PartnerAlithea Z. Sullivan

Alithea is a graduate of Harvard College and Harvard Law School, where she served as Forum Editor of the Harvard Law Review. For nearly two decades, she has represented publicly traded companies at white-shoe and boutique law firms in Austin and in Washington, D.C. She is proud to bring her business-litigation expertise to the Stone Hilton team.

trusted counselor to boardrooms and c-suites

Alithea focuses on counseling corporate clients in shareholder class actions, derivative suits, and big-dollar commercial and corporate-governance disputes. Her litigation experience includes disclosure rules under the Securities Act of 1933 and the Exchange Act of 1934, along with fiduciary-duty, breach-of-contract, and fraud claims. When business rivals start saber-rattling about high-stakes litigation, boardrooms and C-suites turn to this former boxer for fierce advocacy, a gifted pen, and a sophisticated understanding of industries ranging from energy to financial services to telecommunications.

Equally at home in state and federal courts, Alithea is an all-purpose litigator who has represented clients in the U.S. District Court for the Western District of Texas, the Travis County District Court, the Delaware Court of Chancery, and the U.S. Court of Appeals for the Fifth Circuit, among others. She has wrangled massive discovery projects involving reams of documents and hours of testimony. If these litigation expenses can be minimized through dispositive motions, she will deploy her brief-writing prowess to help trial judges cut to the heart of the matter. And when cases go up on appeal, she is adept at boiling down complex disputes for generalist judges with busy dockets.

In one exemplary matter, Alithea authored a series of scholarly amicus briefs that persuaded the U.S. Supreme Court to fundamentally alter its approach to the fraud-on-the-market presumption in securities class actions. See Halliburton Co. v. Erica P. John Fund, Inc., 573 U.S. 258, 279–83 (2014). This complex area continues to vex the federal courts to this day. See Goldman Sachs Grp., Inc. v. Ark. Teacher Ret. Sys., 594 U.S. 113 (2021). But clients who hire Alithea will have an advocate who knows how to navigate difficult terrain.



Representative Matters
  • Halliburton Co. v. Erica P. John Fund, Inc. (Sup. Ct. No. 13-317):
    Authored amicus brief that criticized the fraud-on-the-market presumption in securities class actions, culminating in a favorable citation by the U.S. Supreme Court.

  • HCB Financial Corp. v. McPherson (5th Cir. No. 20-50718):
    Defeated creditor’s RICO claim for treble damages based on a multi-million-dollar judgment that had already been satisfied.

  • Kinnie Ma IRA v. Ascendant Capital, LLC (W.D. Tex. No. 1:19-cv-1050):
    Represented broker-dealers in class action alleging a billion-dollar Ponzi scheme.

  • Texas County & Dist. Ret. Sys. v. Wexford Spectrum Fund, L.P. (W.D. Tex. No. 1:13-cv-370):
    Secured remand, for want of federal diversity jurisdiction, of retirement system’s state-law fraud and breach-of-contract claims against hedge fund.

  • In re ArthroCare Corp. Securities Litig. (W.D. Tex. No. 1:08-cv-574):
    Won dismissal of Section 20(a) control-person claim against corporate officer in shareholder class action involving revenue recognition and allegations of healthcare fraud in sales of medical devices.

  • Fortune 100 Company:
    Represented Chief Audit Executive in SEC/DOJ investigation of alleged violations of the Sarbanes-Oxley Act and the Foreign Corrupt Practices Act.

  • Multinational Energy Company:
    Represented the purchaser in multiple state- and federal-court class actions challenging the acquisition of a $4.4 billion exploration and production company, and defeated shareholders’ motion for a temporary injunction.

  • Energy Investment Vehicle:
    Represented principal of a series of limited partnerships in SEC fraud investigation.

  • Publicly Traded Financial-Services Company:
    Defended CFO in securities class action and in SEC investigation of alleged securities-law violations.

  • Multinational Energy Company:
    Represented C-suite officers in internal investigation of possible securities fraud and tax fraud.

  • Publicly Traded Technology Company:
    Represented a special litigation committee of the board of directors in an internal investigation of shareholders’ accusations, and in their state-court derivative suit.

Professional Memberships
  • State Bar of Texas
  • District of Columbia Bar