VMGAX vs. POGRX

Last updated Jun 4, 2026

VMGAX (Vanguard Mega Cap Growth Index Fund Institutional Shares) and POGRX (PrimeCap Odyssey Growth Fund) are both Large Cap Growth Equities funds. Over the past 10 years, VMGAX returned 19.39%/yr vs 17.39%/yr for POGRX. Their correlation of 0.87 suggests significant overlap in exposure. VMGAX charges 0.06%/yr vs 0.65%/yr for POGRX.

Performance

VMGAX vs. POGRX - 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 PrimeCap Odyssey Growth Fund (POGRX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, VMGAX achieves a 11.29% return, which is significantly lower than POGRX's 26.45% return. Over the past 10 years, VMGAX has outperformed POGRX with an annualized return of 19.39%, while POGRX has yielded a comparatively lower 17.39% annualized return.

VMGAX

• 1D: -0.29%
• 1M: 8.54%
• YTD: 11.29%
• 6M: 10.76%
• 1Y: 31.60%
• 3Y*: 27.29%
• 5Y*: 16.86%
• 10Y*: 19.39%

POGRX

• 1D: -0.02%
• 1M: 15.42%
• YTD: 26.45%
• 6M: 27.81%
• 1Y: 64.17%
• 3Y*: 29.06%
• 5Y*: 16.04%
• 10Y*: 17.39%

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

VMGAX vs. POGRX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VMGAX Vanguard Mega Cap Growth Index Fund Institutional Shares	11.29%	20.73%	32.98%	51.57%	-33.55%	28.50%	41.02%	37.54%	-2.86%	29.49%
POGRX PrimeCap Odyssey Growth Fund	26.45%	32.99%	13.09%	23.85%	-14.61%	18.81%	17.05%	23.98%	-4.56%	32.07%

Correlation

The correlation between VMGAX and POGRX is 0.74, 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	0.74
Correlation (3Y) Calculated over the trailing 3-year period	0.77
Correlation (5Y) Calculated over the trailing 5-year period	0.82
Correlation (10Y) Calculated over the trailing 10-year period	0.82
Correlation (All Time) Calculated using the full available price history since Dec 28, 2007	0.87

The correlation between VMGAX and POGRX shifts across timeframes, from 0.74 (1 year) to 0.87 (all time), reflecting how their relationship changes across market environments.

Return for Risk

VMGAX vs. POGRX — Risk / Return Rank

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

VMGAX

VMGAX Risk / Return Rank: 37
VMGAX Sharpe Ratio Rank: 47
VMGAX Sortino Ratio Rank: 42
VMGAX Omega Ratio Rank: 42
VMGAX Calmar Ratio Rank: 27
VMGAX Martin Ratio Rank: 28

POGRX

POGRX Risk / Return Rank: 93
POGRX Sharpe Ratio Rank: 97
POGRX Sortino Ratio Rank: 94
POGRX Omega Ratio Rank: 90
POGRX Calmar Ratio Rank: 90
POGRX Martin Ratio Rank: 92

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.

VMGAX vs. POGRX - 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 PrimeCap Odyssey Growth Fund (POGRX). 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.

	VMGAX	POGRX	Difference
Sharpe ratio Return per unit of total volatility	2.01	3.69	-1.67
Sortino ratio Return per unit of downside risk	2.71	4.84	-2.12
Omega ratio Gain probability vs. loss probability	1.35	1.65	-0.30
Calmar ratio Return relative to maximum drawdown	1.95	4.60	-2.65
Martin ratio Return relative to average drawdown	6.74	19.58	-12.84
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

VMGAX vs. POGRX - Sharpe Ratio Comparison

The current VMGAX Sharpe Ratio is 2.01, which is lower than the POGRX Sharpe Ratio of 3.69. The chart below compares the historical Sharpe Ratios of VMGAX and POGRX, 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

	VMGAX	POGRX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.01	3.69	-1.67
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.75	0.82	-0.08
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.89	0.85	+0.04
Sharpe Ratio (All Time) Calculated using the full available price history	0.65	0.66	-0.01

Drawdowns

VMGAX vs. POGRX - Drawdown Comparison

The maximum VMGAX drawdown since its inception was -47.97%, smaller than the maximum POGRX drawdown of -51.63%. Use the drawdown chart below to compare losses from any high point for VMGAX and POGRX.

Drawdown Indicators

	VMGAX	POGRX	Difference
Max Drawdown Largest peak-to-trough decline	-47.97%	-51.63%	+3.66%
Max Drawdown (1Y) Largest decline over 1 year	-16.78%	-14.40%	-2.38%
Max Drawdown (3Y) Largest decline over 3 years	-23.45%	-22.13%	-1.32%
Max Drawdown (5Y) Largest decline over 5 years	-36.03%	-26.85%	-9.18%
Max Drawdown (10Y) Largest decline over 10 years	-36.03%	-35.29%	-0.74%
Current Drawdown Current decline from peak	-0.29%	-0.02%	-0.27%
Average Drawdown Average peak-to-trough decline	-7.44%	-7.13%	-0.31%
Ulcer Index Depth and duration of drawdowns from previous peaks	4.83%	3.37%	+1.46%

Volatility

VMGAX vs. POGRX - Volatility Comparison

The current volatility for Vanguard Mega Cap Growth Index Fund Institutional Shares (VMGAX) is 3.80%, while PrimeCap Odyssey Growth Fund (POGRX) has a volatility of 7.05%. This indicates that VMGAX experiences smaller price fluctuations and is considered to be less risky than POGRX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	VMGAX	POGRX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.80%	7.05%	-3.25%
Volatility (6M) Calculated over the trailing 6-month period	12.39%	14.59%	-2.20%
Volatility (1Y) Calculated over the trailing 1-year period	16.23%	17.96%	-1.73%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	22.71%	19.60%	+3.11%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	21.90%	20.47%	+1.43%

VMGAX vs. POGRX - Expense Ratio Comparison

VMGAX has a 0.06% expense ratio, which is lower than POGRX's 0.65% expense ratio.

Dividends

VMGAX vs. POGRX - Dividend Comparison

VMGAX's dividend yield for the trailing twelve months is around 0.32%, less than POGRX's 19.68% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
POGRX PrimeCap Odyssey Growth Fund	19.68%	24.89%	20.79%	13.28%	12.36%	13.68%	12.50%	5.13%	2.45%	1.54%	5.83%	1.29%
VMGAX Vanguard Mega Cap Growth Index Fund Institutional Shares	0.32%	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 POGRX in my portfolio?

VMGAX and POGRX have a correlation of 0.74, 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 POGRX?

POGRX has higher volatility (7.05%) compared to VMGAX (3.80%). In terms of maximum drawdown, VMGAX dropped -47.97% vs POGRX's -51.63%.

Which has better risk-adjusted returns?

POGRX currently has the higher Sharpe Ratio (3.69 vs 2.01), 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.