Sergei has a diverse and deep set of experience, having worked on both litigation and regulatory matters, represented both plaintiffs and defendants, and prepared both expert and fact witnesses. Within that broad set experience, however, there are areas where Sergei has developed particular expertise:

• Merger Litigation. Sergei has taken part in six merger litigations. His accomplishments in this area include:
• Key member of the O’Melveny AT&T-Time Warner merger trial team that prevailed against the DOJ in what the press has dubbed “the antitrust trial of the century.” The representation received Global Competition Review’s 2018 “Merger Matter of the Year – Americas” award.
• Represented US Airways in defending the merger with American Airlines against a DOJ challenge. The airlines settled the DOJ suit, allowing the merger to proceed and paving the way for the creation of the world’s largest airline. The representation garnered Global Competition Review’s 2014 “Matter of the Year” award.
• Played a pivotal part in Honeywell’s challenge to Alarm.com-Icontrol merger, which resulted in favorable settlement for the client. Sergei was the principal drafter of the complaint and the briefing.
• Two-sided markets. Sergei played a pivotal role in developing, preparing, and presenting the expert case in the US Airways v. Sabre litigation. The 2016 Sabre trial was the first district court case where two-sided platform doctrine played a key role after the Second Circuit’s Amex decision established the modern judicial approach to platform markets, and the 2022 trial was the first case after the 2018 Supreme Court Amex decision where evidence of net two-sided anticompetitive effects was presented to a jury. The O’Melveny team obtained favorable verdicts for its client US Airways in both the 2016 and 2022 trials. Sergei is one of the few lawyers to have both plaintiff and defense-side experience in two-sided market cases, giving him a comprehensive perspective on this important area of antitrust law. In 2023, Sergei published the Platform Antitrust Report, a comprehensive summary of legal developments in the law of two-sided markets.
• Economic Experts. While Sergei has worked on virtually all aspects of antitrust litigation, he frequently focuses on the economic case. Sergei has taken the testimony of economic experts in federal court; second-chaired the expert presentations in a merger trial, a rule of reason trial on platform MFNs, and an ICC arbitration; and has deposed both economic and non-economic experts.
• Class Certification. Sergei has experience opposing class certification in antitrust cases in multiple jurisdictions and industries. In North Brevard County Hospital v. C.R. Bard, Sergei defeated class certification in a monopolization case and expunged hundreds of millions of dollars of potential liability. Sergei delivered the winning argument, persuading the district court judge that the class representative failed to present evidence capable of showing injury for any class member, let alone the thousands of hospitals it claimed to represent, and that the class representative was not a typical class member and not an adequate representative of the absent class members’ interests.

In addition to maintaining his busy and successful practice, Sergei is an active member of the antirust bar and regularly contributes thought leadership on cutting edge competition topics. Sergei is a member of ABA Antitrust Law Section Leadership (currently serving as Vice Chair of the Economics Committee) and a founding member of ABA’s Our Curious Amalgam podcast, a weekly program featuring interviews with leading antitrust and consumer protection thinkers and practitioners.