SMXAX vs. FMDGX

Last updated Aug 1, 2026

SMXAX (SEI Institutional Investments Trust Extended Market Index Fund) and FMDGX (Fidelity Mid Cap Growth Index Fund) are both Mid Cap Growth Equities funds. Over the past 5 years, SMXAX returned 6.59%/yr vs 4.43%/yr for FMDGX. Their correlation of 0.93 means they have usually moved in the same direction. SMXAX charges 0.19%/yr vs 0.05%/yr for FMDGX.

Performance

SMXAX vs. FMDGX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in SEI Institutional Investments Trust Extended Market Index Fund (SMXAX) and Fidelity Mid Cap Growth Index Fund (FMDGX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, SMXAX achieves a 13.95% return, which is significantly higher than FMDGX's 0.60% return.

SMXAX

• 1D: 1.45%
• 1M: -2.37%
• 6M: 11.22%
• YTD: 13.95%
• 1Y: 24.69%
• 3Y*: 15.98%
• 5Y*: 6.59%
• 10Y*: 11.87%
• ALL TIME*: 11.45%

FMDGX

• 1D: 2.29%
• 1M: -3.87%
• 6M: 1.50%
• YTD: 0.60%
• 1Y: -0.77%
• 3Y*: 11.99%
• 5Y*: 4.43%
• 10Y*: —
• ALL TIME*: 10.00%

*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)
FMDGX Fidelity Mid Cap Growth Index Fund	$0.00	$0.00	$0.00
SMXAX SEI Institutional Investments Trust Extended Market Index Fund	$0.00	$0.00	$0.00

SMXAX vs. FMDGX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019
SMXAX SEI Institutional Investments Trust Extended Market Index Fund	13.95%	12.61%	16.45%	24.55%	-25.39%	12.19%	32.92%	5.71%
FMDGX Fidelity Mid Cap Growth Index Fund	0.60%	8.60%	22.03%	25.79%	-26.67%	12.67%	34.84%	4.63%

Correlation

The correlation between SMXAX and FMDGX is 0.93, 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.	0.93
Correlation (3Y) Balances recent behavior with more history.	0.92
Correlation (5Y) Shows whether the relationship held over a longer period.	0.94
Correlation (All Time) Calculated using the full available price history since Jul 17, 2019	0.93

The correlation between SMXAX and FMDGX has been stable across timeframes, ranging from 0.92 to 0.94 - a consistent structural relationship.

Return for Risk

SMXAX vs. FMDGX — Risk / Return Rank

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

SMXAX

SMXAX Risk / Return Rank: 45
SMXAX Sharpe Ratio Rank: 38
SMXAX Sortino Ratio Rank: 39
SMXAX Omega Ratio Rank: 36
SMXAX Calmar Ratio Rank: 60
SMXAX Martin Ratio Rank: 52

FMDGX

FMDGX Risk / Return Rank: 3
FMDGX Sharpe Ratio Rank: 3
FMDGX Sortino Ratio Rank: 3
FMDGX Omega Ratio Rank: 3
FMDGX Calmar Ratio Rank: 3
FMDGX Martin Ratio Rank: 3

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.

SMXAX vs. FMDGX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for SEI Institutional Investments Trust Extended Market Index Fund (SMXAX) and Fidelity Mid Cap Growth Index Fund (FMDGX). 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.

	SMXAX	FMDGX	Difference
Sharpe ratio: Return per unit of total volatility	1.24	-0.17	+1.41
Sortino ratio: Return per unit of downside risk	1.82	-0.12	+1.95
Omega ratio: Gain probability vs. loss probability	1.22	0.99	+0.23
Calmar ratio: Return relative to maximum drawdown	2.17	-0.21	+2.38
Martin ratio: Return relative to average drawdown	7.59	-0.57	+8.16

SMXAX vs. FMDGX - Sharpe Ratio Comparison

The current SMXAX Sharpe Ratio is 1.24, which is higher than the FMDGX Sharpe Ratio of -0.17. The chart below compares the historical Sharpe Ratios of SMXAX and FMDGX, 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

SMXAX vs. FMDGX - Drawdown Comparison

The maximum SMXAX drawdown since its inception was -41.48%, which is greater than FMDGX's maximum drawdown of -38.59%. Use the drawdown chart below to compare losses from any high point for SMXAX and FMDGX.

Drawdown Indicators

	SMXAX	FMDGX	Difference
Max Drawdown Largest peak-to-trough decline	-41.48%	-38.59%	-2.89%
Max Drawdown (1Y) Largest decline over 1 year	-10.01%	-14.75%	+4.74%
Max Drawdown (3Y) Largest decline over 3 years	-26.72%	-25.30%	-1.42%
Max Drawdown (5Y) Largest decline over 5 years	-35.28%	-38.59%	+3.31%
Max Drawdown (10Y) Largest decline over 10 years	-41.48%	—	—
Current Drawdown Current decline from peak	-3.35%	-6.20%	+2.85%
Average Drawdown Average peak-to-trough decline	-7.91%	-11.03%	+3.12%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.86%	5.29%	-2.43%

Volatility

SMXAX vs. FMDGX - Volatility Comparison

The current volatility for SEI Institutional Investments Trust Extended Market Index Fund (SMXAX) is 3.85%, while Fidelity Mid Cap Growth Index Fund (FMDGX) has a volatility of 5.15%. This indicates that SMXAX experiences smaller price fluctuations and is considered to be less risky than FMDGX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	SMXAX	FMDGX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.85%	5.15%	-1.30%
Volatility (6M) Calculated over the trailing 6-month period	13.17%	14.00%	-0.83%
Volatility (1Y) Calculated over the trailing 1-year period	17.50%	17.61%	-0.11%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	22.24%	22.54%	-0.30%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	22.32%	24.23%	-1.91%

SMXAX vs. FMDGX - Expense Ratio Comparison

SMXAX has a 0.19% expense ratio, which is higher than FMDGX's 0.05% 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

SMXAX vs. FMDGX - Dividend Comparison

SMXAX's dividend yield for the trailing twelve months is around 9.88%, more than FMDGX's 1.84% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FMDGX Fidelity Mid Cap Growth Index Fund	1.84%	1.85%	0.47%	0.63%	0.81%	6.43%	0.36%	0.29%	0.00%	0.00%	0.00%	0.00%
SMXAX SEI Institutional Investments Trust Extended Market Index Fund	9.88%	10.96%	12.66%	1.72%	4.38%	18.92%	2.78%	3.98%	6.49%	5.19%	3.44%	4.87%

Frequently Asked Questions

Can I hold both SMXAX and FMDGX in my portfolio?

With a correlation of 0.93, SMXAX and FMDGX 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, SMXAX or FMDGX?

FMDGX has higher volatility (5.15%) compared to SMXAX (3.85%). In terms of maximum drawdown, SMXAX dropped -41.48% vs FMDGX's -38.59%.

Which has better risk-adjusted returns?

SMXAX currently has the higher Sharpe Ratio (1.24 vs -0.17), 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.