FUNFX vs. AMCPX

Last updated Jun 4, 2026

FUNFX (American Funds Fundamental Investors® Class F-3) and AMCPX (American Funds AMCAP Fund Class A) are both mutual funds - FUNFX is a Large Cap Blend Equities fund managed by American Funds, while AMCPX is a Large Cap Growth Equities fund managed by American Funds. Over the past 5 years, FUNFX returned 15.27%/yr vs 9.39%/yr for AMCPX. With a 0.96 correlation, they move nearly in lockstep. FUNFX charges 0.28%/yr vs 0.65%/yr for AMCPX.

Performance

FUNFX vs. AMCPX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in American Funds Fundamental Investors® Class F-3 (FUNFX) 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, FUNFX achieves a 15.28% return, which is significantly higher than AMCPX's 6.34% return.

FUNFX

• 1D: 0.01%
• 1M: 5.92%
• YTD: 15.28%
• 6M: 16.32%
• 1Y: 34.95%
• 3Y*: 26.48%
• 5Y*: 15.27%
• 10Y*: —

AMCPX

• 1D: -0.77%
• 1M: 3.82%
• YTD: 6.34%
• 6M: 6.01%
• 1Y: 21.86%
• 3Y*: 19.82%
• 5Y*: 9.39%
• 10Y*: 12.36%

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

FUNFX vs. AMCPX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
FUNFX American Funds Fundamental Investors® Class F-3	15.28%	24.57%	23.13%	26.25%	-16.38%	22.81%	15.28%	27.47%	-7.87%	19.59%
AMCPX American Funds AMCAP Fund Class A	6.34%	17.68%	21.11%	31.04%	-28.67%	20.57%	21.42%	26.35%	-4.42%	18.01%

Correlation

The correlation between FUNFX and AMCPX 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 (5Y) Calculated over the trailing 5-year period	0.96
Correlation (All Time) Calculated using the full available price history since Feb 2, 2017	0.96

The correlation between FUNFX and AMCPX has been stable across timeframes, ranging from 0.94 to 0.96 - a consistent structural relationship.

Return for Risk

FUNFX vs. AMCPX — Risk / Return Rank

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

FUNFX

FUNFX Risk / Return Rank: 76
FUNFX Sharpe Ratio Rank: 81
FUNFX Sortino Ratio Rank: 71
FUNFX Omega Ratio Rank: 71
FUNFX Calmar Ratio Rank: 74
FUNFX Martin Ratio Rank: 83

AMCPX

AMCPX Risk / Return Rank: 27
AMCPX Sharpe Ratio Rank: 30
AMCPX Sortino Ratio Rank: 28
AMCPX Omega Ratio Rank: 30
AMCPX Calmar Ratio Rank: 19
AMCPX 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.

FUNFX vs. AMCPX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Funds Fundamental Investors® Class F-3 (FUNFX) 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.

	FUNFX	AMCPX	Difference
Sharpe ratio: Return per unit of total volatility	2.61	1.56	+1.05
Sortino ratio: Return per unit of downside risk	3.50	2.19	+1.32
Omega ratio: Gain probability vs. loss probability	1.47	1.28	+0.19
Calmar ratio: Return relative to maximum drawdown	3.38	1.60	+1.78
Martin ratio: Return relative to average drawdown	15.68	6.51	+9.17
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

FUNFX vs. AMCPX - Sharpe Ratio Comparison

The current FUNFX Sharpe Ratio is 2.61, which is higher than the AMCPX Sharpe Ratio of 1.56. The chart below compares the historical Sharpe Ratios of FUNFX 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

	FUNFX	AMCPX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.61	1.56	+1.05
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.91	0.49	+0.42
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	0.66	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.84	0.59	+0.24

Drawdowns

FUNFX vs. AMCPX - Drawdown Comparison

The maximum FUNFX drawdown since its inception was -33.92%, smaller than the maximum AMCPX drawdown of -62.37%. Use the drawdown chart below to compare losses from any high point for FUNFX and AMCPX.

Drawdown Indicators

	FUNFX	AMCPX	Difference
Max Drawdown Largest peak-to-trough decline	-33.92%	-62.37%	+28.45%
Max Drawdown (1Y) Largest decline over 1 year	-10.62%	-14.18%	+3.56%
Max Drawdown (3Y) Largest decline over 3 years	-17.93%	-19.71%	+1.78%
Max Drawdown (5Y) Largest decline over 5 years	-24.88%	-36.90%	+12.02%
Max Drawdown (10Y) Largest decline over 10 years	—	-36.90%	—
Current Drawdown Current decline from peak	0.00%	-0.77%	+0.77%
Average Drawdown Average peak-to-trough decline	-4.71%	-9.58%	+4.87%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.29%	3.49%	-1.20%

Volatility

FUNFX vs. AMCPX - Volatility Comparison

American Funds Fundamental Investors® Class F-3 (FUNFX) and American Funds AMCAP Fund Class A (AMCPX) have volatilities of 3.68% and 3.57%, 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

	FUNFX	AMCPX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.68%	3.57%	+0.11%
Volatility (6M) Calculated over the trailing 6-month period	10.82%	11.42%	-0.60%
Volatility (1Y) Calculated over the trailing 1-year period	13.75%	14.56%	-0.81%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	16.80%	19.24%	-2.44%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.11%	18.72%	-0.61%

FUNFX vs. AMCPX - Expense Ratio Comparison

FUNFX has a 0.28% expense ratio, which is lower than AMCPX's 0.65% expense ratio.

Dividends

FUNFX vs. AMCPX - Dividend Comparison

FUNFX's dividend yield for the trailing twelve months is around 7.69%, less than AMCPX's 8.21% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
AMCPX American Funds AMCAP Fund Class A	8.21%	8.73%	8.19%	3.26%	7.54%	3.43%	3.88%	4.90%	7.84%	5.37%	3.81%	8.86%
FUNFX American Funds Fundamental Investors® Class F-3	7.69%	8.83%	9.21%	6.10%	5.33%	11.29%	2.90%	7.21%	9.65%	7.57%	0.00%	0.00%

Frequently Asked Questions

Can I hold both FUNFX and AMCPX in my portfolio?

With a correlation of 0.94, FUNFX 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, FUNFX or AMCPX?

FUNFX has higher volatility (3.68%) compared to AMCPX (3.57%). In terms of maximum drawdown, FUNFX dropped -33.92% vs AMCPX's -62.37%.

Which has better risk-adjusted returns?

FUNFX currently has the higher Sharpe Ratio (2.61 vs 1.56), 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.