Insider Trading Indictment of 30 Defendants Including Big Law Attorneys Signals Escalating US Prosecution of M&A Confidentiality Breaches with Global Professional Conduct Implications

Federal prosecutors in the United States have filed a sweeping indictment against a 30-person network of lawyers, traders and financial professionals, alleging that lawyers at eight of America's most prominent firms — including Wachtell, Latham & Watkins, Willkie Farr, Goodwin Procter, Cleary Gottlieb, Sidley Austin, Weil Gotshal, and DLA Piper — systematically monetised confidential merger intelligence over approximately a decade. Prosecutors describe it as one of the most extensive M&A intelligence-based insider trading schemes ever prosecuted on American soil. The mechanics of the alleged scheme centre on attorneys exploiting the privileged access to live deal information that their transactional roles provided — across due diligence, documentation, and signing processes — to place or facilitate trades in target company securities before public announcements. The duration of the alleged conduct, spanning roughly ten years across multiple firms, suggests a coordinated network rather than isolated opportunistic behaviour. For disputes lawyers, the case raises complex issues around the scope of attorney-client privilege in enforcement proceedings, the evidentiary treatment of documents seized from law firm servers, and potential regulatory referrals to bar associations. In the UK, analogous conduct would engage the FCA's market abuse enforcement regime, the Criminal Justice Act 1993 insider dealing offences, and the Solicitors Regulation Authority (SRA)'s professional conduct rules — all of which UK firms will now be reviewing.