RMBMX vs. FMDGX

Last updated Jun 4, 2026

RMBMX (RMB SMID Cap Fund) and FMDGX (Fidelity Mid Cap Growth Index Fund) are both Mid Cap Growth Equities funds. Over the past 5 years, RMBMX returned 5.44%/yr vs 7.23%/yr for FMDGX. Their correlation of 0.88 suggests significant overlap in exposure. RMBMX charges 0.84%/yr vs 0.05%/yr for FMDGX.

Performance

RMBMX vs. FMDGX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in RMB SMID Cap Fund (RMBMX) 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, RMBMX achieves a 8.47% return, which is significantly higher than FMDGX's 4.88% return.

RMBMX

• 1D: 0.79%
• 1M: 1.59%
• YTD: 8.47%
• 6M: 6.57%
• 1Y: 13.14%
• 3Y*: 12.13%
• 5Y*: 5.44%
• 10Y*: 10.98%

FMDGX

• 1D: -0.22%
• 1M: 5.21%
• YTD: 4.88%
• 6M: 3.96%
• 1Y: 6.81%
• 3Y*: 16.42%
• 5Y*: 7.23%
• 10Y*: —

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

RMBMX vs. FMDGX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019
RMBMX RMB SMID Cap Fund	8.47%	2.46%	10.04%	20.32%	-20.36%	28.05%	24.43%	7.50%
FMDGX Fidelity Mid Cap Growth Index Fund	4.88%	8.60%	22.03%	25.79%	-26.67%	12.67%	34.84%	4.63%

Correlation

The correlation between RMBMX and FMDGX is 0.77, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.77
Correlation (3Y) Calculated over the trailing 3-year period	0.85
Correlation (5Y) Calculated over the trailing 5-year period	0.89
Correlation (All Time) Calculated using the full available price history since Jul 18, 2019	0.88

The correlation between RMBMX and FMDGX shifts across timeframes, from 0.77 (1 year) to 0.89 (5 years), reflecting how their relationship changes across market environments.

Return for Risk

RMBMX vs. FMDGX — Risk / Return Rank

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

RMBMX

RMBMX Risk / Return Rank: 14
RMBMX Sharpe Ratio Rank: 12
RMBMX Sortino Ratio Rank: 13
RMBMX Omega Ratio Rank: 11
RMBMX Calmar Ratio Rank: 16
RMBMX Martin Ratio Rank: 18

FMDGX

FMDGX Risk / Return Rank: 6
FMDGX Sharpe Ratio Rank: 6
FMDGX Sortino Ratio Rank: 6
FMDGX Omega Ratio Rank: 6
FMDGX Calmar Ratio Rank: 6
FMDGX Martin Ratio Rank: 6

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.

RMBMX vs. FMDGX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for RMB SMID Cap Fund (RMBMX) 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.

	RMBMX	FMDGX	Difference
Sharpe ratio: Return per unit of total volatility	0.92	0.49	+0.43
Sortino ratio: Return per unit of downside risk	1.45	0.80	+0.66
Omega ratio: Gain probability vs. loss probability	1.17	1.09	+0.07
Calmar ratio: Return relative to maximum drawdown	1.40	0.54	+0.86
Martin ratio: Return relative to average drawdown	4.90	1.58	+3.32
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

RMBMX vs. FMDGX - Sharpe Ratio Comparison

The current RMBMX Sharpe Ratio is 0.92, which is higher than the FMDGX Sharpe Ratio of 0.49. The chart below compares the historical Sharpe Ratios of RMBMX 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.

Sharpe Ratios by Period

	RMBMX	FMDGX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.92	0.49	+0.43
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.26	0.32	-0.06
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.53	—	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.42	0.45	-0.03

Drawdowns

RMBMX vs. FMDGX - Drawdown Comparison

The maximum RMBMX drawdown since its inception was -52.47%, which is greater than FMDGX's maximum drawdown of -38.59%. Use the drawdown chart below to compare losses from any high point for RMBMX and FMDGX.

Drawdown Indicators

	RMBMX	FMDGX	Difference
Max Drawdown Largest peak-to-trough decline	-52.47%	-38.59%	-13.88%
Max Drawdown (1Y) Largest decline over 1 year	-10.40%	-14.75%	+4.35%
Max Drawdown (3Y) Largest decline over 3 years	-24.10%	-25.30%	+1.20%
Max Drawdown (5Y) Largest decline over 5 years	-29.03%	-38.59%	+9.56%
Max Drawdown (10Y) Largest decline over 10 years	-39.63%	—	—
Current Drawdown Current decline from peak	-0.86%	-1.09%	+0.23%
Average Drawdown Average peak-to-trough decline	-7.92%	-11.21%	+3.29%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.96%	5.05%	-2.09%

Volatility

RMBMX vs. FMDGX - Volatility Comparison

RMB SMID Cap Fund (RMBMX) has a higher volatility of 4.03% compared to Fidelity Mid Cap Growth Index Fund (FMDGX) at 3.52%. This indicates that RMBMX's price experiences larger fluctuations and is considered to be riskier than FMDGX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	RMBMX	FMDGX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.03%	3.52%	+0.51%
Volatility (6M) Calculated over the trailing 6-month period	11.66%	12.64%	-0.98%
Volatility (1Y) Calculated over the trailing 1-year period	15.81%	16.46%	-0.65%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	20.77%	22.37%	-1.60%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	20.84%	24.32%	-3.48%

RMBMX vs. FMDGX - Expense Ratio Comparison

RMBMX has a 0.84% expense ratio, which is higher than FMDGX's 0.05% expense ratio.

Dividends

RMBMX vs. FMDGX - Dividend Comparison

RMBMX's dividend yield for the trailing twelve months is around 18.19%, more than FMDGX's 1.77% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FMDGX Fidelity Mid Cap Growth Index Fund	1.77%	1.85%	0.47%	0.63%	0.81%	6.43%	0.36%	0.29%	0.00%	0.00%	0.00%	0.00%
RMBMX RMB SMID Cap Fund	18.19%	19.73%	9.50%	10.12%	8.40%	5.53%	5.34%	14.27%	15.63%	14.74%	18.84%	6.38%

Frequently Asked Questions

Can I hold both RMBMX and FMDGX in my portfolio?

RMBMX and FMDGX have a correlation of 0.77, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, RMBMX or FMDGX?

RMBMX has higher volatility (4.03%) compared to FMDGX (3.52%). In terms of maximum drawdown, RMBMX dropped -52.47% vs FMDGX's -38.59%.

Which has better risk-adjusted returns?

RMBMX currently has the higher Sharpe Ratio (0.92 vs 0.49), 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.