PRDSX vs. PEXMX

Last updated Jun 4, 2026

PRDSX (T. Rowe Price QM U.S. Small-Cap Growth Equity Fund) and PEXMX (T. Rowe Price Extended Equity Market Index Fund) are both mutual funds - PRDSX is a Small Cap Growth Equities fund managed by T. Rowe Price, while PEXMX is a Mid Cap Growth Equities fund managed by T. Rowe Price. Over the past 10 years, PRDSX returned 11.71%/yr vs 12.22%/yr for PEXMX. With a 0.97 correlation, they move nearly in lockstep. PRDSX charges 0.78%/yr vs 0.23%/yr for PEXMX.

Performance

PRDSX vs. PEXMX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in T. Rowe Price QM U.S. Small-Cap Growth Equity Fund (PRDSX) and T. Rowe Price Extended Equity Market Index Fund (PEXMX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

The year-to-date returns for both stocks are quite close, with PRDSX having a 14.76% return and PEXMX slightly lower at 14.63%. Both investments have delivered pretty close results over the past 10 years, with PRDSX having a 11.71% annualized return and PEXMX not far ahead at 12.22%.

PRDSX

• 1D: 0.93%
• 1M: 3.81%
• YTD: 14.76%
• 6M: 13.56%
• 1Y: 28.98%
• 3Y*: 16.49%
• 5Y*: 7.58%
• 10Y*: 11.71%

PEXMX

• 1D: 1.08%
• 1M: 5.79%
• YTD: 14.63%
• 6M: 13.30%
• 1Y: 29.74%
• 3Y*: 19.87%
• 5Y*: 6.84%
• 10Y*: 12.22%

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

PRDSX vs. PEXMX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
PRDSX T. Rowe Price QM U.S. Small-Cap Growth Equity Fund	14.76%	10.10%	12.97%	21.15%	-22.49%	11.15%	23.85%	32.75%	-6.91%	22.12%
PEXMX T. Rowe Price Extended Equity Market Index Fund	14.63%	11.17%	16.72%	25.32%	-26.15%	12.09%	30.80%	32.57%	-9.61%	16.63%

Correlation

The correlation between PRDSX and PEXMX is 0.92, 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	0.92
Correlation (3Y) Calculated over the trailing 3-year period	0.94
Correlation (5Y) Calculated over the trailing 5-year period	0.96
Correlation (10Y) Calculated over the trailing 10-year period	0.96
Correlation (All Time) Calculated using the full available price history since Feb 2, 1998	0.97

The correlation between PRDSX and PEXMX has been stable across timeframes, ranging from 0.92 to 0.97 - a consistent structural relationship.

Return for Risk

PRDSX vs. PEXMX — Risk / Return Rank

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

PRDSX

PRDSX Risk / Return Rank: 37
PRDSX Sharpe Ratio Rank: 32
PRDSX Sortino Ratio Rank: 32
PRDSX Omega Ratio Rank: 30
PRDSX Calmar Ratio Rank: 45
PRDSX Martin Ratio Rank: 48

PEXMX

PEXMX Risk / Return Rank: 48
PEXMX Sharpe Ratio Rank: 41
PEXMX Sortino Ratio Rank: 40
PEXMX Omega Ratio Rank: 37
PEXMX Calmar Ratio Rank: 67
PEXMX Martin Ratio Rank: 55

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.

PRDSX vs. PEXMX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for T. Rowe Price QM U.S. Small-Cap Growth Equity Fund (PRDSX) 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.

	PRDSX	PEXMX	Difference
Sharpe ratio Return per unit of total volatility	1.64	1.86	-0.23
Sortino ratio Return per unit of downside risk	2.35	2.64	-0.29
Omega ratio Gain probability vs. loss probability	1.28	1.32	-0.04
Calmar ratio Return relative to maximum drawdown	2.55	3.17	-0.62
Martin ratio Return relative to average drawdown	9.89	11.18	-1.29
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

PRDSX vs. PEXMX - Sharpe Ratio Comparison

The current PRDSX Sharpe Ratio is 1.64, which is comparable to the PEXMX Sharpe Ratio of 1.86. The chart below compares the historical Sharpe Ratios of PRDSX 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

	PRDSX	PEXMX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.64	1.86	-0.23
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.36	0.31	+0.05
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.55	0.55	-0.01
Sharpe Ratio (All Time) Calculated using the full available price history	0.37	0.40	-0.03

Drawdowns

PRDSX vs. PEXMX - Drawdown Comparison

The maximum PRDSX drawdown since its inception was -58.95%, roughly equal to the maximum PEXMX drawdown of -57.82%. Use the drawdown chart below to compare losses from any high point for PRDSX and PEXMX.

Drawdown Indicators

	PRDSX	PEXMX	Difference
Max Drawdown Largest peak-to-trough decline	-58.95%	-57.82%	-1.13%
Max Drawdown (1Y) Largest decline over 1 year	-12.08%	-10.30%	-1.78%
Max Drawdown (3Y) Largest decline over 3 years	-25.84%	-27.01%	+1.17%
Max Drawdown (5Y) Largest decline over 5 years	-33.17%	-36.27%	+3.10%
Max Drawdown (10Y) Largest decline over 10 years	-37.61%	-41.27%	+3.66%
Current Drawdown Current decline from peak	-0.33%	0.00%	-0.33%
Average Drawdown Average peak-to-trough decline	-14.16%	-13.62%	-0.54%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.11%	2.88%	+0.23%

Volatility

PRDSX vs. PEXMX - Volatility Comparison

T. Rowe Price QM U.S. Small-Cap Growth Equity Fund (PRDSX) has a higher volatility of 6.03% compared to T. Rowe Price Extended Equity Market Index Fund (PEXMX) at 4.68%. This indicates that PRDSX's price experiences larger fluctuations and is considered to be riskier than PEXMX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	PRDSX	PEXMX	Difference
Volatility (1M) Calculated over the trailing 1-month period	6.03%	4.68%	+1.35%
Volatility (6M) Calculated over the trailing 6-month period	14.75%	13.24%	+1.51%
Volatility (1Y) Calculated over the trailing 1-year period	18.82%	17.49%	+1.33%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	21.37%	22.46%	-1.09%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	21.51%	22.25%	-0.74%

PRDSX vs. PEXMX - Expense Ratio Comparison

PRDSX has a 0.78% expense ratio, which is higher than PEXMX's 0.23% expense ratio.

Dividends

PRDSX vs. PEXMX - Dividend Comparison

PRDSX's dividend yield for the trailing twelve months is around 5.53%, more than PEXMX's 3.51% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
PEXMX T. Rowe Price Extended Equity Market Index Fund	3.51%	4.02%	7.64%	3.64%	7.53%	14.87%	2.99%	8.17%	6.67%	4.50%	5.90%	4.81%
PRDSX T. Rowe Price QM U.S. Small-Cap Growth Equity Fund	5.53%	6.35%	7.96%	2.43%	3.72%	13.97%	2.91%	4.12%	4.53%	0.10%	0.02%	1.83%

Frequently Asked Questions

Can I hold both PRDSX and PEXMX in my portfolio?

With a correlation of 0.92, PRDSX and PEXMX 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, PRDSX or PEXMX?

PRDSX has higher volatility (6.03%) compared to PEXMX (4.68%). In terms of maximum drawdown, PRDSX dropped -58.95% vs PEXMX's -57.82%.

Which has better risk-adjusted returns?

PEXMX currently has the higher Sharpe Ratio (1.86 vs 1.64), 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.