Hilary H. Mattis

Silicon Valley
  • 140 Scott Drive
  • Menlo Park, CA 94025
  • USA
Profile Experience

Hilary Mattis is a litigation and trial partner in the Silicon Valley office of Latham & Watkins.

Ms. Mattis represents public companies, officers, and directors on securities and professional liability litigation, in connection with:

  • Securities class actions
  • Shareholder derivative litigation
  • Securities and Exchange Commission (SEC) and Financial Industry Regulatory Authority (FINRA) investigations and enforcement actions
  • Internal investigations
  • Other complex, high-stakes commercial litigation

Ms. Mattis actively participates in the firm’s pro bono program, having obtained asylum and U visas for a number of domestic violence victims. She previously served on Latham’s Training and Career Enhancement (TACE) Committee. Ms. Mattis rejoined the firm in 2014 following a clerkship with Judge James Donato, United States District Court for the Northern District of California.

While in law school, Ms. Mattis served as a judicial extern for Judge James Ware, United States District Court Judge for the Northern District of California.

A selection of Ms. Mattis’ matters include representing:

  • A Big 4 audit firm in confidential arbitration brought by a state insurance commissioner on behalf of a failed insurance company who sought nine-figure damages. Awarded complete defense judgment following a two-week trial.    
  • Certain former officers and directors of Occam Networks, Inc. in a fiduciary-duty class action in the Delaware Court of Chancery. The case was settled confidentially at trial.
  • The former Chairman and CEO of sTec, Inc., Manouch Moshayedi, in one of the largest insider-trading actions brought by the Securities and Exchange Commission. Following a three-week trial in the Southern District of California, the jury returned a complete defense verdict.
  • American Superconductor Corporation (AMSC) in the District of Massachusetts in a securities class action alleging violations of Section 10(b) and 20(a) of the Securities Exchange Act.
  • Avago Technologies (now Broadcom) in the Central District of California in a securities class action alleging violation of Section 14(e). Resulted in dismissal with prejudice of complaint at the motion to dismiss stage.
  • Broadcom in in the Northern District of California in a securities class action alleging violation of Section 14(a).
  • Excel Trust in the shareholder lawsuits following the company’s US$2 billion sale to Blackstone Group, including successfully defeating plaintiffs’ motion for a preliminary injunction.
  • Virgin America in the shareholder lawsuits following the company’s US$4 billion sale to Alaska Airlines.
  • Relypsa in the shareholder lawsuits and appraisal in Delaware Chancery Court following the company’s US$1.5B sale to Galenica.
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