IOO vs. VOO

Last updated Jun 24, 2026

IOO (iShares Global 100 ETF) and VOO (Vanguard S&P 500 ETF) are both exchange-traded funds - IOO is a Global Equities fund tracking the S&P Global 100 Index (Net), while VOO is a S&P 500 fund tracking the S&P 500 Index. Both are passively managed. Over the past 10 years, IOO returned 16.63%/yr vs 15.61%/yr for VOO. Their correlation of 0.94 suggests significant overlap in exposure. IOO charges 0.40%/yr vs 0.03%/yr for VOO.

Performance

IOO vs. VOO - Performance Comparison

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

Returns By Period

In the year-to-date period, IOO achieves a 7.38% return, which is significantly lower than VOO's 8.19% return. Over the past 10 years, IOO has outperformed VOO with an annualized return of 16.63%, while VOO has yielded a comparatively lower 15.61% annualized return.

IOO

• 1D: -1.40%
• 1M: -3.92%
• YTD: 7.38%
• 6M: 6.92%
• 1Y: 31.18%
• 3Y*: 23.11%
• 5Y*: 15.43%
• 10Y*: 16.63%

VOO

• 1D: -1.42%
• 1M: -1.34%
• YTD: 8.19%
• 6M: 7.24%
• 1Y: 23.69%
• 3Y*: 20.78%
• 5Y*: 13.13%
• 10Y*: 15.61%

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

IOO vs. VOO - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
IOO iShares Global 100 ETF	7.38%	27.02%	26.54%	27.71%	-16.34%	26.03%	18.61%	30.01%	-6.22%	23.56%
VOO Vanguard S&P 500 ETF	8.19%	17.82%	24.98%	26.32%	-18.17%	28.79%	18.32%	31.37%	-4.50%	21.77%

Correlation

The correlation between IOO and VOO 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 Sep 9, 2010	0.94

The correlation between IOO and VOO has been stable across timeframes, ranging from 0.94 to 0.95 - a consistent structural relationship.

IOO vs. VOO - Sectors Allocation Comparison

Sectors	IOO	VOO
Technology	47.0%	39.1%
Communication Services	10.8%	10.5%
Financial Services	9.2%	10.9%
Consumer Cyclical	8.4%	9.8%
Healthcare	8.4%	8.3%
Consumer Defensive	5.6%	4.5%
Industrials	4.8%	7.6%
Energy	3.6%	3.2%
Basic Materials	1.7%	1.7%
Utilities	0.5%	2.5%
Real Estate	0.2%	1.8%

Return for Risk

IOO vs. VOO — Risk / Return Rank

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

IOO

IOO Risk / Return Rank: 69
IOO Sharpe Ratio Rank: 71
IOO Sortino Ratio Rank: 68
IOO Omega Ratio Rank: 68
IOO Calmar Ratio Rank: 66
IOO Martin Ratio Rank: 74

VOO

VOO Risk / Return Rank: 59
VOO Sharpe Ratio Rank: 59
VOO Sortino Ratio Rank: 56
VOO Omega Ratio Rank: 58
VOO Calmar Ratio Rank: 56
VOO Martin Ratio Rank: 67

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.

IOO vs. VOO - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for iShares Global 100 ETF (IOO) and Vanguard S&P 500 ETF (VOO). 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.

Values are calculated on a 1-year rolling basis and updated daily. Risk-adjusted metrics are more stable over longer periods — use the period switch above to explore them.

	IOO	VOO	Difference
Sharpe ratio: Return per unit of total volatility	2.20	1.91	+0.28
Sortino ratio: Return per unit of downside risk	2.98	2.60	+0.38
Omega ratio: Gain probability vs. loss probability	1.39	1.35	+0.04
Calmar ratio: Return relative to maximum drawdown	3.15	2.67	+0.48
Martin ratio: Return relative to average drawdown	13.53	11.96	+1.57

IOO vs. VOO - Sharpe Ratio Comparison

The current IOO Sharpe Ratio is 2.20, which is comparable to the VOO Sharpe Ratio of 1.91. The chart below compares the historical Sharpe Ratios of IOO and VOO, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Drawdowns

IOO vs. VOO - Drawdown Comparison

The maximum IOO drawdown since its inception was -55.85%, which is greater than VOO's maximum drawdown of -33.99%. Use the drawdown chart below to compare losses from any high point for IOO and VOO.

Drawdown Indicators

	IOO	VOO	Difference
Max Drawdown Largest peak-to-trough decline	-55.85%	-33.99%	-21.86%
Max Drawdown (1Y) Largest decline over 1 year	-9.94%	-8.90%	-1.04%
Max Drawdown (3Y) Largest decline over 3 years	-19.19%	-18.69%	-0.50%
Max Drawdown (5Y) Largest decline over 5 years	-23.52%	-24.52%	+1.00%
Max Drawdown (10Y) Largest decline over 10 years	-31.43%	-33.99%	+2.56%
Current Drawdown Current decline from peak	-5.61%	-3.14%	-2.47%
Average Drawdown Average peak-to-trough decline	-11.25%	-3.68%	-7.57%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.31%	1.99%	+0.32%

Volatility

IOO vs. VOO - Volatility Comparison

iShares Global 100 ETF (IOO) has a higher volatility of 5.30% compared to Vanguard S&P 500 ETF (VOO) at 4.83%. This indicates that IOO's price experiences larger fluctuations and is considered to be riskier than VOO based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	IOO	VOO	Difference
Volatility (1M) Calculated over the trailing 1-month period	5.30%	4.83%	+0.47%
Volatility (6M) Calculated over the trailing 6-month period	11.51%	9.82%	+1.69%
Volatility (1Y) Calculated over the trailing 1-year period	14.27%	12.46%	+1.81%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	17.17%	16.91%	+0.26%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	17.73%	18.02%	-0.29%

IOO vs. VOO - Expense Ratio Comparison

IOO has a 0.40% expense ratio, which is higher than VOO's 0.03% expense ratio.

Dividends

IOO vs. VOO - Dividend Comparison

IOO's dividend yield for the trailing twelve months is around 0.86%, less than VOO's 1.05% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
IOO iShares Global 100 ETF	0.86%	0.92%	1.08%	1.49%	2.00%	1.53%	1.49%	2.02%	2.54%	2.23%	2.75%	2.89%
VOO Vanguard S&P 500 ETF	1.05%	1.13%	1.24%	1.46%	1.69%	1.25%	1.54%	1.88%	2.06%	1.78%	2.02%	2.10%

Frequently Asked Questions

Can I hold both IOO and VOO in my portfolio?

With a correlation of 0.94, IOO and VOO 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, IOO or VOO?

IOO has higher volatility (5.30%) compared to VOO (4.83%). In terms of maximum drawdown, IOO dropped -55.85% vs VOO's -33.99%.

Which ETF is better, IOO or VOO?

On 10-year performance, IOO leads with 16.63% vs 15.61% for VOO. On fees, VOO is cheaper at 0.03% per year. On volatility, VOO has been the lower-risk option at 4.83%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, IOO or VOO?

Over the 10-year period, IOO has performed better with a 16.63% return vs 15.61%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, IOO or VOO?

VOO is cheaper with a 0.03% expense ratio, compared with 0.40% for IOO.

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

VOO has the higher dividend yield at 1.05%, compared with 0.86% for IOO.

What is the main difference between IOO and VOO?

IOO is categorized as Global Equities, while VOO is S&P 500. IOO tracks S&P Global 100 Index (Net), while VOO tracks S&P 500 Index. They also come from different issuers: iShares and Vanguard. Their fees differ too: 0.40% for IOO and 0.03% for VOO.

Which has better risk-adjusted returns?

IOO currently has the higher Sharpe Ratio (2.20 vs 1.91), 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.