PIO vs. VOO

Last updated Jun 3, 2026

PIO (Invesco Global Water ETF) and VOO (Vanguard S&P 500 ETF) are both exchange-traded funds - PIO is a Water Equities fund tracking the NASDAQ OMX Global Water Index, while VOO is a S&P 500 fund tracking the S&P 500 Index. Both are passively managed. Over the past 10 years, PIO returned 8.51%/yr vs 15.65%/yr for VOO. A 0.78 correlation means they provide meaningful diversification when combined. PIO charges 0.75%/yr vs 0.03%/yr for VOO.

Performance

PIO vs. VOO - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Invesco Global Water ETF (PIO) 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, PIO achieves a -0.22% return, which is significantly lower than VOO's 11.69% return. Over the past 10 years, PIO has underperformed VOO with an annualized return of 8.51%, while VOO has yielded a comparatively higher 15.65% annualized return.

PIO

• 1D: -0.23%
• 1M: -3.73%
• YTD: -0.22%
• 6M: -1.58%
• 1Y: 3.20%
• 3Y*: 8.84%
• 5Y*: 3.35%
• 10Y*: 8.51%

VOO

• 1D: 0.14%
• 1M: 5.39%
• YTD: 11.69%
• 6M: 12.11%
• 1Y: 29.68%
• 3Y*: 22.73%
• 5Y*: 14.26%
• 10Y*: 15.65%

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

PIO vs. VOO - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
PIO Invesco Global Water ETF	-0.22%	14.25%	-0.44%	22.19%	-24.06%	25.97%	14.22%	35.59%	-9.71%	26.52%
VOO Vanguard S&P 500 ETF	11.69%	17.82%	24.98%	26.32%	-18.17%	28.79%	18.32%	31.37%	-4.50%	21.77%

Correlation

The correlation between PIO and VOO is 0.68, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.68
Correlation (3Y) Calculated over the trailing 3-year period	0.71
Correlation (5Y) Calculated over the trailing 5-year period	0.76
Correlation (10Y) Calculated over the trailing 10-year period	0.75
Correlation (All Time) Calculated using the full available price history since Sep 10, 2010	0.78

The correlation between PIO and VOO shifts across timeframes, from 0.68 (1 year) to 0.78 (all time), reflecting how their relationship changes across market environments.

PIO vs. VOO - Sectors Allocation Comparison

Sectors	PIO	VOO
Industrials	56.4%	8.3%
Basic Materials	8.6%	1.8%
Technology	8.0%	35.7%
Utilities	7.7%	2.4%
Consumer Cyclical	6.3%	10.2%
Healthcare	4.6%	8.5%
Financial Services	0.2%	11.6%
Communication Services	-	11.3%
Consumer Defensive	-	4.9%
Energy	-	3.5%
Real Estate	-	1.9%

Return for Risk

PIO vs. VOO — Risk / Return Rank

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

PIO

PIO Risk / Return Rank: 12
PIO Sharpe Ratio Rank: 12
PIO Sortino Ratio Rank: 11
PIO Omega Ratio Rank: 11
PIO Calmar Ratio Rank: 11
PIO Martin Ratio Rank: 12

VOO

VOO Risk / Return Rank: 75
VOO Sharpe Ratio Rank: 77
VOO Sortino Ratio Rank: 75
VOO Omega Ratio Rank: 76
VOO Calmar Ratio Rank: 68
VOO Martin Ratio Rank: 80

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.

PIO vs. VOO - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Invesco Global Water ETF (PIO) 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.

	PIO	VOO	Difference
Sharpe ratio Return per unit of total volatility	0.22	2.53	-2.31
Sortino ratio Return per unit of downside risk	0.42	3.43	-3.01
Omega ratio Gain probability vs. loss probability	1.05	1.46	-0.41
Calmar ratio Return relative to maximum drawdown	0.26	3.42	-3.16
Martin ratio Return relative to average drawdown	0.74	15.95	-15.20
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

PIO vs. VOO - Sharpe Ratio Comparison

The current PIO Sharpe Ratio is 0.22, which is lower than the VOO Sharpe Ratio of 2.53. The chart below compares the historical Sharpe Ratios of PIO 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.

Sharpe Ratios by Period

	PIO	VOO	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.22	2.53	-2.31
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.19	0.85	-0.66
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.47	0.87	-0.40
Sharpe Ratio (All Time) Calculated using the full available price history	0.20	0.89	-0.69

Drawdowns

PIO vs. VOO - Drawdown Comparison

The maximum PIO drawdown since its inception was -64.88%, which is greater than VOO's maximum drawdown of -33.99%. Use the drawdown chart below to compare losses from any high point for PIO and VOO.

Drawdown Indicators

	PIO	VOO	Difference
Max Drawdown Largest peak-to-trough decline	-64.88%	-33.99%	-30.89%
Max Drawdown (1Y) Largest decline over 1 year	-13.14%	-8.90%	-4.24%
Max Drawdown (3Y) Largest decline over 3 years	-17.08%	-18.69%	+1.61%
Max Drawdown (5Y) Largest decline over 5 years	-34.27%	-24.52%	-9.75%
Max Drawdown (10Y) Largest decline over 10 years	-35.76%	-33.99%	-1.77%
Current Drawdown Current decline from peak	-9.40%	0.00%	-9.40%
Average Drawdown Average peak-to-trough decline	-15.43%	-3.69%	-11.74%
Ulcer Index Depth and duration of drawdowns from previous peaks	4.57%	1.91%	+2.66%

Volatility

PIO vs. VOO - Volatility Comparison

Invesco Global Water ETF (PIO) has a higher volatility of 4.48% compared to Vanguard S&P 500 ETF (VOO) at 2.74%. This indicates that PIO'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

	PIO	VOO	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.48%	2.74%	+1.74%
Volatility (6M) Calculated over the trailing 6-month period	12.16%	8.88%	+3.28%
Volatility (1Y) Calculated over the trailing 1-year period	14.57%	11.78%	+2.79%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	17.64%	16.81%	+0.83%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.22%	18.01%	+0.21%

PIO vs. VOO - Expense Ratio Comparison

PIO has a 0.75% expense ratio, which is higher than VOO's 0.03% expense ratio.

Dividends

PIO vs. VOO - Dividend Comparison

PIO's dividend yield for the trailing twelve months is around 1.02%, which matches VOO's 1.02% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
PIO Invesco Global Water ETF	1.02%	1.04%	0.78%	0.84%	1.02%	1.19%	0.88%	1.20%	2.00%	1.00%	1.45%	1.63%
VOO Vanguard S&P 500 ETF	1.02%	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 PIO and VOO in my portfolio?

PIO and VOO have a correlation of 0.68, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, PIO or VOO?

PIO has higher volatility (4.48%) compared to VOO (2.74%). In terms of maximum drawdown, PIO dropped -64.88% vs VOO's -33.99%.

Which ETF is better, PIO or VOO?

On 10-year performance, VOO leads with 15.65% vs 8.51% for PIO. On fees, VOO is cheaper at 0.03% per year. On volatility, VOO has been the lower-risk option at 2.74%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, PIO or VOO?

Over the 10-year period, VOO has performed better with a 15.65% return vs 8.51%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, PIO or VOO?

VOO is cheaper with a 0.03% expense ratio, compared with 0.75% for PIO.

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

PIO and VOO have nearly identical dividend yields, around 1.02%.

What is the main difference between PIO and VOO?

PIO is categorized as Water Equities, while VOO is S&P 500. PIO tracks NASDAQ OMX Global Water Index, while VOO tracks S&P 500 Index. They also come from different issuers: Invesco and Vanguard. Their fees differ too: 0.75% for PIO and 0.03% for VOO.

Which has better risk-adjusted returns?

VOO currently has the higher Sharpe Ratio (2.53 vs 0.22), 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.