BBGSX vs. FSMDX

Last updated Jun 23, 2026

BBGSX (Bridge Builder Small/Mid Cap Growth Fund) and FSMDX (Fidelity Mid Cap Index Fund) are both mutual funds - BBGSX is a Mid Cap Growth Equities fund managed by Bridge Builder, while FSMDX is a Mid Cap Blend Equities fund tracking the Russell Midcap Index. Over the past 10 years, BBGSX returned 10.94%/yr vs 11.79%/yr for FSMDX. Their correlation of 0.92 suggests significant overlap in exposure. BBGSX charges 0.38%/yr vs 0.03%/yr for FSMDX.

Performance

BBGSX vs. FSMDX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Bridge Builder Small/Mid Cap Growth Fund (BBGSX) and Fidelity Mid Cap Index Fund (FSMDX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, BBGSX achieves a 10.44% return, which is significantly lower than FSMDX's 13.43% return. Over the past 10 years, BBGSX has underperformed FSMDX with an annualized return of 10.94%, while FSMDX has yielded a comparatively higher 11.79% annualized return.

BBGSX

• 1D: 1.81%
• 1M: 2.98%
• YTD: 10.44%
• 6M: 7.66%
• 1Y: 13.43%
• 3Y*: 11.22%
• 5Y*: 3.10%
• 10Y*: 10.94%

FSMDX

• 1D: 0.99%
• 1M: 2.77%
• YTD: 13.43%
• 6M: 11.53%
• 1Y: 22.95%
• 3Y*: 16.47%
• 5Y*: 8.89%
• 10Y*: 11.79%

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

BBGSX vs. FSMDX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
BBGSX Bridge Builder Small/Mid Cap Growth Fund	10.44%	0.99%	14.47%	20.98%	-29.84%	16.57%	34.41%	29.01%	-2.18%	21.47%
FSMDX Fidelity Mid Cap Index Fund	13.43%	10.58%	15.55%	17.20%	-17.27%	22.56%	17.13%	30.53%	-9.38%	18.04%

Correlation

The correlation between BBGSX and FSMDX is 0.86, 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	0.86
Correlation (3Y) Calculated over the trailing 3-year period	0.86
Correlation (5Y) Calculated over the trailing 5-year period	0.91
Correlation (10Y) Calculated over the trailing 10-year period	0.92
Correlation (All Time) Calculated using the full available price history since Jan 4, 2016	0.92

The correlation between BBGSX and FSMDX has been stable across timeframes, ranging from 0.86 to 0.92 - a consistent structural relationship.

Return for Risk

BBGSX vs. FSMDX — Risk / Return Rank

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

BBGSX

BBGSX Risk / Return Rank: 9
BBGSX Sharpe Ratio Rank: 9
BBGSX Sortino Ratio Rank: 9
BBGSX Omega Ratio Rank: 9
BBGSX Calmar Ratio Rank: 9
BBGSX Martin Ratio Rank: 9

FSMDX

FSMDX Risk / Return Rank: 46
FSMDX Sharpe Ratio Rank: 38
FSMDX Sortino Ratio Rank: 39
FSMDX Omega Ratio Rank: 35
FSMDX Calmar Ratio Rank: 60
FSMDX Martin Ratio Rank: 57

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.

BBGSX vs. FSMDX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Bridge Builder Small/Mid Cap Growth Fund (BBGSX) and Fidelity Mid Cap Index Fund (FSMDX). 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.

	BBGSX	FSMDX	Difference
Sharpe ratio: Return per unit of total volatility	0.74	1.68	-0.94
Sortino ratio: Return per unit of downside risk	1.14	2.40	-1.27
Omega ratio: Gain probability vs. loss probability	1.14	1.29	-0.15
Calmar ratio: Return relative to maximum drawdown	0.82	2.84	-2.02
Martin ratio: Return relative to average drawdown	2.44	10.86	-8.42

BBGSX vs. FSMDX - Sharpe Ratio Comparison

The current BBGSX Sharpe Ratio is 0.74, which is lower than the FSMDX Sharpe Ratio of 1.68. The chart below compares the historical Sharpe Ratios of BBGSX and FSMDX, 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

BBGSX vs. FSMDX - Drawdown Comparison

The maximum BBGSX drawdown since its inception was -37.95%, smaller than the maximum FSMDX drawdown of -40.35%. Use the drawdown chart below to compare losses from any high point for BBGSX and FSMDX.

Drawdown Indicators

	BBGSX	FSMDX	Difference
Max Drawdown Largest peak-to-trough decline	-37.95%	-40.35%	+2.40%
Max Drawdown (1Y) Largest decline over 1 year	-16.72%	-8.16%	-8.56%
Max Drawdown (3Y) Largest decline over 3 years	-26.11%	-20.92%	-5.19%
Max Drawdown (5Y) Largest decline over 5 years	-37.95%	-26.07%	-11.88%
Max Drawdown (10Y) Largest decline over 10 years	-37.95%	-40.35%	+2.40%
Current Drawdown Current decline from peak	-0.39%	-0.78%	+0.39%
Average Drawdown Average peak-to-trough decline	-9.53%	-4.94%	-4.59%
Ulcer Index Depth and duration of drawdowns from previous peaks	5.53%	2.13%	+3.40%

Volatility

BBGSX vs. FSMDX - Volatility Comparison

Bridge Builder Small/Mid Cap Growth Fund (BBGSX) has a higher volatility of 6.78% compared to Fidelity Mid Cap Index Fund (FSMDX) at 4.57%. This indicates that BBGSX's price experiences larger fluctuations and is considered to be riskier than FSMDX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	BBGSX	FSMDX	Difference
Volatility (1M) Calculated over the trailing 1-month period	6.78%	4.57%	+2.21%
Volatility (6M) Calculated over the trailing 6-month period	14.98%	10.47%	+4.51%
Volatility (1Y) Calculated over the trailing 1-year period	18.53%	13.82%	+4.71%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	21.83%	18.33%	+3.50%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	21.03%	19.35%	+1.68%

BBGSX vs. FSMDX - Expense Ratio Comparison

BBGSX has a 0.38% expense ratio, which is higher than FSMDX's 0.03% expense ratio.

Dividends

BBGSX vs. FSMDX - Dividend Comparison

BBGSX has not paid dividends to shareholders, while FSMDX's dividend yield for the trailing twelve months is around 0.97%.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BBGSX Bridge Builder Small/Mid Cap Growth Fund	0.00%	0.00%	0.58%	0.32%	0.19%	18.00%	12.59%	4.07%	6.12%	1.09%	0.36%	0.00%
FSMDX Fidelity Mid Cap Index Fund	0.97%	1.10%	2.46%	1.39%	2.07%	3.35%	2.34%	2.86%	2.21%	2.17%	2.23%	2.84%

Frequently Asked Questions

Can I hold both BBGSX and FSMDX in my portfolio?

BBGSX and FSMDX have a correlation of 0.86, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, BBGSX or FSMDX?

BBGSX has higher volatility (6.78%) compared to FSMDX (4.57%). In terms of maximum drawdown, BBGSX dropped -37.95% vs FSMDX's -40.35%.

Which has better risk-adjusted returns?

FSMDX currently has the higher Sharpe Ratio (1.68 vs 0.74), 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.