AMCPX vs. ONERX

Last updated Jun 4, 2026

AMCPX (American Funds AMCAP Fund Class A) and ONERX (One Rock Fund) are both Large Cap Growth Equities funds. Over the past 5 years, AMCPX returned 9.39%/yr vs 34.52%/yr for ONERX. Their correlation of 0.84 suggests significant overlap in exposure. AMCPX charges 0.65%/yr vs 1.75%/yr for ONERX.

Performance

AMCPX vs. ONERX - Performance Comparison

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

Returns By Period

In the year-to-date period, AMCPX achieves a 6.34% return, which is significantly lower than ONERX's 66.81% return.

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%

ONERX

• 1D: 3.19%
• 1M: 23.36%
• YTD: 66.81%
• 6M: 66.34%
• 1Y: 129.67%
• 3Y*: 57.09%
• 5Y*: 34.52%
• 10Y*: —

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

AMCPX vs. ONERX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020
AMCPX American Funds AMCAP Fund Class A	6.34%	17.68%	21.11%	31.04%	-28.67%	20.57%	42.37%
ONERX One Rock Fund	66.81%	49.37%	21.76%	72.41%	-42.06%	45.70%	104.46%

Correlation

The correlation between AMCPX and ONERX is 0.71, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.71
Correlation (3Y) Calculated over the trailing 3-year period	0.81
Correlation (5Y) Calculated over the trailing 5-year period	0.85
Correlation (All Time) Calculated using the full available price history since Mar 16, 2020	0.84

The correlation between AMCPX and ONERX shifts across timeframes, from 0.71 (1 year) to 0.85 (5 years), reflecting how their relationship changes across market environments.

Return for Risk

AMCPX vs. ONERX — Risk / Return Rank

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

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

ONERX

ONERX Risk / Return Rank: 88
ONERX Sharpe Ratio Rank: 97
ONERX Sortino Ratio Rank: 73
ONERX Omega Ratio Rank: 77
ONERX Calmar Ratio Rank: 98
ONERX Martin Ratio Rank: 97

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.

AMCPX vs. ONERX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Funds AMCAP Fund Class A (AMCPX) and One Rock Fund (ONERX). 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.

	AMCPX	ONERX	Difference
Sharpe ratio: Return per unit of total volatility	1.56	3.59	-2.02
Sortino ratio: Return per unit of downside risk	2.19	3.57	-1.38
Omega ratio: Gain probability vs. loss probability	1.28	1.50	-0.22
Calmar ratio: Return relative to maximum drawdown	1.60	7.71	-6.11
Martin ratio: Return relative to average drawdown	6.51	27.26	-20.75
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

AMCPX vs. ONERX - Sharpe Ratio Comparison

The current AMCPX Sharpe Ratio is 1.56, which is lower than the ONERX Sharpe Ratio of 3.59. The chart below compares the historical Sharpe Ratios of AMCPX and ONERX, 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

	AMCPX	ONERX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.56	3.59	-2.02
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.49	0.89	-0.40
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.66	—	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.59	1.11	-0.52

Drawdowns

AMCPX vs. ONERX - Drawdown Comparison

The maximum AMCPX drawdown since its inception was -62.37%, which is greater than ONERX's maximum drawdown of -47.44%. Use the drawdown chart below to compare losses from any high point for AMCPX and ONERX.

Drawdown Indicators

	AMCPX	ONERX	Difference
Max Drawdown Largest peak-to-trough decline	-62.37%	-47.44%	-14.93%
Max Drawdown (1Y) Largest decline over 1 year	-14.18%	-17.63%	+3.45%
Max Drawdown (3Y) Largest decline over 3 years	-19.71%	-47.44%	+27.73%
Max Drawdown (5Y) Largest decline over 5 years	-36.90%	-47.44%	+10.54%
Max Drawdown (10Y) Largest decline over 10 years	-36.90%	—	—
Current Drawdown Current decline from peak	-0.77%	0.00%	-0.77%
Average Drawdown Average peak-to-trough decline	-9.58%	-13.80%	+4.22%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.49%	4.98%	-1.49%

Volatility

AMCPX vs. ONERX - Volatility Comparison

The current volatility for American Funds AMCAP Fund Class A (AMCPX) is 3.57%, while One Rock Fund (ONERX) has a volatility of 11.93%. This indicates that AMCPX experiences smaller price fluctuations and is considered to be less risky than ONERX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	AMCPX	ONERX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.57%	11.93%	-8.36%
Volatility (6M) Calculated over the trailing 6-month period	11.42%	29.84%	-18.42%
Volatility (1Y) Calculated over the trailing 1-year period	14.56%	37.90%	-23.34%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	19.24%	39.12%	-19.88%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.72%	38.21%	-19.49%

AMCPX vs. ONERX - Expense Ratio Comparison

AMCPX has a 0.65% expense ratio, which is lower than ONERX's 1.75% expense ratio.

Dividends

AMCPX vs. ONERX - Dividend Comparison

AMCPX's dividend yield for the trailing twelve months is around 8.21%, less than ONERX's 14.46% 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%
ONERX One Rock Fund	14.46%	24.12%	0.00%	0.00%	10.57%	28.88%	18.66%	0.00%	0.00%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both AMCPX and ONERX in my portfolio?

AMCPX and ONERX have a correlation of 0.71, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, AMCPX or ONERX?

ONERX has higher volatility (11.93%) compared to AMCPX (3.57%). In terms of maximum drawdown, AMCPX dropped -62.37% vs ONERX's -47.44%.

Which has better risk-adjusted returns?

ONERX currently has the higher Sharpe Ratio (3.59 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.