INVESTIGATION REMINDER: The Schall Law Firm Announces it is Investigating Claims Against ProPetro Holding Corp. and Encourages Investors with Losses in Excess of $100,000 to Contact the Firm

The Schall Law Firm , a national shareholder rights litigation firm, announces that it is investigating claims on behalf of investors in ProPetro Holding Corp. (ProPetro or the Company) (NYSE: PUMP ) for potential breaches of fiduciary duty on the part of its former directors and management.