FKMCX vs. FSMAX

Last updated Jun 24, 2026

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

Performance

FKMCX vs. FSMAX - Performance Comparison

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

Returns By Period

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

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%

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

FKMCX vs. FSMAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
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%
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%

Correlation

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

Return for Risk

FKMCX vs. FSMAX — Risk / Return Rank

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

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

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

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.

FKMCX vs. FSMAX - Risk-Adjusted Trends Comparison

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

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

FKMCX vs. FSMAX - Sharpe Ratio Comparison

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

FKMCX vs. FSMAX - Drawdown Comparison

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

Drawdown Indicators

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

Volatility

FKMCX vs. FSMAX - Volatility Comparison

The current volatility for Fidelity Mid-Cap Stock Fund Class K (FKMCX) is 5.54%, while Fidelity Extended Market Index Fund (FSMAX) has a volatility of 6.07%. This indicates that FKMCX experiences smaller price fluctuations and is considered to be less risky than FSMAX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

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

FKMCX vs. FSMAX - Expense Ratio Comparison

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

Dividends

FKMCX vs. FSMAX - Dividend Comparison

FKMCX's dividend yield for the trailing twelve months is around 5.18%, more than FSMAX's 0.50% 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 FKMCX and FSMAX in my portfolio?

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

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

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.