SPY vs. IOO

Last updated Jun 7, 2026

SPY (State Street SPDR S&P 500 ETF) and IOO (iShares Global 100 ETF) are both exchange-traded funds - SPY is a S&P 500 fund tracking the S&P 500 Index, while IOO is a Global Equities fund tracking the S&P Global 100 Index (Net). Both are passively managed. Over the past 10 years, SPY returned 15.16%/yr vs 16.27%/yr for IOO. Their correlation of 0.91 suggests significant overlap in exposure. SPY charges 0.09%/yr vs 0.40%/yr for IOO.

Performance

SPY vs. IOO - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in State Street SPDR S&P 500 ETF (SPY) and iShares Global 100 ETF (IOO). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, SPY achieves a 8.45% return, which is significantly lower than IOO's 9.40% return. Over the past 10 years, SPY has underperformed IOO with an annualized return of 15.16%, while IOO has yielded a comparatively higher 16.27% annualized return.

SPY

• 1D: -2.58%
• 1M: 0.82%
• YTD: 8.45%
• 6M: 8.18%
• 1Y: 24.51%
• 3Y*: 21.43%
• 5Y*: 13.32%
• 10Y*: 15.16%

IOO

• 1D: -2.98%
• 1M: -0.01%
• YTD: 9.40%
• 6M: 9.74%
• 1Y: 33.39%
• 3Y*: 24.42%
• 5Y*: 16.08%
• 10Y*: 16.27%

*Multi-year figures are annualized to reflect compound growth (CAGR)

SPY vs. IOO - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
SPY State Street SPDR S&P 500 ETF	8.45%	17.72%	24.89%	26.18%	-18.18%	28.73%	18.33%	31.22%	-4.57%	21.71%
IOO iShares Global 100 ETF	9.40%	27.02%	26.54%	27.71%	-16.34%	26.03%	18.61%	30.01%	-6.22%	23.56%

Correlation

The correlation between SPY and IOO is 0.94, indicating a strong positive relationship between their price movements. Combining them offers limited diversification - they tend to fall together during downturns.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.94
Correlation (3Y) Calculated over the trailing 3-year period	0.94
Correlation (5Y) Calculated over the trailing 5-year period	0.95
Correlation (10Y) Calculated over the trailing 10-year period	0.94
Correlation (All Time) Calculated using the full available price history since Dec 11, 2000	0.91

The correlation between SPY and IOO has been stable across timeframes, ranging from 0.91 to 0.95 - a consistent structural relationship.

SPY vs. IOO - Sectors Allocation Comparison

Sectors	SPY	IOO
Technology	35.9%	46.2%
Financial Services	11.8%	9.1%
Communication Services	11.3%	11.0%
Consumer Cyclical	10.3%	8.4%
Healthcare	8.4%	8.4%
Industrials	7.8%	4.8%
Consumer Defensive	4.8%	5.6%
Energy	3.6%	3.6%
Utilities	2.4%	0.5%
Real Estate	1.9%	0.2%
Basic Materials	1.8%	1.7%

Return for Risk

SPY vs. IOO — Risk / Return Rank

Compare risk-adjusted metric ranks to identify better-performing investments over the past 12 months.

SPY

SPY Risk / Return Rank: 66
SPY Sharpe Ratio Rank: 66
SPY Sortino Ratio Rank: 63
SPY Omega Ratio Rank: 66
SPY Calmar Ratio Rank: 60
SPY Martin Ratio Rank: 73

IOO

IOO Risk / Return Rank: 78
IOO Sharpe Ratio Rank: 79
IOO Sortino Ratio Rank: 77
IOO Omega Ratio Rank: 77
IOO Calmar Ratio Rank: 72
IOO Martin Ratio Rank: 82

The rank (0–100) shows how this investment's returns compare to the risk taken. Higher = better. Based on the past 12 months of data, combining Sharpe, Sortino, and other metrics used by quantitative funds and institutional investors.

SPY vs. IOO - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for State Street SPDR S&P 500 ETF (SPY) and iShares Global 100 ETF (IOO). Risk-adjusted metrics are performance indicators that assess an investment's returns in relation to its risk, enabling a more accurate comparison of different investment options.

	SPY	IOO	Difference
Sharpe ratio: Return per unit of total volatility	2.14	2.51	-0.37
Sortino ratio: Return per unit of downside risk	2.88	3.36	-0.49
Omega ratio: Gain probability vs. loss probability	1.39	1.45	-0.06
Calmar ratio: Return relative to maximum drawdown	2.92	3.51	-0.59
Martin ratio: Return relative to average drawdown	13.50	16.17	-2.66
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

SPY vs. IOO - Sharpe Ratio Comparison

The current SPY Sharpe Ratio is 2.14, which is comparable to the IOO Sharpe Ratio of 2.51. The chart below compares the historical Sharpe Ratios of SPY and IOO, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Sharpe Ratios by Period

	SPY	IOO	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.14	2.51	-0.37
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.78	0.94	-0.16
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.85	0.92	-0.07
Sharpe Ratio (All Time) Calculated using the full available price history	0.58	0.39	+0.20

Drawdowns

SPY vs. IOO - Drawdown Comparison

The maximum SPY drawdown since its inception was -55.19%, roughly equal to the maximum IOO drawdown of -55.85%. Use the drawdown chart below to compare losses from any high point for SPY and IOO.

Drawdown Indicators

	SPY	IOO	Difference
Max Drawdown Largest peak-to-trough decline	-55.19%	-55.85%	+0.66%
Max Drawdown (1Y) Largest decline over 1 year	-8.88%	-9.94%	+1.06%
Max Drawdown (3Y) Largest decline over 3 years	-18.76%	-19.19%	+0.43%
Max Drawdown (5Y) Largest decline over 5 years	-24.50%	-23.52%	-0.98%
Max Drawdown (10Y) Largest decline over 10 years	-33.72%	-31.43%	-2.29%
Current Drawdown Current decline from peak	-2.90%	-3.84%	+0.94%
Average Drawdown Average peak-to-trough decline	-9.05%	-11.27%	+2.22%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.91%	2.15%	-0.24%

Volatility

SPY vs. IOO - Volatility Comparison

The current volatility for State Street SPDR S&P 500 ETF (SPY) is 3.73%, while iShares Global 100 ETF (IOO) has a volatility of 4.49%. This indicates that SPY experiences smaller price fluctuations and is considered to be less risky than IOO based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	SPY	IOO	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.73%	4.49%	-0.76%
Volatility (6M) Calculated over the trailing 6-month period	9.31%	11.05%	-1.74%
Volatility (1Y) Calculated over the trailing 1-year period	12.12%	13.89%	-1.77%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	17.09%	17.09%	0.00%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	17.95%	17.80%	+0.15%

SPY vs. IOO - Expense Ratio Comparison

SPY has a 0.09% expense ratio, which is lower than IOO's 0.40% expense ratio.

Dividends

SPY vs. IOO - Dividend Comparison

SPY's dividend yield for the trailing twelve months is around 1.00%, more than IOO's 0.84% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
IOO iShares Global 100 ETF	0.84%	0.92%	1.08%	1.49%	2.00%	1.53%	1.49%	2.02%	2.54%	2.23%	2.75%	2.89%
SPY State Street SPDR S&P 500 ETF	1.00%	1.07%	1.21%	1.40%	1.65%	1.20%	1.52%	1.75%	2.04%	1.80%	2.03%	2.06%

Frequently Asked Questions

Can I hold both SPY and IOO in my portfolio?

With a correlation of 0.94, SPY and IOO move almost identically. Holding both adds very little diversification - you're essentially doubling your position in the same market segment. Choosing one is usually more capital-efficient.

Which is riskier, SPY or IOO?

IOO has higher volatility (4.49%) compared to SPY (3.73%). In terms of maximum drawdown, SPY dropped -55.19% vs IOO's -55.85%.

Which ETF is better, SPY or IOO?

On 10-year performance, IOO leads with 16.27% vs 15.16% for SPY. On fees, SPY is cheaper at 0.09% per year. On volatility, SPY has been the lower-risk option at 3.73%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, SPY or IOO?

Over the 10-year period, IOO has performed better with a 16.27% return vs 15.16%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, SPY or IOO?

SPY is cheaper with a 0.09% expense ratio, compared with 0.40% for IOO.

Which ETF pays a higher dividend yield, SPY or IOO?

SPY has the higher dividend yield at 1.00%, compared with 0.84% for IOO.

What is the main difference between SPY and IOO?

SPY is categorized as S&P 500, while IOO is Global Equities. SPY tracks S&P 500 Index, while IOO tracks S&P Global 100 Index (Net). They also come from different issuers: State Street and iShares. Their fees differ too: 0.09% for SPY and 0.40% for IOO.

Which has better risk-adjusted returns?

IOO currently has the higher Sharpe Ratio (2.51 vs 2.14), meaning it's delivered slightly more return per unit of risk over the trailing 12 months. However, this ranking shifts over time - use the Risk/Return Score above for a more comprehensive view that combines Sharpe, Sortino, and other measures used by quantitative funds.