Mark Popofsky

Practice Areas

Mark S. Popofsky, a veteran of the landmark Microsoft and Google antitrust trials, chairs Ropes & Gray’s antitrust practice. A first-chair trial lawyer with over 30 years of experience, Mark litigates antitrust, intellectual property and other complex business litigation matters. Mark’s litigation practice includes jury trials, class actions (including cartel cases), arbitrations and appeals throughout the federal and states courts.

Mark regularly counsels Fortune 500 companies on the full-range of antitrust matters across numerous industries, including high technology (including Gen AI), telecommunications, medical device, pharmaceuticals, aerospace, manufacturing, health care and consumer products. With deep and recognized experience in the intersection of intellectual property and antitrust, Mark advises leading Internet, semiconductor, hardware, software and telecommunications clients on business practices, competitor collaborations and distribution arrangements. He also represents parties in civil and criminal antitrust investigations and transactions before the U.S. Department of Justice and the Federal Trade Commission.

Mark served in the late 1990s as Senior Counsel to Assistant Attorney General Joel Klein in the U.S. Department of Justice’s Antitrust Division, where he played a key role in the landmark United States v. Microsoft Corp. monopolization trial, among other high profile matters. Mark previously served in the Division’s Appellate Section, where he argued the landmark victory in United States v. Nippon Paper – which established the extraterritorial application of U.S. antitrust law in cartel cases – and as a Special Assistant U.S. Attorney in Alexandria, Virginia (the “Rocket Docket”), where he tried numerous jury cases to verdict. Following government service, Mark in 1999 was named the youngest partner in the history of a renowned international law firm and served as Chair of its Technology and Competition Group.

Recently, Mark has served as trial counsel for Google in United States v. Google, the Government’s Search monopolization suit, and achieved a landmark victory for Biogen in the California Supreme Court in Ixchel Pharma, LLC v. Biogen, Inc., 9 Cal. 5th 1130 (2020), a case at the intersection of antitrust, non-compete, and tortious interference law. This victory garnered Mark LMG Life Science’s Antitrust Litigator of the Year award, as well as recognition in 2021 for Impact Case of the Year US Non-IP Litigation. Mark also has represented major telecommunications firms in transactions before the U.S. Department of Justice and in government litigation. In cases raising antitrust counterclaims in intellectual property disputes, Mark has achieved notable motion to dismiss wins.

Mark has served for over 25 years as an Adjunct Professor of Antitrust, Advanced Antitrust Law and Economics, and the Intellectual Property/Antitrust Intersection, including at Harvard Law School, the Georgetown University Law Center, the U. Penn Carey Law School, NYU Law School, and the George Washington University Law School, where he holds the title of Distinguished Scholar in the Competition Law Center. He writes and speaks frequently on antitrust law and policy and has been interviewed by The Wall Street Journal, Bloomberg, Global Competition Review and Law360. His Article on the Sherman Act’s Criminal Extraterritoriality won the 2012 Burton Award for Legal Achievement. Mark is a longtime leader in the ABA Section of Antitrust law and has served on leading Antitrust boards, including the BNA Antitrust Advisory Board.

Mark is sought for his antitrust experience by The Wall Street Journal, The Washington Post, The Los Angeles Times, NBC News, and BBC America.