VIMSX vs. BTMFX

Last updated Jun 4, 2026

VIMSX (Vanguard Mid Cap Index Fund) and BTMFX (Boston Trust Midcap Fund) are both Mid Cap Blend Equities funds. Over the past 10 years, VIMSX returned 11.40%/yr vs 10.08%/yr for BTMFX. Their correlation of 0.95 suggests significant overlap in exposure. VIMSX charges 0.17%/yr vs 1.00%/yr for BTMFX.

Performance

VIMSX vs. BTMFX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Vanguard Mid Cap Index Fund (VIMSX) 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, VIMSX achieves a 10.48% return, which is significantly higher than BTMFX's 1.92% return. Over the past 10 years, VIMSX has outperformed BTMFX with an annualized return of 11.40%, while BTMFX has yielded a comparatively lower 10.08% annualized return.

VIMSX

• 1D: 0.90%
• 1M: 3.66%
• YTD: 10.48%
• 6M: 10.13%
• 1Y: 18.59%
• 3Y*: 16.52%
• 5Y*: 7.88%
• 10Y*: 11.40%

BTMFX

• 1D: 0.26%
• 1M: 1.74%
• YTD: 1.92%
• 6M: 1.46%
• 1Y: 5.64%
• 3Y*: 9.29%
• 5Y*: 5.63%
• 10Y*: 10.08%

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

VIMSX vs. BTMFX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VIMSX Vanguard Mid Cap Index Fund	10.48%	11.08%	14.52%	16.40%	-18.80%	24.36%	18.04%	30.85%	-9.35%	19.12%
BTMFX Boston Trust Midcap Fund	1.92%	4.29%	10.27%	13.06%	-10.91%	24.77%	9.72%	33.00%	-3.36%	20.01%

Correlation

The correlation between VIMSX and BTMFX 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	0.93
Correlation (10Y) Calculated over the trailing 10-year period	0.93
Correlation (All Time) Calculated using the full available price history since Oct 1, 2007	0.95

The correlation between VIMSX and BTMFX has been stable across timeframes, ranging from 0.88 to 0.95 - a consistent structural relationship.

Return for Risk

VIMSX vs. BTMFX — Risk / Return Rank

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

VIMSX

VIMSX Risk / Return Rank: 35
VIMSX Sharpe Ratio Rank: 31
VIMSX Sortino Ratio Rank: 30
VIMSX Omega Ratio Rank: 29
VIMSX Calmar Ratio Rank: 41
VIMSX Martin Ratio Rank: 44

BTMFX

BTMFX Risk / Return Rank: 7
BTMFX Sharpe Ratio Rank: 7
BTMFX Sortino Ratio Rank: 7
BTMFX Omega Ratio Rank: 6
BTMFX Calmar Ratio Rank: 8
BTMFX Martin Ratio Rank: 8

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.

VIMSX vs. BTMFX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Vanguard Mid Cap Index Fund (VIMSX) 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.

	VIMSX	BTMFX	Difference
Sharpe ratio Return per unit of total volatility	1.60	0.56	+1.04
Sortino ratio Return per unit of downside risk	2.29	0.91	+1.38
Omega ratio Gain probability vs. loss probability	1.28	1.10	+0.18
Calmar ratio Return relative to maximum drawdown	2.42	0.84	+1.58
Martin ratio Return relative to average drawdown	9.19	2.35	+6.84
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

VIMSX vs. BTMFX - Sharpe Ratio Comparison

The current VIMSX Sharpe Ratio is 1.60, which is higher than the BTMFX Sharpe Ratio of 0.56. The chart below compares the historical Sharpe Ratios of VIMSX 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

	VIMSX	BTMFX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.60	0.56	+1.04
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.45	0.36	+0.09
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.60	0.58	+0.02
Sharpe Ratio (All Time) Calculated using the full available price history	0.48	0.48	0.00

Drawdowns

VIMSX vs. BTMFX - Drawdown Comparison

The maximum VIMSX drawdown since its inception was -58.96%, which is greater than BTMFX's maximum drawdown of -49.26%. Use the drawdown chart below to compare losses from any high point for VIMSX and BTMFX.

Drawdown Indicators

	VIMSX	BTMFX	Difference
Max Drawdown Largest peak-to-trough decline	-58.96%	-49.26%	-9.70%
Max Drawdown (1Y) Largest decline over 1 year	-8.14%	-7.79%	-0.35%
Max Drawdown (3Y) Largest decline over 3 years	-19.31%	-17.77%	-1.54%
Max Drawdown (5Y) Largest decline over 5 years	-27.63%	-20.79%	-6.84%
Max Drawdown (10Y) Largest decline over 10 years	-39.29%	-37.14%	-2.15%
Current Drawdown Current decline from peak	0.00%	-2.54%	+2.54%
Average Drawdown Average peak-to-trough decline	-8.07%	-6.16%	-1.91%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.14%	2.80%	-0.66%

Volatility

VIMSX vs. BTMFX - Volatility Comparison

Vanguard Mid Cap Index Fund (VIMSX) and Boston Trust Midcap Fund (BTMFX) have volatilities of 2.97% and 2.88%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	VIMSX	BTMFX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.97%	2.88%	+0.09%
Volatility (6M) Calculated over the trailing 6-month period	9.28%	7.99%	+1.29%
Volatility (1Y) Calculated over the trailing 1-year period	12.30%	11.80%	+0.50%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	17.64%	15.75%	+1.89%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.93%	17.44%	+1.49%

VIMSX vs. BTMFX - Expense Ratio Comparison

VIMSX has a 0.17% expense ratio, which is lower than BTMFX's 1.00% expense ratio.

Dividends

VIMSX vs. BTMFX - Dividend Comparison

VIMSX's dividend yield for the trailing twelve months is around 1.23%, less than BTMFX's 10.66% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BTMFX Boston Trust Midcap Fund	10.66%	10.86%	4.23%	4.41%	4.71%	4.91%	1.98%	6.95%	5.96%	6.61%	7.03%	6.60%
VIMSX Vanguard Mid Cap Index Fund	1.23%	1.03%	1.37%	1.39%	1.46%	1.00%	1.34%	1.37%	1.68%	1.24%	1.34%	1.33%

Frequently Asked Questions

Can I hold both VIMSX and BTMFX in my portfolio?

VIMSX and BTMFX 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, VIMSX or BTMFX?

VIMSX has higher volatility (2.97%) compared to BTMFX (2.88%). In terms of maximum drawdown, VIMSX dropped -58.96% vs BTMFX's -49.26%.

Which has better risk-adjusted returns?

VIMSX currently has the higher Sharpe Ratio (1.60 vs 0.56), 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.