VMGAX vs. AMRGX

Last updated Aug 1, 2026

VMGAX (Vanguard Mega Cap Growth Index Fund Institutional Shares) and AMRGX (American Growth Fund Series One) are both Large Cap Growth Equities funds. Over the past 10 years, VMGAX returned 18.05%/yr vs 11.79%/yr for AMRGX. Their correlation of 0.85 means they have usually moved in the same direction. VMGAX charges 0.05%/yr vs 4.07%/yr for AMRGX.

Performance

VMGAX vs. AMRGX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Vanguard Mega Cap Growth Index Fund Institutional Shares (VMGAX) and American Growth Fund Series One (AMRGX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, VMGAX achieves a 3.59% return, which is significantly lower than AMRGX's 17.06% return. Over the past 10 years, VMGAX has outperformed AMRGX with an annualized return of 18.05%, while AMRGX has yielded a comparatively lower 11.79% annualized return.

VMGAX

• 1D: 2.74%
• 1M: -2.05%
• 6M: 5.39%
• YTD: 3.59%
• 1Y: 15.11%
• 3Y*: 21.22%
• 5Y*: 12.81%
• 10Y*: 18.05%
• ALL TIME*: 13.38%

AMRGX

• 1D: 2.55%
• 1M: -0.50%
• 6M: 12.78%
• YTD: 17.06%
• 1Y: 37.70%
• 3Y*: 17.59%
• 5Y*: 9.71%
• 10Y*: 11.79%
• ALL TIME*: 2.94%

*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)
AMRGX American Growth Fund Series One	$0.00	$0.00	$0.00
VMGAX Vanguard Mega Cap Growth Index Fund Institutional Shares	$0.00	$0.00	$0.00

VMGAX vs. AMRGX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VMGAX Vanguard Mega Cap Growth Index Fund Institutional Shares	3.59%	20.73%	32.98%	51.57%	-33.55%	28.50%	41.02%	37.54%	-2.86%	29.49%
AMRGX American Growth Fund Series One	17.06%	11.18%	16.61%	24.38%	-19.93%	15.64%	18.65%	36.73%	-9.07%	13.37%

Correlation

The correlation between VMGAX and AMRGX is 0.64, which is moderate. They have sometimes moved together and sometimes differently, sharing some price drivers without tracking each other closely.

	Correlation
Correlation (1Y) Focuses on recent behavior, but can change the most.	0.64
Correlation (3Y) Balances recent behavior with more history.	0.72
Correlation (5Y) Shows whether the relationship held over a longer period.	0.79
Correlation (10Y) Provides a long-term view across more market conditions.	0.82
Correlation (All Time) Calculated using the full available price history since Dec 27, 2007	0.85

Over the past year, the correlation between VMGAX and AMRGX has dropped to 0.64 - well below their long-term average of 0.85, suggesting their price drivers have been diverging.

Return for Risk

VMGAX vs. AMRGX — Risk / Return Rank

Compare historical risk-adjusted metric ranks over the past 12 months.

VMGAX

VMGAX Risk / Return Rank: 19
VMGAX Sharpe Ratio Rank: 20
VMGAX Sortino Ratio Rank: 20
VMGAX Omega Ratio Rank: 20
VMGAX Calmar Ratio Rank: 16
VMGAX Martin Ratio Rank: 18

AMRGX

AMRGX Risk / Return Rank: 56
AMRGX Sharpe Ratio Rank: 43
AMRGX Sortino Ratio Rank: 49
AMRGX Omega Ratio Rank: 69
AMRGX Calmar Ratio Rank: 78
AMRGX Martin Ratio Rank: 41

The rank (0–100) uses a weighted average of the Sharpe, Sortino, Omega, Calmar, and Martin percentile ranks for the trailing 12 months. Higher means stronger historical risk-adjusted performance within the peer group.

VMGAX vs. AMRGX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Vanguard Mega Cap Growth Index Fund Institutional Shares (VMGAX) and American Growth Fund Series One (AMRGX). 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.

	VMGAX	AMRGX	Difference
Sharpe ratio: Return per unit of total volatility	0.70	1.22	-0.52
Sortino ratio: Return per unit of downside risk	1.08	1.88	-0.80
Omega ratio: Gain probability vs. loss probability	1.13	1.30	-0.17
Calmar ratio: Return relative to maximum drawdown	0.76	2.50	-1.74
Martin ratio: Return relative to average drawdown	2.39	5.86	-3.47

VMGAX vs. AMRGX - Sharpe Ratio Comparison

The current VMGAX Sharpe Ratio is 0.70, which is lower than the AMRGX Sharpe Ratio of 1.22. The chart below compares the historical Sharpe Ratios of VMGAX and AMRGX, 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

VMGAX vs. AMRGX - Drawdown Comparison

The maximum VMGAX drawdown since its inception was -47.97%, smaller than the maximum AMRGX drawdown of -80.32%. Use the drawdown chart below to compare losses from any high point for VMGAX and AMRGX.

Drawdown Indicators

	VMGAX	AMRGX	Difference
Max Drawdown Largest peak-to-trough decline	-47.97%	-80.32%	+32.35%
Max Drawdown (1Y) Largest decline over 1 year	-16.78%	-13.98%	-2.80%
Max Drawdown (3Y) Largest decline over 3 years	-23.45%	-21.15%	-2.30%
Max Drawdown (5Y) Largest decline over 5 years	-36.03%	-35.42%	-0.61%
Max Drawdown (10Y) Largest decline over 10 years	-36.03%	-35.42%	-0.61%
Current Drawdown Current decline from peak	-7.18%	-5.31%	-1.87%
Average Drawdown Average peak-to-trough decline	-7.42%	-40.05%	+32.63%
Ulcer Index Depth and duration of drawdowns from previous peaks	5.33%	5.91%	-0.58%

Volatility

VMGAX vs. AMRGX - Volatility Comparison

The current volatility for Vanguard Mega Cap Growth Index Fund Institutional Shares (VMGAX) is 5.69%, while American Growth Fund Series One (AMRGX) has a volatility of 6.43%. This indicates that VMGAX experiences smaller price fluctuations and is considered to be less risky than AMRGX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	VMGAX	AMRGX	Difference
Volatility (1M) Calculated over the trailing 1-month period	5.69%	6.43%	-0.74%
Volatility (6M) Calculated over the trailing 6-month period	14.67%	17.26%	-2.59%
Volatility (1Y) Calculated over the trailing 1-year period	18.22%	28.73%	-10.51%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	23.00%	22.64%	+0.36%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	22.02%	21.64%	+0.38%

VMGAX vs. AMRGX - Expense Ratio Comparison

VMGAX has a 0.05% expense ratio, which is lower than AMRGX's 4.07% expense ratio.

Dividends

VMGAX vs. AMRGX - Dividend Comparison

VMGAX's dividend yield for the trailing twelve months is around 0.35%, less than AMRGX's 15.23% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
AMRGX American Growth Fund Series One	15.23%	17.82%	12.39%	8.17%	7.77%	12.21%	2.36%	0.00%	0.00%	0.00%	0.00%	0.00%
VMGAX Vanguard Mega Cap Growth Index Fund Institutional Shares	0.35%	0.36%	0.44%	0.51%	0.71%	0.42%	0.65%	0.86%	1.13%	1.23%	1.53%	1.44%

Frequently Asked Questions

Can I hold both VMGAX and AMRGX in my portfolio?

VMGAX and AMRGX have a correlation of 0.64, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, VMGAX or AMRGX?

AMRGX has higher volatility (6.43%) compared to VMGAX (5.69%). In terms of maximum drawdown, VMGAX dropped -47.97% vs AMRGX's -80.32%.

Which has better risk-adjusted returns?

AMRGX currently has the higher Sharpe Ratio (1.22 vs 0.70), 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.