BUFEX vs. AMCPX

Last updated Jun 3, 2026

BUFEX (Buffalo Large Cap Fund) and AMCPX (American Funds AMCAP Fund Class A) are both Large Cap Growth Equities funds. Over the past 10 years, BUFEX returned 16.07%/yr vs 12.45%/yr for AMCPX. Their correlation of 0.92 suggests significant overlap in exposure. BUFEX charges 0.93%/yr vs 0.65%/yr for AMCPX.

Performance

BUFEX vs. AMCPX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Buffalo Large Cap Fund (BUFEX) and American Funds AMCAP Fund Class A (AMCPX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, BUFEX achieves a 10.44% return, which is significantly higher than AMCPX's 7.17% return. Over the past 10 years, BUFEX has outperformed AMCPX with an annualized return of 16.07%, while AMCPX has yielded a comparatively lower 12.45% annualized return.

BUFEX

• 1D: 0.74%
• 1M: 6.09%
• YTD: 10.44%
• 6M: 9.64%
• 1Y: 27.67%
• 3Y*: 23.53%
• 5Y*: 13.83%
• 10Y*: 16.07%

AMCPX

• 1D: 0.35%
• 1M: 4.40%
• YTD: 7.17%
• 6M: 7.07%
• 1Y: 23.60%
• 3Y*: 20.13%
• 5Y*: 9.41%
• 10Y*: 12.45%

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

BUFEX vs. AMCPX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
BUFEX Buffalo Large Cap Fund	10.44%	16.27%	28.86%	40.39%	-28.64%	25.55%	28.08%	31.76%	-1.60%	24.86%
AMCPX American Funds AMCAP Fund Class A	7.17%	17.68%	21.11%	31.04%	-28.67%	20.57%	21.42%	26.35%	-4.42%	22.08%

Correlation

The correlation between BUFEX and AMCPX 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	0.93
Correlation (5Y) Calculated over the trailing 5-year period	0.95
Correlation (10Y) Calculated over the trailing 10-year period	0.94
Correlation (All Time) Calculated using the full available price history since May 22, 1995	0.92

The correlation between BUFEX and AMCPX has been stable across timeframes, ranging from 0.92 to 0.95 - a consistent structural relationship.

Return for Risk

BUFEX vs. AMCPX — Risk / Return Rank

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

BUFEX

BUFEX Risk / Return Rank: 39
BUFEX Sharpe Ratio Rank: 48
BUFEX Sortino Ratio Rank: 43
BUFEX Omega Ratio Rank: 43
BUFEX Calmar Ratio Rank: 29
BUFEX Martin Ratio Rank: 31

AMCPX

AMCPX Risk / Return Rank: 29
AMCPX Sharpe Ratio Rank: 32
AMCPX Sortino Ratio Rank: 30
AMCPX Omega Ratio Rank: 33
AMCPX Calmar Ratio Rank: 20
AMCPX Martin Ratio Rank: 29

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.

BUFEX vs. AMCPX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Buffalo Large Cap Fund (BUFEX) and American Funds AMCAP Fund Class A (AMCPX). 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.

	BUFEX	AMCPX	Difference
Sharpe ratio Return per unit of total volatility	2.05	1.67	+0.38
Sortino ratio Return per unit of downside risk	2.77	2.32	+0.45
Omega ratio Gain probability vs. loss probability	1.36	1.30	+0.05
Calmar ratio Return relative to maximum drawdown	2.06	1.71	+0.36
Martin ratio Return relative to average drawdown	7.35	6.95	+0.41
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

BUFEX vs. AMCPX - Sharpe Ratio Comparison

The current BUFEX Sharpe Ratio is 2.05, which is comparable to the AMCPX Sharpe Ratio of 1.67. The chart below compares the historical Sharpe Ratios of BUFEX and AMCPX, 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

	BUFEX	AMCPX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.05	1.67	+0.38
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.70	0.49	+0.21
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.83	0.67	+0.16
Sharpe Ratio (All Time) Calculated using the full available price history	0.56	0.59	-0.03

Drawdowns

BUFEX vs. AMCPX - Drawdown Comparison

The maximum BUFEX drawdown since its inception was -54.12%, smaller than the maximum AMCPX drawdown of -62.37%. Use the drawdown chart below to compare losses from any high point for BUFEX and AMCPX.

Drawdown Indicators

	BUFEX	AMCPX	Difference
Max Drawdown Largest peak-to-trough decline	-54.12%	-62.37%	+8.25%
Max Drawdown (1Y) Largest decline over 1 year	-13.76%	-14.18%	+0.42%
Max Drawdown (3Y) Largest decline over 3 years	-21.46%	-19.71%	-1.75%
Max Drawdown (5Y) Largest decline over 5 years	-32.54%	-36.90%	+4.36%
Max Drawdown (10Y) Largest decline over 10 years	-32.54%	-36.90%	+4.36%
Current Drawdown Current decline from peak	0.00%	0.00%	0.00%
Average Drawdown Average peak-to-trough decline	-9.23%	-9.58%	+0.35%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.86%	3.49%	+0.37%

Volatility

BUFEX vs. AMCPX - Volatility Comparison

Buffalo Large Cap Fund (BUFEX) and American Funds AMCAP Fund Class A (AMCPX) have volatilities of 3.31% and 3.43%, 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

	BUFEX	AMCPX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.31%	3.43%	-0.12%
Volatility (6M) Calculated over the trailing 6-month period	10.69%	11.40%	-0.71%
Volatility (1Y) Calculated over the trailing 1-year period	14.00%	14.56%	-0.56%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	19.75%	19.23%	+0.52%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	19.49%	18.72%	+0.77%

BUFEX vs. AMCPX - Expense Ratio Comparison

BUFEX has a 0.93% expense ratio, which is higher than AMCPX's 0.65% expense ratio.

Dividends

BUFEX vs. AMCPX - Dividend Comparison

BUFEX's dividend yield for the trailing twelve months is around 6.11%, less than AMCPX's 8.14% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
AMCPX American Funds AMCAP Fund Class A	8.14%	8.73%	8.19%	3.26%	7.54%	3.43%	3.88%	4.90%	7.84%	5.37%	3.81%	8.86%
BUFEX Buffalo Large Cap Fund	6.11%	6.75%	3.65%	0.03%	3.07%	25.69%	0.14%	1.42%	6.00%	5.33%	0.00%	6.83%

Frequently Asked Questions

Can I hold both BUFEX and AMCPX in my portfolio?

With a correlation of 0.93, BUFEX and AMCPX 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, BUFEX or AMCPX?

AMCPX has higher volatility (3.43%) compared to BUFEX (3.31%). In terms of maximum drawdown, BUFEX dropped -54.12% vs AMCPX's -62.37%.

Which has better risk-adjusted returns?

BUFEX currently has the higher Sharpe Ratio (2.05 vs 1.67), 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.