AULDX vs. VIGIX

Last updated Jun 26, 2026

AULDX (American Century Ultra Fund Class R6) and VIGIX (Vanguard Growth Index Fund Institutional Shares) are both Large Cap Growth Equities funds. AULDX is actively managed, while VIGIX is passively managed. Over the past 10 years, AULDX returned 18.22%/yr vs 17.99%/yr for VIGIX. With a 0.99 correlation, they move nearly in lockstep. AULDX charges 0.52%/yr vs 0.04%/yr for VIGIX.

Performance

AULDX vs. VIGIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in American Century Ultra Fund Class R6 (AULDX) 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, AULDX achieves a 1.71% return, which is significantly lower than VIGIX's 3.20% return. Both investments have delivered pretty close results over the past 10 years, with AULDX having a 18.22% annualized return and VIGIX not far behind at 17.99%.

AULDX

• 1D: -0.14%
• 1M: -5.81%
• YTD: 1.71%
• 6M: 0.16%
• 1Y: 14.05%
• 3Y*: 18.51%
• 5Y*: 10.07%
• 10Y*: 18.22%

VIGIX

• 1D: -0.33%
• 1M: -4.92%
• YTD: 3.20%
• 6M: 1.71%
• 1Y: 17.49%
• 3Y*: 22.62%
• 5Y*: 12.71%
• 10Y*: 17.99%

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

AULDX vs. VIGIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
AULDX American Century Ultra Fund Class R6	1.71%	13.05%	29.99%	43.86%	-32.15%	23.89%	50.31%	35.23%	1.04%	32.36%
VIGIX Vanguard Growth Index Fund Institutional Shares	3.20%	19.44%	32.68%	46.77%	-33.13%	27.27%	40.19%	37.26%	-3.34%	27.81%

Correlation

The correlation between AULDX and VIGIX is 0.98 - these two move nearly in lockstep. At this level, holding both provides almost no diversification benefit. If you already own one, adding the other does little to reduce portfolio risk.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.98
Correlation (3Y) Calculated over the trailing 3-year period	0.99
Correlation (5Y) Calculated over the trailing 5-year period	0.99
Correlation (10Y) Calculated over the trailing 10-year period	0.99
Correlation (All Time) Calculated using the full available price history since Jan 2, 2014	0.99

The correlation between AULDX and VIGIX has been stable across timeframes, ranging from 0.98 to 0.99 - a consistent structural relationship.

Return for Risk

AULDX vs. VIGIX — Risk / Return Rank

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

AULDX

AULDX Risk / Return Rank: 14
AULDX Sharpe Ratio Rank: 15
AULDX Sortino Ratio Rank: 14
AULDX Omega Ratio Rank: 14
AULDX Calmar Ratio Rank: 13
AULDX Martin Ratio Rank: 15

VIGIX

VIGIX Risk / Return Rank: 18
VIGIX Sharpe Ratio Rank: 20
VIGIX Sortino Ratio Rank: 19
VIGIX Omega Ratio Rank: 20
VIGIX Calmar Ratio Rank: 15
VIGIX Martin Ratio Rank: 17

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.

AULDX vs. VIGIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Century Ultra Fund Class R6 (AULDX) 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.

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.

	AULDX	VIGIX	Difference
Sharpe ratio: Return per unit of total volatility	0.85	1.07	-0.22
Sortino ratio: Return per unit of downside risk	1.24	1.51	-0.28
Omega ratio: Gain probability vs. loss probability	1.16	1.19	-0.04
Calmar ratio: Return relative to maximum drawdown	0.94	1.09	-0.15
Martin ratio: Return relative to average drawdown	3.18	3.72	-0.54

AULDX vs. VIGIX - Sharpe Ratio Comparison

The current AULDX Sharpe Ratio is 0.85, which is comparable to the VIGIX Sharpe Ratio of 1.07. The chart below compares the historical Sharpe Ratios of AULDX 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.

Drawdowns

AULDX vs. VIGIX - Drawdown Comparison

The maximum AULDX drawdown since its inception was -35.03%, smaller than the maximum VIGIX drawdown of -56.95%. Use the drawdown chart below to compare losses from any high point for AULDX and VIGIX.

Drawdown Indicators

	AULDX	VIGIX	Difference
Max Drawdown Largest peak-to-trough decline	-35.03%	-56.95%	+21.92%
Max Drawdown (1Y) Largest decline over 1 year	-15.60%	-16.51%	+0.91%
Max Drawdown (3Y) Largest decline over 3 years	-24.78%	-23.03%	-1.75%
Max Drawdown (5Y) Largest decline over 5 years	-35.03%	-35.62%	+0.59%
Max Drawdown (10Y) Largest decline over 10 years	-35.03%	-35.62%	+0.59%
Current Drawdown Current decline from peak	-7.75%	-7.15%	-0.60%
Average Drawdown Average peak-to-trough decline	-6.18%	-16.25%	+10.07%
Ulcer Index Depth and duration of drawdowns from previous peaks	4.61%	4.84%	-0.23%

Volatility

AULDX vs. VIGIX - Volatility Comparison

American Century Ultra Fund Class R6 (AULDX) and Vanguard Growth Index Fund Institutional Shares (VIGIX) have volatilities of 6.77% and 6.87%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	AULDX	VIGIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	6.77%	6.87%	-0.10%
Volatility (6M) Calculated over the trailing 6-month period	13.52%	13.42%	+0.10%
Volatility (1Y) Calculated over the trailing 1-year period	17.33%	16.97%	+0.36%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	22.72%	22.51%	+0.21%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	22.13%	21.65%	+0.48%

AULDX vs. VIGIX - Expense Ratio Comparison

AULDX has a 0.52% expense ratio, which is higher than VIGIX's 0.04% expense ratio.

Dividends

AULDX vs. VIGIX - Dividend Comparison

AULDX's dividend yield for the trailing twelve months is around 10.42%, more than VIGIX's 0.40% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
AULDX American Century Ultra Fund Class R6	10.42%	10.60%	3.32%	5.68%	6.97%	6.42%	2.67%	4.18%	7.94%	6.19%	4.45%	5.06%
VIGIX Vanguard Growth Index Fund Institutional Shares	0.40%	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 AULDX and VIGIX in my portfolio?

With a correlation of 0.98, AULDX 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, AULDX or VIGIX?

VIGIX has higher volatility (6.87%) compared to AULDX (6.77%). In terms of maximum drawdown, AULDX dropped -35.03% vs VIGIX's -56.95%.

Which has better risk-adjusted returns?

VIGIX currently has the higher Sharpe Ratio (1.06 vs 0.85), 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.