Joseph De Simone

Global Investigations & White Collar Defense, Securities Litigation & Enforcement, Litigation & Dispute Resolution


Joe is an experienced, well-respected litigator whose practice is focused primarily on securities class actions, complex litigation, regulatory disputes, internal corporate and government investigations, and general corporate litigation. According to Chambers USA 2015, Joe is a “highly regarded securities litigator,” who is “well versed in a range of complex disputes” and “highlighted for his impressive client roster and expertise in cross-border work.” Previous editions have reported that Joe wins respect for a “business-oriented mentality” that helps to ease the passage of SEC investigations and securities-related disputes. . . . “he not only knows the law, he understands its impact." He has served as the Office Practice Leader for Litigation in Mayer Brown’s New York office and the Head of the Hiring Committee in New York.


Securities Litigation Experience

  • Successfully represents issuers, underwriters and individual directors and officers in federal securities fraud class actions and shareholder derivative litigation.
  • Provides advice to clients’ boards of directors on pending securities litigation matters, litigation and special committees, and strategic issues.
  • Represented Peter Aceto, the ex-CEO of CannTrust, a Cannabis company, in a securities class action in the United States District Court for the Southern District of New York and a related securities action in California. Shareholder plaintiffs allege violations of Section 10(b) and 20(a) in connection with alleged material misstatements and omissions in CannTrust’s SEC disclosure documents and the Company’s public statements. There were parallel securities actions and investigations in Canada. Case settled in 2021 after a complex mediation process.


  • Fordham University School of Law, JD
    Associate Editor, Fordham Law Review, Dean's List
  • Princeton University, AB


  • New York


  • US Court of Appeals for the Second Circuit
  • US District Court for the Southern District of New York
  • US District Court for the Eastern District of New York
  • US Supreme Court