PRXAX vs. PREIX

Last updated Jun 24, 2026

PRXAX (T. Rowe Price GNMA Fund Class I) and PREIX (T. Rowe Price Equity Index 500 Fund) are both mutual funds - PRXAX is a Mortgage Backed Securities fund actively managed by T. Rowe Price, while PREIX is a Large Cap Blend Equities fund tracking the S&P 500 Index. PRXAX is actively managed, while PREIX is passively managed. Over the past 5 years, PRXAX returned 0.20%/yr vs 13.41%/yr for PREIX. At a 0.10 correlation, their price movements are largely independent. PRXAX charges 0.41%/yr vs 0.15%/yr for PREIX.

Performance

PRXAX vs. PREIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in T. Rowe Price GNMA Fund Class I (PRXAX) and T. Rowe Price Equity Index 500 Fund (PREIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, PRXAX achieves a 0.65% return, which is significantly lower than PREIX's 9.68% return.

PRXAX

• 1D: -0.24%
• 1M: 0.70%
• YTD: 0.65%
• 6M: 1.11%
• 1Y: 5.57%
• 3Y*: 4.07%
• 5Y*: 0.20%
• 10Y*: —

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%

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

PRXAX vs. PREIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
PRXAX T. Rowe Price GNMA Fund Class I	0.65%	7.72%	1.15%	4.79%	-11.41%	-2.07%	4.34%	5.29%	0.58%	0.82%
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%	12.82%

Correlation

The correlation between PRXAX and PREIX is 0.30, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.30
Correlation (3Y) Calculated over the trailing 3-year period	0.23
Correlation (5Y) Calculated over the trailing 5-year period	0.20
Correlation (All Time) Calculated using the full available price history since May 4, 2017	0.10

Over the past year, PRXAX and PREIX have become more correlated (0.30) than their long-term average of 0.10, meaning their price movements have been converging.

Return for Risk

PRXAX vs. PREIX — Risk / Return Rank

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

PRXAX

PRXAX Risk / Return Rank: 28
PRXAX Sharpe Ratio Rank: 26
PRXAX Sortino Ratio Rank: 28
PRXAX Omega Ratio Rank: 26
PRXAX Calmar Ratio Rank: 30
PRXAX Martin Ratio Rank: 29

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

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.

PRXAX vs. PREIX - Risk-Adjusted Trends Comparison

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

	PRXAX	PREIX	Difference
Sharpe ratio: Return per unit of total volatility	1.33	2.13	-0.80
Sortino ratio: Return per unit of downside risk	2.02	2.88	-0.86
Omega ratio: Gain probability vs. loss probability	1.25	1.39	-0.14
Calmar ratio: Return relative to maximum drawdown	1.93	2.98	-1.05
Martin ratio: Return relative to average drawdown	6.23	13.43	-7.20

PRXAX vs. PREIX - Sharpe Ratio Comparison

The current PRXAX Sharpe Ratio is 1.33, which is lower than the PREIX Sharpe Ratio of 2.13. The chart below compares the historical Sharpe Ratios of PRXAX and PREIX, 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

PRXAX vs. PREIX - Drawdown Comparison

The maximum PRXAX drawdown since its inception was -18.04%, smaller than the maximum PREIX drawdown of -55.32%. Use the drawdown chart below to compare losses from any high point for PRXAX and PREIX.

Drawdown Indicators

	PRXAX	PREIX	Difference
Max Drawdown Largest peak-to-trough decline	-18.04%	-55.32%	+37.28%
Max Drawdown (1Y) Largest decline over 1 year	-2.97%	-8.93%	+5.96%
Max Drawdown (3Y) Largest decline over 3 years	-7.10%	-18.78%	+11.68%
Max Drawdown (5Y) Largest decline over 5 years	-17.14%	-24.60%	+7.46%
Max Drawdown (10Y) Largest decline over 10 years	—	-33.81%	—
Current Drawdown Current decline from peak	-1.44%	-1.73%	+0.29%
Average Drawdown Average peak-to-trough decline	-4.32%	-8.71%	+4.39%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.92%	1.98%	-1.06%

Volatility

PRXAX vs. PREIX - Volatility Comparison

The current volatility for T. Rowe Price GNMA Fund Class I (PRXAX) is 1.40%, while T. Rowe Price Equity Index 500 Fund (PREIX) has a volatility of 4.68%. This indicates that PRXAX experiences smaller price fluctuations and is considered to be less risky than PREIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	PRXAX	PREIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.40%	4.68%	-3.28%
Volatility (6M) Calculated over the trailing 6-month period	3.35%	9.84%	-6.49%
Volatility (1Y) Calculated over the trailing 1-year period	4.31%	12.51%	-8.20%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	6.44%	17.09%	-10.65%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.97%	18.15%	-13.18%

PRXAX vs. PREIX - Expense Ratio Comparison

PRXAX has a 0.41% expense ratio, which is higher than PREIX's 0.15% expense ratio.

Dividends

PRXAX vs. PREIX - Dividend Comparison

PRXAX's dividend yield for the trailing twelve months is around 3.95%, more than PREIX's 2.14% 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%
PRXAX T. Rowe Price GNMA Fund Class I	3.95%	3.92%	3.78%	2.77%	1.56%	0.70%	1.56%	2.48%	2.89%	2.13%	0.00%	0.00%

Frequently Asked Questions

Can I hold both PRXAX and PREIX in my portfolio?

PRXAX and PREIX have a correlation of 0.30, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, PRXAX or PREIX?

PREIX has higher volatility (4.68%) compared to PRXAX (1.40%). In terms of maximum drawdown, PRXAX dropped -18.04% vs PREIX's -55.32%.

Which has better risk-adjusted returns?

PREIX currently has the higher Sharpe Ratio (2.13 vs 1.33), 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.