IWO vs SPY
iShares Russell 2000 Growth ETF vs State Street SPDR S&P 500 ETF Trust
Quick Verdict
SPY has a lower expense ratio. IWO delivered stronger 1-year returns. IWO offers more diversification with 1,125 holdings.
Side-by-Side Comparison
| Metric | IWO | SPY | Winner |
|---|---|---|---|
| Expense Ratio | 0.24% | 0.09% | |
| AUM | $15.0B | $821.1B | |
| Dividend Yield | 0.44% | 1.01% | |
| Holdings | 1,125 | 505 | |
| YTD Return | +20.99% | +14.24% | |
| 1Y Return | +32.17% | +21.71% | |
| 3Y Return (annualized) | +19.07% | +22.10% | |
| 5Y Return (annualized) | +6.80% | +13.21% | |
| Volatility (annualized) | 21.6% | 15.3% | |
| Max Drawdown | -60.3% | -56.5% | |
| Fund Family | iShares by BlackRock (US) | State Street Investment Management | |
| Category | Equity | Equity | |
| Inception | Jul 24, 2000 | Jan 22, 1993 |
IWO vs SPY Performance
iShares Russell 2000 Growth ETF (IWO) is a ETF from iShares by BlackRock (US) and State Street SPDR S&P 500 ETF Trust (SPY) is a ETF from State Street Investment Management. Over the past year IWO returned +32.17% while SPY returned +21.71%. Year to date, IWO is up 20.99% versus a gain of 14.24% for SPY.
Over three years, IWO compounded at +19.07% per year against +22.10% for SPY; over five years the annualized figures are +6.80% and +13.21% respectively. Across the full 26-year window we track, SPY has the edge at +8.86% annualized vs +6.70%. Past performance does not guarantee future results.
Risk: Volatility and Drawdowns
IWO has been the more volatile fund, with annualized monthly volatility of 21.6% compared with 15.3% for SPY. Lower volatility generally means a smoother ride, though it often comes with lower long-run returns.
The deepest peak-to-trough decline in our data was -60.3% for IWO and -56.5% for SPY. Drawdown depth is worth weighing if you expect to sell during market stress rather than ride it out.
The two funds' monthly returns correlate at 0.87. They usually move together, but the gap leaves some room for diversification.
Fees and Cost Over Time
IWO charges 0.24% per year while SPY charges 0.09%. On a $10,000 position that is $24 vs $9 annually, a gap of $15 per year that compounds over a long holding period. On income, IWO currently yields 0.44% against 1.01% for SPY.
Holdings Overlap
IWO and SPY share 0 holdings out of 1539 unique holdings combined, representing a 0.0% weight overlap.
Moderate overlap means holding both could provide meaningful diversification benefits.
Frequently Asked Questions
Which is cheaper, IWO or SPY?
IWO has an expense ratio of 0.24% while SPY charges 0.09%. SPY is the cheaper option. On a $10,000 investment, that is $15 per year of difference.
Which performed better, IWO or SPY?
Over the past year IWO returned +32.17% vs +21.71% for SPY, so IWO leads on 1-year performance. Over the longest common window we track (26 years), IWO annualized +6.70% vs +8.86% for SPY. Past performance does not guarantee future results.
Which is riskier, IWO or SPY?
IWO has been the more volatile fund at 21.6% annualized versus 15.3% for SPY. Worst drawdown: IWO -60.3% vs SPY -56.5%.
Should I hold both IWO and SPY?
IWO and SPY have a monthly-return correlation of 0.87, so combining them can provide real diversification depending on your allocation goals.
What is the holdings overlap between IWO and SPY?
IWO and SPY share 0 common holdings with a 0.0% weight overlap. Combined, they hold 1539 unique securities.
Which pays a higher dividend, IWO or SPY?
IWO yields 0.44% while SPY yields 1.01%, so SPY currently pays the higher dividend yield.
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