ETF comparison
IWM vs VIOO
Both US Small Cap.
iShares Russell 2000 ETF · Vanguard S&P Small-Cap 600 Index Fund ETF Shares
Holdings overlap
543 positions appear in both funds. Buying equal dollars of IWM and VIOO would leave roughly 46.0% 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
VIOO is 12 bps cheaper than IWM. On a $100,000 position that's about $120/yr more in fees for IWM.
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 VIOO.
Top shared holdings
543 shared in total| # | Holding | In IWM | In VIOO | Overlap |
|---|---|---|---|---|
| 1 | Viasat, Inc. | 0.35% | 0.64% | 0.35% |
| 2 | BrightSpring Health Services, Inc. | 0.35% | 0.48% | 0.35% |
| 3 | MaxLinear, Inc. | 0.34% | 0.44% | 0.34% |
| 4 | Argan, Inc. | 0.34% | 0.54% | 0.34% |
| 5 | Krystal Biotech, Inc. | 0.30% | 0.47% | 0.30% |
| 6 | ESCO Technologies, Inc. | 0.29% | 0.44% | 0.29% |
| 7 | Alkermes plc | 0.27% | 0.35% | 0.27% |
| 8 | StoneX Group, Inc. | 0.27% | 0.47% | 0.27% |
| 9 | Plexus Corp. | 0.25% | 0.42% | 0.25% |
| 10 | Enpro, Inc. | 0.25% | 0.38% | 0.25% |
| 11 | Ryman Hospitality Properties, Inc. | 0.25% | 0.43% | 0.25% |
| 12 | Glaukos Corp. | 0.25% | 0.35% | 0.25% |
Only in IWM
1,471 total- Moog, Inc. 0.38%
- Hut 8 Corp. 0.37%
- Cytokinetics, Inc. 0.35%
- UMB Financial Corp. 0.33%
- JFrog Ltd. 0.31%
- Riot Platforms, Inc. 0.30%
- CareTrust REIT, Inc. 0.28%
- Old National Bancorp 0.28%
- FirstCash Holdings, Inc. 0.28%
- Compass, Inc. 0.27%
Only in VIOO
60 total- Sanmina Corp 0.83%
- Semtech Corp 0.83%
- Viavi Solutions Inc 0.66%
- FormFactor Inc 0.57%
- Element Solutions Inc 0.57%
- Enphase Energy Inc 0.53%
- Molina Healthcare Inc 0.53%
- Qorvo Inc 0.51%
- Eastman Chemical Co 0.51%
- Match Group Inc 0.50%
Related comparisons
More comparisons with IWM
- IWM vs FNDA · Schwab Fundamental U.S. Small Company ETF 38.1%
- IWM vs DFAT · U.S. Targeted Value Portfolio-ETF Class Shares 33.7%
- IWM vs IJS · iShares S&P Small-Cap 600 Value ETF 31.8%
- IWM vs VIOV · Vanguard S&P Small-Cap 600 Value Index Fund ETF Shares 31.2%
- IWM vs VIOG · Vanguard S&P Small-Cap 600 Growth Index Fund ETF Shares 30.7%
- IWM vs IJT · iShares S&P Small-Cap 600 Growth ETF 30.1%
More comparisons with VIOO
- VIOO vs IWN · iShares Russell 2000 Value ETF 43.5%
- VIOO vs VTWO · Vanguard Russell 2000 Index Fund ETF Shares 40.9%
- VIOO vs IWO · iShares Russell 2000 Growth ETF 37.7%
- VIOO vs FNDA · Schwab Fundamental U.S. Small Company ETF 36.3%
- VIOO vs SCHA · Schwab U.S. Small-Cap ETF 34.1%
- VIOO vs DFAS · U.S. Small Cap Portfolio-ETF Class Shares 33.5%
Percentages are holdings overlap with the named fund.
Open IWM or VIOO 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.