AIOIX vs. ACFOX

Last updated Jun 23, 2026

AIOIX (American Century International Opportunities Fund) and ACFOX (American Century Investments Focused Dynamic Growth Fund) are both mutual funds - AIOIX is a Foreign Small & Mid Cap Equities fund managed by American Century, while ACFOX is a Large Cap Growth Equities fund managed by American Century. Over the past 10 years, AIOIX returned 8.26%/yr vs 19.22%/yr for ACFOX. A 0.70 correlation means they provide meaningful diversification when combined. AIOIX charges 1.48%/yr vs 0.85%/yr for ACFOX.

Performance

AIOIX vs. ACFOX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in American Century International Opportunities Fund (AIOIX) and American Century Investments Focused Dynamic Growth Fund (ACFOX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, AIOIX achieves a 15.29% return, which is significantly higher than ACFOX's 5.91% return. Over the past 10 years, AIOIX has underperformed ACFOX with an annualized return of 8.26%, while ACFOX has yielded a comparatively higher 19.22% annualized return.

AIOIX

• 1D: 1.56%
• 1M: 0.52%
• YTD: 15.29%
• 6M: 15.00%
• 1Y: 30.98%
• 3Y*: 13.99%
• 5Y*: 3.36%
• 10Y*: 8.26%

ACFOX

• 1D: 1.86%
• 1M: -2.05%
• YTD: 5.91%
• 6M: 4.50%
• 1Y: 29.60%
• 3Y*: 25.36%
• 5Y*: 9.68%
• 10Y*: 19.22%

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

AIOIX vs. ACFOX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
AIOIX American Century International Opportunities Fund	15.29%	29.62%	1.31%	8.63%	-30.19%	5.79%	31.07%	28.95%	-22.19%	45.09%
ACFOX American Century Investments Focused Dynamic Growth Fund	5.91%	20.51%	43.30%	35.66%	-36.32%	7.08%	73.31%	32.30%	6.51%	34.55%

Correlation

The correlation between AIOIX and ACFOX is 0.72, 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	0.72
Correlation (3Y) Calculated over the trailing 3-year period	0.69
Correlation (5Y) Calculated over the trailing 5-year period	0.72
Correlation (10Y) Calculated over the trailing 10-year period	0.70
Correlation (All Time) Calculated using the full available price history since May 31, 2006	0.70

The correlation between AIOIX and ACFOX has been stable across timeframes, ranging from 0.69 to 0.72 - a consistent structural relationship.

Return for Risk

AIOIX vs. ACFOX — Risk / Return Rank

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

AIOIX

AIOIX Risk / Return Rank: 33
AIOIX Sharpe Ratio Rank: 31
AIOIX Sortino Ratio Rank: 28
AIOIX Omega Ratio Rank: 30
AIOIX Calmar Ratio Rank: 35
AIOIX Martin Ratio Rank: 40

ACFOX

ACFOX Risk / Return Rank: 27
ACFOX Sharpe Ratio Rank: 30
ACFOX Sortino Ratio Rank: 26
ACFOX Omega Ratio Rank: 27
ACFOX Calmar Ratio Rank: 25
ACFOX Martin Ratio Rank: 27

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.

AIOIX vs. ACFOX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Century International Opportunities Fund (AIOIX) and American Century Investments Focused Dynamic Growth Fund (ACFOX). 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.

	AIOIX	ACFOX	Difference
Sharpe ratio: Return per unit of total volatility	1.49	1.45	+0.03
Sortino ratio: Return per unit of downside risk	2.07	1.98	+0.08
Omega ratio: Gain probability vs. loss probability	1.27	1.25	+0.02
Calmar ratio: Return relative to maximum drawdown	2.13	1.76	+0.38
Martin ratio: Return relative to average drawdown	8.19	6.02	+2.16

AIOIX vs. ACFOX - Sharpe Ratio Comparison

The current AIOIX Sharpe Ratio is 1.49, which is comparable to the ACFOX Sharpe Ratio of 1.45. The chart below compares the historical Sharpe Ratios of AIOIX and ACFOX, 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

AIOIX vs. ACFOX - Drawdown Comparison

The maximum AIOIX drawdown since its inception was -66.16%, which is greater than ACFOX's maximum drawdown of -58.92%. Use the drawdown chart below to compare losses from any high point for AIOIX and ACFOX.

Drawdown Indicators

	AIOIX	ACFOX	Difference
Max Drawdown Largest peak-to-trough decline	-66.16%	-58.92%	-7.24%
Max Drawdown (1Y) Largest decline over 1 year	-14.00%	-16.52%	+2.52%
Max Drawdown (3Y) Largest decline over 3 years	-18.46%	-27.03%	+8.57%
Max Drawdown (5Y) Largest decline over 5 years	-41.19%	-43.77%	+2.58%
Max Drawdown (10Y) Largest decline over 10 years	-41.19%	-43.77%	+2.58%
Current Drawdown Current decline from peak	-2.36%	-4.11%	+1.75%
Average Drawdown Average peak-to-trough decline	-16.00%	-14.68%	-1.32%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.64%	4.81%	-1.17%

Volatility

AIOIX vs. ACFOX - Volatility Comparison

American Century International Opportunities Fund (AIOIX) has a higher volatility of 8.50% compared to American Century Investments Focused Dynamic Growth Fund (ACFOX) at 7.93%. This indicates that AIOIX's price experiences larger fluctuations and is considered to be riskier than ACFOX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	AIOIX	ACFOX	Difference
Volatility (1M) Calculated over the trailing 1-month period	8.50%	7.93%	+0.57%
Volatility (6M) Calculated over the trailing 6-month period	17.59%	16.19%	+1.40%
Volatility (1Y) Calculated over the trailing 1-year period	20.10%	19.98%	+0.12%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	19.17%	25.43%	-6.26%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	19.05%	23.91%	-4.86%

AIOIX vs. ACFOX - Expense Ratio Comparison

AIOIX has a 1.48% expense ratio, which is higher than ACFOX's 0.85% expense ratio.

Dividends

AIOIX vs. ACFOX - Dividend Comparison

AIOIX's dividend yield for the trailing twelve months is around 0.24%, less than ACFOX's 7.13% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
ACFOX American Century Investments Focused Dynamic Growth Fund	7.13%	7.56%	0.00%	0.00%	0.00%	2.48%	0.62%	0.00%	0.00%	0.00%	1.15%	1.33%
AIOIX American Century International Opportunities Fund	0.24%	0.27%	0.32%	0.23%	0.00%	17.80%	3.18%	0.92%	5.28%	9.09%	0.04%	7.15%

Frequently Asked Questions

Can I hold both AIOIX and ACFOX in my portfolio?

AIOIX and ACFOX have a correlation of 0.72, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, AIOIX or ACFOX?

AIOIX has higher volatility (8.50%) compared to ACFOX (7.93%). In terms of maximum drawdown, AIOIX dropped -66.16% vs ACFOX's -58.92%.

Which has better risk-adjusted returns?

AIOIX currently has the higher Sharpe Ratio (1.49 vs 1.45), 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.