PARMX vs. FSMAX

Last updated Jun 24, 2026

PARMX (Parnassus Mid Cap Fund) and FSMAX (Fidelity Extended Market Index Fund) are both Mid Cap Blend Equities funds. Over the past 10 years, PARMX returned 9.42%/yr vs 12.60%/yr for FSMAX. Their correlation of 0.89 suggests significant overlap in exposure. PARMX charges 0.96%/yr vs 0.04%/yr for FSMAX.

Performance

PARMX vs. FSMAX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Parnassus Mid Cap Fund (PARMX) and Fidelity Extended Market Index Fund (FSMAX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, PARMX achieves a 10.36% return, which is significantly lower than FSMAX's 15.43% return. Over the past 10 years, PARMX has underperformed FSMAX with an annualized return of 9.42%, while FSMAX has yielded a comparatively higher 12.60% annualized return.

PARMX

• 1D: 0.40%
• 1M: 5.02%
• YTD: 10.36%
• 6M: 8.60%
• 1Y: 20.06%
• 3Y*: 15.16%
• 5Y*: 5.50%
• 10Y*: 9.42%

FSMAX

• 1D: -0.11%
• 1M: 4.21%
• YTD: 15.43%
• 6M: 13.08%
• 1Y: 29.23%
• 3Y*: 20.24%
• 5Y*: 6.38%
• 10Y*: 12.60%

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

PARMX vs. FSMAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
PARMX Parnassus Mid Cap Fund	10.36%	12.86%	10.05%	12.66%	-21.41%	16.38%	14.88%	28.74%	-6.67%	15.80%
FSMAX Fidelity Extended Market Index Fund	15.43%	11.40%	16.99%	25.36%	-26.44%	12.41%	32.28%	28.01%	-9.44%	18.04%

Correlation

The correlation between PARMX and FSMAX is 0.88, 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	0.88
Correlation (3Y) Calculated over the trailing 3-year period	0.87
Correlation (5Y) Calculated over the trailing 5-year period	0.88
Correlation (10Y) Calculated over the trailing 10-year period	0.88
Correlation (All Time) Calculated using the full available price history since Sep 8, 2011	0.89

The correlation between PARMX and FSMAX has been stable across timeframes, ranging from 0.87 to 0.89 - a consistent structural relationship.

Return for Risk

PARMX vs. FSMAX — Risk / Return Rank

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

PARMX

PARMX Risk / Return Rank: 31
PARMX Sharpe Ratio Rank: 28
PARMX Sortino Ratio Rank: 30
PARMX Omega Ratio Rank: 25
PARMX Calmar Ratio Rank: 33
PARMX Martin Ratio Rank: 39

FSMAX

FSMAX Risk / Return Rank: 47
FSMAX Sharpe Ratio Rank: 41
FSMAX Sortino Ratio Rank: 38
FSMAX Omega Ratio Rank: 35
FSMAX Calmar Ratio Rank: 66
FSMAX Martin Ratio Rank: 55

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. FSMAX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Parnassus Mid Cap Fund (PARMX) and Fidelity Extended Market Index Fund (FSMAX). 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.

	PARMX	FSMAX	Difference
Sharpe ratio: Return per unit of total volatility	1.41	1.71	-0.30
Sortino ratio: Return per unit of downside risk	2.11	2.39	-0.28
Omega ratio: Gain probability vs. loss probability	1.24	1.29	-0.05
Calmar ratio: Return relative to maximum drawdown	2.05	2.97	-0.92
Martin ratio: Return relative to average drawdown	8.06	10.42	-2.36

PARMX vs. FSMAX - Sharpe Ratio Comparison

The current PARMX Sharpe Ratio is 1.41, which is comparable to the FSMAX Sharpe Ratio of 1.71. The chart below compares the historical Sharpe Ratios of PARMX and FSMAX, 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

PARMX vs. FSMAX - Drawdown Comparison

The maximum PARMX drawdown since its inception was -49.88%, roughly equal to the maximum FSMAX drawdown of -50.55%. Use the drawdown chart below to compare losses from any high point for PARMX and FSMAX.

Drawdown Indicators

	PARMX	FSMAX	Difference
Max Drawdown Largest peak-to-trough decline	-49.88%	-50.55%	+0.67%
Max Drawdown (1Y) Largest decline over 1 year	-10.49%	-10.26%	-0.23%
Max Drawdown (3Y) Largest decline over 3 years	-20.73%	-26.82%	+6.09%
Max Drawdown (5Y) Largest decline over 5 years	-29.27%	-36.31%	+7.04%
Max Drawdown (10Y) Largest decline over 10 years	-37.39%	-50.55%	+13.16%
Current Drawdown Current decline from peak	0.00%	-0.22%	+0.22%
Average Drawdown Average peak-to-trough decline	-6.88%	-12.13%	+5.25%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.66%	2.92%	-0.26%

Volatility

PARMX vs. FSMAX - Volatility Comparison

The current volatility for Parnassus Mid Cap Fund (PARMX) is 5.06%, while Fidelity Extended Market Index Fund (FSMAX) has a volatility of 6.07%. This indicates that PARMX experiences smaller price fluctuations and is considered to be less risky than FSMAX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	PARMX	FSMAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	5.06%	6.07%	-1.01%
Volatility (6M) Calculated over the trailing 6-month period	11.96%	13.28%	-1.32%
Volatility (1Y) Calculated over the trailing 1-year period	15.26%	17.83%	-2.57%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	17.65%	22.43%	-4.78%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	17.75%	30.28%	-12.53%

PARMX vs. FSMAX - Expense Ratio Comparison

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

Dividends

PARMX vs. FSMAX - Dividend Comparison

PARMX's dividend yield for the trailing twelve months is around 9.28%, more than FSMAX's 0.50% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FSMAX Fidelity Extended Market Index Fund	0.50%	0.57%	0.48%	1.17%	1.90%	7.49%	2.14%	4.30%	6.09%	5.44%	4.85%	6.34%
PARMX Parnassus Mid Cap Fund	9.28%	10.25%	9.92%	2.29%	4.90%	4.88%	0.36%	4.15%	3.90%	4.19%	2.76%	6.42%

Frequently Asked Questions

Can I hold both PARMX and FSMAX in my portfolio?

PARMX and FSMAX have a correlation of 0.88, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, PARMX or FSMAX?

FSMAX has higher volatility (6.07%) compared to PARMX (5.06%). In terms of maximum drawdown, PARMX dropped -49.88% vs FSMAX's -50.55%.

Which has better risk-adjusted returns?

FSMAX currently has the higher Sharpe Ratio (1.71 vs 1.41), 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.