STMSX vs. RIVSX

Last updated Jun 4, 2026

STMSX (SEI Institutional Managed Trust Tax-Managed Small/Mid Cap Fund) and RIVSX (River Oak Discovery Fund) are both Small Cap Blend Equities funds. Over the past 10 years, STMSX returned 9.35%/yr vs 12.25%/yr for RIVSX. Their correlation of 0.91 suggests significant overlap in exposure. STMSX charges 1.11%/yr vs 1.18%/yr for RIVSX.

Performance

STMSX vs. RIVSX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in SEI Institutional Managed Trust Tax-Managed Small/Mid Cap Fund (STMSX) and River Oak Discovery Fund (RIVSX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, STMSX achieves a 13.21% return, which is significantly lower than RIVSX's 32.82% return. Over the past 10 years, STMSX has underperformed RIVSX with an annualized return of 9.35%, while RIVSX has yielded a comparatively higher 12.25% annualized return.

STMSX

• 1D: 1.05%
• 1M: 2.23%
• YTD: 13.21%
• 6M: 13.30%
• 1Y: 26.59%
• 3Y*: 15.64%
• 5Y*: 6.41%
• 10Y*: 9.35%

RIVSX

• 1D: 1.77%
• 1M: 7.32%
• YTD: 32.82%
• 6M: 32.38%
• 1Y: 54.84%
• 3Y*: 17.61%
• 5Y*: 9.28%
• 10Y*: 12.25%

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

STMSX vs. RIVSX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
STMSX SEI Institutional Managed Trust Tax-Managed Small/Mid Cap Fund	13.21%	8.67%	13.34%	12.97%	-16.91%	23.68%	10.41%	21.99%	-12.34%	15.89%
RIVSX River Oak Discovery Fund	32.82%	9.11%	4.42%	8.18%	-14.53%	24.78%	29.00%	30.36%	-13.72%	11.33%

Correlation

The correlation between STMSX and RIVSX is 0.88, 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	0.88
Correlation (3Y) Calculated over the trailing 3-year period	0.90
Correlation (5Y) Calculated over the trailing 5-year period	0.91
Correlation (10Y) Calculated over the trailing 10-year period	0.90
Correlation (All Time) Calculated using the full available price history since Jan 4, 2006	0.91

The correlation between STMSX and RIVSX has been stable across timeframes, ranging from 0.88 to 0.91 - a consistent structural relationship.

Return for Risk

STMSX vs. RIVSX — Risk / Return Rank

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

STMSX

STMSX Risk / Return Rank: 42
STMSX Sharpe Ratio Rank: 34
STMSX Sortino Ratio Rank: 35
STMSX Omega Ratio Rank: 32
STMSX Calmar Ratio Rank: 57
STMSX Martin Ratio Rank: 49

RIVSX

RIVSX Risk / Return Rank: 90
RIVSX Sharpe Ratio Rank: 92
RIVSX Sortino Ratio Rank: 87
RIVSX Omega Ratio Rank: 78
RIVSX Calmar Ratio Rank: 96
RIVSX Martin Ratio Rank: 95

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.

STMSX vs. RIVSX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for SEI Institutional Managed Trust Tax-Managed Small/Mid Cap Fund (STMSX) and River Oak Discovery Fund (RIVSX). 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.

	STMSX	RIVSX	Difference
Sharpe ratio: Return per unit of total volatility	1.69	3.08	-1.39
Sortino ratio: Return per unit of downside risk	2.48	4.14	-1.66
Omega ratio: Gain probability vs. loss probability	1.30	1.52	-0.22
Calmar ratio: Return relative to maximum drawdown	2.90	6.32	-3.42
Martin ratio: Return relative to average drawdown	10.15	22.36	-12.21
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

STMSX vs. RIVSX - Sharpe Ratio Comparison

The current STMSX Sharpe Ratio is 1.69, which is lower than the RIVSX Sharpe Ratio of 3.08. The chart below compares the historical Sharpe Ratios of STMSX and RIVSX, 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

	STMSX	RIVSX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.69	3.08	-1.39
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.28	0.46	-0.18
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.41	0.56	-0.15
Sharpe Ratio (All Time) Calculated using the full available price history	0.35	0.38	-0.03

Drawdowns

STMSX vs. RIVSX - Drawdown Comparison

The maximum STMSX drawdown since its inception was -60.78%, roughly equal to the maximum RIVSX drawdown of -60.61%. Use the drawdown chart below to compare losses from any high point for STMSX and RIVSX.

Drawdown Indicators

	STMSX	RIVSX	Difference
Max Drawdown Largest peak-to-trough decline	-60.78%	-60.61%	-0.17%
Max Drawdown (1Y) Largest decline over 1 year	-9.69%	-9.11%	-0.58%
Max Drawdown (3Y) Largest decline over 3 years	-34.36%	-24.52%	-9.84%
Max Drawdown (5Y) Largest decline over 5 years	-34.36%	-25.75%	-8.61%
Max Drawdown (10Y) Largest decline over 10 years	-43.16%	-41.45%	-1.71%
Current Drawdown Current decline from peak	-2.32%	0.00%	-2.32%
Average Drawdown Average peak-to-trough decline	-10.62%	-10.49%	-0.13%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.77%	2.57%	+0.20%

Volatility

STMSX vs. RIVSX - Volatility Comparison

The current volatility for SEI Institutional Managed Trust Tax-Managed Small/Mid Cap Fund (STMSX) is 4.61%, while River Oak Discovery Fund (RIVSX) has a volatility of 5.33%. This indicates that STMSX experiences smaller price fluctuations and is considered to be less risky than RIVSX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	STMSX	RIVSX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.61%	5.33%	-0.72%
Volatility (6M) Calculated over the trailing 6-month period	11.97%	12.35%	-0.38%
Volatility (1Y) Calculated over the trailing 1-year period	16.64%	18.68%	-2.04%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	23.10%	20.26%	+2.84%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	22.88%	21.92%	+0.96%

STMSX vs. RIVSX - Expense Ratio Comparison

STMSX has a 1.11% expense ratio, which is lower than RIVSX's 1.18% expense ratio.

Dividends

STMSX vs. RIVSX - Dividend Comparison

STMSX's dividend yield for the trailing twelve months is around 3.82%, more than RIVSX's 0.22% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
RIVSX River Oak Discovery Fund	0.22%	0.29%	0.00%	0.00%	0.15%	16.84%	14.54%	3.81%	17.54%	5.48%	0.00%	0.11%
STMSX SEI Institutional Managed Trust Tax-Managed Small/Mid Cap Fund	3.82%	4.41%	21.88%	3.11%	0.84%	9.68%	0.29%	2.54%	9.26%	1.89%	0.41%	0.25%

Frequently Asked Questions

Can I hold both STMSX and RIVSX in my portfolio?

STMSX and RIVSX have a correlation of 0.88, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, STMSX or RIVSX?

RIVSX has higher volatility (5.33%) compared to STMSX (4.61%). In terms of maximum drawdown, STMSX dropped -60.78% vs RIVSX's -60.61%.

Which has better risk-adjusted returns?

RIVSX currently has the higher Sharpe Ratio (3.08 vs 1.69), 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.