Mark heads the firm's corporate governance litigation practice, focusing on derivative suits and transactional litigation. Working with his institutional investor clients, he fights to hold management accountable, pursuing meaningful and novel challenges to alleged corporate governance-related misconduct and anti-shareholder practices. His cases have created key legal precedents while helping recoup billions of dollars for investors and improving corporate governance practices in numerous industries.
Most recently, Mark led the Allergan Proxy Violation Litigation, alleging an unprecedented insider trading scheme by billionaire hedge fund manager Bill Ackman, Ackman’s Pershing Square Capital Management fund and Valeant Pharmaceuticals International, Inc. After a ferocious three-year legal battle over this attempt to circumvent the spirit of the U.S. securities laws, defendants accepted a $250 million settlement for Allergan investors. In 2017, before the birth of the #metoo movement, he led the prosecution of an unprecedented shareholder derivative litigation against Fox News parent 21st Century Fox, Inc. arising from the systemic sexual and workplace harassment at the embattled network. The case resulted in one of the largest financial recoveries – $90 million – ever obtained in a pure corporate board oversight dispute; and the creation of an independent council of experts - named the "Fox News Workplace Professionalism and Inclusion Council" — which is expected to serve as a model for public companies in all industries.
Other select current and past representations include:
Mark pioneered challenges to the improper but widespread practice of using “Proxy Put” provisions in corporate debt agreements, obtaining pro-shareholder rulings in cases like In re Amylin Shareholders Litigation, In re SandRidge Energy, Inc. Shareholder Litigation, and In re Healthways, Inc. Shareholder Litigation, which have caused the industry to materially change its use of such provisions. He also prosecutes securities litigations, and in that capacity, was the lead litigation attorney in In re Merrill Lynch Bondholders Litigation, which settled for $150 million; and a member of the team prosecuting In re Bank of America Securities Litigation, which settled for $2.425 billion. Currently, he is the lead attorney prosecuting In re Allergan Proxy Securities Litigation.
Mark has received national recognition for his work in securities and M&A litigation. The National Law Journal named Mark, as a “Plaintiffs’ Lawyers Trailblazer,” recognizing him among the top practitioners in the nation. He was selected 2016 national “Plaintiff Attorney of the Year” by Benchmark Litigation and is regularly honored as a New York “Litigation Star” by Benchmark in its exclusive annual list of top practitioners. Named a leading lawyer in M&A litigation by Best Lawyers®, Mark was selected as its 2016 M&A Litigation “Lawyer of the Year” for New York City. He is one of Lawdragon’s “500 Leading Lawyers in America,” a New York Super Lawyer, and is recognized by Chambers USA and Legal 500 as one of an elite group of notable practitioners in securities and M&A litigation. In 2013, Law360 named him as one of its five “Rising Stars” nationally in the area of securities litigation – the only plaintiff-side attorney so selected, and in 2018 honored him as a “Titan of the Plaintiffs Bar.” In 2012, The Deal magazine prominently profiled Mark as one of the top three lawyers nationally representing shareholder plaintiffs in M&A litigation in its feature article, “The Troika Atop the M&A Plaintiffs’ Bar.”
Mark serves as an Adviser on the prestigious American Law Institute’s Restatement of the Law, Corporate Governance project. He is also a member of the Board of Advisors for both the Institute for Law and Economics and the NYU Institute for Corporate Governance and Finance, and is an author and a frequent speaker and commentator at industry events on a wide range of corporate governance and securities related issues. His publications include "Of Babies and Bathwater: Deterring Frivolous Stockholder Suits Without Closing the Courthouse Doors to Legitimate Claims” (Delaware Journal of Corporate Law, Vol. 40, 2015), “Making Order Out of Chaos: A Proposal To Improve Organization and Coordination in Multi-Jurisdictional Merger-Related Litigation" (ABA Journal), "‘Novel Issues’ or a Return to Core Principles? Analyzing the Common Link Between the Delaware Chancery Court’s Recent Rulings in Option Backdating and Transactional Cases" (NYU Journal of Law & Business, Volume 4, Number 2), “Calling a Duck a Duck: Determining the Validity of Deal Protection Provisions in Merger of Equals Transactions” (2001 Columbia Business Law Review 1) and “Practical Refinement” (The Daily Deal, January 2002), each of which discussed evolving developments in the law of directors’ fiduciary duties.
Mark clerked for Vice Chancellor Stephen P. Lamb on the Court of Chancery of the State of Delaware, and was a litigation associate at Skadden, Arps, Slate, Meagher & Flom in New York, where he represented clients in a variety of corporate governance, commercial and federal securities matters.