BBMIX vs. FMDGX

Last updated Jun 26, 2026

BBMIX (BBH Select Series - Mid Cap Fund) and FMDGX (Fidelity Mid Cap Growth Index Fund) are both Mid Cap Growth Equities funds. Over the past 5 years, BBMIX returned 2.56%/yr vs 5.28%/yr for FMDGX. Their correlation of 0.83 suggests significant overlap in exposure. BBMIX charges 0.90%/yr vs 0.05%/yr for FMDGX.

Performance

BBMIX vs. FMDGX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in BBH Select Series - Mid Cap Fund (BBMIX) and Fidelity Mid Cap Growth Index Fund (FMDGX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, BBMIX achieves a 2.86% return, which is significantly lower than FMDGX's 3.45% return.

BBMIX

• 1D: 0.00%
• 1M: 0.00%
• YTD: 2.86%
• 6M: 2.86%
• 1Y: -1.29%
• 3Y*: 6.50%
• 5Y*: 2.56%
• 10Y*: —

FMDGX

• 1D: 0.97%
• 1M: 0.53%
• YTD: 3.45%
• 6M: 1.23%
• 1Y: 3.73%
• 3Y*: 15.55%
• 5Y*: 5.28%
• 10Y*: —

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

BBMIX vs. FMDGX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021
BBMIX BBH Select Series - Mid Cap Fund	2.86%	-6.45%	11.41%	26.01%	-24.76%	13.50%
FMDGX Fidelity Mid Cap Growth Index Fund	3.45%	8.60%	22.03%	25.79%	-26.67%	11.25%

Correlation

The correlation between BBMIX and FMDGX is 0.40, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.40
Correlation (3Y) Calculated over the trailing 3-year period	0.74
Correlation (5Y) Calculated over the trailing 5-year period	0.84
Correlation (All Time) Calculated using the full available price history since May 24, 2021	0.83

Over the past year, the correlation between BBMIX and FMDGX has dropped to 0.40 - well below their long-term average of 0.83, suggesting their price drivers have been diverging.

Return for Risk

BBMIX vs. FMDGX — Risk / Return Rank

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

BBMIX

BBMIX Risk / Return Rank: 2
BBMIX Sharpe Ratio Rank: 2
BBMIX Sortino Ratio Rank: 2
BBMIX Omega Ratio Rank: 2
BBMIX Calmar Ratio Rank: 2
BBMIX Martin Ratio Rank: 2

FMDGX

FMDGX Risk / Return Rank: 5
FMDGX Sharpe Ratio Rank: 5
FMDGX Sortino Ratio Rank: 5
FMDGX Omega Ratio Rank: 5
FMDGX Calmar Ratio Rank: 5
FMDGX Martin Ratio Rank: 5

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.

BBMIX vs. FMDGX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for BBH Select Series - Mid Cap Fund (BBMIX) and Fidelity Mid Cap Growth Index Fund (FMDGX). 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.

	BBMIX	FMDGX	Difference
Sharpe ratio: Return per unit of total volatility	-0.25	0.17	-0.43
Sortino ratio: Return per unit of downside risk	-0.29	0.37	-0.66
Omega ratio: Gain probability vs. loss probability	0.95	1.04	-0.09
Calmar ratio: Return relative to maximum drawdown	-0.31	0.20	-0.52
Martin ratio: Return relative to average drawdown	-0.47	0.58	-1.05

BBMIX vs. FMDGX - Sharpe Ratio Comparison

The current BBMIX Sharpe Ratio is -0.25, which is lower than the FMDGX Sharpe Ratio of 0.17. The chart below compares the historical Sharpe Ratios of BBMIX and FMDGX, 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

BBMIX vs. FMDGX - Drawdown Comparison

The maximum BBMIX drawdown since its inception was -28.90%, smaller than the maximum FMDGX drawdown of -38.59%. Use the drawdown chart below to compare losses from any high point for BBMIX and FMDGX.

Drawdown Indicators

	BBMIX	FMDGX	Difference
Max Drawdown Largest peak-to-trough decline	-28.90%	-38.59%	+9.69%
Max Drawdown (1Y) Largest decline over 1 year	-8.89%	-14.75%	+5.86%
Max Drawdown (3Y) Largest decline over 3 years	-23.79%	-25.30%	+1.51%
Max Drawdown (5Y) Largest decline over 5 years	-28.90%	-38.59%	+9.69%
Current Drawdown Current decline from peak	-11.28%	-2.43%	-8.85%
Average Drawdown Average peak-to-trough decline	-10.51%	-11.13%	+0.62%
Ulcer Index Depth and duration of drawdowns from previous peaks	5.33%	5.10%	+0.23%

Volatility

BBMIX vs. FMDGX - Volatility Comparison

The current volatility for BBH Select Series - Mid Cap Fund (BBMIX) is 0.00%, while Fidelity Mid Cap Growth Index Fund (FMDGX) has a volatility of 5.85%. This indicates that BBMIX experiences smaller price fluctuations and is considered to be less risky than FMDGX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	BBMIX	FMDGX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.00%	5.85%	-5.85%
Volatility (6M) Calculated over the trailing 6-month period	5.87%	13.42%	-7.55%
Volatility (1Y) Calculated over the trailing 1-year period	11.00%	17.10%	-6.10%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	19.70%	22.46%	-2.76%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	19.55%	24.30%	-4.75%

BBMIX vs. FMDGX - Expense Ratio Comparison

BBMIX has a 0.90% expense ratio, which is higher than FMDGX's 0.05% expense ratio.

Dividends

BBMIX vs. FMDGX - Dividend Comparison

BBMIX has not paid dividends to shareholders, while FMDGX's dividend yield for the trailing twelve months is around 1.79%.

Position	TTM	2025	2024	2023	2022	2021	2020	2019
BBMIX BBH Select Series - Mid Cap Fund	0.00%	0.00%	0.32%	0.10%	0.00%	0.00%	0.00%	0.00%
FMDGX Fidelity Mid Cap Growth Index Fund	1.79%	1.85%	0.47%	0.63%	0.81%	6.43%	0.36%	0.29%

Frequently Asked Questions

Can I hold both BBMIX and FMDGX in my portfolio?

BBMIX and FMDGX have a correlation of 0.40, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, BBMIX or FMDGX?

FMDGX has higher volatility (5.85%) compared to BBMIX (0.00%). In terms of maximum drawdown, BBMIX dropped -28.90% vs FMDGX's -38.59%.

Which has better risk-adjusted returns?

FMDGX currently has the higher Sharpe Ratio (0.17 vs -0.25), 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.