PRUIX vs. PEXMX

Last updated Jun 3, 2026

PRUIX (T. Rowe Price Equity Index 500 Fund - I Class) and PEXMX (T. Rowe Price Extended Equity Market Index Fund) are both mutual funds - PRUIX is a Large Cap Blend Equities fund tracking the S&P 500 Index, while PEXMX is a Mid Cap Growth Equities fund managed by T. Rowe Price. Over the past 10 years, PRUIX returned 15.56%/yr vs 12.10%/yr for PEXMX. Their correlation of 0.86 suggests significant overlap in exposure. PRUIX charges 0.05%/yr vs 0.23%/yr for PEXMX.

Performance

PRUIX vs. PEXMX - Performance Comparison

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

Returns By Period

In the year-to-date period, PRUIX achieves a 11.53% return, which is significantly lower than PEXMX's 13.41% return. Over the past 10 years, PRUIX has outperformed PEXMX with an annualized return of 15.56%, while PEXMX has yielded a comparatively lower 12.10% annualized return.

PRUIX

• 1D: 0.27%
• 1M: 5.24%
• YTD: 11.53%
• 6M: 11.90%
• 1Y: 29.51%
• 3Y*: 22.64%
• 5Y*: 14.12%
• 10Y*: 15.56%

PEXMX

• 1D: 0.28%
• 1M: 4.27%
• YTD: 13.41%
• 6M: 13.60%
• 1Y: 30.17%
• 3Y*: 19.44%
• 5Y*: 6.40%
• 10Y*: 12.10%

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

PRUIX vs. PEXMX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
PRUIX T. Rowe Price Equity Index 500 Fund - I Class	11.53%	17.82%	24.95%	26.24%	-18.14%	28.62%	18.31%	31.63%	-4.44%	21.14%
PEXMX T. Rowe Price Extended Equity Market Index Fund	13.41%	11.17%	16.72%	25.32%	-26.15%	12.09%	30.80%	32.57%	-9.61%	16.63%

Correlation

The correlation between PRUIX and PEXMX is 0.80, 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	0.80
Correlation (3Y) Calculated over the trailing 3-year period	0.81
Correlation (5Y) Calculated over the trailing 5-year period	0.85
Correlation (10Y) Calculated over the trailing 10-year period	0.85
Correlation (All Time) Calculated using the full available price history since Jan 5, 2016	0.86

The correlation between PRUIX and PEXMX has been stable across timeframes, ranging from 0.80 to 0.86 - a consistent structural relationship.

Return for Risk

PRUIX vs. PEXMX — Risk / Return Rank

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

PRUIX

PRUIX Risk / Return Rank: 74
PRUIX Sharpe Ratio Rank: 77
PRUIX Sortino Ratio Rank: 69
PRUIX Omega Ratio Rank: 68
PRUIX Calmar Ratio Rank: 74
PRUIX Martin Ratio Rank: 83

PEXMX

PEXMX Risk / Return Rank: 41
PEXMX Sharpe Ratio Rank: 38
PEXMX Sortino Ratio Rank: 37
PEXMX Omega Ratio Rank: 34
PEXMX Calmar Ratio Rank: 51
PEXMX Martin Ratio Rank: 47

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.

PRUIX vs. PEXMX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for T. Rowe Price Equity Index 500 Fund - I Class (PRUIX) and T. Rowe Price Extended Equity Market Index Fund (PEXMX). 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.

	PRUIX	PEXMX	Difference
Sharpe ratio Return per unit of total volatility	2.55	1.80	+0.75
Sortino ratio Return per unit of downside risk	3.45	2.55	+0.90
Omega ratio Gain probability vs. loss probability	1.46	1.31	+0.15
Calmar ratio Return relative to maximum drawdown	3.37	2.77	+0.61
Martin ratio Return relative to average drawdown	15.79	9.90	+5.89
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

PRUIX vs. PEXMX - Sharpe Ratio Comparison

The current PRUIX Sharpe Ratio is 2.55, which is higher than the PEXMX Sharpe Ratio of 1.80. The chart below compares the historical Sharpe Ratios of PRUIX and PEXMX, 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

	PRUIX	PEXMX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.55	1.80	+0.75
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.84	0.29	+0.55
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.86	0.55	+0.32
Sharpe Ratio (All Time) Calculated using the full available price history	0.86	0.40	+0.46

Drawdowns

PRUIX vs. PEXMX - Drawdown Comparison

The maximum PRUIX drawdown since its inception was -33.80%, smaller than the maximum PEXMX drawdown of -57.82%. Use the drawdown chart below to compare losses from any high point for PRUIX and PEXMX.

Drawdown Indicators

	PRUIX	PEXMX	Difference
Max Drawdown Largest peak-to-trough decline	-33.80%	-57.82%	+24.02%
Max Drawdown (1Y) Largest decline over 1 year	-8.91%	-10.30%	+1.39%
Max Drawdown (3Y) Largest decline over 3 years	-18.76%	-27.01%	+8.25%
Max Drawdown (5Y) Largest decline over 5 years	-24.52%	-36.27%	+11.75%
Max Drawdown (10Y) Largest decline over 10 years	-33.80%	-41.27%	+7.47%
Current Drawdown Current decline from peak	0.00%	0.00%	0.00%
Average Drawdown Average peak-to-trough decline	-4.23%	-13.62%	+9.39%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.90%	2.88%	-0.98%

Volatility

PRUIX vs. PEXMX - Volatility Comparison

The current volatility for T. Rowe Price Equity Index 500 Fund - I Class (PRUIX) is 2.82%, while T. Rowe Price Extended Equity Market Index Fund (PEXMX) has a volatility of 4.61%. This indicates that PRUIX experiences smaller price fluctuations and is considered to be less risky than PEXMX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	PRUIX	PEXMX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.82%	4.61%	-1.79%
Volatility (6M) Calculated over the trailing 6-month period	8.98%	13.21%	-4.23%
Volatility (1Y) Calculated over the trailing 1-year period	11.88%	17.50%	-5.62%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	16.99%	22.45%	-5.46%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.10%	22.25%	-4.15%

PRUIX vs. PEXMX - Expense Ratio Comparison

PRUIX has a 0.05% expense ratio, which is lower than PEXMX's 0.23% expense ratio. Despite the difference, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

PRUIX vs. PEXMX - Dividend Comparison

PRUIX's dividend yield for the trailing twelve months is around 2.22%, less than PEXMX's 3.55% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
PEXMX T. Rowe Price Extended Equity Market Index Fund	3.55%	4.02%	7.64%	3.64%	7.53%	14.87%	2.99%	8.17%	6.67%	4.50%	5.90%	4.81%
PRUIX T. Rowe Price Equity Index 500 Fund - I Class	2.22%	2.44%	1.28%	1.44%	1.69%	1.64%	2.09%	2.25%	2.77%	1.39%	2.16%	0.00%

Frequently Asked Questions

Can I hold both PRUIX and PEXMX in my portfolio?

PRUIX and PEXMX have a correlation of 0.80, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, PRUIX or PEXMX?

PEXMX has higher volatility (4.61%) compared to PRUIX (2.82%). In terms of maximum drawdown, PRUIX dropped -33.80% vs PEXMX's -57.82%.

Which has better risk-adjusted returns?

PRUIX currently has the higher Sharpe Ratio (2.55 vs 1.80), 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.