The Parnassus Mid Cap Fund normally invests at least 80% of its net assets (plus borrowings for investment purposes) in mid‑sized companies. The Fund considers 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 (which was between $2.0 billion and $58.5 billion as of April 30, 2025) measured at the time of purchase. The Russell Midcap^® Index includes approximately 800 of the smallest companies in the Russell 1000^® Index. The Fund will not automatically sell or cease to purchase stock of a company it already owns just because the company’s market capitalization grows or falls outside the ranges of the Russell Midcap^® Index, which are subject to change. The Fund may normally invest up to 20% of its net assets in smaller- and larger-capitalization companies. The portfolio managers focus on seeking downside protection. The Fund invests mainly in domestic stocks of companies that are financially sound and have good prospects for the future, and may invest up to 20% of its assets in foreign

securities of similar companies. The Fund may purchase foreign securities directly on foreign markets.

Using a value-oriented investment process, the Fund seeks to invest in equity securities that have the potential for long-term capital appreciation. To determine a company’s prospects, the Fund’s investment adviser, Parnassus Investments, LLC (the “Adviser”) reviews the company’s income statement, cash flow statement and balance sheet, and analyzes the company’s sustainable strategic advantage and management team. Upon initial investment, a company’s stock must be trading below its intrinsic value, which means that the Adviser seeks to purchase stock trading at a discount to the Adviser’s assessment of the company’s estimated value. As part of the Adviser’s investment approach, the Adviser seeks to invest in companies with sustainable business practices, in alignment with our investment philosophy, as we believe these factors are relevant to our assessment of quality and the risk-return profiles of companies in the Funds. The Fund will evaluate whether it will continue to hold or sell a security if the Adviser believes a company’s fundamentals will deteriorate, if it believes a company’s stock has little potential for appreciation or if the company no longer meets the Adviser’s sustainable investment expectations and the Adviser does not believe it is an appropriate investment for the Fund following such changes.