BOSOX vs. BTMFX

Last updated Jun 4, 2026

BOSOX (Boston Trust Small Cap Fund) and BTMFX (Boston Trust Midcap Fund) are both mutual funds - BOSOX is a Small Cap Blend Equities fund managed by Boston Trust Walden, while BTMFX is a Mid Cap Blend Equities fund managed by Boston Trust Walden. Over the past 10 years, BOSOX returned 10.23%/yr vs 10.05%/yr for BTMFX. Their correlation of 0.92 suggests significant overlap in exposure. Both charge a 1.00% expense ratio.

Performance

BOSOX vs. BTMFX - Performance Comparison

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

Returns By Period

In the year-to-date period, BOSOX achieves a 6.63% return, which is significantly higher than BTMFX's 1.66% return. Both investments have delivered pretty close results over the past 10 years, with BOSOX having a 10.23% annualized return and BTMFX not far behind at 10.05%.

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%

BTMFX

• 1D: 0.21%
• 1M: 0.82%
• YTD: 1.66%
• 6M: 1.84%
• 1Y: 6.28%
• 3Y*: 9.20%
• 5Y*: 5.59%
• 10Y*: 10.05%

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

BOSOX vs. BTMFX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
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%
BTMFX Boston Trust Midcap Fund	1.66%	4.29%	10.27%	13.06%	-10.91%	24.77%	9.72%	33.00%	-3.36%	20.01%

Correlation

The correlation between BOSOX and BTMFX 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	0.91
Correlation (5Y) Calculated over the trailing 5-year period	0.92
Correlation (10Y) Calculated over the trailing 10-year period	0.91
Correlation (All Time) Calculated using the full available price history since Oct 1, 2007	0.92

The correlation between BOSOX and BTMFX has been stable across timeframes, ranging from 0.87 to 0.92 - a consistent structural relationship.

Return for Risk

BOSOX vs. BTMFX — Risk / Return Rank

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

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

BTMFX

BTMFX Risk / Return Rank: 6
BTMFX Sharpe Ratio Rank: 6
BTMFX Sortino Ratio Rank: 6
BTMFX Omega Ratio Rank: 6
BTMFX Calmar Ratio Rank: 7
BTMFX 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.

BOSOX vs. BTMFX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Boston Trust Small Cap Fund (BOSOX) and Boston Trust Midcap Fund (BTMFX). 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.

	BOSOX	BTMFX	Difference
Sharpe ratio Return per unit of total volatility	0.53	0.51	+0.01
Sortino ratio Return per unit of downside risk	0.89	0.85	+0.05
Omega ratio Gain probability vs. loss probability	1.10	1.10	0.00
Calmar ratio Return relative to maximum drawdown	0.74	0.76	-0.02
Martin ratio Return relative to average drawdown	2.22	2.12	+0.09
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

BOSOX vs. BTMFX - Sharpe Ratio Comparison

The current BOSOX Sharpe Ratio is 0.53, which is comparable to the BTMFX Sharpe Ratio of 0.51. The chart below compares the historical Sharpe Ratios of BOSOX and BTMFX, 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

	BOSOX	BTMFX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.53	0.51	+0.01
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.28	0.36	-0.08
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.53	0.58	-0.05
Sharpe Ratio (All Time) Calculated using the full available price history	0.43	0.48	-0.05

Drawdowns

BOSOX vs. BTMFX - Drawdown Comparison

The maximum BOSOX drawdown since its inception was -51.32%, roughly equal to the maximum BTMFX drawdown of -49.26%. Use the drawdown chart below to compare losses from any high point for BOSOX and BTMFX.

Drawdown Indicators

	BOSOX	BTMFX	Difference
Max Drawdown Largest peak-to-trough decline	-51.32%	-49.26%	-2.06%
Max Drawdown (1Y) Largest decline over 1 year	-10.69%	-7.79%	-2.90%
Max Drawdown (3Y) Largest decline over 3 years	-22.36%	-17.77%	-4.59%
Max Drawdown (5Y) Largest decline over 5 years	-22.36%	-20.79%	-1.57%
Max Drawdown (10Y) Largest decline over 10 years	-36.79%	-37.14%	+0.35%
Current Drawdown Current decline from peak	-6.67%	-2.79%	-3.88%
Average Drawdown Average peak-to-trough decline	-7.27%	-6.17%	-1.10%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.57%	2.79%	+0.78%

Volatility

BOSOX vs. BTMFX - Volatility Comparison

Boston Trust Small Cap Fund (BOSOX) has a higher volatility of 3.90% compared to Boston Trust Midcap Fund (BTMFX) at 2.90%. This indicates that BOSOX's price experiences larger fluctuations and is considered to be riskier than BTMFX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	BOSOX	BTMFX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.90%	2.90%	+1.00%
Volatility (6M) Calculated over the trailing 6-month period	10.08%	7.99%	+2.09%
Volatility (1Y) Calculated over the trailing 1-year period	15.10%	11.82%	+3.28%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	17.82%	15.75%	+2.07%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	19.56%	17.44%	+2.12%

BOSOX vs. BTMFX - Expense Ratio Comparison

Both BOSOX and BTMFX have an expense ratio of 1.00%.

Dividends

BOSOX vs. BTMFX - Dividend Comparison

BOSOX's dividend yield for the trailing twelve months is around 4.14%, less than BTMFX's 10.69% 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%
BTMFX Boston Trust Midcap Fund	10.69%	10.86%	4.23%	4.41%	4.71%	4.91%	1.98%	6.95%	5.96%	6.61%	7.03%	6.60%

Frequently Asked Questions

Can I hold both BOSOX and BTMFX in my portfolio?

BOSOX and BTMFX 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, BOSOX or BTMFX?

BOSOX has higher volatility (3.90%) compared to BTMFX (2.90%). In terms of maximum drawdown, BOSOX dropped -51.32% vs BTMFX's -49.26%.

Which has better risk-adjusted returns?

BOSOX currently has the higher Sharpe Ratio (0.53 vs 0.51), 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.