IOO vs SPY
iShares Global 100 ETF vs State Street SPDR S&P 500 ETF Trust
Quick Verdict
SPY has a lower expense ratio. IOO delivered stronger 1-year returns. SPY offers more diversification with 503 holdings.
Side-by-Side Comparison
| Metric | IOO | SPY | Winner |
|---|---|---|---|
| Expense Ratio | 0.40% | 0.09% | |
| AUM | $8.7B | $789.1B | |
| Dividend Yield | 0.85% | 1.01% | |
| Holdings | 117 | 505 | |
| YTD Return | +14.82% | +13.68% | |
| 1Y Return | +28.23% | +21.53% | |
| 3Y Return (annualized) | +25.51% | +21.44% | |
| 5Y Return (annualized) | +16.03% | +13.18% | |
| Volatility (annualized) | 15.8% | 15.3% | |
| Max Drawdown | -57.9% | -56.5% | |
| Fund Family | iShares by BlackRock (US) | State Street Investment Management | |
| Category | Equity | Equity | |
| Inception | Dec 5, 2000 | Jan 22, 1993 |
IOO vs SPY Performance
iShares Global 100 ETF (IOO) 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 IOO returned +28.23% while SPY returned +21.53%. Year to date, IOO is up 14.82% versus a gain of 13.68% for SPY.
Over three years, IOO compounded at +25.51% per year against +21.44% for SPY; over five years the annualized figures are +16.03% and +13.18% respectively. Across the full 26-year window we track, SPY has the edge at +8.85% annualized vs +5.87%. Past performance does not guarantee future results.
Risk: Volatility and Drawdowns
IOO has been the more volatile fund, with annualized monthly volatility of 15.8% 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 -57.9% for IOO 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 0.95. They move almost in lockstep, so holding both mostly duplicates the same exposure.
Fees and Cost Over Time
IOO charges 0.40% per year while SPY charges 0.09%. On a $10,000 position that is $40 vs $9 annually, a gap of $31 per year that compounds over a long holding period. On income, IOO currently yields 0.85% against 1.01% for SPY.
Holdings Overlap
IOO and SPY share 53 holdings out of 552 unique holdings combined, representing a 49.1% weight overlap.
Moderate overlap means holding both could provide meaningful diversification benefits.
Frequently Asked Questions
Which is cheaper, IOO or SPY?
IOO has an expense ratio of 0.40% while SPY charges 0.09%. SPY is the cheaper option. On a $10,000 investment, that is $31 per year of difference.
Which performed better, IOO or SPY?
Over the past year IOO returned +28.23% vs +21.53% for SPY, so IOO leads on 1-year performance. Over the longest common window we track (26 years), IOO annualized +5.87% vs +8.85% for SPY. Past performance does not guarantee future results.
Which is riskier, IOO or SPY?
IOO has been the more volatile fund at 15.8% annualized versus 15.3% for SPY. Worst drawdown: IOO -57.9% vs SPY -56.5%.
Should I hold both IOO and SPY?
IOO and SPY have a monthly-return correlation of 0.95, so they move almost identically. Holding both adds little diversification - most investors pick one, usually on fees or the specific index tracked.
What is the holdings overlap between IOO and SPY?
IOO and SPY share 53 common holdings with a 49.1% weight overlap. Combined, they hold 552 unique securities.
Which pays a higher dividend, IOO or SPY?
IOO yields 0.85% while SPY yields 1.01%, so SPY currently pays the higher dividend yield.
Popular ETF Comparisons
Get Full ETF Analytics
Access complete holdings data, overlap analysis, screener tools, and more with FundXLS.