A key contact for directors, Mayer Brown is well equipped to defend its clients in shareholder actions in Chancery courts. The team is headed by Joseph De Simone, Richard Rosenfeld, and Jackie Vallette, Simone primarily deals with SEC investigations and is highly active in derivative matters and securities investigations throughout the country and on an international level. Working alongside Simon in recent mandates is Michelle Annunziata, who represents issuers, directors and officers of global financial institutions in civil matters with a connection to DOJ and CFTC investigations. Hiral Mehta joined the firm as a partner in 2025.
Legal 500 Editorial commentary
Testimonials
Collated independently by Legal 500 research team.
‘Smart and very knowledgeable about securities litigation. In my experience, they are fully engaged and client-focused.’
'Mayer Brown has incredibly smart securities litigators. They are practical, hard working, and work very well in a joint defense arrangement. They have a deep knowledge of damages models and use that knowledge to squeeze out excellent settlements for their clients.'
'Jackie Vallette is smart, hard working, and practical in bringing together the full spectrum of co-counsel in securities litigation.'
Key clients
- Horizon Bancorp
- Generac, Inc.
- Vestis Corporation
- GPB Capital Management and the GPB Funds
- GoHealth, Inc.
- Altisource Residential Corporation (RESI) and Altisource Asset Management Company (AAMC)
- Peter Aceto, the ex-CEO of CannTrust
- FNA Group, Inc.
- Zillow Group, Inc.
- Cantor Fitzgerald and BGC Partners, Inc. (Cantor’s affiliate)
Work highlights
Obtained dismissal with prejudice of the major shareholder securities class action filed in the United States District Court for the Eastern District of New York, pursuant to our motion to dismiss the amended complaint on behalf of Horizon Bancorp, its CEO and CFO, and its board of directors.
Achieved another full dismissal in a securities class action—one on behalf of FNA Group—where the court agreed that the plaintiffs had not sufficiently alleged scheme liability based on conduct occurring in connection with FNA’s asset purchase from Renewable Innovations, Inc.
Representing NYSE-listed Generac, its directors and senior officers in a federal securities class action, entitled Oakland County v. Generac, et al., in the United States District Court for the Eastern District of Wisconsin relating to a stock drop of allegedly more than $1 billion.
Practice head
Joseph De Simone; Richard M. Rosenfeld; Jackie Vallette
Other key lawyers
Michelle Annunziata; Matthew Fenn