ETF comparison
IWM vs SPSM
Both US Small Cap.
iShares Russell 2000 ETF · State Street SPDR Portfolio S&P 600 Small Cap ETF
Holdings overlap
541 positions appear in both funds. Buying equal dollars of IWM and SPSM would leave roughly 47.1% 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
SPSM is 16 bps cheaper than IWM. On a $100,000 position that's about $160/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 SPSM.
Top shared holdings
541 shared in total| # | Holding | In IWM | In SPSM | Overlap |
|---|---|---|---|---|
| 1 | Viasat, Inc. | 0.35% | 0.66% | 0.35% |
| 2 | BrightSpring Health Services, Inc. | 0.35% | 0.60% | 0.35% |
| 3 | MaxLinear, Inc. | 0.34% | 0.58% | 0.34% |
| 4 | Argan, Inc. | 0.34% | 0.60% | 0.34% |
| 5 | Krystal Biotech, Inc. | 0.30% | 0.53% | 0.30% |
| 6 | ESCO Technologies, Inc. | 0.29% | 0.49% | 0.29% |
| 7 | Alkermes plc | 0.27% | 0.47% | 0.27% |
| 8 | StoneX Group, Inc. | 0.27% | 0.45% | 0.27% |
| 9 | Plexus Corp. | 0.25% | 0.44% | 0.25% |
| 10 | Enpro, Inc. | 0.25% | 0.43% | 0.25% |
| 11 | Ryman Hospitality Properties, Inc. | 0.25% | 0.44% | 0.25% |
| 12 | Glaukos Corp. | 0.25% | 0.45% | 0.25% |
Only in IWM
1,473 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 SPSM
63 total- FormFactor Inc 0.68%
- Molina Healthcare Inc 0.65%
- Element Solutions Inc 0.59%
- Match Group Inc 0.48%
- Everus Construction Group Inc 0.46%
- Corcept Therapeutics Inc 0.45%
- Ralliant Corp 0.45%
- Powell Industries Inc 0.44%
- Eastman Chemical Co 0.42%
- CarMax Inc 0.41%
Related comparisons
More comparisons with IWM
- 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%
- 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%
More comparisons with SPSM
- SPSM vs IWN · iShares Russell 2000 Value ETF 43.5%
- SPSM vs IWO · iShares Russell 2000 Growth ETF 40.6%
- SPSM vs VTWO · Vanguard Russell 2000 Index Fund ETF Shares 40.4%
- SPSM vs FNDA · Schwab Fundamental U.S. Small Company ETF 35.7%
- SPSM vs DFAS · U.S. Small Cap Portfolio-ETF Class Shares 34.3%
- SPSM vs SCHA · Schwab U.S. Small-Cap ETF 34.0%
Percentages are holdings overlap with the named fund.
Open IWM or SPSM 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.