ETF comparison
IWMvsIWO
Both US Small Cap.
Holdings overlap
1,131 positions appear in both funds. Buying equal dollars of IWM and IWO would leave roughly71.7%of each dollar exposed to the same underlying securities.
Side by side
Sub-score comparison
Tracking quality isn't part of the composite — seewhat we don't scorefor 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 thecost calculator pre-filled with IWM vs IWO.
Top shared holdings
1,131 shared in total| # | Holding | In IWM | In IWO | Overlap |
|---|---|---|---|---|
| 1 | BlackRock Funds III | 17.02% | 14.75% | 14.75% |
| 2 | Moog, Inc. | 0.38% | 0.73% | 0.38% |
| 3 | Hut 8 Corp. | 0.37% | 0.38% | 0.37% |
| 4 | BrightSpring Health Services, Inc. | 0.35% | 0.68% | 0.35% |
| 5 | MaxLinear, Inc. | 0.34% | 0.66% | 0.34% |
| 6 | Argan, Inc. | 0.34% | 0.66% | 0.34% |
| 7 | JFrog Ltd. | 0.31% | 0.59% | 0.31% |
| 8 | Riot Platforms, Inc. | 0.30% | 0.39% | 0.30% |
| 9 | Krystal Biotech, Inc. | 0.30% | 0.58% | 0.30% |
| 10 | ESCO Technologies, Inc. | 0.29% | 0.56% | 0.29% |
| 11 | FirstCash Holdings, Inc. | 0.28% | 0.53% | 0.28% |
| 12 | Compass, Inc. | 0.27% | 0.45% | 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
4 total- BlackRock Funds III0.01%
- Shimmick Corp.0.01%
- WeShop Holdings Ltd.0.00%
- LanzaTech Global, Inc.0.00%
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 methodologyand 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.