OAKMX vs. ACIIX

Last updated Jun 26, 2026

OAKMX (Oakmark Fund Investor Class) and ACIIX (American Century Equity Income Fund Class I) are both Large Cap Value Equities funds. Over the past 10 years, OAKMX returned 13.87%/yr vs 9.17%/yr for ACIIX. Their correlation of 0.87 suggests significant overlap in exposure. OAKMX charges 0.89%/yr vs 0.72%/yr for ACIIX.

Performance

OAKMX vs. ACIIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Oakmark Fund Investor Class (OAKMX) and American Century Equity Income Fund Class I (ACIIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, OAKMX achieves a -1.17% return, which is significantly lower than ACIIX's 8.24% return. Over the past 10 years, OAKMX has outperformed ACIIX with an annualized return of 13.87%, while ACIIX has yielded a comparatively lower 9.17% annualized return.

OAKMX

• 1D: 0.63%
• 1M: 0.09%
• YTD: -1.17%
• 6M: -2.13%
• 1Y: 8.95%
• 3Y*: 14.65%
• 5Y*: 9.55%
• 10Y*: 13.87%

ACIIX

• 1D: 0.33%
• 1M: 0.82%
• YTD: 8.24%
• 6M: 7.48%
• 1Y: 17.20%
• 3Y*: 11.38%
• 5Y*: 7.59%
• 10Y*: 9.17%

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

OAKMX vs. ACIIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
OAKMX Oakmark Fund Investor Class	-1.17%	14.13%	16.02%	30.92%	-13.38%	34.85%	12.90%	27.14%	-12.76%	21.12%
ACIIX American Century Equity Income Fund Class I	8.24%	12.05%	10.58%	4.25%	-2.96%	17.16%	1.19%	24.50%	-3.53%	13.69%

Correlation

The correlation between OAKMX and ACIIX is 0.75, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.75
Correlation (3Y) Calculated over the trailing 3-year period	0.79
Correlation (5Y) Calculated over the trailing 5-year period	0.81
Correlation (10Y) Calculated over the trailing 10-year period	0.83
Correlation (All Time) Calculated using the full available price history since Jul 8, 1998	0.87

The correlation between OAKMX and ACIIX shifts across timeframes, from 0.75 (1 year) to 0.87 (all time), reflecting how their relationship changes across market environments.

Return for Risk

OAKMX vs. ACIIX — Risk / Return Rank

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

OAKMX

OAKMX Risk / Return Rank: 12
OAKMX Sharpe Ratio Rank: 10
OAKMX Sortino Ratio Rank: 10
OAKMX Omega Ratio Rank: 10
OAKMX Calmar Ratio Rank: 18
OAKMX Martin Ratio Rank: 13

ACIIX

ACIIX Risk / Return Rank: 60
ACIIX Sharpe Ratio Rank: 65
ACIIX Sortino Ratio Rank: 72
ACIIX Omega Ratio Rank: 57
ACIIX Calmar Ratio Rank: 61
ACIIX Martin Ratio Rank: 47

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.

OAKMX vs. ACIIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Oakmark Fund Investor Class (OAKMX) and American Century Equity Income Fund Class I (ACIIX). 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.

	OAKMX	ACIIX	Difference
Sharpe ratio: Return per unit of total volatility	0.65	1.96	-1.30
Sortino ratio: Return per unit of downside risk	1.02	2.94	-1.92
Omega ratio: Gain probability vs. loss probability	1.12	1.34	-0.22
Calmar ratio: Return relative to maximum drawdown	1.23	2.60	-1.37
Martin ratio: Return relative to average drawdown	2.99	8.47	-5.47

OAKMX vs. ACIIX - Sharpe Ratio Comparison

The current OAKMX Sharpe Ratio is 0.65, which is lower than the ACIIX Sharpe Ratio of 1.96. The chart below compares the historical Sharpe Ratios of OAKMX and ACIIX, 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

OAKMX vs. ACIIX - Drawdown Comparison

The maximum OAKMX drawdown since its inception was -56.19%, which is greater than ACIIX's maximum drawdown of -39.16%. Use the drawdown chart below to compare losses from any high point for OAKMX and ACIIX.

Drawdown Indicators

	OAKMX	ACIIX	Difference
Max Drawdown Largest peak-to-trough decline	-56.19%	-39.16%	-17.03%
Max Drawdown (1Y) Largest decline over 1 year	-6.98%	-6.38%	-0.60%
Max Drawdown (3Y) Largest decline over 3 years	-17.05%	-10.15%	-6.90%
Max Drawdown (5Y) Largest decline over 5 years	-23.68%	-13.49%	-10.19%
Max Drawdown (10Y) Largest decline over 10 years	-41.43%	-32.76%	-8.67%
Current Drawdown Current decline from peak	-3.70%	-0.67%	-3.03%
Average Drawdown Average peak-to-trough decline	-6.39%	-5.23%	-1.16%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.86%	1.96%	+0.90%

Volatility

OAKMX vs. ACIIX - Volatility Comparison

Oakmark Fund Investor Class (OAKMX) has a higher volatility of 3.80% compared to American Century Equity Income Fund Class I (ACIIX) at 2.54%. This indicates that OAKMX's price experiences larger fluctuations and is considered to be riskier than ACIIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	OAKMX	ACIIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.80%	2.54%	+1.26%
Volatility (6M) Calculated over the trailing 6-month period	9.47%	6.23%	+3.24%
Volatility (1Y) Calculated over the trailing 1-year period	13.19%	8.48%	+4.71%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	18.28%	10.76%	+7.52%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	20.33%	13.36%	+6.97%

OAKMX vs. ACIIX - Expense Ratio Comparison

OAKMX has a 0.89% expense ratio, which is higher than ACIIX's 0.72% expense ratio.

Dividends

OAKMX vs. ACIIX - Dividend Comparison

OAKMX's dividend yield for the trailing twelve months is around 0.93%, less than ACIIX's 9.93% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
ACIIX American Century Equity Income Fund Class I	9.93%	10.55%	11.71%	8.21%	8.96%	7.02%	2.18%	7.57%	9.05%	12.14%	8.08%	10.72%
OAKMX Oakmark Fund Investor Class	0.93%	0.92%	1.12%	1.02%	0.92%	1.94%	0.17%	8.33%	8.13%	4.06%	2.58%	1.43%

Frequently Asked Questions

Can I hold both OAKMX and ACIIX in my portfolio?

OAKMX and ACIIX have a correlation of 0.75, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, OAKMX or ACIIX?

OAKMX has higher volatility (3.80%) compared to ACIIX (2.54%). In terms of maximum drawdown, OAKMX dropped -56.19% vs ACIIX's -39.16%.

Which has better risk-adjusted returns?

ACIIX currently has the higher Sharpe Ratio (1.96 vs 0.65), 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.