RBFFX vs. AMCPX

Last updated Jun 4, 2026

RBFFX (American Funds The Bond Fund of America) and AMCPX (American Funds AMCAP Fund Class A) are both mutual funds - RBFFX is a Intermediate Core Bond fund managed by American Funds, while AMCPX is a Large Cap Growth Equities fund managed by American Funds. Over the past 10 years, RBFFX returned 2.01%/yr vs 12.36%/yr for AMCPX. At a correlation of -0.11, they often move in opposite directions. RBFFX charges 0.29%/yr vs 0.65%/yr for AMCPX.

Performance

RBFFX vs. AMCPX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in American Funds The Bond Fund of America (RBFFX) 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, RBFFX achieves a 0.22% return, which is significantly lower than AMCPX's 6.34% return. Over the past 10 years, RBFFX has underperformed AMCPX with an annualized return of 2.01%, while AMCPX has yielded a comparatively higher 12.36% annualized return.

RBFFX

• 1D: 0.00%
• 1M: 0.47%
• YTD: 0.22%
• 6M: 0.16%
• 1Y: 5.34%
• 3Y*: 3.98%
• 5Y*: 0.16%
• 10Y*: 2.01%

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)

RBFFX vs. AMCPX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
RBFFX American Funds The Bond Fund of America	0.22%	7.49%	1.47%	4.65%	-13.03%	-0.64%	11.07%	8.13%	0.17%	3.53%
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%	22.08%

Correlation

The correlation between RBFFX and AMCPX is 0.27, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.27
Correlation (3Y) Calculated over the trailing 3-year period	0.20
Correlation (5Y) Calculated over the trailing 5-year period	0.16
Correlation (10Y) Calculated over the trailing 10-year period	0.02
Correlation (All Time) Calculated using the full available price history since Jan 3, 2003	-0.11

The correlation between RBFFX and AMCPX shifts across timeframes, from -0.11 (all time) to 0.27 (1 year), reflecting how their relationship changes across market environments.

Return for Risk

RBFFX vs. AMCPX — Risk / Return Rank

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

RBFFX

RBFFX Risk / Return Rank: 22
RBFFX Sharpe Ratio Rank: 22
RBFFX Sortino Ratio Rank: 24
RBFFX Omega Ratio Rank: 21
RBFFX Calmar Ratio Rank: 22
RBFFX Martin Ratio Rank: 20

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.

RBFFX vs. AMCPX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Funds The Bond Fund of America (RBFFX) 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.

	RBFFX	AMCPX	Difference
Sharpe ratio: Return per unit of total volatility	1.36	1.56	-0.20
Sortino ratio: Return per unit of downside risk	2.06	2.19	-0.12
Omega ratio: Gain probability vs. loss probability	1.24	1.28	-0.04
Calmar ratio: Return relative to maximum drawdown	1.74	1.60	+0.13
Martin ratio: Return relative to average drawdown	5.20	6.51	-1.31
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

RBFFX vs. AMCPX - Sharpe Ratio Comparison

The current RBFFX Sharpe Ratio is 1.36, which is comparable to the AMCPX Sharpe Ratio of 1.56. The chart below compares the historical Sharpe Ratios of RBFFX 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

	RBFFX	AMCPX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.36	1.56	-0.20
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.03	0.49	-0.46
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.41	0.66	-0.25
Sharpe Ratio (All Time) Calculated using the full available price history	0.82	0.59	+0.22

Drawdowns

RBFFX vs. AMCPX - Drawdown Comparison

The maximum RBFFX drawdown since its inception was -17.62%, smaller than the maximum AMCPX drawdown of -62.37%. Use the drawdown chart below to compare losses from any high point for RBFFX and AMCPX.

Drawdown Indicators

	RBFFX	AMCPX	Difference
Max Drawdown Largest peak-to-trough decline	-17.62%	-62.37%	+44.75%
Max Drawdown (1Y) Largest decline over 1 year	-3.09%	-14.18%	+11.09%
Max Drawdown (3Y) Largest decline over 3 years	-6.11%	-19.71%	+13.60%
Max Drawdown (5Y) Largest decline over 5 years	-17.62%	-36.90%	+19.28%
Max Drawdown (10Y) Largest decline over 10 years	-17.62%	-36.90%	+19.28%
Current Drawdown Current decline from peak	-1.50%	-0.77%	-0.73%
Average Drawdown Average peak-to-trough decline	-2.81%	-9.58%	+6.77%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.03%	3.49%	-2.46%

Volatility

RBFFX vs. AMCPX - Volatility Comparison

The current volatility for American Funds The Bond Fund of America (RBFFX) is 1.40%, while American Funds AMCAP Fund Class A (AMCPX) has a volatility of 3.57%. This indicates that RBFFX experiences smaller price fluctuations and is considered to be less risky than AMCPX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	RBFFX	AMCPX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.40%	3.57%	-2.17%
Volatility (6M) Calculated over the trailing 6-month period	2.84%	11.42%	-8.58%
Volatility (1Y) Calculated over the trailing 1-year period	3.96%	14.56%	-10.60%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	5.97%	19.24%	-13.27%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.90%	18.72%	-13.82%

RBFFX vs. AMCPX - Expense Ratio Comparison

RBFFX has a 0.29% expense ratio, which is lower than AMCPX's 0.65% expense ratio.

Dividends

RBFFX vs. AMCPX - Dividend Comparison

RBFFX's dividend yield for the trailing twelve months is around 4.45%, 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%
RBFFX American Funds The Bond Fund of America	4.45%	4.43%	4.61%	3.53%	2.42%	2.31%	5.34%	3.76%	2.67%	2.14%	2.07%	2.30%

Frequently Asked Questions

Can I hold both RBFFX and AMCPX in my portfolio?

RBFFX and AMCPX have a correlation of 0.27, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, RBFFX or AMCPX?

AMCPX has higher volatility (3.57%) compared to RBFFX (1.40%). In terms of maximum drawdown, RBFFX dropped -17.62% vs AMCPX's -62.37%.

Which has better risk-adjusted returns?

AMCPX currently has the higher Sharpe Ratio (1.56 vs 1.36), 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.