Parnassus Mid Cap Fund Investor Shares 

The fund normally invests at least 80% of its net assets in mid-sized companies. The fund's managers consider a mid-sized company to be one that has a market capitalization between that of the smallest and largest constituents of the Russell Midcap® Index measured at the time of purchase. The Russell Midcap® Index includes approximately 800 of the smallest companies in the Russell 1000® Index. The fund may normally invest up to 20% of its net assets in smaller- and larger-capitalization companies.