AOMIX vs. CSTAX

Last updated Jun 4, 2026

AOMIX (American Century Investments One Choice Portfolio: Moderate) and CSTAX (American Funds College 2027 Fund) are both Diversified Portfolio funds. Over the past 10 years, AOMIX returned 8.11%/yr vs 4.99%/yr for CSTAX. Their correlation of 0.85 suggests significant overlap in exposure. AOMIX charges 0.00%/yr vs 0.41%/yr for CSTAX.

Performance

AOMIX vs. CSTAX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in American Century Investments One Choice Portfolio: Moderate (AOMIX) and American Funds College 2027 Fund (CSTAX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, AOMIX achieves a 6.36% return, which is significantly higher than CSTAX's 1.47% return. Over the past 10 years, AOMIX has outperformed CSTAX with an annualized return of 8.11%, while CSTAX has yielded a comparatively lower 4.99% annualized return.

AOMIX

• 1D: 0.18%
• 1M: 2.88%
• YTD: 6.36%
• 6M: 6.63%
• 1Y: 15.90%
• 3Y*: 12.13%
• 5Y*: 5.49%
• 10Y*: 8.11%

CSTAX

• 1D: 0.08%
• 1M: 0.65%
• YTD: 1.47%
• 6M: 1.68%
• 1Y: 6.99%
• 3Y*: 6.87%
• 5Y*: 2.83%
• 10Y*: 4.99%

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

AOMIX vs. CSTAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
AOMIX American Century Investments One Choice Portfolio: Moderate	6.36%	12.97%	10.07%	13.04%	-16.37%	11.82%	16.08%	20.14%	-5.23%	14.27%
CSTAX American Funds College 2027 Fund	1.47%	9.00%	5.57%	6.57%	-9.87%	6.52%	7.66%	13.35%	-2.23%	11.77%

Correlation

The correlation between AOMIX and CSTAX is 0.73, 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	0.74
Correlation (3Y) Calculated over the trailing 3-year period	0.74
Correlation (5Y) Calculated over the trailing 5-year period	0.75
Correlation (10Y) Calculated over the trailing 10-year period	0.82
Correlation (All Time) Calculated using the full available price history since Jan 3, 2013	0.85

The correlation between AOMIX and CSTAX shifts across timeframes, from 0.73 (1 year) to 0.85 (all time), reflecting how their relationship changes across market environments.

Return for Risk

AOMIX vs. CSTAX — Risk / Return Rank

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

AOMIX

AOMIX Risk / Return Rank: 44
AOMIX Sharpe Ratio Rank: 45
AOMIX Sortino Ratio Rank: 44
AOMIX Omega Ratio Rank: 45
AOMIX Calmar Ratio Rank: 38
AOMIX Martin Ratio Rank: 48

CSTAX

CSTAX Risk / Return Rank: 60
CSTAX Sharpe Ratio Rank: 64
CSTAX Sortino Ratio Rank: 71
CSTAX Omega Ratio Rank: 70
CSTAX Calmar Ratio Rank: 47
CSTAX Martin Ratio Rank: 49

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.

AOMIX vs. CSTAX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Century Investments One Choice Portfolio: Moderate (AOMIX) and American Funds College 2027 Fund (CSTAX). 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.

	AOMIX	CSTAX	Difference
Sharpe ratio: Return per unit of total volatility	1.97	2.34	-0.37
Sortino ratio: Return per unit of downside risk	2.80	3.52	-0.72
Omega ratio: Gain probability vs. loss probability	1.37	1.47	-0.10
Calmar ratio: Return relative to maximum drawdown	2.33	2.61	-0.28
Martin ratio: Return relative to average drawdown	9.95	10.06	-0.11
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

AOMIX vs. CSTAX - Sharpe Ratio Comparison

The current AOMIX Sharpe Ratio is 1.97, which is comparable to the CSTAX Sharpe Ratio of 2.34. The chart below compares the historical Sharpe Ratios of AOMIX and CSTAX, 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

	AOMIX	CSTAX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.97	2.34	-0.37
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.52	0.55	-0.03
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.72	0.86	-0.14
Sharpe Ratio (All Time) Calculated using the full available price history	0.59	0.88	-0.29

Drawdowns

AOMIX vs. CSTAX - Drawdown Comparison

The maximum AOMIX drawdown since its inception was -38.62%, which is greater than CSTAX's maximum drawdown of -14.52%. Use the drawdown chart below to compare losses from any high point for AOMIX and CSTAX.

Drawdown Indicators

	AOMIX	CSTAX	Difference
Max Drawdown Largest peak-to-trough decline	-38.62%	-14.52%	-24.10%
Max Drawdown (1Y) Largest decline over 1 year	-6.91%	-2.72%	-4.19%
Max Drawdown (3Y) Largest decline over 3 years	-10.84%	-4.89%	-5.95%
Max Drawdown (5Y) Largest decline over 5 years	-23.24%	-14.52%	-8.72%
Max Drawdown (10Y) Largest decline over 10 years	-24.91%	-14.52%	-10.39%
Current Drawdown Current decline from peak	0.00%	-0.40%	+0.40%
Average Drawdown Average peak-to-trough decline	-4.91%	-2.35%	-2.56%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.62%	0.70%	+0.92%

Volatility

AOMIX vs. CSTAX - Volatility Comparison

American Century Investments One Choice Portfolio: Moderate (AOMIX) has a higher volatility of 2.42% compared to American Funds College 2027 Fund (CSTAX) at 1.11%. This indicates that AOMIX's price experiences larger fluctuations and is considered to be riskier than CSTAX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	AOMIX	CSTAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.42%	1.11%	+1.31%
Volatility (6M) Calculated over the trailing 6-month period	6.50%	2.32%	+4.18%
Volatility (1Y) Calculated over the trailing 1-year period	8.18%	3.03%	+5.15%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	10.51%	5.16%	+5.35%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	11.28%	5.79%	+5.49%

AOMIX vs. CSTAX - Expense Ratio Comparison

AOMIX has a 0.00% expense ratio, which is lower than CSTAX's 0.41% expense ratio.

Dividends

AOMIX vs. CSTAX - Dividend Comparison

AOMIX's dividend yield for the trailing twelve months is around 6.22%, more than CSTAX's 5.19% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
AOMIX American Century Investments One Choice Portfolio: Moderate	6.22%	6.69%	2.53%	2.29%	10.49%	9.55%	8.48%	6.61%	8.27%	2.11%	3.64%	7.11%
CSTAX American Funds College 2027 Fund	5.19%	5.26%	3.78%	3.17%	3.40%	7.52%	5.72%	4.00%	4.78%	3.90%	4.34%	4.49%

Frequently Asked Questions

Can I hold both AOMIX and CSTAX in my portfolio?

AOMIX and CSTAX have a correlation of 0.73, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, AOMIX or CSTAX?

AOMIX has higher volatility (2.42%) compared to CSTAX (1.11%). In terms of maximum drawdown, AOMIX dropped -38.62% vs CSTAX's -14.52%.

Which has better risk-adjusted returns?

CSTAX currently has the higher Sharpe Ratio (2.34 vs 1.97), 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.