AIOIX vs. VFSNX
AIOIX (American Century International Opportunities Fund) and VFSNX (Vanguard FTSE All-World ex-US Small-Cap Index Fund Institutional Shares) are both Foreign Small & Mid Cap Equities funds. Over the past 10 years, AIOIX returned 7.07%/yr vs 7.46%/yr for VFSNX. Their correlation of 0.91 means they have usually moved in the same direction. AIOIX charges 1.48%/yr vs 0.11%/yr for VFSNX.
Performance
AIOIX vs. VFSNX - Performance Comparison
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Returns By Period
The year-to-date returns for both stocks are quite close, with AIOIX having a 5.49% return and VFSNX slightly lower at 5.36%. Over the past 10 years, AIOIX has underperformed VFSNX with an annualized return of 7.07%, while VFSNX has yielded a comparatively higher 7.46% annualized return.
AIOIX
- 1D
- -0.32%
- 1M
- -4.87%
- 6M
- -2.65%
- YTD
- 5.49%
- 1Y
- 15.65%
- 3Y*
- 11.23%
- 5Y*
- 0.67%
- 10Y*
- 7.07%
- ALL TIME*
- 10.18%
VFSNX
- 1D
- -0.16%
- 1M
- -2.56%
- 6M
- -0.48%
- YTD
- 5.36%
- 1Y
- 16.24%
- 3Y*
- 13.11%
- 5Y*
- 4.95%
- 10Y*
- 7.46%
- ALL TIME*
- 9.16%
Liquidity Comparison
| Position | Avg. Volume Value (2W) | Avg. Volume Value (1M) | Avg. Volume Value (3M) |
|---|---|---|---|
| $0.00 | $0.00 | $0.00 | |
| $0.00 | $0.00 | $0.00 |
AIOIX vs. VFSNX - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
AIOIX American Century International Opportunities Fund | 5.49% | 29.62% | 1.31% | 8.63% | -30.19% | 5.79% | 31.07% | 28.95% | -22.19% | 45.09% |
VFSNX Vanguard FTSE All-World ex-US Small-Cap Index Fund Institutional Shares | 5.36% | 29.97% | 2.63% | 15.18% | -21.26% | 12.74% | 11.92% | 21.72% | -18.46% | 30.30% |
Correlation
The correlation between AIOIX and VFSNX is 0.93, meaning they have usually moved in the same direction, including during past declines.
| Correlation | |
|---|---|
Correlation (1Y) Focuses on recent behavior, but can change the most. | 0.93 |
Correlation (3Y) Balances recent behavior with more history. | 0.93 |
Correlation (5Y) Shows whether the relationship held over a longer period. | 0.94 |
Correlation (10Y) Provides a long-term view across more market conditions. | 0.93 |
Correlation (All Time) Calculated using the full available price history since Mar 20, 2009 | 0.91 |
The correlation between AIOIX and VFSNX has been stable across timeframes, ranging from 0.91 to 0.94 - a consistent structural relationship.
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Return for Risk
AIOIX vs. VFSNX — Risk / Return Rank
AIOIX
VFSNX
AIOIX vs. VFSNX - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for American Century International Opportunities Fund (AIOIX) and Vanguard FTSE All-World ex-US Small-Cap Index Fund Institutional Shares (VFSNX). 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 | VFSNX | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | -0.38 | ||
| Sortino ratioReturn per unit of downside risk | -0.46 | ||
| Omega ratioGain probability vs. loss probability | 1.14 | 1.20 | -0.06 |
| Calmar ratioReturn relative to maximum drawdown | 1.11 | 1.41 | -0.30 |
| Martin ratioReturn relative to average drawdown | 3.42 | 4.49 | -1.07 |
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Drawdowns
AIOIX vs. VFSNX - Drawdown Comparison
The maximum AIOIX drawdown since its inception was -66.16%, which is greater than VFSNX's maximum drawdown of -43.65%. Use the drawdown chart below to compare losses from any high point for AIOIX and VFSNX.
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Drawdown Indicators
| AIOIX | VFSNX | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -66.16% | -43.65% | -22.51% |
Max Drawdown (1Y)Largest decline over 1 year | -14.00% | -11.47% | -2.53% |
Max Drawdown (3Y)Largest decline over 3 years | -17.09% | -14.70% | -2.39% |
Max Drawdown (5Y)Largest decline over 5 years | -41.19% | -33.75% | -7.44% |
Max Drawdown (10Y)Largest decline over 10 years | -41.19% | -43.65% | +2.46% |
Current DrawdownCurrent decline from peak | -10.66% | -6.75% | -3.91% |
Average DrawdownAverage peak-to-trough decline | -15.96% | -9.44% | -6.52% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 4.55% | 3.60% | +0.95% |
Volatility
AIOIX vs. VFSNX - Volatility Comparison
American Century International Opportunities Fund (AIOIX) has a higher volatility of 7.94% compared to Vanguard FTSE All-World ex-US Small-Cap Index Fund Institutional Shares (VFSNX) at 4.99%. This indicates that AIOIX's price experiences larger fluctuations and is considered to be riskier than VFSNX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.
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Volatility by Period
| AIOIX | VFSNX | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 7.94% | 4.99% | +2.95% |
Volatility (6M)Calculated over the trailing 6-month period | 19.30% | 13.02% | +6.28% |
Volatility (1Y)Calculated over the trailing 1-year period | 21.79% | 14.81% | +6.98% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 19.49% | 15.26% | +4.23% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 19.03% | 15.65% | +3.38% |
AIOIX vs. VFSNX - Expense Ratio Comparison
AIOIX has a 1.48% expense ratio, which is higher than VFSNX's 0.11% expense ratio.
Dividends
AIOIX vs. VFSNX - Dividend Comparison
AIOIX's dividend yield for the trailing twelve months is around 0.26%, less than VFSNX's 3.29% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
AIOIX American Century International Opportunities Fund | 0.26% | 0.27% | 0.32% | 0.23% | 0.00% | 17.80% | 3.18% | 0.92% | 5.28% | 9.09% | 0.04% | 7.15% |
VFSNX Vanguard FTSE All-World ex-US Small-Cap Index Fund Institutional Shares | 3.29% | 3.36% | 3.41% | 3.11% | 2.26% | 2.70% | 1.90% | 3.25% | 2.81% | 2.85% | 2.93% | 2.69% |
Frequently Asked Questions
With a correlation of 0.93, AIOIX and VFSNX 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.
AIOIX has higher volatility (7.94%) compared to VFSNX (4.99%). In terms of maximum drawdown, AIOIX dropped -66.16% vs VFSNX's -43.65%.
VFSNX currently has the higher Sharpe Ratio (1.09 vs 0.72), 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.
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