I doubt Parnassus will "promise" 11.19% over 10 years. And considering the fund only started in 2001, they don't even have a 10 year track record to compare against so I'm not even sure what return numbers they're presenting. Maybe they estimate based on what they might have done in the past? If you look at the performance record, the 3/5 year performance match nearly perfectly with the S&P500.
* http://quicktake.morningstar.com/fundne ... b=snapshot
Of course, is the S&P500 even the proper comparison? Let's look at the fund makeup.
* http://quicktake.morningstar.com/fundne ... =portfolio
50% is in medium/small/micro so a better comparison is 50% S&P500, 50% Extended Market Index. Let's look at the performance for VEXMX (Vanguard Extended Market):
* http://quicktake.morningstar.com/FundNe ... mbol=VEXMX
Take half the difference compared to the S&P500 and then substract out the Parnassus numbers. You end up with Parnassus underperforming the "market" by 2.75% over the last 5 years and 2.1% over the last 3 years. Now if being green is worth losing 2%-3% of performance, that could be a valid choice to make.