SKTAX vs. SPIIX

Last updated Jun 4, 2026

SKTAX (SEI Asset Allocation Trust Core Market Strategy Allocation Fund) and SPIIX (SEI S&P 500 Index Fund Class I) are both mutual funds - SKTAX is a Diversified Portfolio fund managed by SEI, while SPIIX is a Large Cap Blend Equities fund tracking the S&P 500 Index. Over the past 10 years, SKTAX returned 10.86%/yr vs 14.89%/yr for SPIIX. Their correlation of 0.94 suggests significant overlap in exposure. SKTAX charges 0.61%/yr vs 0.65%/yr for SPIIX.

Performance

SKTAX vs. SPIIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in SEI Asset Allocation Trust Core Market Strategy Allocation Fund (SKTAX) and SEI S&P 500 Index Fund Class I (SPIIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, SKTAX achieves a 9.30% return, which is significantly lower than SPIIX's 11.33% return. Over the past 10 years, SKTAX has underperformed SPIIX with an annualized return of 10.86%, while SPIIX has yielded a comparatively higher 14.89% annualized return.

SKTAX

• 1D: 0.33%
• 1M: 3.42%
• YTD: 9.30%
• 6M: 10.21%
• 1Y: 23.25%
• 3Y*: 16.77%
• 5Y*: 8.84%
• 10Y*: 10.86%

SPIIX

• 1D: 0.12%
• 1M: 5.72%
• YTD: 11.33%
• 6M: 11.21%
• 1Y: 27.96%
• 3Y*: 21.87%
• 5Y*: 13.46%
• 10Y*: 14.89%

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

SKTAX vs. SPIIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
SKTAX SEI Asset Allocation Trust Core Market Strategy Allocation Fund	9.30%	18.49%	11.72%	16.13%	-14.36%	20.88%	11.19%	24.43%	-8.94%	20.06%
SPIIX SEI S&P 500 Index Fund Class I	11.33%	16.97%	24.11%	25.49%	-18.84%	28.04%	17.66%	30.72%	-5.00%	21.06%

Correlation

The correlation between SKTAX and SPIIX is 0.92, 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	0.92
Correlation (3Y) Calculated over the trailing 3-year period	0.89
Correlation (5Y) Calculated over the trailing 5-year period	0.91
Correlation (10Y) Calculated over the trailing 10-year period	0.93
Correlation (All Time) Calculated using the full available price history since Nov 19, 2003	0.94

The correlation between SKTAX and SPIIX has been stable across timeframes, ranging from 0.89 to 0.94 - a consistent structural relationship.

Return for Risk

SKTAX vs. SPIIX — Risk / Return Rank

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

SKTAX

SKTAX Risk / Return Rank: 61
SKTAX Sharpe Ratio Rank: 60
SKTAX Sortino Ratio Rank: 62
SKTAX Omega Ratio Rank: 58
SKTAX Calmar Ratio Rank: 59
SKTAX Martin Ratio Rank: 66

SPIIX

SPIIX Risk / Return Rank: 68
SPIIX Sharpe Ratio Rank: 70
SPIIX Sortino Ratio Rank: 62
SPIIX Omega Ratio Rank: 63
SPIIX Calmar Ratio Rank: 69
SPIIX Martin Ratio Rank: 79

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.

SKTAX vs. SPIIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for SEI Asset Allocation Trust Core Market Strategy Allocation Fund (SKTAX) and SEI S&P 500 Index Fund Class I (SPIIX). 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.

	SKTAX	SPIIX	Difference
Sharpe ratio: Return per unit of total volatility	2.31	2.44	-0.13
Sortino ratio: Return per unit of downside risk	3.31	3.31	0.00
Omega ratio: Gain probability vs. loss probability	1.42	1.44	-0.02
Calmar ratio: Return relative to maximum drawdown	2.94	3.20	-0.25
Martin ratio: Return relative to average drawdown	12.78	14.82	-2.04
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

SKTAX vs. SPIIX - Sharpe Ratio Comparison

The current SKTAX Sharpe Ratio is 2.31, which is comparable to the SPIIX Sharpe Ratio of 2.44. The chart below compares the historical Sharpe Ratios of SKTAX and SPIIX, 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

	SKTAX	SPIIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.31	2.44	-0.13
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.56	0.73	-0.17
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.66	0.79	-0.13
Sharpe Ratio (All Time) Calculated using the full available price history	0.49	0.57	-0.08

Drawdowns

SKTAX vs. SPIIX - Drawdown Comparison

The maximum SKTAX drawdown since its inception was -56.93%, roughly equal to the maximum SPIIX drawdown of -55.78%. Use the drawdown chart below to compare losses from any high point for SKTAX and SPIIX.

Drawdown Indicators

	SKTAX	SPIIX	Difference
Max Drawdown Largest peak-to-trough decline	-56.93%	-55.78%	-1.15%
Max Drawdown (1Y) Largest decline over 1 year	-8.12%	-9.02%	+0.90%
Max Drawdown (3Y) Largest decline over 3 years	-20.28%	-25.70%	+5.42%
Max Drawdown (5Y) Largest decline over 5 years	-26.66%	-25.70%	-0.96%
Max Drawdown (10Y) Largest decline over 10 years	-34.50%	-33.85%	-0.65%
Current Drawdown Current decline from peak	0.00%	0.00%	0.00%
Average Drawdown Average peak-to-trough decline	-8.22%	-7.28%	-0.94%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.87%	1.94%	-0.07%

Volatility

SKTAX vs. SPIIX - Volatility Comparison

SEI Asset Allocation Trust Core Market Strategy Allocation Fund (SKTAX) and SEI S&P 500 Index Fund Class I (SPIIX) have volatilities of 2.82% and 2.83%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	SKTAX	SPIIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.82%	2.83%	-0.01%
Volatility (6M) Calculated over the trailing 6-month period	7.98%	8.94%	-0.96%
Volatility (1Y) Calculated over the trailing 1-year period	10.37%	11.83%	-1.46%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	15.88%	18.44%	-2.56%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	16.50%	18.87%	-2.37%

SKTAX vs. SPIIX - Expense Ratio Comparison

SKTAX has a 0.61% expense ratio, which is lower than SPIIX's 0.65% expense ratio.

Dividends

SKTAX vs. SPIIX - Dividend Comparison

SKTAX's dividend yield for the trailing twelve months is around 15.79%, more than SPIIX's 7.57% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
SKTAX SEI Asset Allocation Trust Core Market Strategy Allocation Fund	15.79%	17.11%	11.93%	6.63%	10.78%	8.42%	5.73%	4.81%	3.68%	4.45%	1.29%	1.14%
SPIIX SEI S&P 500 Index Fund Class I	7.57%	8.42%	12.20%	4.10%	10.27%	7.03%	5.78%	4.04%	3.90%	2.08%	4.34%	1.53%

Frequently Asked Questions

Can I hold both SKTAX and SPIIX in my portfolio?

With a correlation of 0.92, SKTAX and SPIIX 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, SKTAX or SPIIX?

SPIIX has higher volatility (2.83%) compared to SKTAX (2.82%). In terms of maximum drawdown, SKTAX dropped -56.93% vs SPIIX's -55.78%.

Which has better risk-adjusted returns?

SPIIX currently has the higher Sharpe Ratio (2.44 vs 2.31), 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.