AFEIX vs. SSEYX

Last updated Jun 6, 2026

AFEIX (American Century Large Cap Equity Fund Institutional Class) and SSEYX (State Street Equity 500 Index II Portfolio) are both Large Cap Blend Equities funds. Over the past 10 years, AFEIX returned 14.57%/yr vs 15.48%/yr for SSEYX. With a 0.99 correlation, they move nearly in lockstep. AFEIX charges 0.59%/yr vs 0.02%/yr for SSEYX.

Performance

AFEIX vs. SSEYX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in American Century Large Cap Equity Fund Institutional Class (AFEIX) and State Street Equity 500 Index II Portfolio (SSEYX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, AFEIX achieves a 8.38% return, which is significantly lower than SSEYX's 11.35% return. Over the past 10 years, AFEIX has underperformed SSEYX with an annualized return of 14.57%, while SSEYX has yielded a comparatively higher 15.48% annualized return.

AFEIX

• 1D: 0.56%
• 1M: 2.43%
• YTD: 8.38%
• 6M: 7.55%
• 1Y: 22.29%
• 3Y*: 17.44%
• 5Y*: 10.76%
• 10Y*: 14.57%

SSEYX

• 1D: 0.42%
• 1M: 3.11%
• YTD: 11.35%
• 6M: 10.75%
• 1Y: 28.87%
• 3Y*: 22.59%
• 5Y*: 13.92%
• 10Y*: 15.48%

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

AFEIX vs. SSEYX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
AFEIX American Century Large Cap Equity Fund Institutional Class	8.38%	11.41%	19.80%	24.47%	-19.36%	28.92%	19.54%	34.04%	-4.19%	26.04%
SSEYX State Street Equity 500 Index II Portfolio	11.35%	17.52%	25.01%	26.29%	-18.18%	28.58%	18.28%	31.42%	-4.54%	21.72%

Correlation

The correlation between AFEIX and SSEYX is 0.99 - these two move nearly in lockstep. At this level, holding both provides almost no diversification benefit. If you already own one, adding the other does little to reduce portfolio risk.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.99
Correlation (3Y) Calculated over the trailing 3-year period	0.99
Correlation (5Y) Calculated over the trailing 5-year period	0.99
Correlation (10Y) Calculated over the trailing 10-year period	0.99
Correlation (All Time) Calculated using the full available price history since Aug 15, 2014	0.99

The correlation between AFEIX and SSEYX has been stable across timeframes, ranging from 0.99 to 0.99 - a consistent structural relationship.

Return for Risk

AFEIX vs. SSEYX — Risk / Return Rank

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

AFEIX

AFEIX Risk / Return Rank: 41
AFEIX Sharpe Ratio Rank: 41
AFEIX Sortino Ratio Rank: 39
AFEIX Omega Ratio Rank: 40
AFEIX Calmar Ratio Rank: 36
AFEIX Martin Ratio Rank: 50

SSEYX

SSEYX Risk / Return Rank: 72
SSEYX Sharpe Ratio Rank: 72
SSEYX Sortino Ratio Rank: 65
SSEYX Omega Ratio Rank: 65
SSEYX Calmar Ratio Rank: 73
SSEYX Martin Ratio Rank: 83

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.

AFEIX vs. SSEYX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Century Large Cap Equity Fund Institutional Class (AFEIX) and State Street Equity 500 Index II Portfolio (SSEYX). 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.

	AFEIX	SSEYX	Difference
Sharpe ratio: Return per unit of total volatility	1.80	2.39	-0.59
Sortino ratio: Return per unit of downside risk	2.51	3.26	-0.75
Omega ratio: Gain probability vs. loss probability	1.33	1.43	-0.11
Calmar ratio: Return relative to maximum drawdown	2.18	3.19	-1.01
Martin ratio: Return relative to average drawdown	9.89	14.90	-5.01
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

AFEIX vs. SSEYX - Sharpe Ratio Comparison

The current AFEIX Sharpe Ratio is 1.80, which is comparable to the SSEYX Sharpe Ratio of 2.39. The chart below compares the historical Sharpe Ratios of AFEIX and SSEYX, 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

	AFEIX	SSEYX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.80	2.39	-0.59
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.62	0.83	-0.20
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.79	0.86	-0.07
Sharpe Ratio (All Time) Calculated using the full available price history	0.58	0.79	-0.21

Drawdowns

AFEIX vs. SSEYX - Drawdown Comparison

The maximum AFEIX drawdown since its inception was -52.69%, which is greater than SSEYX's maximum drawdown of -33.75%. Use the drawdown chart below to compare losses from any high point for AFEIX and SSEYX.

Drawdown Indicators

	AFEIX	SSEYX	Difference
Max Drawdown Largest peak-to-trough decline	-52.69%	-33.75%	-18.94%
Max Drawdown (1Y) Largest decline over 1 year	-10.13%	-8.88%	-1.25%
Max Drawdown (3Y) Largest decline over 3 years	-20.51%	-18.74%	-1.77%
Max Drawdown (5Y) Largest decline over 5 years	-26.42%	-24.52%	-1.90%
Max Drawdown (10Y) Largest decline over 10 years	-34.33%	-33.75%	-0.58%
Current Drawdown Current decline from peak	-0.35%	-0.32%	-0.03%
Average Drawdown Average peak-to-trough decline	-7.52%	-4.09%	-3.43%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.23%	1.90%	+0.33%

Volatility

AFEIX vs. SSEYX - Volatility Comparison

American Century Large Cap Equity Fund Institutional Class (AFEIX) and State Street Equity 500 Index II Portfolio (SSEYX) have volatilities of 2.91% and 2.87%, 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

	AFEIX	SSEYX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.91%	2.87%	+0.04%
Volatility (6M) Calculated over the trailing 6-month period	9.34%	8.97%	+0.37%
Volatility (1Y) Calculated over the trailing 1-year period	12.24%	11.86%	+0.38%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	17.35%	16.91%	+0.44%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.61%	18.06%	+0.55%

AFEIX vs. SSEYX - Expense Ratio Comparison

AFEIX has a 0.59% expense ratio, which is higher than SSEYX's 0.02% expense ratio.

Dividends

AFEIX vs. SSEYX - Dividend Comparison

AFEIX's dividend yield for the trailing twelve months is around 21.58%, more than SSEYX's 1.24% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
AFEIX American Century Large Cap Equity Fund Institutional Class	21.58%	23.38%	6.88%	1.97%	0.83%	2.58%	0.60%	0.80%	9.11%	3.14%	1.38%	1.28%
SSEYX State Street Equity 500 Index II Portfolio	1.24%	1.38%	1.93%	1.46%	1.57%	2.48%	3.63%	2.36%	5.91%	5.37%	2.29%	3.47%

Frequently Asked Questions

Can I hold both AFEIX and SSEYX in my portfolio?

With a correlation of 0.99, AFEIX and SSEYX 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, AFEIX or SSEYX?

AFEIX has higher volatility (2.91%) compared to SSEYX (2.87%). In terms of maximum drawdown, AFEIX dropped -52.69% vs SSEYX's -33.75%.

Which has better risk-adjusted returns?

SSEYX currently has the higher Sharpe Ratio (2.39 vs 1.80), 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.