BTMFX vs. BOSOX

Last updated Jun 23, 2026

BTMFX (Boston Trust Midcap Fund) and BOSOX (Boston Trust Small Cap Fund) are both mutual funds - BTMFX is a Mid Cap Blend Equities fund managed by Boston Trust Walden, while BOSOX is a Small Cap Blend Equities fund managed by Boston Trust Walden. Over the past 10 years, BTMFX returned 10.15%/yr vs 10.61%/yr for BOSOX. Their correlation of 0.92 suggests significant overlap in exposure. Both charge a 1.00% expense ratio.

Performance

BTMFX vs. BOSOX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Boston Trust Midcap Fund (BTMFX) 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, BTMFX achieves a 2.05% return, which is significantly lower than BOSOX's 10.25% return. Both investments have delivered pretty close results over the past 10 years, with BTMFX having a 10.15% annualized return and BOSOX not far ahead at 10.61%.

BTMFX

• 1D: 0.64%
• 1M: 0.77%
• YTD: 2.05%
• 6M: 0.69%
• 1Y: 7.62%
• 3Y*: 8.12%
• 5Y*: 6.26%
• 10Y*: 10.15%

BOSOX

• 1D: 1.22%
• 1M: 3.92%
• YTD: 10.25%
• 6M: 7.09%
• 1Y: 12.15%
• 3Y*: 8.22%
• 5Y*: 6.17%
• 10Y*: 10.61%

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

BTMFX vs. BOSOX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
BTMFX Boston Trust Midcap Fund	2.05%	4.29%	10.27%	13.06%	-10.91%	24.77%	9.72%	33.00%	-3.36%	20.01%
BOSOX Boston Trust Small Cap Fund	10.25%	-4.04%	12.52%	10.09%	-9.05%	28.10%	8.27%	38.35%	-6.01%	12.24%

Correlation

The correlation between BTMFX 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	0.91
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 Sep 28, 2007	0.92

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

Return for Risk

BTMFX vs. BOSOX — Risk / Return Rank

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

BTMFX

BTMFX Risk / Return Rank: 9
BTMFX Sharpe Ratio Rank: 8
BTMFX Sortino Ratio Rank: 9
BTMFX Omega Ratio Rank: 8
BTMFX Calmar Ratio Rank: 11
BTMFX Martin Ratio Rank: 10

BOSOX

BOSOX Risk / Return Rank: 11
BOSOX Sharpe Ratio Rank: 10
BOSOX Sortino Ratio Rank: 11
BOSOX Omega Ratio Rank: 10
BOSOX Calmar Ratio Rank: 12
BOSOX Martin Ratio Rank: 12

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.

BTMFX vs. BOSOX - Risk-Adjusted Trends Comparison

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

Values are calculated on a 1-year rolling basis and updated daily. Risk-adjusted metrics are more stable over longer periods — use the period switch above to explore them.

	BTMFX	BOSOX	Difference
Sharpe ratio: Return per unit of total volatility	0.65	0.78	-0.13
Sortino ratio: Return per unit of downside risk	1.05	1.27	-0.22
Omega ratio: Gain probability vs. loss probability	1.12	1.14	-0.02
Calmar ratio: Return relative to maximum drawdown	1.00	1.11	-0.11
Martin ratio: Return relative to average drawdown	2.75	3.34	-0.60

BTMFX vs. BOSOX - Sharpe Ratio Comparison

The current BTMFX Sharpe Ratio is 0.65, which is comparable to the BOSOX Sharpe Ratio of 0.78. The chart below compares the historical Sharpe Ratios of BTMFX 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.

Drawdowns

BTMFX vs. BOSOX - Drawdown Comparison

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

Drawdown Indicators

	BTMFX	BOSOX	Difference
Max Drawdown Largest peak-to-trough decline	-49.26%	-51.32%	+2.06%
Max Drawdown (1Y) Largest decline over 1 year	-7.79%	-10.69%	+2.90%
Max Drawdown (3Y) Largest decline over 3 years	-17.77%	-22.36%	+4.59%
Max Drawdown (5Y) Largest decline over 5 years	-20.79%	-22.36%	+1.57%
Max Drawdown (10Y) Largest decline over 10 years	-37.14%	-36.79%	-0.35%
Current Drawdown Current decline from peak	-2.42%	-3.50%	+1.08%
Average Drawdown Average peak-to-trough decline	-6.15%	-7.27%	+1.12%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.83%	3.54%	-0.71%

Volatility

BTMFX vs. BOSOX - Volatility Comparison

The current volatility for Boston Trust Midcap Fund (BTMFX) is 3.28%, while Boston Trust Small Cap Fund (BOSOX) has a volatility of 4.20%. This indicates that BTMFX experiences smaller price fluctuations and is considered to be less risky than BOSOX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	BTMFX	BOSOX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.28%	4.20%	-0.92%
Volatility (6M) Calculated over the trailing 6-month period	8.18%	10.25%	-2.07%
Volatility (1Y) Calculated over the trailing 1-year period	11.90%	15.20%	-3.30%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	15.76%	17.84%	-2.08%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	17.44%	19.57%	-2.13%

BTMFX vs. BOSOX - Expense Ratio Comparison

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

Dividends

BTMFX vs. BOSOX - Dividend Comparison

BTMFX's dividend yield for the trailing twelve months is around 10.64%, more than BOSOX's 4.00% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BOSOX Boston Trust Small Cap Fund	4.00%	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	10.64%	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 BTMFX and BOSOX in my portfolio?

BTMFX 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, BTMFX or BOSOX?

BOSOX has higher volatility (4.20%) compared to BTMFX (3.28%). In terms of maximum drawdown, BTMFX dropped -49.26% vs BOSOX's -51.32%.

Which has better risk-adjusted returns?

BOSOX currently has the higher Sharpe Ratio (0.78 vs 0.65), 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.