OTCAX vs. FSMDX

Last updated Jun 4, 2026

OTCAX (MFS Mid Cap Growth Fund) and FSMDX (Fidelity Mid Cap Index Fund) are both mutual funds - OTCAX is a Mid Cap Growth Equities fund managed by MFS, while FSMDX is a Mid Cap Blend Equities fund managed by Fidelity. Over the past 10 years, OTCAX returned 12.24%/yr vs 11.69%/yr for FSMDX. Their correlation of 0.90 suggests significant overlap in exposure. OTCAX charges 1.00%/yr vs 0.03%/yr for FSMDX.

Performance

OTCAX vs. FSMDX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in MFS Mid Cap Growth Fund (OTCAX) 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, OTCAX achieves a 4.87% return, which is significantly lower than FSMDX's 12.78% return. Both investments have delivered pretty close results over the past 10 years, with OTCAX having a 12.24% annualized return and FSMDX not far behind at 11.69%.

OTCAX

• 1D: 0.61%
• 1M: 3.80%
• YTD: 4.87%
• 6M: 3.45%
• 1Y: 4.29%
• 3Y*: 14.31%
• 5Y*: 5.78%
• 10Y*: 12.24%

FSMDX

• 1D: 0.70%
• 1M: 4.12%
• YTD: 12.78%
• 6M: 12.57%
• 1Y: 22.14%
• 3Y*: 17.58%
• 5Y*: 8.41%
• 10Y*: 11.69%

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

OTCAX vs. FSMDX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
OTCAX MFS Mid Cap Growth Fund	4.87%	3.32%	23.47%	21.00%	-28.53%	13.66%	35.34%	37.43%	0.82%	25.95%
FSMDX Fidelity Mid Cap Index Fund	12.78%	10.58%	15.55%	17.20%	-17.27%	22.56%	17.13%	30.53%	-9.38%	18.04%

Correlation

The correlation between OTCAX and FSMDX is 0.83, 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	0.83
Correlation (3Y) Calculated over the trailing 3-year period	0.86
Correlation (5Y) Calculated over the trailing 5-year period	0.90
Correlation (10Y) Calculated over the trailing 10-year period	0.88
Correlation (All Time) Calculated using the full available price history since Sep 12, 2011	0.90

The correlation between OTCAX and FSMDX has been stable across timeframes, ranging from 0.83 to 0.90 - a consistent structural relationship.

Return for Risk

OTCAX vs. FSMDX — Risk / Return Rank

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

OTCAX

OTCAX Risk / Return Rank: 4
OTCAX Sharpe Ratio Rank: 4
OTCAX Sortino Ratio Rank: 4
OTCAX Omega Ratio Rank: 4
OTCAX Calmar Ratio Rank: 4
OTCAX Martin Ratio Rank: 4

FSMDX

FSMDX Risk / Return Rank: 43
FSMDX Sharpe Ratio Rank: 37
FSMDX Sortino Ratio Rank: 36
FSMDX Omega Ratio Rank: 33
FSMDX Calmar Ratio Rank: 56
FSMDX Martin Ratio Rank: 55

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.

OTCAX vs. FSMDX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for MFS Mid Cap Growth Fund (OTCAX) 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.

	OTCAX	FSMDX	Difference
Sharpe ratio: Return per unit of total volatility	0.31	1.75	-1.44
Sortino ratio: Return per unit of downside risk	0.55	2.51	-1.96
Omega ratio: Gain probability vs. loss probability	1.06	1.30	-0.24
Calmar ratio: Return relative to maximum drawdown	0.31	2.87	-2.56
Martin ratio: Return relative to average drawdown	0.79	11.06	-10.27
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

OTCAX vs. FSMDX - Sharpe Ratio Comparison

The current OTCAX Sharpe Ratio is 0.31, which is lower than the FSMDX Sharpe Ratio of 1.75. The chart below compares the historical Sharpe Ratios of OTCAX 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.

Sharpe Ratios by Period

	OTCAX	FSMDX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.31	1.75	-1.44
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.29	0.46	-0.17
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.62	0.61	+0.01
Sharpe Ratio (All Time) Calculated using the full available price history	0.39	0.70	-0.31

Drawdowns

OTCAX vs. FSMDX - Drawdown Comparison

The maximum OTCAX drawdown since its inception was -74.39%, which is greater than FSMDX's maximum drawdown of -40.35%. Use the drawdown chart below to compare losses from any high point for OTCAX and FSMDX.

Drawdown Indicators

	OTCAX	FSMDX	Difference
Max Drawdown Largest peak-to-trough decline	-74.39%	-40.35%	-34.04%
Max Drawdown (1Y) Largest decline over 1 year	-16.46%	-8.16%	-8.30%
Max Drawdown (3Y) Largest decline over 3 years	-21.05%	-20.92%	-0.13%
Max Drawdown (5Y) Largest decline over 5 years	-36.85%	-26.07%	-10.78%
Max Drawdown (10Y) Largest decline over 10 years	-36.85%	-40.35%	+3.50%
Current Drawdown Current decline from peak	-3.02%	0.00%	-3.02%
Average Drawdown Average peak-to-trough decline	-23.13%	-4.96%	-18.17%
Ulcer Index Depth and duration of drawdowns from previous peaks	6.39%	2.11%	+4.28%

Volatility

OTCAX vs. FSMDX - Volatility Comparison

MFS Mid Cap Growth Fund (OTCAX) has a higher volatility of 4.19% compared to Fidelity Mid Cap Index Fund (FSMDX) at 3.31%. This indicates that OTCAX'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

	OTCAX	FSMDX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.19%	3.31%	+0.88%
Volatility (6M) Calculated over the trailing 6-month period	13.34%	9.93%	+3.41%
Volatility (1Y) Calculated over the trailing 1-year period	16.53%	13.42%	+3.11%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	20.18%	18.26%	+1.92%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	19.96%	19.32%	+0.64%

OTCAX vs. FSMDX - Expense Ratio Comparison

OTCAX has a 1.00% expense ratio, which is higher than FSMDX's 0.03% expense ratio.

Dividends

OTCAX vs. FSMDX - Dividend Comparison

OTCAX's dividend yield for the trailing twelve months is around 15.98%, more than FSMDX's 0.98% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FSMDX Fidelity Mid Cap Index Fund	0.98%	1.10%	2.46%	1.39%	2.07%	3.35%	2.34%	2.86%	2.21%	2.17%	2.23%	2.84%
OTCAX MFS Mid Cap Growth Fund	15.98%	16.76%	15.59%	0.00%	0.00%	3.64%	0.83%	0.86%	4.70%	8.80%	5.67%	2.84%

Frequently Asked Questions

Can I hold both OTCAX and FSMDX in my portfolio?

OTCAX and FSMDX have a correlation of 0.83, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, OTCAX or FSMDX?

OTCAX has higher volatility (4.19%) compared to FSMDX (3.31%). In terms of maximum drawdown, OTCAX dropped -74.39% vs FSMDX's -40.35%.

Which has better risk-adjusted returns?

FSMDX currently has the higher Sharpe Ratio (1.75 vs 0.31), 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.