.1% and IWO +7.9% with distributions reinvested, a gap of 6.2 points.
- Size. IWM has $75.5bn in net assets and IWO $14.0bn (net assets, as of Oct 27, 2026); IWM is 5.4 times larger.
Data as of Oct 28, 2026.
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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.
IWO
IWO tracks the Russell 2000 Growth. Over the year to Oct 28, 2026 it returned +7.9% with distributions reinvested, against +8.0% for its benchmark, the Russell 2000 Growth Index. The prospectus expense ratio is 0.24% 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 1,122 positions, with the top ten at 6.4%. It sat 9.9% below its high of Aug 14, 2026 on Oct 28, 2026.
Questions people ask
- Which returned more over the last year, IWM or IWO?
- In the year to Oct 28, 2026, with distributions reinvested, IWM returned +14.1% and IWO +7.9%.
- Which is cheaper, IWM or IWO?
- IWM is cheaper, by 0.05 percentage points a year. That is about $5 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, IWM against IWO, data as of Oct 28, 2026. https://etfiq.com/compare/any/iwm-vs-iwo
ETFIQ. (Oct 28, 2026). IWM against IWO. Retrieved from https://etfiq.com/compare/any/iwm-vs-iwo
[IWM against IWO (ETFIQ, Oct 28, 2026)](https://etfiq.com/compare/any/iwm-vs-iwo)
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