RGABX vs. VPMCX

Last updated Jul 29, 2026

RGABX (American Funds The Growth Fund of America Class R-2) and VPMCX (Vanguard PRIMECAP Fund Investor Shares) are both Large Cap Growth Equities funds. RGABX is passively managed, while VPMCX is actively managed. Over the past 10 years, RGABX returned 14.12%/yr vs 16.61%/yr for VPMCX. Their correlation of 0.94 means they have usually moved in the same direction. RGABX charges 1.38%/yr vs 0.35%/yr for VPMCX.

Performance

RGABX vs. VPMCX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in American Funds The Growth Fund of America Class R-2 (RGABX) and Vanguard PRIMECAP Fund Investor Shares (VPMCX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, RGABX achieves a 3.82% return, which is significantly lower than VPMCX's 20.66% return. Over the past 10 years, RGABX has underperformed VPMCX with an annualized return of 14.12%, while VPMCX has yielded a comparatively higher 16.61% annualized return.

RGABX

• 1D: -0.38%
• 1M: -2.39%
• 6M: 1.78%
• YTD: 3.82%
• 1Y: 9.23%
• 3Y*: 18.79%
• 5Y*: 9.13%
• 10Y*: 14.12%
• ALL TIME*: 10.02%

VPMCX

• 1D: 0.07%
• 1M: -5.05%
• 6M: 14.10%
• YTD: 20.66%
• 1Y: 41.95%
• 3Y*: 23.49%
• 5Y*: 14.85%
• 10Y*: 16.61%
• ALL TIME*: 15.26%

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

Liquidity Comparison

Position	Avg. Volume Value (2W)	Avg. Volume Value (1M)	Avg. Volume Value (3M)
RGABX American Funds The Growth Fund of America Class R-2	$0.00	$0.00	$0.00
VPMCX Vanguard PRIMECAP Fund Investor Shares	$0.00	$0.00	$0.00

RGABX vs. VPMCX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
RGABX American Funds The Growth Fund of America Class R-2	3.82%	18.77%	27.02%	36.16%	-31.29%	18.37%	36.83%	27.14%	-3.93%	25.17%
VPMCX Vanguard PRIMECAP Fund Investor Shares	20.66%	29.60%	13.23%	28.16%	-15.22%	21.64%	17.16%	27.78%	-1.99%	28.17%

Correlation

The correlation between RGABX and VPMCX is 0.86, meaning they have usually moved in the same direction, including during past declines.

	Correlation
Correlation (1Y) Focuses on recent behavior, but can change the most.	0.86
Correlation (3Y) Balances recent behavior with more history.	0.87
Correlation (5Y) Shows whether the relationship held over a longer period.	0.91
Correlation (10Y) Provides a long-term view across more market conditions.	0.90
Correlation (All Time) Calculated using the full available price history since May 21, 2002	0.94

The correlation between RGABX and VPMCX has been stable across timeframes, ranging from 0.86 to 0.94 - a consistent structural relationship.

Return for Risk

RGABX vs. VPMCX — Risk / Return Rank

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

RGABX

RGABX Risk / Return Rank: 14
RGABX Sharpe Ratio Rank: 14
RGABX Sortino Ratio Rank: 14
RGABX Omega Ratio Rank: 14
RGABX Calmar Ratio Rank: 14
RGABX Martin Ratio Rank: 17

VPMCX

VPMCX Risk / Return Rank: 89
VPMCX Sharpe Ratio Rank: 90
VPMCX Sortino Ratio Rank: 86
VPMCX Omega Ratio Rank: 84
VPMCX Calmar Ratio Rank: 91
VPMCX Martin Ratio Rank: 93

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.

RGABX vs. VPMCX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Funds The Growth Fund of America Class R-2 (RGABX) and Vanguard PRIMECAP Fund Investor Shares (VPMCX). 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.

	RGABX	VPMCX	Difference
Sharpe ratio: Return per unit of total volatility	0.56	2.25	-1.69
Sortino ratio: Return per unit of downside risk	0.87	3.08	-2.21
Omega ratio: Gain probability vs. loss probability	1.11	1.40	-0.29
Calmar ratio: Return relative to maximum drawdown	0.67	3.58	-2.91
Martin ratio: Return relative to average drawdown	2.47	13.98	-11.51

RGABX vs. VPMCX - Sharpe Ratio Comparison

The current RGABX Sharpe Ratio is 0.56, which is lower than the VPMCX Sharpe Ratio of 2.25. The chart below compares the historical Sharpe Ratios of RGABX and VPMCX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Drawdowns

RGABX vs. VPMCX - Drawdown Comparison

The maximum RGABX drawdown since its inception was -52.36%, roughly equal to the maximum VPMCX drawdown of -50.45%. Use the drawdown chart below to compare losses from any high point for RGABX and VPMCX.

Drawdown Indicators

	RGABX	VPMCX	Difference
Max Drawdown Largest peak-to-trough decline	-52.36%	-50.45%	-1.91%
Max Drawdown (1Y) Largest decline over 1 year	-13.92%	-11.73%	-2.19%
Max Drawdown (3Y) Largest decline over 3 years	-21.67%	-20.56%	-1.11%
Max Drawdown (5Y) Largest decline over 5 years	-36.83%	-25.25%	-11.58%
Max Drawdown (10Y) Largest decline over 10 years	-36.83%	-32.65%	-4.18%
Current Drawdown Current decline from peak	-5.69%	-7.52%	+1.83%
Average Drawdown Average peak-to-trough decline	-8.73%	-7.39%	-1.34%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.78%	3.00%	+0.78%

Volatility

RGABX vs. VPMCX - Volatility Comparison

The current volatility for American Funds The Growth Fund of America Class R-2 (RGABX) is 4.46%, while Vanguard PRIMECAP Fund Investor Shares (VPMCX) has a volatility of 5.56%. This indicates that RGABX experiences smaller price fluctuations and is considered to be less risky than VPMCX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	RGABX	VPMCX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.46%	5.56%	-1.10%
Volatility (6M) Calculated over the trailing 6-month period	13.37%	15.75%	-2.38%
Volatility (1Y) Calculated over the trailing 1-year period	16.76%	18.75%	-1.99%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	20.54%	18.74%	+1.80%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	19.78%	19.36%	+0.42%

RGABX vs. VPMCX - Expense Ratio Comparison

RGABX has a 1.38% expense ratio, which is higher than VPMCX's 0.35% expense ratio.

Dividends

RGABX vs. VPMCX - Dividend Comparison

RGABX's dividend yield for the trailing twelve months is around 11.44%, less than VPMCX's 13.56% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
RGABX American Funds The Growth Fund of America Class R-2	11.44%	11.87%	9.61%	7.53%	4.08%	8.80%	4.34%	6.82%	11.94%	6.86%	6.28%	8.54%
VPMCX Vanguard PRIMECAP Fund Investor Shares	13.56%	16.36%	6.62%	7.16%	9.85%	10.08%	9.74%	7.15%	8.32%	4.53%	5.05%	5.91%

Frequently Asked Questions

Can I hold both RGABX and VPMCX in my portfolio?

RGABX and VPMCX have a correlation of 0.86, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, RGABX or VPMCX?

VPMCX has higher volatility (5.56%) compared to RGABX (4.46%). In terms of maximum drawdown, RGABX dropped -52.36% vs VPMCX's -50.45%.

Which has better risk-adjusted returns?

VPMCX currently has the higher Sharpe Ratio (2.25 vs 0.56), 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.