FSMAX vs. FKMCX

Last updated Jun 24, 2026

FSMAX (Fidelity Extended Market Index Fund) and FKMCX (Fidelity Mid-Cap Stock Fund Class K) are both Mid Cap Blend Equities funds from Fidelity. Over the past 10 years, FSMAX returned 12.60%/yr vs 13.09%/yr for FKMCX. Their correlation of 0.92 suggests significant overlap in exposure. FSMAX charges 0.04%/yr vs 0.76%/yr for FKMCX.

Performance

FSMAX vs. FKMCX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Fidelity Extended Market Index Fund (FSMAX) and Fidelity Mid-Cap Stock Fund Class K (FKMCX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, FSMAX achieves a 15.43% return, which is significantly lower than FKMCX's 20.09% return. Both investments have delivered pretty close results over the past 10 years, with FSMAX having a 12.60% annualized return and FKMCX not far ahead at 13.09%.

FSMAX

• 1D: -0.11%
• 1M: 4.21%
• YTD: 15.43%
• 6M: 13.08%
• 1Y: 29.23%
• 3Y*: 20.24%
• 5Y*: 6.38%
• 10Y*: 12.60%

FKMCX

• 1D: 0.17%
• 1M: 4.72%
• YTD: 20.09%
• 6M: 17.79%
• 1Y: 33.40%
• 3Y*: 19.39%
• 5Y*: 11.54%
• 10Y*: 13.09%

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

FSMAX vs. FKMCX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
FSMAX Fidelity Extended Market Index Fund	15.43%	11.40%	16.99%	25.36%	-26.44%	12.41%	32.28%	28.01%	-9.44%	18.04%
FKMCX Fidelity Mid-Cap Stock Fund Class K	20.09%	11.87%	14.65%	11.11%	-6.30%	28.72%	11.56%	25.50%	-10.21%	18.03%

Correlation

The correlation between FSMAX and FKMCX is 0.91, 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	0.91
Correlation (3Y) Calculated over the trailing 3-year period	0.93
Correlation (5Y) Calculated over the trailing 5-year period	0.91
Correlation (10Y) Calculated over the trailing 10-year period	0.90
Correlation (All Time) Calculated using the full available price history since Sep 8, 2011	0.92

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

Return for Risk

FSMAX vs. FKMCX — Risk / Return Rank

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

FSMAX

FSMAX Risk / Return Rank: 47
FSMAX Sharpe Ratio Rank: 41
FSMAX Sortino Ratio Rank: 38
FSMAX Omega Ratio Rank: 35
FSMAX Calmar Ratio Rank: 66
FSMAX Martin Ratio Rank: 55

FKMCX

FKMCX Risk / Return Rank: 71
FKMCX Sharpe Ratio Rank: 64
FKMCX Sortino Ratio Rank: 61
FKMCX Omega Ratio Rank: 55
FKMCX Calmar Ratio Rank: 88
FKMCX Martin Ratio Rank: 88

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.

FSMAX vs. FKMCX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity Extended Market Index Fund (FSMAX) and Fidelity Mid-Cap Stock Fund Class K (FKMCX). 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.

	FSMAX	FKMCX	Difference
Sharpe ratio: Return per unit of total volatility	1.71	2.16	-0.45
Sortino ratio: Return per unit of downside risk	2.39	3.00	-0.61
Omega ratio: Gain probability vs. loss probability	1.29	1.38	-0.08
Calmar ratio: Return relative to maximum drawdown	2.97	4.10	-1.13
Martin ratio: Return relative to average drawdown	10.42	15.73	-5.31

FSMAX vs. FKMCX - Sharpe Ratio Comparison

The current FSMAX Sharpe Ratio is 1.71, which is comparable to the FKMCX Sharpe Ratio of 2.16. The chart below compares the historical Sharpe Ratios of FSMAX and FKMCX, 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

FSMAX vs. FKMCX - Drawdown Comparison

The maximum FSMAX drawdown since its inception was -50.55%, smaller than the maximum FKMCX drawdown of -59.55%. Use the drawdown chart below to compare losses from any high point for FSMAX and FKMCX.

Drawdown Indicators

	FSMAX	FKMCX	Difference
Max Drawdown Largest peak-to-trough decline	-50.55%	-59.55%	+9.00%
Max Drawdown (1Y) Largest decline over 1 year	-10.26%	-8.55%	-1.71%
Max Drawdown (3Y) Largest decline over 3 years	-26.82%	-22.31%	-4.51%
Max Drawdown (5Y) Largest decline over 5 years	-36.31%	-22.31%	-14.00%
Max Drawdown (10Y) Largest decline over 10 years	-50.55%	-40.56%	-9.99%
Current Drawdown Current decline from peak	-0.22%	-0.52%	+0.30%
Average Drawdown Average peak-to-trough decline	-12.13%	-7.53%	-4.60%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.92%	2.22%	+0.70%

Volatility

FSMAX vs. FKMCX - Volatility Comparison

Fidelity Extended Market Index Fund (FSMAX) has a higher volatility of 6.07% compared to Fidelity Mid-Cap Stock Fund Class K (FKMCX) at 5.54%. This indicates that FSMAX's price experiences larger fluctuations and is considered to be riskier than FKMCX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FSMAX	FKMCX	Difference
Volatility (1M) Calculated over the trailing 1-month period	6.07%	5.54%	+0.53%
Volatility (6M) Calculated over the trailing 6-month period	13.28%	12.89%	+0.39%
Volatility (1Y) Calculated over the trailing 1-year period	17.83%	16.25%	+1.58%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	22.43%	17.77%	+4.66%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	30.28%	18.66%	+11.62%

FSMAX vs. FKMCX - Expense Ratio Comparison

FSMAX has a 0.04% expense ratio, which is lower than FKMCX's 0.76% expense ratio.

Dividends

FSMAX vs. FKMCX - Dividend Comparison

FSMAX's dividend yield for the trailing twelve months is around 0.50%, less than FKMCX's 5.18% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FKMCX Fidelity Mid-Cap Stock Fund Class K	5.18%	1.85%	8.91%	2.69%	5.49%	12.87%	6.82%	6.73%	13.52%	6.66%	8.36%	14.27%
FSMAX Fidelity Extended Market Index Fund	0.50%	0.57%	0.48%	1.17%	1.90%	7.49%	2.14%	4.30%	6.09%	5.44%	4.85%	6.34%

Frequently Asked Questions

Can I hold both FSMAX and FKMCX in my portfolio?

With a correlation of 0.91, FSMAX and FKMCX 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, FSMAX or FKMCX?

FSMAX has higher volatility (6.07%) compared to FKMCX (5.54%). In terms of maximum drawdown, FSMAX dropped -50.55% vs FKMCX's -59.55%.

Which has better risk-adjusted returns?

FKMCX currently has the higher Sharpe Ratio (2.16 vs 1.71), 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.