ETF comparison
IWO vs VIOO
Both US Small Cap.
iShares Russell 2000 Growth ETF · Vanguard S&P Small-Cap 600 Index Fund ETF Shares
Holdings overlap
278 positions appear in both funds. Buying equal dollars of IWO and VIOO would leave roughly 37.7% 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 17 bps cheaper than IWO. On a $100,000 position that's about $170/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 IWO vs VIOO.
Top shared holdings
278 shared in total| # | Holding | In IWO | In VIOO | Overlap |
|---|---|---|---|---|
| 1 | Argan, Inc. | 0.66% | 0.54% | 0.54% |
| 2 | BrightSpring Health Services, Inc. | 0.68% | 0.48% | 0.48% |
| 3 | Krystal Biotech, Inc. | 0.58% | 0.47% | 0.47% |
| 4 | StoneX Group, Inc. | 0.52% | 0.47% | 0.47% |
| 5 | ESCO Technologies, Inc. | 0.56% | 0.44% | 0.44% |
| 6 | MaxLinear, Inc. | 0.66% | 0.44% | 0.44% |
| 7 | Ryman Hospitality Properties, Inc. | 0.48% | 0.43% | 0.43% |
| 8 | MYR Group, Inc. | 0.47% | 0.42% | 0.42% |
| 9 | Plexus Corp. | 0.49% | 0.42% | 0.42% |
| 10 | Zurn Elkay Water Solutions Corp. | 0.46% | 0.41% | 0.41% |
| 11 | Federal Signal Corp. | 0.47% | 0.38% | 0.38% |
| 12 | Enpro, Inc. | 0.46% | 0.38% | 0.38% |
Only in IWO
855 total- Moog, Inc. 0.73%
- JFrog Ltd. 0.59%
- FirstCash Holdings, Inc. 0.53%
- D-Wave Quantum, Inc. 0.53%
- Praxis Precision Medicines, Inc. 0.51%
- Cipher Digital, Inc. 0.50%
- EnerSys 0.49%
- HealthEquity, Inc. 0.46%
- Compass, Inc. 0.45%
- Hims & Hers Health, Inc. 0.45%
Only in VIOO
325 total- Sanmina Corp 0.83%
- Semtech Corp 0.83%
- Viavi Solutions Inc 0.66%
- Viasat Inc 0.64%
- Lumen Technologies Inc 0.61%
- FormFactor Inc 0.57%
- Element Solutions Inc 0.57%
- Enphase Energy Inc 0.53%
- Molina Healthcare Inc 0.53%
- Qorvo Inc 0.51%
Related comparisons
More comparisons with IWO
- IWO vs IJT · iShares S&P Small-Cap 600 Growth ETF 37.2%
- IWO vs VIOG · Vanguard S&P Small-Cap 600 Growth Index Fund ETF Shares 36.9%
- IWO vs SCHA · Schwab U.S. Small-Cap ETF 32.4%
- IWO vs DFAS · U.S. Small Cap Portfolio-ETF Class Shares 28.3%
- IWO vs VBK · Vanguard Morningstar Small-Cap Growth ETF 20.7%
- IWO vs FNDA · Schwab Fundamental U.S. Small Company ETF 20.4%
More comparisons with VIOO
- 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%
- VIOO vs DFSV · DFA U.S. Small Cap Value Portfolio – ETF Class Shares 31.9%
- VIOO vs DFAT · U.S. Targeted Value Portfolio-ETF Class Shares 31.0%
- VIOO vs AVUV · Avantis US Small Cap Value ETF 29.3%
Percentages are holdings overlap with the named fund.
Open IWO 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.