🤝 BFF Take
VB Wins for Long-Term Holders — IWM's Only Advantage Is Options Liquidity
IWM (iShares Russell 2000 ETF) and VB (Vanguard Small-Cap ETF) both provide exposure to US small-cap stocks, but with a significant cost difference. IWM charges 0.19% and tracks the Russell 2000 index — roughly 2,000 small-cap US companies including many unprofitable ones. VB charges just 0.05% and tracks the CRSP US Small Cap index with ~1,500 holdings, which tends to have a slightly higher-quality tilt and excludes the very smallest micro-caps. On $100K over 20 years, the 14 basis point fee gap compounds to roughly $3,500 more in fees paid to IWM. The exception: IWM dominates the small-cap options market, making it essential for options traders. Long-term buy-and-hold investors should prefer VB.
📋 Quick Takeaways
💰VB costs 0.05% vs IWM's 0.19% — nearly 4x cheaper for similar small-cap exposure
📊IWM tracks Russell 2000 (~2,000 stocks including many money-losers); VB uses CRSP (~1,500 slightly higher quality)
🎯IWM dominates small-cap options trading — it's the only choice if you trade options on small-caps
📊 Data-Based Take: VB has the lower fee
Whether the lower-cost fund suits your situation depends on your existing holdings, account type, tax situation, and how you use each fund. This is a cost comparison, not a personalized recommendation.
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Reviewed by a CFA® Charterholder · Data updated Jun 2026 · Educational only, not financial advice
IWM
iShares Russell 2000 ETF
VB
Vanguard Small-Cap ETF
📋 IWM vs VB — Key Facts Side by Side
| Metric |
IWM |
VB |
| Fund Name |
iShares Russell 2000 ETF |
Vanguard Small-Cap ETF |
| Issuer |
iShares |
Vanguard |
| Tracks Index |
Russell 2000 |
CRSP US Small Cap |
| Expense Ratio |
0.19% |
0.05% ✓ |
| Cost per $10K/yr |
$19.00 |
$5.00 |
| AUM |
$70B |
$60B |
| Holdings |
2,000 |
1,500 |
| Inception |
2000 |
2004 |
| 1-Year Return |
+8.50% |
+9.20% |
| 3-Year Return |
+2.10% |
+2.80% |
| 5-Year Return |
+8.20% |
+8.90% |
| Avg Bid-Ask Spread |
0.00% |
0.00% |
Data from ETF BFF database. Returns are annualised. Not investment advice.
📊 IWM vs VB — Annualised Returns
Annualised returns (trailing, price-based). Past performance does not guarantee future results.
🎯 Should You Buy IWM or VB?
Choose if...
IWM
- You already use iShares and prefer staying within their fund family
Choose if...
VB
- You want the lowest fees — saves ~$14/yr per $10K vs IWM
- You already use Vanguard and prefer staying within their fund family
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❓ IWM vs VB — Frequently Asked Questions
What is the difference between IWM and VB?
IWM tracks the Russell 2000 index (2,000 US small-cap stocks) while VB tracks the CRSP US Small Cap index (~1,500 stocks). The key differences: expense ratio (IWM 0.19% vs VB 0.05%), index construction (Russell 2000 includes more unprofitable micro-caps; CRSP small-cap excludes the very smallest companies), and fund size (similar at ~$60-70B). For long-term investors, VB's lower cost is a meaningful advantage.
Why is IWM so expensive compared to other ETFs?
IWM was launched in 2000 when expense ratios were generally higher, and it has maintained its 0.19% fee because its primary users are institutional traders who need its options market liquidity and are less fee-sensitive than long-term retail investors. The Russell 2000 index also charges higher licensing fees than CRSP. Despite the higher fee, IWM remains the dominant small-cap trading vehicle.
Has small-cap outperformed large-cap historically?
The "small-cap premium" — the historical tendency of small-caps to outperform large-caps over very long periods — is one of the most debated topics in investing. Historically (looking at data back to the 1920s), small-caps have outperformed, but the premium has been inconsistent and largely absent in recent decades where large-cap tech dominated. Many investors add small-cap exposure expecting eventual mean reversion.
Should I add small-cap ETFs to a VOO/VTI portfolio?
VTI already includes small-cap stocks in proportion to their market cap, so you have some exposure. Adding IWM or VB intentionally overweights small-caps — a deliberate tilt away from market-cap weighting. Some investors do this to capture the potential small-cap premium; others prefer market-cap weighting for simplicity. If you hold VOO (S&P 500 only), adding a small-cap ETF completes your US coverage.
Is AVUV better than IWM or VB for small-cap exposure?
AVUV (Avantis US Small Cap Value) is an actively managed ETF that tilts specifically toward small-cap value stocks with strong profitability — a factor-based approach with academic support. It charges 0.25% (more than VB but less than some alternatives). AVUV is worth considering for investors who believe in the small-cap value premium specifically. Compare AVUV vs VBR for that specific matchup.
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ℹ️ Data shown is for educational purposes and may not reflect the most current figures. Returns are trailing price-based and exclude dividend reinvestment. Past performance does not guarantee future results. ETF BFF is not a licensed financial advisor — this is not personalized financial advice.