PARNX vs. IUSG

Last updated Jun 4, 2026

PARNX (Parnassus Mid Cap Growth Fund) and IUSG (iShares Core S&P U.S. Growth ETF) are both funds - PARNX is a Mid Cap Growth Equities fund managed by Parnassus, while IUSG is a Large Cap Growth Equities fund tracking the Russell 3000 Growth Index. Over the past 10 years, PARNX returned 9.44%/yr vs 17.88%/yr for IUSG. Their correlation of 0.85 suggests significant overlap in exposure. PARNX charges 0.80%/yr vs 0.04%/yr for IUSG.

Performance

PARNX vs. IUSG - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Parnassus Mid Cap Growth Fund (PARNX) and iShares Core S&P U.S. Growth ETF (IUSG). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, PARNX achieves a 6.00% return, which is significantly lower than IUSG's 14.08% return. Over the past 10 years, PARNX has underperformed IUSG with an annualized return of 9.44%, while IUSG has yielded a comparatively higher 17.88% annualized return.

PARNX

• 1D: -0.51%
• 1M: 6.10%
• YTD: 6.00%
• 6M: 3.61%
• 1Y: 17.63%
• 3Y*: 15.27%
• 5Y*: 4.53%
• 10Y*: 9.44%

IUSG

• 1D: -0.89%
• 1M: 7.35%
• YTD: 14.08%
• 6M: 13.91%
• 1Y: 33.89%
• 3Y*: 27.59%
• 5Y*: 15.69%
• 10Y*: 17.88%

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

PARNX vs. IUSG - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
PARNX Parnassus Mid Cap Growth Fund	6.00%	9.14%	10.58%	35.60%	-33.54%	9.35%	28.75%	29.82%	-9.80%	16.12%
IUSG iShares Core S&P U.S. Growth ETF	14.08%	21.23%	34.70%	29.28%	-28.81%	31.26%	32.65%	30.62%	-0.79%	27.02%

Correlation

The correlation between PARNX and IUSG 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	0.78
Correlation (5Y) Calculated over the trailing 5-year period	0.84
Correlation (10Y) Calculated over the trailing 10-year period	0.85
Correlation (All Time) Calculated using the full available price history since Jul 31, 2000	0.85

The correlation between PARNX and IUSG shifts across timeframes, from 0.74 (1 year) to 0.85 (10 years), reflecting how their relationship changes across market environments.

Return for Risk

PARNX vs. IUSG — 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: 15
PARNX Martin Ratio Rank: 16

IUSG

IUSG Risk / Return Rank: 59
IUSG Sharpe Ratio Rank: 64
IUSG Sortino Ratio Rank: 61
IUSG Omega Ratio Rank: 60
IUSG Calmar Ratio Rank: 52
IUSG Martin Ratio Rank: 61

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. IUSG - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Parnassus Mid Cap Growth Fund (PARNX) and iShares Core S&P U.S. Growth ETF (IUSG). 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.

	PARNX	IUSG	Difference
Sharpe ratio: Return per unit of total volatility	1.05	2.17	-1.12
Sortino ratio: Return per unit of downside risk	1.58	2.93	-1.35
Omega ratio: Gain probability vs. loss probability	1.18	1.37	-0.19
Calmar ratio: Return relative to maximum drawdown	1.35	2.61	-1.26
Martin ratio: Return relative to average drawdown	4.46	11.09	-6.63
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

PARNX vs. IUSG - Sharpe Ratio Comparison

The current PARNX Sharpe Ratio is 1.05, which is lower than the IUSG Sharpe Ratio of 2.17. The chart below compares the historical Sharpe Ratios of PARNX and IUSG, 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

	PARNX	IUSG	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.05	2.17	-1.12
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.19	0.76	-0.57
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.43	0.88	-0.45
Sharpe Ratio (All Time) Calculated using the full available price history	0.44	0.38	+0.06

Drawdowns

PARNX vs. IUSG - Drawdown Comparison

The maximum PARNX drawdown since its inception was -54.34%, smaller than the maximum IUSG drawdown of -63.41%. Use the drawdown chart below to compare losses from any high point for PARNX and IUSG.

Drawdown Indicators

	PARNX	IUSG	Difference
Max Drawdown Largest peak-to-trough decline	-54.34%	-63.41%	+9.07%
Max Drawdown (1Y) Largest decline over 1 year	-14.49%	-13.07%	-1.42%
Max Drawdown (3Y) Largest decline over 3 years	-27.87%	-22.28%	-5.59%
Max Drawdown (5Y) Largest decline over 5 years	-41.75%	-32.21%	-9.54%
Max Drawdown (10Y) Largest decline over 10 years	-41.75%	-32.35%	-9.40%
Current Drawdown Current decline from peak	-0.51%	-0.98%	+0.47%
Average Drawdown Average peak-to-trough decline	-12.68%	-21.44%	+8.76%
Ulcer Index Depth and duration of drawdowns from previous peaks	4.36%	3.06%	+1.30%

Volatility

PARNX vs. IUSG - Volatility Comparison

Parnassus Mid Cap Growth Fund (PARNX) has a higher volatility of 4.60% compared to iShares Core S&P U.S. Growth ETF (IUSG) at 4.23%. This indicates that PARNX's price experiences larger fluctuations and is considered to be riskier than IUSG based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	PARNX	IUSG	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.60%	4.23%	+0.37%
Volatility (6M) Calculated over the trailing 6-month period	14.12%	12.23%	+1.89%
Volatility (1Y) Calculated over the trailing 1-year period	18.63%	15.72%	+2.91%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	23.88%	20.87%	+3.01%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	21.88%	20.40%	+1.48%

PARNX vs. IUSG - Expense Ratio Comparison

PARNX has a 0.80% expense ratio, which is higher than IUSG's 0.04% expense ratio.

Dividends

PARNX vs. IUSG - Dividend Comparison

PARNX's dividend yield for the trailing twelve months is around 16.37%, more than IUSG's 0.47% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
IUSG iShares Core S&P U.S. Growth ETF	0.47%	0.53%	0.59%	1.12%	1.07%	0.59%	0.93%	1.64%	1.32%	1.28%	1.48%	1.29%
PARNX Parnassus Mid Cap Growth Fund	16.37%	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 IUSG in my portfolio?

PARNX and IUSG 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, PARNX or IUSG?

PARNX has higher volatility (4.60%) compared to IUSG (4.23%). In terms of maximum drawdown, PARNX dropped -54.34% vs IUSG's -63.41%.

Which has better risk-adjusted returns?

IUSG currently has the higher Sharpe Ratio (2.17 vs 1.05), 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.