PREIX vs. VOO

Last updated Jun 24, 2026

PREIX (T. Rowe Price Equity Index 500 Fund) and VOO (Vanguard S&P 500 ETF) are both funds - PREIX is a Large Cap Blend Equities fund tracking the S&P 500 Index, while VOO is a S&P 500 fund tracking the S&P 500 Index. Both are passively managed. Over the past 10 years, PREIX returned 15.55%/yr vs 15.61%/yr for VOO. With a 0.99 correlation, they move nearly in lockstep. PREIX charges 0.15%/yr vs 0.03%/yr for VOO.

Performance

PREIX vs. VOO - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in T. Rowe Price Equity Index 500 Fund (PREIX) 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, PREIX achieves a 9.68% return, which is significantly higher than VOO's 8.19% return. Both investments have delivered pretty close results over the past 10 years, with PREIX having a 15.55% annualized return and VOO not far ahead at 15.61%.

PREIX

• 1D: -0.37%
• 1M: 0.08%
• YTD: 9.68%
• 6M: 8.67%
• 1Y: 25.27%
• 3Y*: 21.17%
• 5Y*: 13.41%
• 10Y*: 15.55%

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)

PREIX vs. VOO - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
PREIX T. Rowe Price Equity Index 500 Fund	9.68%	17.66%	24.78%	26.07%	-18.27%	28.48%	18.17%	31.47%	-4.59%	21.01%
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 PREIX and VOO is 1.00 - these two move nearly in lockstep. At this level, holding both provides almost no diversification benefit. If you already own one, adding the other does little to reduce portfolio risk.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	1.00
Correlation (3Y) Calculated over the trailing 3-year period	0.98
Correlation (5Y) Calculated over the trailing 5-year period	0.99
Correlation (10Y) Calculated over the trailing 10-year period	0.99
Correlation (All Time) Calculated using the full available price history since Sep 9, 2010	0.99

The correlation between PREIX and VOO has been stable across timeframes, ranging from 0.98 to 1.00 - a consistent structural relationship.

Return for Risk

PREIX vs. VOO — Risk / Return Rank

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

PREIX

PREIX Risk / Return Rank: 64
PREIX Sharpe Ratio Rank: 62
PREIX Sortino Ratio Rank: 56
PREIX Omega Ratio Rank: 58
PREIX Calmar Ratio Rank: 66
PREIX Martin Ratio Rank: 77

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.

PREIX vs. VOO - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for T. Rowe Price Equity Index 500 Fund (PREIX) 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.

	PREIX	VOO	Difference
Sharpe ratio: Return per unit of total volatility	2.13	1.91	+0.22
Sortino ratio: Return per unit of downside risk	2.88	2.60	+0.28
Omega ratio: Gain probability vs. loss probability	1.39	1.35	+0.04
Calmar ratio: Return relative to maximum drawdown	2.98	2.67	+0.30
Martin ratio: Return relative to average drawdown	13.43	11.96	+1.47

PREIX vs. VOO - Sharpe Ratio Comparison

The current PREIX Sharpe Ratio is 2.13, which is comparable to the VOO Sharpe Ratio of 1.91. The chart below compares the historical Sharpe Ratios of PREIX 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

PREIX vs. VOO - Drawdown Comparison

The maximum PREIX drawdown since its inception was -55.32%, which is greater than VOO's maximum drawdown of -33.99%. Use the drawdown chart below to compare losses from any high point for PREIX and VOO.

Drawdown Indicators

	PREIX	VOO	Difference
Max Drawdown Largest peak-to-trough decline	-55.32%	-33.99%	-21.33%
Max Drawdown (1Y) Largest decline over 1 year	-8.93%	-8.90%	-0.03%
Max Drawdown (3Y) Largest decline over 3 years	-18.78%	-18.69%	-0.09%
Max Drawdown (5Y) Largest decline over 5 years	-24.60%	-24.52%	-0.08%
Max Drawdown (10Y) Largest decline over 10 years	-33.81%	-33.99%	+0.18%
Current Drawdown Current decline from peak	-1.73%	-3.14%	+1.41%
Average Drawdown Average peak-to-trough decline	-8.71%	-3.68%	-5.03%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.98%	1.99%	-0.01%

Volatility

PREIX vs. VOO - Volatility Comparison

T. Rowe Price Equity Index 500 Fund (PREIX) and Vanguard S&P 500 ETF (VOO) have volatilities of 4.68% and 4.83%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	PREIX	VOO	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.68%	4.83%	-0.15%
Volatility (6M) Calculated over the trailing 6-month period	9.84%	9.82%	+0.02%
Volatility (1Y) Calculated over the trailing 1-year period	12.51%	12.46%	+0.05%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	17.09%	16.91%	+0.18%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.15%	18.02%	+0.13%

PREIX vs. VOO - Expense Ratio Comparison

PREIX has a 0.15% expense ratio, which is higher than VOO's 0.03% expense ratio. However, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

PREIX vs. VOO - Dividend Comparison

PREIX's dividend yield for the trailing twelve months is around 2.14%, more than VOO's 1.05% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
PREIX T. Rowe Price Equity Index 500 Fund	2.14%	2.32%	1.17%	1.32%	1.50%	1.56%	1.97%	2.13%	2.60%	1.30%	2.03%	2.02%
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 PREIX and VOO in my portfolio?

With a correlation of 1.00, PREIX 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, PREIX or VOO?

VOO has higher volatility (4.83%) compared to PREIX (4.68%). In terms of maximum drawdown, PREIX dropped -55.32% vs VOO's -33.99%.

Which has better risk-adjusted returns?

PREIX currently has the higher Sharpe Ratio (2.13 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.