Margaret E. Mazzeo


  • Franklin & Marshall College
    B.A. 2007, magna cum laude
  • Temple University Beasley School of Law
    J.D. 2011, cum laude
  • Pennsylvania
  • New Jersey
  • USDC, District of New Jersey
  • USDC, Eastern District of Pennsylvania

Margaret E. Mazzeo, a partner of the Firm, concentrates her practice in the area of securities fraud litigation. Since joining the firm, Margaret has represented shareholders in several securities fraud class actions and direct actions, through all aspects of pre-trial proceedings, including complaint drafting, litigating motions to dismiss and for summary judgment, conducting document, deposition and expert discovery, and appeal. Margaret was a member of the trial team that recently won a jury verdict in favor of investors in the In re Longtop Financial Technologies Ltd. Securities Litigation, No. 11-cv-3658 (S.D.N.Y.) action.

Representative Outcomes
  • As co-lead counsel representing the Maine Public Employees’ Retirement System, secured a $500 million settlement for a class of plaintiffs that purchased mortgage-backed securities (MBS) issued by Countrywide Financial Corporation (Countrywide).

    Plaintiffs alleged that Countrywide and various of its subsidiaries, officers and investment banks made false and misleading statements in more than 450 prospectus supplements relating to the issuance of subprime and Alt-A MBS—in particular, the quality of the underlying loans. When information about the loans became public, the plaintiffs’ investments declined in value. The ensuing six-year litigation raised several issues of first impression in the Ninth Circuit.

  • Represented the Alameda County Employees’ Retirement Association, former shareholders of Lehman Brothers Holdings, Inc., (Lehman) in a case alleging that Lehman made false and misleading statements prior to its unprecedented bankruptcy filing in 2008. 

    The statements, which concerned Lehman’s net leverage, risk management and concentration of risks, were made ’in registration statements and prospectuses used to market numerous offerings leading up to the bankruptcy filing. Despite Lehman’s bankruptcy, we were able to negotiate a $616 million settlement funded by Lehman’s underwriters, auditor and officers and directors. 


Matthew L. Mustokoff and Margaret E. Mazzeo, “Proving Securities Fraud Damages at Trial,” 46 Rev. of Securities & Commodities Regulation, 145-54 (2013)

Matthew L. Mustokoff and Margaret Mazzeo, “The Maintenance Theory of Inflation in Fraud-on-the-Market Cases,” 40 Securities Regulation Law Journal (2012)