FZFLX vs. FSMAX

Last updated Jun 23, 2026

FZFLX (Fidelity SAI Small-Mid Cap 500 Index Fund) and FSMAX (Fidelity Extended Market Index Fund) are both Mid Cap Blend Equities funds from Fidelity. Over the past 10 years, FZFLX returned 14.30%/yr vs 12.31%/yr for FSMAX. With a 0.96 correlation, they move nearly in lockstep. FZFLX charges 0.05%/yr vs 0.04%/yr for FSMAX.

Performance

FZFLX vs. FSMAX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Fidelity SAI Small-Mid Cap 500 Index Fund (FZFLX) 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, FZFLX achieves a 35.27% return, which is significantly higher than FSMAX's 15.56% return. Over the past 10 years, FZFLX has outperformed FSMAX with an annualized return of 14.30%, while FSMAX has yielded a comparatively lower 12.31% annualized return.

FZFLX

• 1D: 1.51%
• 1M: 3.77%
• YTD: 35.27%
• 6M: 31.17%
• 1Y: 50.77%
• 3Y*: 23.69%
• 5Y*: 12.86%
• 10Y*: 14.30%

FSMAX

• 1D: 1.67%
• 1M: 4.32%
• YTD: 15.56%
• 6M: 12.55%
• 1Y: 30.47%
• 3Y*: 19.09%
• 5Y*: 6.93%
• 10Y*: 12.31%

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

FZFLX vs. FSMAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
FZFLX Fidelity SAI Small-Mid Cap 500 Index Fund	35.27%	10.76%	15.52%	17.75%	-15.62%	20.40%	19.78%	31.96%	-9.25%	18.41%
FSMAX Fidelity Extended Market Index Fund	15.56%	11.40%	16.99%	25.36%	-26.44%	12.41%	32.28%	28.01%	-9.44%	18.04%

Correlation

The correlation between FZFLX and FSMAX is 0.90, 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	0.90
Correlation (3Y) Calculated over the trailing 3-year period	0.93
Correlation (5Y) Calculated over the trailing 5-year period	0.95
Correlation (10Y) Calculated over the trailing 10-year period	0.96
Correlation (All Time) Calculated using the full available price history since Aug 20, 2015	0.96

The correlation between FZFLX and FSMAX has been stable across timeframes, ranging from 0.90 to 0.96 - a consistent structural relationship.

Return for Risk

FZFLX vs. FSMAX — Risk / Return Rank

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

FZFLX

FZFLX Risk / Return Rank: 80
FZFLX Sharpe Ratio Rank: 78
FZFLX Sortino Ratio Rank: 67
FZFLX Omega Ratio Rank: 66
FZFLX Calmar Ratio Rank: 93
FZFLX Martin Ratio Rank: 95

FSMAX

FSMAX Risk / Return Rank: 46
FSMAX Sharpe Ratio Rank: 40
FSMAX Sortino Ratio Rank: 38
FSMAX Omega Ratio Rank: 35
FSMAX Calmar Ratio Rank: 65
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.

FZFLX vs. FSMAX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity SAI Small-Mid Cap 500 Index Fund (FZFLX) 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.

	FZFLX	FSMAX	Difference
Sharpe ratio: Return per unit of total volatility	2.38	1.71	+0.68
Sortino ratio: Return per unit of downside risk	3.12	2.38	+0.73
Omega ratio: Gain probability vs. loss probability	1.41	1.29	+0.12
Calmar ratio: Return relative to maximum drawdown	4.82	2.96	+1.86
Martin ratio: Return relative to average drawdown	20.04	10.38	+9.66

FZFLX vs. FSMAX - Sharpe Ratio Comparison

The current FZFLX Sharpe Ratio is 2.38, which is higher than the FSMAX Sharpe Ratio of 1.71. The chart below compares the historical Sharpe Ratios of FZFLX 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

FZFLX vs. FSMAX - Drawdown Comparison

The maximum FZFLX drawdown since its inception was -42.03%, smaller than the maximum FSMAX drawdown of -50.55%. Use the drawdown chart below to compare losses from any high point for FZFLX and FSMAX.

Drawdown Indicators

	FZFLX	FSMAX	Difference
Max Drawdown Largest peak-to-trough decline	-42.03%	-50.55%	+8.52%
Max Drawdown (1Y) Largest decline over 1 year	-10.68%	-10.26%	-0.42%
Max Drawdown (3Y) Largest decline over 3 years	-22.29%	-26.82%	+4.53%
Max Drawdown (5Y) Largest decline over 5 years	-24.77%	-36.31%	+11.54%
Max Drawdown (10Y) Largest decline over 10 years	-42.03%	-50.55%	+8.52%
Current Drawdown Current decline from peak	-0.33%	-0.11%	-0.22%
Average Drawdown Average peak-to-trough decline	-5.72%	-12.13%	+6.41%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.56%	2.92%	-0.36%

Volatility

FZFLX vs. FSMAX - Volatility Comparison

Fidelity SAI Small-Mid Cap 500 Index Fund (FZFLX) has a higher volatility of 7.53% compared to Fidelity Extended Market Index Fund (FSMAX) at 6.36%. This indicates that FZFLX's price experiences larger fluctuations and is considered to be riskier than FSMAX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FZFLX	FSMAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	7.53%	6.36%	+1.17%
Volatility (6M) Calculated over the trailing 6-month period	18.63%	13.32%	+5.31%
Volatility (1Y) Calculated over the trailing 1-year period	21.61%	17.80%	+3.81%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	21.28%	22.44%	-1.16%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	21.18%	30.27%	-9.09%

FZFLX vs. FSMAX - Expense Ratio Comparison

FZFLX has a 0.05% expense ratio, which is higher than FSMAX's 0.04% expense ratio. However, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

FZFLX vs. FSMAX - Dividend Comparison

FZFLX's dividend yield for the trailing twelve months is around 42.71%, more than FSMAX's 0.50% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
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%
FZFLX Fidelity SAI Small-Mid Cap 500 Index Fund	42.71%	57.77%	10.20%	2.35%	79.79%	50.77%	7.19%	6.49%	7.69%	1.68%	0.93%	0.67%

Frequently Asked Questions

Can I hold both FZFLX and FSMAX in my portfolio?

FZFLX and FSMAX have a correlation of 0.90, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, FZFLX or FSMAX?

FZFLX has higher volatility (7.53%) compared to FSMAX (6.36%). In terms of maximum drawdown, FZFLX dropped -42.03% vs FSMAX's -50.55%.

Which has better risk-adjusted returns?

FZFLX currently has the higher Sharpe Ratio (2.38 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.