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ACIHX vs. BUFGX
Performance
Return for Risk
Drawdowns
Volatility
Dividends

ACIHX vs. BUFGX

Last updated Jun 23, 2026

ACIHX (American Century Growth Fund G Class) and BUFGX (Buffalo Growth Fund) are both Large Cap Growth Equities funds. Over the past 3 years, ACIHX returned 20.56%/yr vs 15.86%/yr for BUFGX. With a 0.97 correlation, they move nearly in lockstep. ACIHX charges 0.01%/yr vs 0.92%/yr for BUFGX.

Performance

ACIHX vs. BUFGX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in American Century Growth Fund G Class (ACIHX) and Buffalo Growth Fund (BUFGX). The values are adjusted to include any dividend payments, if applicable.

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Returns By Period

In the year-to-date period, ACIHX achieves a 4.95% return, which is significantly higher than BUFGX's -0.94% return.

ACIHX

1D
1.47%
1M
-0.26%
YTD
4.95%
6M
4.49%
1Y
23.59%
3Y*
20.56%
5Y*
—
10Y*
—

BUFGX

1D
1.48%
1M
-1.80%
YTD
-0.94%
6M
-0.94%
1Y
13.90%
3Y*
15.86%
5Y*
9.04%
10Y*
13.30%
*Multi-year figures are annualized to reflect compound growth (CAGR)

ACIHX vs. BUFGX - Yearly Performance Comparison

2026 (YTD)2025202420232022
ACIHX
American Century Growth Fund G Class		4.95%16.26%27.35%44.64%-6.24%
BUFGX
Buffalo Growth Fund		-0.94%13.95%25.13%42.67%-9.05%

Correlation

The correlation between ACIHX and BUFGX is 0.94, 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

0.94

Correlation (3Y)
Calculated over the trailing 3-year period

0.96

Correlation (All Time)
Calculated using the full available price history since May 16, 2022

0.97

The correlation between ACIHX and BUFGX has been stable across timeframes, ranging from 0.94 to 0.97 - a consistent structural relationship.

Compare stocks, funds, or ETFs

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American Century Growth Fund G Class

Buffalo Growth Fund

Often compared with ACIHX:
ACIHX vs. TWCUXACIHX vs. FDGRXACIHX vs. TRBCXACIHX vs. FCNTXACIHX vs. GEGTXACIHX vs. FBCGXACIHX vs. ADX
Often compared with BUFGX:
BUFGX vs. BUFEXBUFGX vs. SPYBUFGX vs. VOOBUFGX vs. BUFDXBUFGX vs. BUFMXBUFGX vs. BUFOXBUFGX vs. BUFTX

Return for Risk

ACIHX vs. BUFGX — Risk / Return Rank

Compare risk-adjusted metric ranks to identify better-performing investments over the past 12 months.
ACIHX
ACIHX Risk / Return Rank: 2222
Overall Rank
ACIHX Sharpe Ratio Rank: 2727
Sharpe Ratio Rank
ACIHX Sortino Ratio Rank: 2424
Sortino Ratio Rank
ACIHX Omega Ratio Rank: 2525
Omega Ratio Rank
ACIHX Calmar Ratio Rank: 1717
Calmar Ratio Rank
ACIHX Martin Ratio Rank: 1919
Martin Ratio Rank
BUFGX
BUFGX Risk / Return Rank: 1010
Overall Rank
BUFGX Sharpe Ratio Rank: 1111
Sharpe Ratio Rank
BUFGX Sortino Ratio Rank: 1111
Sortino Ratio Rank
BUFGX Omega Ratio Rank: 1111
Omega Ratio Rank
BUFGX Calmar Ratio Rank: 88
Calmar Ratio Rank
BUFGX Martin Ratio Rank: 99
Martin Ratio Rank
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.

ACIHX vs. BUFGX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Century Growth Fund G Class (ACIHX) and Buffalo Growth Fund (BUFGX). 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.

ACIHXBUFGXDifference
Sharpe ratioReturn per unit of total volatility
1.38
0.84

+0.55

Sortino ratioReturn per unit of downside risk
1.91
1.21

+0.71

Omega ratioGain probability vs. loss probability

1.24

1.16

+0.09

Calmar ratioReturn relative to maximum drawdown

1.39

0.75

+0.64

Martin ratioReturn relative to average drawdown

4.58

2.47

+2.11

ACIHX vs. BUFGX - Sharpe Ratio Comparison

The current ACIHX Sharpe Ratio is 1.38, which is higher than the BUFGX Sharpe Ratio of 0.84. The chart below compares the historical Sharpe Ratios of ACIHX and BUFGX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

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Drawdowns

ACIHX vs. BUFGX - Drawdown Comparison

The maximum ACIHX drawdown since its inception was -24.00%, smaller than the maximum BUFGX drawdown of -50.17%. Use the drawdown chart below to compare losses from any high point for ACIHX and BUFGX.

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Drawdown Indicators

ACIHXBUFGXDifference

Max Drawdown

Largest peak-to-trough decline

-24.00%

-50.17%

+26.17%

Max Drawdown (1Y)

Largest decline over 1 year

-16.40%

-17.63%

+1.23%

Max Drawdown (3Y)

Largest decline over 3 years

-24.00%

-21.93%

-2.07%

Max Drawdown (5Y)

Largest decline over 5 years

—

-35.68%

—

Max Drawdown (10Y)

Largest decline over 10 years

—

-35.68%

—

Current Drawdown

Current decline from peak

-4.16%

-3.86%

-0.30%

Average Drawdown

Average peak-to-trough decline

-4.88%

-8.96%

+4.08%

Ulcer Index

Depth and duration of drawdowns from previous peaks

4.98%

5.35%

-0.37%

Volatility

ACIHX vs. BUFGX - Volatility Comparison

American Century Growth Fund G Class (ACIHX) has a higher volatility of 6.36% compared to Buffalo Growth Fund (BUFGX) at 6.01%. This indicates that ACIHX's price experiences larger fluctuations and is considered to be riskier than BUFGX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

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Volatility by Period

ACIHXBUFGXDifference

Volatility (1M)

Calculated over the trailing 1-month period

6.36%

6.01%

+0.35%

Volatility (6M)

Calculated over the trailing 6-month period

13.07%

12.79%

+0.28%

Volatility (1Y)

Calculated over the trailing 1-year period

16.53%

15.85%

+0.68%

Volatility (5Y)

Calculated over the trailing 5-year period, annualized

21.11%

21.49%

-0.38%

Volatility (10Y)

Calculated over the trailing 10-year period, annualized

21.11%

20.77%

+0.34%

ACIHX vs. BUFGX - Expense Ratio Comparison

ACIHX has a 0.01% expense ratio, which is lower than BUFGX's 0.92% expense ratio.

Dividends

ACIHX vs. BUFGX - Dividend Comparison

ACIHX's dividend yield for the trailing twelve months is around 15.20%, more than BUFGX's 6.18% yield.

PositionTTM20252024202320222021202020192018201720162015
ACIHX
American Century Growth Fund G Class		15.20%15.95%5.65%4.61%2.86%0.00%0.00%0.00%0.00%0.00%0.00%0.00%
BUFGX
Buffalo Growth Fund		6.18%6.12%8.55%5.55%4.77%9.90%4.97%13.60%34.64%20.49%0.00%18.46%

Frequently Asked Questions

With a correlation of 0.94, ACIHX and BUFGX 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.

ACIHX has higher volatility (6.36%) compared to BUFGX (6.01%). In terms of maximum drawdown, ACIHX dropped -24.00% vs BUFGX's -50.17%.

ACIHX currently has the higher Sharpe Ratio (1.38 vs 0.84), 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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