REBYX vs. BOSOX

Last updated Jun 4, 2026

REBYX (Russell Investments U.S. Small Cap Equity Fund) and BOSOX (Boston Trust Small Cap Fund) are both Small Cap Blend Equities funds. Over the past 10 years, REBYX returned 9.36%/yr vs 10.23%/yr for BOSOX. Their correlation of 0.94 suggests significant overlap in exposure. REBYX charges 0.90%/yr vs 1.00%/yr for BOSOX.

Performance

REBYX vs. BOSOX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Russell Investments U.S. Small Cap Equity Fund (REBYX) and Boston Trust Small Cap Fund (BOSOX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, REBYX achieves a 17.23% return, which is significantly higher than BOSOX's 6.63% return. Over the past 10 years, REBYX has underperformed BOSOX with an annualized return of 9.36%, while BOSOX has yielded a comparatively higher 10.23% annualized return.

REBYX

• 1D: 0.47%
• 1M: 4.17%
• YTD: 17.23%
• 6M: 16.82%
• 1Y: 36.24%
• 3Y*: 15.12%
• 5Y*: 6.27%
• 10Y*: 9.36%

BOSOX

• 1D: 0.80%
• 1M: 2.85%
• YTD: 6.63%
• 6M: 4.71%
• 1Y: 6.71%
• 3Y*: 7.74%
• 5Y*: 4.92%
• 10Y*: 10.23%

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

REBYX vs. BOSOX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
REBYX Russell Investments U.S. Small Cap Equity Fund	17.23%	8.86%	8.16%	13.81%	-16.14%	26.28%	13.04%	23.74%	-12.22%	2.12%
BOSOX Boston Trust Small Cap Fund	6.63%	-4.04%	12.52%	10.09%	-9.05%	28.10%	8.27%	38.35%	-6.01%	12.24%

Correlation

The correlation between REBYX and BOSOX is 0.87, 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	0.87
Correlation (3Y) Calculated over the trailing 3-year period	0.90
Correlation (5Y) Calculated over the trailing 5-year period	0.92
Correlation (10Y) Calculated over the trailing 10-year period	0.92
Correlation (All Time) Calculated using the full available price history since Dec 20, 2005	0.94

The correlation between REBYX and BOSOX has been stable across timeframes, ranging from 0.87 to 0.94 - a consistent structural relationship.

Return for Risk

REBYX vs. BOSOX — Risk / Return Rank

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

REBYX

REBYX Risk / Return Rank: 64
REBYX Sharpe Ratio Rank: 54
REBYX Sortino Ratio Rank: 54
REBYX Omega Ratio Rank: 47
REBYX Calmar Ratio Rank: 87
REBYX Martin Ratio Rank: 78

BOSOX

BOSOX Risk / Return Rank: 7
BOSOX Sharpe Ratio Rank: 6
BOSOX Sortino Ratio Rank: 7
BOSOX Omega Ratio Rank: 6
BOSOX Calmar Ratio Rank: 7
BOSOX Martin Ratio Rank: 7

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.

REBYX vs. BOSOX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Russell Investments U.S. Small Cap Equity Fund (REBYX) and Boston Trust Small Cap Fund (BOSOX). 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.

	REBYX	BOSOX	Difference
Sharpe ratio: Return per unit of total volatility	2.17	0.53	+1.65
Sortino ratio: Return per unit of downside risk	3.09	0.89	+2.19
Omega ratio: Gain probability vs. loss probability	1.37	1.10	+0.27
Calmar ratio: Return relative to maximum drawdown	4.23	0.74	+3.49
Martin ratio: Return relative to average drawdown	14.63	2.22	+12.41
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

REBYX vs. BOSOX - Sharpe Ratio Comparison

The current REBYX Sharpe Ratio is 2.17, which is higher than the BOSOX Sharpe Ratio of 0.53. The chart below compares the historical Sharpe Ratios of REBYX and BOSOX, 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

	REBYX	BOSOX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.17	0.53	+1.65
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.28	0.28	0.00
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.40	0.53	-0.13
Sharpe Ratio (All Time) Calculated using the full available price history	0.34	0.43	-0.09

Drawdowns

REBYX vs. BOSOX - Drawdown Comparison

The maximum REBYX drawdown since its inception was -62.03%, which is greater than BOSOX's maximum drawdown of -51.32%. Use the drawdown chart below to compare losses from any high point for REBYX and BOSOX.

Drawdown Indicators

	REBYX	BOSOX	Difference
Max Drawdown Largest peak-to-trough decline	-62.03%	-51.32%	-10.71%
Max Drawdown (1Y) Largest decline over 1 year	-9.16%	-10.69%	+1.53%
Max Drawdown (3Y) Largest decline over 3 years	-32.68%	-22.36%	-10.32%
Max Drawdown (5Y) Largest decline over 5 years	-32.68%	-22.36%	-10.32%
Max Drawdown (10Y) Largest decline over 10 years	-44.79%	-36.79%	-8.00%
Current Drawdown Current decline from peak	-0.23%	-6.67%	+6.44%
Average Drawdown Average peak-to-trough decline	-11.18%	-7.27%	-3.91%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.65%	3.57%	-0.92%

Volatility

REBYX vs. BOSOX - Volatility Comparison

Russell Investments U.S. Small Cap Equity Fund (REBYX) has a higher volatility of 5.06% compared to Boston Trust Small Cap Fund (BOSOX) at 3.90%. This indicates that REBYX's price experiences larger fluctuations and is considered to be riskier than BOSOX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	REBYX	BOSOX	Difference
Volatility (1M) Calculated over the trailing 1-month period	5.06%	3.90%	+1.16%
Volatility (6M) Calculated over the trailing 6-month period	12.42%	10.08%	+2.34%
Volatility (1Y) Calculated over the trailing 1-year period	17.84%	15.10%	+2.74%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	22.76%	17.82%	+4.94%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	23.53%	19.56%	+3.97%

REBYX vs. BOSOX - Expense Ratio Comparison

REBYX has a 0.90% expense ratio, which is lower than BOSOX's 1.00% expense ratio.

Dividends

REBYX vs. BOSOX - Dividend Comparison

REBYX's dividend yield for the trailing twelve months is around 7.06%, more than BOSOX's 4.14% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BOSOX Boston Trust Small Cap Fund	4.14%	4.41%	6.52%	0.78%	5.09%	8.93%	2.56%	12.46%	16.19%	9.13%	3.14%	18.92%
REBYX Russell Investments U.S. Small Cap Equity Fund	7.06%	8.28%	13.03%	2.64%	5.30%	31.12%	0.64%	4.46%	18.61%	0.33%	0.88%	8.23%

Frequently Asked Questions

Can I hold both REBYX and BOSOX in my portfolio?

REBYX and BOSOX have a correlation of 0.87, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, REBYX or BOSOX?

REBYX has higher volatility (5.06%) compared to BOSOX (3.90%). In terms of maximum drawdown, REBYX dropped -62.03% vs BOSOX's -51.32%.

Which has better risk-adjusted returns?

REBYX currently has the higher Sharpe Ratio (2.17 vs 0.53), 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.