FSMDX vs. FSSNX

Last updated Aug 4, 2026

FSMDX (Fidelity Mid Cap Index Fund) and FSSNX (Fidelity Small Cap Index Fund) are both mutual funds - FSMDX is a Mid Cap Blend Equities fund tracking the Russell Midcap Index, while FSSNX is a Small Cap Blend Equities fund tracking the Russell 2000 Index. Both are passively managed. Over the past 10 years, FSMDX returned 11.54%/yr vs 10.85%/yr for FSSNX. Their correlation of 0.93 means they have usually moved in the same direction. Both charge a 0.03% expense ratio.

Performance

FSMDX vs. FSSNX - Performance Comparison

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

Returns By Period

In the year-to-date period, FSMDX achieves a 14.62% return, which is significantly lower than FSSNX's 18.92% return. Over the past 10 years, FSMDX has outperformed FSSNX with an annualized return of 11.54%, while FSSNX has yielded a comparatively lower 10.85% annualized return.

FSMDX

• 1D: -0.28%
• 1M: -0.61%
• 6M: 10.55%
• YTD: 14.62%
• 1Y: 20.38%
• 3Y*: 14.99%
• 5Y*: 8.24%
• 10Y*: 11.54%
• ALL TIME*: 12.62%

FSSNX

• 1D: -0.49%
• 1M: -2.11%
• 6M: 11.73%
• YTD: 18.92%
• 1Y: 37.08%
• 3Y*: 15.40%
• 5Y*: 7.24%
• 10Y*: 10.85%
• ALL TIME*: 11.76%

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

Liquidity Comparison

Position	Avg. Volume Value (2W)	Avg. Volume Value (1M)	Avg. Volume Value (3M)
FSMDX Fidelity Mid Cap Index Fund	$0.00	$0.00	$0.00
FSSNX Fidelity Small Cap Index Fund	$0.00	$0.00	$0.00

FSMDX vs. FSSNX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
FSMDX Fidelity Mid Cap Index Fund	14.62%	10.58%	15.55%	17.20%	-17.27%	22.56%	17.13%	30.53%	-9.38%	18.04%
FSSNX Fidelity Small Cap Index Fund	18.92%	12.94%	11.71%	17.11%	-20.28%	14.70%	19.99%	25.70%	-11.24%	14.54%

Correlation

The correlation between FSMDX and FSSNX is 0.90, meaning they have usually moved in the same direction, including during past declines.

	Correlation
Correlation (1Y) Focuses on recent behavior, but can change the most.	0.90
Correlation (3Y) Balances recent behavior with more history.	0.92
Correlation (5Y) Shows whether the relationship held over a longer period.	0.93
Correlation (10Y) Provides a long-term view across more market conditions.	0.93
Correlation (All Time) Calculated using the full available price history since Sep 9, 2011	0.93

The correlation between FSMDX and FSSNX has been stable across timeframes, ranging from 0.90 to 0.93 - a consistent structural relationship.

Return for Risk

FSMDX vs. FSSNX — Risk / Return Rank

Compare historical risk-adjusted metric ranks over the past 12 months.

FSMDX

FSMDX Risk / Return Rank: 54
FSMDX Sharpe Ratio Rank: 46
FSMDX Sortino Ratio Rank: 46
FSMDX Omega Ratio Rank: 42
FSMDX Calmar Ratio Rank: 66
FSMDX Martin Ratio Rank: 67

FSSNX

FSSNX Risk / Return Rank: 76
FSSNX Sharpe Ratio Rank: 74
FSSNX Sortino Ratio Rank: 72
FSSNX Omega Ratio Rank: 64
FSSNX Calmar Ratio Rank: 87
FSSNX Martin Ratio Rank: 85

The rank (0–100) uses a weighted average of the Sharpe, Sortino, Omega, Calmar, and Martin percentile ranks for the trailing 12 months. Higher means stronger historical risk-adjusted performance within the peer group.

FSMDX vs. FSSNX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity Mid Cap Index Fund (FSMDX) and Fidelity Small Cap Index Fund (FSSNX). 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.

	FSMDX	FSSNX	Difference
Sharpe ratio: Return per unit of total volatility	1.38	1.78	-0.40
Sortino ratio: Return per unit of downside risk	2.01	2.53	-0.52
Omega ratio: Gain probability vs. loss probability	1.24	1.30	-0.06
Calmar ratio: Return relative to maximum drawdown	2.31	3.13	-0.83
Martin ratio: Return relative to average drawdown	8.94	11.12	-2.18

FSMDX vs. FSSNX - Sharpe Ratio Comparison

The current FSMDX Sharpe Ratio is 1.38, which is comparable to the FSSNX Sharpe Ratio of 1.78. The chart below compares the historical Sharpe Ratios of FSMDX and FSSNX, 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

FSMDX vs. FSSNX - Drawdown Comparison

The maximum FSMDX drawdown since its inception was -40.35%, roughly equal to the maximum FSSNX drawdown of -41.72%. Use the drawdown chart below to compare losses from any high point for FSMDX and FSSNX.

Drawdown Indicators

	FSMDX	FSSNX	Difference
Max Drawdown Largest peak-to-trough decline	-40.35%	-41.72%	+1.37%
Max Drawdown (1Y) Largest decline over 1 year	-8.16%	-11.00%	+2.84%
Max Drawdown (3Y) Largest decline over 3 years	-20.92%	-27.45%	+6.53%
Max Drawdown (5Y) Largest decline over 5 years	-26.07%	-31.87%	+5.80%
Max Drawdown (10Y) Largest decline over 10 years	-40.35%	-41.72%	+1.37%
Current Drawdown Current decline from peak	-0.94%	-3.01%	+2.07%
Average Drawdown Average peak-to-trough decline	-4.91%	-8.22%	+3.31%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.10%	3.10%	-1.00%

Volatility

FSMDX vs. FSSNX - Volatility Comparison

The current volatility for Fidelity Mid Cap Index Fund (FSMDX) is 2.43%, while Fidelity Small Cap Index Fund (FSSNX) has a volatility of 3.82%. This indicates that FSMDX experiences smaller price fluctuations and is considered to be less risky than FSSNX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FSMDX	FSSNX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.43%	3.82%	-1.39%
Volatility (6M) Calculated over the trailing 6-month period	10.22%	14.15%	-3.93%
Volatility (1Y) Calculated over the trailing 1-year period	13.71%	19.42%	-5.71%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	18.26%	22.54%	-4.28%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	19.27%	23.42%	-4.15%

FSMDX vs. FSSNX - Expense Ratio Comparison

Both FSMDX and FSSNX have an expense ratio of 0.03%, making them cost-effective options compared to the broader market, where average expense ratios typically range from 0.3% to 0.9%.

Dividends

FSMDX vs. FSSNX - Dividend Comparison

FSMDX's dividend yield for the trailing twelve months is around 0.76%, less than FSSNX's 1.06% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FSMDX Fidelity Mid Cap Index Fund	0.76%	1.10%	2.46%	1.39%	2.07%	3.35%	2.34%	2.86%	2.21%	2.17%	2.23%	2.84%
FSSNX Fidelity Small Cap Index Fund	1.06%	1.08%	1.04%	1.43%	1.26%	3.92%	0.94%	2.96%	4.94%	3.37%	2.27%	2.66%

Frequently Asked Questions

Can I hold both FSMDX and FSSNX in my portfolio?

With a correlation of 0.90, FSMDX and FSSNX move almost identically. Holding both adds very little diversification - you're essentially doubling your position in the same market segment. Choosing one is usually more capital-efficient.

Which is riskier, FSMDX or FSSNX?

FSSNX has higher volatility (3.82%) compared to FSMDX (2.43%). In terms of maximum drawdown, FSMDX dropped -40.35% vs FSSNX's -41.72%.

Which has better risk-adjusted returns?

FSSNX currently has the higher Sharpe Ratio (1.78 vs 1.38), 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.