ACFOX vs. VIGIX

Last updated Jun 4, 2026

ACFOX (American Century Investments Focused Dynamic Growth Fund) and VIGIX (Vanguard Growth Index Fund Institutional Shares) are both Large Cap Growth Equities funds. Over the past 10 years, ACFOX returned 19.58%/yr vs 18.40%/yr for VIGIX. Their correlation of 0.93 suggests significant overlap in exposure. ACFOX charges 0.85%/yr vs 0.04%/yr for VIGIX.

Performance

ACFOX vs. VIGIX - Performance Comparison

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

Returns By Period

In the year-to-date period, ACFOX achieves a 9.28% return, which is significantly lower than VIGIX's 10.83% return. Over the past 10 years, ACFOX has outperformed VIGIX with an annualized return of 19.58%, while VIGIX has yielded a comparatively lower 18.40% annualized return.

ACFOX

• 1D: -1.06%
• 1M: 5.78%
• YTD: 9.28%
• 6M: 10.92%
• 1Y: 33.16%
• 3Y*: 28.29%
• 5Y*: 11.86%
• 10Y*: 19.58%

VIGIX

• 1D: -0.28%
• 1M: 7.55%
• YTD: 10.83%
• 6M: 10.12%
• 1Y: 29.46%
• 3Y*: 26.47%
• 5Y*: 15.72%
• 10Y*: 18.40%

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

ACFOX vs. VIGIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
ACFOX American Century Investments Focused Dynamic Growth Fund	9.28%	20.51%	43.30%	35.66%	-36.32%	7.08%	73.31%	32.30%	6.51%	34.55%
VIGIX Vanguard Growth Index Fund Institutional Shares	10.83%	19.44%	32.68%	46.77%	-33.13%	27.27%	40.19%	37.26%	-3.34%	27.81%

Correlation

The correlation between ACFOX and VIGIX is 0.93, indicating a strong positive relationship between their price movements. Combining them offers limited diversification - they tend to fall together during downturns.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.93
Correlation (3Y) Calculated over the trailing 3-year period	0.94
Correlation (5Y) Calculated over the trailing 5-year period	0.95
Correlation (10Y) Calculated over the trailing 10-year period	0.93
Correlation (All Time) Calculated using the full available price history since Jun 1, 2006	0.93

The correlation between ACFOX and VIGIX has been stable across timeframes, ranging from 0.93 to 0.95 - a consistent structural relationship.

Return for Risk

ACFOX vs. VIGIX — Risk / Return Rank

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

ACFOX

ACFOX Risk / Return Rank: 34
ACFOX Sharpe Ratio Rank: 38
ACFOX Sortino Ratio Rank: 34
ACFOX Omega Ratio Rank: 34
ACFOX Calmar Ratio Rank: 30
ACFOX Martin Ratio Rank: 31

VIGIX

VIGIX Risk / Return Rank: 34
VIGIX Sharpe Ratio Rank: 43
VIGIX Sortino Ratio Rank: 38
VIGIX Omega Ratio Rank: 39
VIGIX Calmar Ratio Rank: 25
VIGIX 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.

ACFOX vs. VIGIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Century Investments Focused Dynamic Growth Fund (ACFOX) and Vanguard Growth Index Fund Institutional Shares (VIGIX). 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.

	ACFOX	VIGIX	Difference
Sharpe ratio: Return per unit of total volatility	1.80	1.92	-0.12
Sortino ratio: Return per unit of downside risk	2.43	2.59	-0.16
Omega ratio: Gain probability vs. loss probability	1.31	1.33	-0.02
Calmar ratio: Return relative to maximum drawdown	2.05	1.85	+0.20
Martin ratio: Return relative to average drawdown	7.24	6.49	+0.74
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

ACFOX vs. VIGIX - Sharpe Ratio Comparison

The current ACFOX Sharpe Ratio is 1.80, which is comparable to the VIGIX Sharpe Ratio of 1.92. The chart below compares the historical Sharpe Ratios of ACFOX and VIGIX, 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

	ACFOX	VIGIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.80	1.92	-0.12
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.47	0.71	-0.24
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.83	0.86	-0.03
Sharpe Ratio (All Time) Calculated using the full available price history	0.58	0.47	+0.11

Drawdowns

ACFOX vs. VIGIX - Drawdown Comparison

The maximum ACFOX drawdown since its inception was -58.92%, roughly equal to the maximum VIGIX drawdown of -56.95%. Use the drawdown chart below to compare losses from any high point for ACFOX and VIGIX.

Drawdown Indicators

	ACFOX	VIGIX	Difference
Max Drawdown Largest peak-to-trough decline	-58.92%	-56.95%	-1.97%
Max Drawdown (1Y) Largest decline over 1 year	-16.52%	-16.51%	-0.01%
Max Drawdown (3Y) Largest decline over 3 years	-27.03%	-23.03%	-4.00%
Max Drawdown (5Y) Largest decline over 5 years	-43.77%	-35.62%	-8.15%
Max Drawdown (10Y) Largest decline over 10 years	-43.77%	-35.62%	-8.15%
Current Drawdown Current decline from peak	-1.06%	-0.28%	-0.78%
Average Drawdown Average peak-to-trough decline	-14.71%	-16.28%	+1.57%
Ulcer Index Depth and duration of drawdowns from previous peaks	4.67%	4.68%	-0.01%

Volatility

ACFOX vs. VIGIX - Volatility Comparison

American Century Investments Focused Dynamic Growth Fund (ACFOX) has a higher volatility of 5.17% compared to Vanguard Growth Index Fund Institutional Shares (VIGIX) at 3.62%. This indicates that ACFOX's price experiences larger fluctuations and is considered to be riskier than VIGIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	ACFOX	VIGIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	5.17%	3.62%	+1.55%
Volatility (6M) Calculated over the trailing 6-month period	14.56%	12.10%	+2.46%
Volatility (1Y) Calculated over the trailing 1-year period	18.80%	15.87%	+2.93%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	25.28%	22.35%	+2.93%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	23.81%	21.59%	+2.22%

ACFOX vs. VIGIX - Expense Ratio Comparison

ACFOX has a 0.85% expense ratio, which is higher than VIGIX's 0.04% expense ratio.

Dividends

ACFOX vs. VIGIX - Dividend Comparison

ACFOX's dividend yield for the trailing twelve months is around 6.91%, more than VIGIX's 0.37% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
ACFOX American Century Investments Focused Dynamic Growth Fund	6.91%	7.56%	0.00%	0.00%	0.00%	2.48%	0.62%	0.00%	0.00%	0.00%	1.15%	1.33%
VIGIX Vanguard Growth Index Fund Institutional Shares	0.37%	0.41%	0.47%	0.58%	0.70%	0.48%	0.66%	0.95%	1.32%	1.15%	1.40%	1.31%

Frequently Asked Questions

Can I hold both ACFOX and VIGIX in my portfolio?

With a correlation of 0.93, ACFOX and VIGIX 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, ACFOX or VIGIX?

ACFOX has higher volatility (5.17%) compared to VIGIX (3.62%). In terms of maximum drawdown, ACFOX dropped -58.92% vs VIGIX's -56.95%.

Which has better risk-adjusted returns?

VIGIX currently has the higher Sharpe Ratio (1.92 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.