SMXAX vs. NEEIX

Last updated Jun 4, 2026

SMXAX (SEI Institutional Investments Trust Extended Market Index Fund) and NEEIX (Needham Growth Fund Institutional Class) are both Mid Cap Growth Equities funds. Over the past 5 years, SMXAX returned 7.13%/yr vs 16.33%/yr for NEEIX. Their correlation of 0.86 suggests significant overlap in exposure. SMXAX charges 0.19%/yr vs 1.21%/yr for NEEIX.

Performance

SMXAX vs. NEEIX - 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 Needham Growth Fund Institutional Class (NEEIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, SMXAX achieves a 14.20% return, which is significantly lower than NEEIX's 59.61% return.

SMXAX

• 1D: 0.99%
• 1M: 5.71%
• YTD: 14.20%
• 6M: 13.10%
• 1Y: 29.94%
• 3Y*: 19.88%
• 5Y*: 7.13%
• 10Y*: 12.38%

NEEIX

• 1D: 4.73%
• 1M: 16.98%
• YTD: 59.61%
• 6M: 57.27%
• 1Y: 98.30%
• 3Y*: 30.88%
• 5Y*: 16.33%
• 10Y*: —

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

SMXAX vs. NEEIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
SMXAX SEI Institutional Investments Trust Extended Market Index Fund	14.20%	12.61%	16.45%	24.55%	-25.39%	12.19%	32.92%	27.93%	-9.08%	17.45%
NEEIX Needham Growth Fund Institutional Class	59.61%	9.32%	19.26%	27.30%	-33.26%	28.13%	42.39%	43.15%	-10.13%	8.47%

Correlation

The correlation between SMXAX and NEEIX is 0.81, 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	0.81
Correlation (3Y) Calculated over the trailing 3-year period	0.81
Correlation (5Y) Calculated over the trailing 5-year period	0.85
Correlation (All Time) Calculated using the full available price history since Jan 4, 2017	0.86

The correlation between SMXAX and NEEIX has been stable across timeframes, ranging from 0.81 to 0.86 - a consistent structural relationship.

Return for Risk

SMXAX vs. NEEIX — Risk / Return Rank

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

SMXAX

SMXAX Risk / Return Rank: 49
SMXAX Sharpe Ratio Rank: 41
SMXAX Sortino Ratio Rank: 40
SMXAX Omega Ratio Rank: 37
SMXAX Calmar Ratio Rank: 68
SMXAX Martin Ratio Rank: 58

NEEIX

NEEIX Risk / Return Rank: 93
NEEIX Sharpe Ratio Rank: 98
NEEIX Sortino Ratio Rank: 88
NEEIX Omega Ratio Rank: 83
NEEIX Calmar Ratio Rank: 98
NEEIX Martin Ratio Rank: 97

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.

SMXAX vs. NEEIX - 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 Needham Growth Fund Institutional Class (NEEIX). 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.

	SMXAX	NEEIX	Difference
Sharpe ratio: Return per unit of total volatility	1.89	3.83	-1.94
Sortino ratio: Return per unit of downside risk	2.65	4.35	-1.70
Omega ratio: Gain probability vs. loss probability	1.33	1.57	-0.24
Calmar ratio: Return relative to maximum drawdown	3.19	7.85	-4.66
Martin ratio: Return relative to average drawdown	11.59	26.70	-15.11
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

SMXAX vs. NEEIX - Sharpe Ratio Comparison

The current SMXAX Sharpe Ratio is 1.89, which is lower than the NEEIX Sharpe Ratio of 3.83. The chart below compares the historical Sharpe Ratios of SMXAX and NEEIX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Sharpe Ratios by Period

	SMXAX	NEEIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.89	3.83	-1.94
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.32	0.58	-0.26
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.56	—	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.56	0.67	-0.12

Drawdowns

SMXAX vs. NEEIX - Drawdown Comparison

The maximum SMXAX drawdown since its inception was -41.48%, roughly equal to the maximum NEEIX drawdown of -43.11%. Use the drawdown chart below to compare losses from any high point for SMXAX and NEEIX.

Drawdown Indicators

	SMXAX	NEEIX	Difference
Max Drawdown Largest peak-to-trough decline	-41.48%	-43.11%	+1.63%
Max Drawdown (1Y) Largest decline over 1 year	-10.01%	-13.22%	+3.21%
Max Drawdown (3Y) Largest decline over 3 years	-26.72%	-36.13%	+9.41%
Max Drawdown (5Y) Largest decline over 5 years	-35.28%	-43.11%	+7.83%
Max Drawdown (10Y) Largest decline over 10 years	-41.48%	—	—
Current Drawdown Current decline from peak	0.00%	0.00%	0.00%
Average Drawdown Average peak-to-trough decline	-7.99%	-10.87%	+2.88%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.75%	3.88%	-1.13%

Volatility

SMXAX vs. NEEIX - Volatility Comparison

The current volatility for SEI Institutional Investments Trust Extended Market Index Fund (SMXAX) is 4.72%, while Needham Growth Fund Institutional Class (NEEIX) has a volatility of 9.69%. This indicates that SMXAX experiences smaller price fluctuations and is considered to be less risky than NEEIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	SMXAX	NEEIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.72%	9.69%	-4.97%
Volatility (6M) Calculated over the trailing 6-month period	12.34%	20.89%	-8.55%
Volatility (1Y) Calculated over the trailing 1-year period	16.88%	27.10%	-10.22%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	22.17%	28.31%	-6.14%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	22.34%	25.79%	-3.45%

SMXAX vs. NEEIX - Expense Ratio Comparison

SMXAX has a 0.19% expense ratio, which is lower than NEEIX's 1.21% expense ratio.

Dividends

SMXAX vs. NEEIX - Dividend Comparison

SMXAX's dividend yield for the trailing twelve months is around 9.66%, more than NEEIX's 4.49% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
NEEIX Needham Growth Fund Institutional Class	4.49%	7.16%	7.48%	0.00%	1.72%	6.70%	5.58%	11.09%	17.58%	9.64%	0.00%	0.00%
SMXAX SEI Institutional Investments Trust Extended Market Index Fund	9.66%	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 NEEIX in my portfolio?

SMXAX and NEEIX have a correlation of 0.81, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, SMXAX or NEEIX?

NEEIX has higher volatility (9.69%) compared to SMXAX (4.72%). In terms of maximum drawdown, SMXAX dropped -41.48% vs NEEIX's -43.11%.

Which has better risk-adjusted returns?

NEEIX currently has the higher Sharpe Ratio (3.83 vs 1.89), 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.