VPMCX vs. ONERX

Last updated Aug 6, 2026

VPMCX (Vanguard PRIMECAP Fund Investor Shares) and ONERX (One Rock Fund) are both Large Cap Growth Equities funds. Over the past 5 years, VPMCX returned 15.31%/yr vs 28.30%/yr for ONERX. Their 0.79 correlation means they have sometimes moved together and sometimes differently. VPMCX charges 0.35%/yr vs 1.75%/yr for ONERX.

Performance

VPMCX vs. ONERX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Vanguard PRIMECAP Fund Investor Shares (VPMCX) 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, VPMCX achieves a 25.06% return, which is significantly lower than ONERX's 44.62% return.

VPMCX

• 1D: 2.62%
• 1M: -0.89%
• 6M: 19.43%
• YTD: 25.06%
• 1Y: 50.56%
• 3Y*: 25.81%
• 5Y*: 15.31%
• 10Y*: 16.88%
• ALL TIME*: 15.35%

ONERX

• 1D: 6.85%
• 1M: -5.06%
• 6M: 45.70%
• YTD: 44.62%
• 1Y: 66.41%
• 3Y*: 43.78%
• 5Y*: 28.30%
• 10Y*: —
• ALL TIME*: 37.97%

*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)
ONERX One Rock Fund	$0.00	$0.00	$0.00
VPMCX Vanguard PRIMECAP Fund Investor Shares	$0.00	$0.00	$0.00

VPMCX vs. ONERX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020
VPMCX Vanguard PRIMECAP Fund Investor Shares	25.06%	29.60%	13.23%	28.16%	-15.22%	21.64%	56.47%
ONERX One Rock Fund	44.62%	49.37%	21.76%	72.41%	-42.06%	45.70%	104.46%

Correlation

The correlation between VPMCX and ONERX is 0.80, 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.	0.80
Correlation (3Y) Balances recent behavior with more history.	0.78
Correlation (5Y) Shows whether the relationship held over a longer period.	0.81
Correlation (All Time) Calculated using the full available price history since Mar 13, 2020	0.79

The correlation between VPMCX and ONERX has been stable across timeframes, ranging from 0.78 to 0.81 - a consistent structural relationship.

Return for Risk

VPMCX vs. ONERX — Risk / Return Rank

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

VPMCX

VPMCX Risk / Return Rank: 92
VPMCX Sharpe Ratio Rank: 94
VPMCX Sortino Ratio Rank: 91
VPMCX Omega Ratio Rank: 89
VPMCX Calmar Ratio Rank: 94
VPMCX Martin Ratio Rank: 93

ONERX

ONERX Risk / Return Rank: 42
ONERX Sharpe Ratio Rank: 40
ONERX Sortino Ratio Rank: 34
ONERX Omega Ratio Rank: 35
ONERX Calmar Ratio Rank: 48
ONERX Martin Ratio Rank: 55

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.

VPMCX vs. ONERX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Vanguard PRIMECAP Fund Investor Shares (VPMCX) 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.

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.

	VPMCX	ONERX	Difference
Sharpe ratio: Return per unit of total volatility	2.64	1.44	+1.20
Sortino ratio: Return per unit of downside risk	3.55	1.91	+1.64
Omega ratio: Gain probability vs. loss probability	1.46	1.25	+0.21
Calmar ratio: Return relative to maximum drawdown	4.30	2.12	+2.17
Martin ratio: Return relative to average drawdown	15.80	8.51	+7.29

VPMCX vs. ONERX - Sharpe Ratio Comparison

The current VPMCX Sharpe Ratio is 2.64, which is higher than the ONERX Sharpe Ratio of 1.44. The chart below compares the historical Sharpe Ratios of VPMCX 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.

Drawdowns

VPMCX vs. ONERX - Drawdown Comparison

The maximum VPMCX drawdown since its inception was -50.45%, which is greater than ONERX's maximum drawdown of -47.44%. Use the drawdown chart below to compare losses from any high point for VPMCX and ONERX.

Drawdown Indicators

	VPMCX	ONERX	Difference
Max Drawdown Largest peak-to-trough decline	-50.45%	-47.44%	-3.01%
Max Drawdown (1Y) Largest decline over 1 year	-11.73%	-31.29%	+19.56%
Max Drawdown (3Y) Largest decline over 3 years	-20.56%	-47.44%	+26.88%
Max Drawdown (5Y) Largest decline over 5 years	-25.25%	-47.44%	+22.19%
Max Drawdown (10Y) Largest decline over 10 years	-32.65%	—	—
Current Drawdown Current decline from peak	-4.15%	-14.65%	+10.50%
Average Drawdown Average peak-to-trough decline	-7.39%	-13.75%	+6.36%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.19%	7.79%	-4.60%

Volatility

VPMCX vs. ONERX - Volatility Comparison

The current volatility for Vanguard PRIMECAP Fund Investor Shares (VPMCX) is 6.44%, while One Rock Fund (ONERX) has a volatility of 21.28%. This indicates that VPMCX 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

	VPMCX	ONERX	Difference
Volatility (1M) Calculated over the trailing 1-month period	6.44%	21.28%	-14.84%
Volatility (6M) Calculated over the trailing 6-month period	16.29%	39.23%	-22.94%
Volatility (1Y) Calculated over the trailing 1-year period	19.14%	46.27%	-27.13%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	18.84%	40.96%	-22.12%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	19.41%	39.30%	-19.89%

VPMCX vs. ONERX - Expense Ratio Comparison

VPMCX has a 0.35% expense ratio, which is lower than ONERX's 1.75% expense ratio.

Dividends

VPMCX vs. ONERX - Dividend Comparison

VPMCX's dividend yield for the trailing twelve months is around 13.08%, less than ONERX's 16.68% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
ONERX One Rock Fund	16.68%	24.12%	0.00%	0.00%	10.57%	28.88%	18.66%	0.00%	0.00%	0.00%	0.00%	0.00%
VPMCX Vanguard PRIMECAP Fund Investor Shares	13.08%	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 VPMCX and ONERX in my portfolio?

VPMCX and ONERX have a correlation of 0.80, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, VPMCX or ONERX?

ONERX has higher volatility (21.28%) compared to VPMCX (6.44%). In terms of maximum drawdown, VPMCX dropped -50.45% vs ONERX's -47.44%.

Which has better risk-adjusted returns?

VPMCX currently has the higher Sharpe Ratio (2.64 vs 1.44), 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.