ETF comparison
IWM vs IWO
Both US Small Cap.
Holdings overlap
1,130 positions appear in both funds. Buying equal dollars of IWM and IWO would leave roughly 56.9% of each dollar exposed to the same underlying securities.
Unmatched is the part of a fund's weight the other fund doesn't match: names only it holds, plus any extra weight it puts in names both funds hold.
Side by side
Sub-score comparison
Tracking quality isn't part of the composite — see what we don't score for why.
Cost difference
IWM is 5 bps cheaper than IWO. On a $100,000 position that's about $50/yr more in fees for IWO.
Fee figure is the annual expense charged on $100,000. To see how the gap compounds over a multi-decade holding period, open the cost calculator pre-filled with IWM vs IWO.
Top shared holdings
1,130 shared in total| # | Holding | In IWM | In IWO | Overlap |
|---|---|---|---|---|
| 1 | Moog, Inc. | 0.38% | 0.73% | 0.38% |
| 2 | Hut 8 Corp. | 0.37% | 0.38% | 0.37% |
| 3 | BrightSpring Health Services, Inc. | 0.35% | 0.68% | 0.35% |
| 4 | MaxLinear, Inc. | 0.34% | 0.66% | 0.34% |
| 5 | Argan, Inc. | 0.34% | 0.66% | 0.34% |
| 6 | JFrog Ltd. | 0.31% | 0.59% | 0.31% |
| 7 | Riot Platforms, Inc. | 0.30% | 0.39% | 0.30% |
| 8 | Krystal Biotech, Inc. | 0.30% | 0.58% | 0.30% |
| 9 | ESCO Technologies, Inc. | 0.29% | 0.56% | 0.29% |
| 10 | FirstCash Holdings, Inc. | 0.28% | 0.53% | 0.28% |
| 11 | Compass, Inc. | 0.27% | 0.45% | 0.27% |
| 12 | D-Wave Quantum, Inc. | 0.27% | 0.53% | 0.27% |
Only in IWM
884 total- Viasat, Inc. 0.35%
- CareTrust REIT, Inc. 0.28%
- Terex Corp. 0.26%
- JBT Marel Corp. 0.24%
- Lumen Technologies, Inc. 0.23%
- Macerich Co. (The) 0.22%
- Terreno Realty Corp. 0.21%
- Taylor Morrison Home Corp. 0.21%
- Vishay Intertechnology, Inc. 0.21%
- Essential Properties Realty Trust, Inc. 0.20%
Only in IWO
3 total- Shimmick Corp. 0.01%
- WeShop Holdings Ltd. 0.00%
- LanzaTech Global, Inc. 0.00%
Related comparisons
More comparisons with IWM
- IWM vs SCHA · Schwab U.S. Small-Cap ETF 56.1%
- IWM vs IWN · iShares Russell 2000 Value ETF 53.6%
- IWM vs DFAS · U.S. Small Cap Portfolio-ETF Class Shares 50.7%
- IWM vs SPSM · State Street SPDR Portfolio S&P 600 Small Cap ETF 47.1%
- IWM vs IJR · iShares Core S&P Small-Cap ETF 46.8%
- IWM vs VIOO · Vanguard S&P Small-Cap 600 Index Fund ETF Shares 46.0%
More comparisons with IWO
- IWO vs VTWO · Vanguard Russell 2000 Index Fund ETF Shares 45.4%
- IWO vs BBSC · JPMorgan BetaBuilders U.S. Small Cap Equity ETF 44.7%
- IWO vs SPSM · State Street SPDR Portfolio S&P 600 Small Cap ETF 40.6%
- IWO vs IJR · iShares Core S&P Small-Cap ETF 40.1%
- IWO vs VIOO · Vanguard S&P Small-Cap 600 Index Fund ETF Shares 37.7%
- IWO vs IJT · iShares S&P Small-Cap 600 Growth ETF 37.2%
Percentages are holdings overlap with the named fund.
Open IWM or IWO at a brokerage
Both funds trade commission-free at major US brokerages.
Affiliate links — opening an account through these earns PlainIndex a one-time referral. Scoring is computed before any affiliate consideration; see our methodology and funding disclosure.
Holdings overlap is the sum of min(weight_a, weight_b) over positions
matched on ISIN (CUSIP fallback). Methodology: see
/methodology/.
Comparing two funds doesn't endorse swapping one for the other. Tax-lot history, account type, and personal goals matter — PlainIndex publishes data and methodology, not investment advice.