PARMX vs. VMCIX

Last updated Jun 4, 2026

PARMX (Parnassus Mid Cap Fund) and VMCIX (Vanguard Mid-Cap Index Fund Institutional Shares) are both Mid Cap Blend Equities funds. Over the past 10 years, PARMX returned 8.75%/yr vs 11.59%/yr for VMCIX. Their correlation of 0.93 suggests significant overlap in exposure. PARMX charges 0.96%/yr vs 0.04%/yr for VMCIX.

Performance

PARMX vs. VMCIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Parnassus Mid Cap Fund (PARMX) and Vanguard Mid-Cap Index Fund Institutional Shares (VMCIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, PARMX achieves a 6.18% return, which is significantly lower than VMCIX's 10.56% return. Over the past 10 years, PARMX has underperformed VMCIX with an annualized return of 8.75%, while VMCIX has yielded a comparatively higher 11.59% annualized return.

PARMX

• 1D: 0.52%
• 1M: 1.80%
• YTD: 6.18%
• 6M: 5.41%
• 1Y: 17.48%
• 3Y*: 14.11%
• 5Y*: 4.88%
• 10Y*: 8.75%

VMCIX

• 1D: 0.90%
• 1M: 3.69%
• YTD: 10.56%
• 6M: 10.21%
• 1Y: 18.75%
• 3Y*: 16.83%
• 5Y*: 8.11%
• 10Y*: 11.59%

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

PARMX vs. VMCIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
PARMX Parnassus Mid Cap Fund	6.18%	12.86%	10.05%	12.66%	-21.41%	16.38%	14.88%	28.74%	-6.67%	15.80%
VMCIX Vanguard Mid-Cap Index Fund Institutional Shares	10.56%	11.67%	14.68%	16.54%	-18.70%	24.53%	18.20%	31.04%	-9.25%	19.30%

Correlation

The correlation between PARMX and VMCIX is 0.90, indicating a strong positive relationship between their price movements. Combining them offers limited diversification - they tend to fall together during downturns.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.90
Correlation (3Y) Calculated over the trailing 3-year period	0.92
Correlation (5Y) Calculated over the trailing 5-year period	0.94
Correlation (10Y) Calculated over the trailing 10-year period	0.93
Correlation (All Time) Calculated using the full available price history since May 2, 2005	0.93

The correlation between PARMX and VMCIX has been stable across timeframes, ranging from 0.90 to 0.94 - a consistent structural relationship.

Return for Risk

PARMX vs. VMCIX — Risk / Return Rank

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

PARMX

PARMX Risk / Return Rank: 23
PARMX Sharpe Ratio Rank: 21
PARMX Sortino Ratio Rank: 22
PARMX Omega Ratio Rank: 19
PARMX Calmar Ratio Rank: 24
PARMX Martin Ratio Rank: 31

VMCIX

VMCIX Risk / Return Rank: 35
VMCIX Sharpe Ratio Rank: 32
VMCIX Sortino Ratio Rank: 31
VMCIX Omega Ratio Rank: 29
VMCIX Calmar Ratio Rank: 42
VMCIX Martin Ratio Rank: 44

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.

PARMX vs. VMCIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Parnassus Mid Cap Fund (PARMX) and Vanguard Mid-Cap Index Fund Institutional Shares (VMCIX). 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.

	PARMX	VMCIX	Difference
Sharpe ratio: Return per unit of total volatility	1.31	1.62	-0.31
Sortino ratio: Return per unit of downside risk	1.97	2.31	-0.34
Omega ratio: Gain probability vs. loss probability	1.23	1.28	-0.06
Calmar ratio: Return relative to maximum drawdown	1.84	2.45	-0.61
Martin ratio: Return relative to average drawdown	7.22	9.29	-2.07
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

PARMX vs. VMCIX - Sharpe Ratio Comparison

The current PARMX Sharpe Ratio is 1.31, which is comparable to the VMCIX Sharpe Ratio of 1.62. The chart below compares the historical Sharpe Ratios of PARMX and VMCIX, 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

	PARMX	VMCIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.31	1.62	-0.31
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.28	0.46	-0.18
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.50	0.61	-0.12
Sharpe Ratio (All Time) Calculated using the full available price history	0.47	0.49	-0.02

Drawdowns

PARMX vs. VMCIX - Drawdown Comparison

The maximum PARMX drawdown since its inception was -49.88%, smaller than the maximum VMCIX drawdown of -58.86%. Use the drawdown chart below to compare losses from any high point for PARMX and VMCIX.

Drawdown Indicators

	PARMX	VMCIX	Difference
Max Drawdown Largest peak-to-trough decline	-49.88%	-58.86%	+8.98%
Max Drawdown (1Y) Largest decline over 1 year	-10.49%	-8.13%	-2.36%
Max Drawdown (3Y) Largest decline over 3 years	-20.73%	-18.93%	-1.80%
Max Drawdown (5Y) Largest decline over 5 years	-29.27%	-27.54%	-1.73%
Max Drawdown (10Y) Largest decline over 10 years	-37.39%	-39.30%	+1.91%
Current Drawdown Current decline from peak	-0.61%	0.00%	-0.61%
Average Drawdown Average peak-to-trough decline	-6.90%	-7.97%	+1.07%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.66%	2.14%	+0.52%

Volatility

PARMX vs. VMCIX - Volatility Comparison

Parnassus Mid Cap Fund (PARMX) has a higher volatility of 3.93% compared to Vanguard Mid-Cap Index Fund Institutional Shares (VMCIX) at 2.97%. This indicates that PARMX's price experiences larger fluctuations and is considered to be riskier than VMCIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	PARMX	VMCIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.93%	2.97%	+0.96%
Volatility (6M) Calculated over the trailing 6-month period	11.30%	9.29%	+2.01%
Volatility (1Y) Calculated over the trailing 1-year period	14.76%	12.31%	+2.45%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	17.55%	17.63%	-0.08%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	17.70%	18.92%	-1.22%

PARMX vs. VMCIX - Expense Ratio Comparison

PARMX has a 0.96% expense ratio, which is higher than VMCIX's 0.04% expense ratio.

Dividends

PARMX vs. VMCIX - Dividend Comparison

PARMX's dividend yield for the trailing twelve months is around 9.65%, more than VMCIX's 1.35% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
PARMX Parnassus Mid Cap Fund	9.65%	10.25%	9.92%	2.29%	4.90%	4.88%	0.36%	4.15%	3.90%	4.19%	2.76%	6.42%
VMCIX Vanguard Mid-Cap Index Fund Institutional Shares	1.35%	1.52%	1.49%	1.51%	1.60%	1.12%	1.45%	1.48%	1.83%	1.36%	1.46%	1.48%

Frequently Asked Questions

Can I hold both PARMX and VMCIX in my portfolio?

With a correlation of 0.90, PARMX and VMCIX move almost identically. Holding both adds very little diversification - you're essentially doubling your position in the same market segment. Choosing one is usually more capital-efficient.

Which is riskier, PARMX or VMCIX?

PARMX has higher volatility (3.93%) compared to VMCIX (2.97%). In terms of maximum drawdown, PARMX dropped -49.88% vs VMCIX's -58.86%.

Which has better risk-adjusted returns?

VMCIX currently has the higher Sharpe Ratio (1.62 vs 1.31), 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.