TRSSX vs. STMGX

Last updated Jun 4, 2026

TRSSX (T. Rowe Price Institutional Small Cap Stock Fund) and STMGX (American Beacon Stephens Mid-Cap Growth Fund) are both mutual funds - TRSSX is a Small Cap Growth Equities fund managed by T. Rowe Price, while STMGX is a Mid Cap Growth Equities fund managed by American Beacon. Over the past 10 years, TRSSX returned 11.50%/yr vs 13.85%/yr for STMGX. Their correlation of 0.89 suggests significant overlap in exposure. TRSSX charges 0.66%/yr vs 1.14%/yr for STMGX.

Performance

TRSSX vs. STMGX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in T. Rowe Price Institutional Small Cap Stock Fund (TRSSX) and American Beacon Stephens Mid-Cap Growth Fund (STMGX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, TRSSX achieves a 10.46% return, which is significantly lower than STMGX's 11.65% return. Over the past 10 years, TRSSX has underperformed STMGX with an annualized return of 11.50%, while STMGX has yielded a comparatively higher 13.85% annualized return.

TRSSX

• 1D: 0.07%
• 1M: 0.94%
• YTD: 10.46%
• 6M: 9.53%
• 1Y: 21.88%
• 3Y*: 14.23%
• 5Y*: 4.75%
• 10Y*: 11.50%

STMGX

• 1D: 0.71%
• 1M: 8.63%
• YTD: 11.65%
• 6M: 10.19%
• 1Y: 21.54%
• 3Y*: 17.25%
• 5Y*: 7.34%
• 10Y*: 13.85%

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

TRSSX vs. STMGX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
TRSSX T. Rowe Price Institutional Small Cap Stock Fund	10.46%	8.21%	10.93%	17.65%	-23.36%	16.81%	25.07%	33.96%	-3.07%	15.41%
STMGX American Beacon Stephens Mid-Cap Growth Fund	11.65%	12.98%	13.16%	25.22%	-28.31%	12.29%	39.82%	31.31%	1.71%	27.97%

Correlation

The correlation between TRSSX and STMGX is 0.79, 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	0.79
Correlation (3Y) Calculated over the trailing 3-year period	0.80
Correlation (5Y) Calculated over the trailing 5-year period	0.86
Correlation (10Y) Calculated over the trailing 10-year period	0.85
Correlation (All Time) Calculated using the full available price history since Feb 3, 2006	0.89

The correlation between TRSSX and STMGX shifts across timeframes, from 0.79 (1 year) to 0.89 (all time), reflecting how their relationship changes across market environments.

Return for Risk

TRSSX vs. STMGX — Risk / Return Rank

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

TRSSX

TRSSX Risk / Return Rank: 28
TRSSX Sharpe Ratio Rank: 22
TRSSX Sortino Ratio Rank: 24
TRSSX Omega Ratio Rank: 21
TRSSX Calmar Ratio Rank: 35
TRSSX Martin Ratio Rank: 39

STMGX

STMGX Risk / Return Rank: 26
STMGX Sharpe Ratio Rank: 24
STMGX Sortino Ratio Rank: 23
STMGX Omega Ratio Rank: 21
STMGX Calmar Ratio Rank: 32
STMGX Martin Ratio Rank: 33

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.

TRSSX vs. STMGX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for T. Rowe Price Institutional Small Cap Stock Fund (TRSSX) and American Beacon Stephens Mid-Cap Growth Fund (STMGX). 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.

	TRSSX	STMGX	Difference
Sharpe ratio: Return per unit of total volatility	1.35	1.41	-0.06
Sortino ratio: Return per unit of downside risk	2.04	2.02	+0.02
Omega ratio: Gain probability vs. loss probability	1.24	1.24	0.00
Calmar ratio: Return relative to maximum drawdown	2.24	2.11	+0.13
Martin ratio: Return relative to average drawdown	8.52	7.45	+1.08
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

TRSSX vs. STMGX - Sharpe Ratio Comparison

The current TRSSX Sharpe Ratio is 1.35, which is comparable to the STMGX Sharpe Ratio of 1.41. The chart below compares the historical Sharpe Ratios of TRSSX and STMGX, 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

	TRSSX	STMGX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.35	1.41	-0.06
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.22	0.35	-0.14
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.54	0.67	-0.13
Sharpe Ratio (All Time) Calculated using the full available price history	0.46	0.46	0.00

Drawdowns

TRSSX vs. STMGX - Drawdown Comparison

The maximum TRSSX drawdown since its inception was -56.38%, roughly equal to the maximum STMGX drawdown of -57.58%. Use the drawdown chart below to compare losses from any high point for TRSSX and STMGX.

Drawdown Indicators

	TRSSX	STMGX	Difference
Max Drawdown Largest peak-to-trough decline	-56.38%	-57.58%	+1.20%
Max Drawdown (1Y) Largest decline over 1 year	-10.73%	-10.84%	+0.11%
Max Drawdown (3Y) Largest decline over 3 years	-30.88%	-22.50%	-8.38%
Max Drawdown (5Y) Largest decline over 5 years	-32.12%	-36.59%	+4.47%
Max Drawdown (10Y) Largest decline over 10 years	-37.85%	-36.59%	-1.26%
Current Drawdown Current decline from peak	-2.07%	0.00%	-2.07%
Average Drawdown Average peak-to-trough decline	-9.00%	-10.16%	+1.16%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.78%	3.07%	-0.29%

Volatility

TRSSX vs. STMGX - Volatility Comparison

T. Rowe Price Institutional Small Cap Stock Fund (TRSSX) has a higher volatility of 5.04% compared to American Beacon Stephens Mid-Cap Growth Fund (STMGX) at 4.24%. This indicates that TRSSX's price experiences larger fluctuations and is considered to be riskier than STMGX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	TRSSX	STMGX	Difference
Volatility (1M) Calculated over the trailing 1-month period	5.04%	4.24%	+0.80%
Volatility (6M) Calculated over the trailing 6-month period	14.27%	12.70%	+1.57%
Volatility (1Y) Calculated over the trailing 1-year period	17.87%	16.27%	+1.60%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	22.21%	20.83%	+1.38%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	21.55%	20.89%	+0.66%

TRSSX vs. STMGX - Expense Ratio Comparison

TRSSX has a 0.66% expense ratio, which is lower than STMGX's 1.14% expense ratio.

Dividends

TRSSX vs. STMGX - Dividend Comparison

TRSSX's dividend yield for the trailing twelve months is around 9.57%, less than STMGX's 30.79% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
STMGX American Beacon Stephens Mid-Cap Growth Fund	30.79%	34.38%	4.86%	0.00%	3.42%	7.49%	1.45%	3.60%	9.39%	5.40%	6.65%	5.62%
TRSSX T. Rowe Price Institutional Small Cap Stock Fund	9.57%	10.57%	19.63%	5.45%	5.37%	8.52%	4.54%	6.13%	13.45%	6.53%	0.80%	7.07%

Frequently Asked Questions

Can I hold both TRSSX and STMGX in my portfolio?

TRSSX and STMGX have a correlation of 0.79, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, TRSSX or STMGX?

TRSSX has higher volatility (5.04%) compared to STMGX (4.24%). In terms of maximum drawdown, TRSSX dropped -56.38% vs STMGX's -57.58%.

Which has better risk-adjusted returns?

STMGX currently has the higher Sharpe Ratio (1.41 vs 1.35), 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.