PARNX vs. FSMDX

Last updated Jun 24, 2026

PARNX (Parnassus Mid Cap Growth Fund) and FSMDX (Fidelity Mid Cap Index Fund) are both mutual funds - PARNX is a Mid Cap Growth Equities fund managed by Parnassus, while FSMDX is a Mid Cap Blend Equities fund tracking the Russell Midcap Index. Over the past 10 years, PARNX returned 10.08%/yr vs 12.12%/yr for FSMDX. Their correlation of 0.89 suggests significant overlap in exposure. PARNX charges 0.80%/yr vs 0.03%/yr for FSMDX.

Performance

PARNX vs. FSMDX - Performance Comparison

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

Returns By Period

In the year-to-date period, PARNX achieves a 6.67% return, which is significantly lower than FSMDX's 14.03% return. Over the past 10 years, PARNX has underperformed FSMDX with an annualized return of 10.08%, while FSMDX has yielded a comparatively higher 12.12% annualized return.

PARNX

• 1D: -0.30%
• 1M: 5.07%
• YTD: 6.67%
• 6M: 4.64%
• 1Y: 17.61%
• 3Y*: 14.97%
• 5Y*: 3.61%
• 10Y*: 10.08%

FSMDX

• 1D: 0.53%
• 1M: 3.31%
• YTD: 14.03%
• 6M: 12.50%
• 1Y: 22.60%
• 3Y*: 17.64%
• 5Y*: 8.51%
• 10Y*: 12.12%

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

PARNX vs. FSMDX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
PARNX Parnassus Mid Cap Growth Fund	6.67%	9.14%	10.58%	35.60%	-33.54%	9.35%	28.75%	29.82%	-9.80%	16.12%
FSMDX Fidelity Mid Cap Index Fund	14.03%	10.58%	15.55%	17.20%	-17.27%	22.56%	17.13%	30.53%	-9.38%	18.04%

Correlation

The correlation between PARNX and FSMDX 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	0.89
Correlation (10Y) Calculated over the trailing 10-year period	0.87
Correlation (All Time) Calculated using the full available price history since Sep 9, 2011	0.89

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

Return for Risk

PARNX vs. FSMDX — Risk / Return Rank

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

PARNX

PARNX Risk / Return Rank: 15
PARNX Sharpe Ratio Rank: 14
PARNX Sortino Ratio Rank: 15
PARNX Omega Ratio Rank: 13
PARNX Calmar Ratio Rank: 16
PARNX Martin Ratio Rank: 18

FSMDX

FSMDX Risk / Return Rank: 48
FSMDX Sharpe Ratio Rank: 41
FSMDX Sortino Ratio Rank: 40
FSMDX Omega Ratio Rank: 36
FSMDX Calmar Ratio Rank: 63
FSMDX Martin Ratio Rank: 59

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.

PARNX vs. FSMDX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Parnassus Mid Cap Growth Fund (PARNX) and Fidelity Mid Cap Index Fund (FSMDX). 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.

	PARNX	FSMDX	Difference
Sharpe ratio: Return per unit of total volatility	0.98	1.72	-0.74
Sortino ratio: Return per unit of downside risk	1.47	2.45	-0.98
Omega ratio: Gain probability vs. loss probability	1.17	1.30	-0.12
Calmar ratio: Return relative to maximum drawdown	1.31	2.90	-1.60
Martin ratio: Return relative to average drawdown	4.31	11.11	-6.80

PARNX vs. FSMDX - Sharpe Ratio Comparison

The current PARNX Sharpe Ratio is 0.98, which is lower than the FSMDX Sharpe Ratio of 1.72. The chart below compares the historical Sharpe Ratios of PARNX and FSMDX, 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

PARNX vs. FSMDX - Drawdown Comparison

The maximum PARNX drawdown since its inception was -54.34%, which is greater than FSMDX's maximum drawdown of -40.35%. Use the drawdown chart below to compare losses from any high point for PARNX and FSMDX.

Drawdown Indicators

	PARNX	FSMDX	Difference
Max Drawdown Largest peak-to-trough decline	-54.34%	-40.35%	-13.99%
Max Drawdown (1Y) Largest decline over 1 year	-14.49%	-8.16%	-6.33%
Max Drawdown (3Y) Largest decline over 3 years	-27.87%	-20.92%	-6.95%
Max Drawdown (5Y) Largest decline over 5 years	-41.75%	-26.07%	-15.68%
Max Drawdown (10Y) Largest decline over 10 years	-41.75%	-40.35%	-1.40%
Current Drawdown Current decline from peak	-0.52%	-0.26%	-0.26%
Average Drawdown Average peak-to-trough decline	-12.67%	-4.94%	-7.73%
Ulcer Index Depth and duration of drawdowns from previous peaks	4.38%	2.13%	+2.25%

Volatility

PARNX vs. FSMDX - Volatility Comparison

Parnassus Mid Cap Growth Fund (PARNX) has a higher volatility of 7.16% compared to Fidelity Mid Cap Index Fund (FSMDX) at 4.43%. This indicates that PARNX's price experiences larger fluctuations and is considered to be riskier than FSMDX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	PARNX	FSMDX	Difference
Volatility (1M) Calculated over the trailing 1-month period	7.16%	4.43%	+2.73%
Volatility (6M) Calculated over the trailing 6-month period	15.29%	10.46%	+4.83%
Volatility (1Y) Calculated over the trailing 1-year period	19.41%	13.85%	+5.56%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	24.03%	18.32%	+5.71%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	21.96%	19.35%	+2.61%

PARNX vs. FSMDX - Expense Ratio Comparison

PARNX has a 0.80% expense ratio, which is higher than FSMDX's 0.03% expense ratio.

Dividends

PARNX vs. FSMDX - Dividend Comparison

PARNX's dividend yield for the trailing twelve months is around 16.27%, more than FSMDX's 0.97% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FSMDX Fidelity Mid Cap Index Fund	0.97%	1.10%	2.46%	1.39%	2.07%	3.35%	2.34%	2.86%	2.21%	2.17%	2.23%	2.84%
PARNX Parnassus Mid Cap Growth Fund	16.27%	17.36%	7.38%	2.86%	1.23%	4.50%	5.20%	4.21%	7.94%	7.96%	2.04%	19.70%

Frequently Asked Questions

Can I hold both PARNX and FSMDX in my portfolio?

PARNX and FSMDX 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, PARNX or FSMDX?

PARNX has higher volatility (7.16%) compared to FSMDX (4.43%). In terms of maximum drawdown, PARNX dropped -54.34% vs FSMDX's -40.35%.

Which has better risk-adjusted returns?

FSMDX currently has the higher Sharpe Ratio (1.72 vs 0.98), 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.