Prosecutors charge 30 in BigLaw M&A insider trading ring

Federal prosecutors unsealed indictments against 30 defendants on Monday, charging a decadelong international insider trading scheme in which M&A lawyers at six of the largest US law firms stole confidential deal data from their own firms and fed it to a network of traders who profited on nearly 30 public-company transactions.

The charging documents, filed in the Southern District of New York, describe an operation that ran from March 2014 to August 2024 and reached into the technology, biopharmaceutical, insurance, real estate and retail sectors. Several of the targeted deals ranked among the largest M&A transactions of the last decade. The Securities and Exchange Commission separately charged 21 individuals in a parallel civil action.

At the centre of the ring is Nicolo Nourafchan, a 43-year-old Yale Law graduate who worked at Sidley Austin, Latham & Watkins and Goodwin Procter during the scheme’s run. According to prosecutors, Nourafchan mined his firms’ internal M&A databases for nonpublic information on pending deals — the names of targets, offer prices, expected completion dates — and passed the intelligence to a network of traders operating through brokerage accounts in the US and abroad.

He did not act alone.

Prosecutors describe a coordinated relay in which Robert Yadgarov, a New York-licensed attorney, acted as the information hub. Yadgarov collected deal tips from Nourafchan and other recruited lawyers, funnelled them to traders, and distributed the proceeds back to the lawyers as kickbacks. By the indictment’s account, Yadgarov alone collected more than $6.3 million from a single Russian trader over the first five years of the operation. Portions were parcelled out to other attorneys in the ring.

Gabriel Gershowitz, an M&A lawyer at Weil Gotshal and a Columbia Law graduate, joined the scheme in 2019, prosecutors allege.

“What’s outstanding about this is it was a really comprehensive plan over almost a decade to mine law firm information for serial mergers,” David Axelrod, a litigator at Ballard Spahr and former US federal prosecutor, told the Financial Times.

The indictment details one large single-trade profit. In the summer of 2022, the ring allegedly netted $1.7 million on an insider trade tied to Amazon’s acquisition of iRobot Corp, a transaction on which Nourafchan’s firm had been retained for legal work.

Six firms. Thirty defendants. A decadelong timeline. The scope of the breach has rattled the legal industry. Ex-SEC enforcement lawyers and white-collar defence attorneys told Law.com that the case is likely to force changes in how law firms control access to confidential client data, particularly inside M&A practice groups where junior and mid-level associates routinely have visibility into deal pipelines across multiple clients.

“The misappropriation of confidential M&A data from six top law firms may lead to changes in firms’ controls over client data,” those lawyers said.

How the scheme worked

Across the six firms, the scheme may expose systemic weaknesses in how BigLaw manages deal-room confidentiality. Most large firms operate centralised M&A databases that track every live mandate — a tool designed for staffing and conflicts checks, accessible to any associate assigned to the practice group. That same architecture, the indictment makes clear, gave Nourafchan a single point of access to the nonpublic details of nearly three dozen transactions. From his desk, he could see which targets were in play, at what price, and on what timeline.

The scheme’s longevity points to a deeper compliance gap. Nourafchan moved between three major firms over the course of the alleged conspiracy — Sidley Austin, Latham & Watkins, and Goodwin Procter — without detection. Each lateral move would have triggered a standard conflicts check but not, apparently, a review of his trading patterns or those of his associates.

The compliance reckoning

The case also raises the stakes for law firm compliance programmes at a moment when M&A activity is climbing. Global deal volumes topped $3.5 trillion in 2025, according to data from Dealogic, and the first quarter of 2026 has already outpaced the same period a year earlier. More deals mean more lawyers with access to material nonpublic information — and more pressure on the internal controls that failed here.

For law firm general counsel, the lesson is blunt. Physical information barriers — separate floors, restricted-access deal rooms, isolated document management systems — have been standard practice in investment banking for decades. Law firms, by contrast, have relied more heavily on professional ethics rules and the threat of disbarment. The indictment suggests that approach left a gap wide enough for a decadelong scheme to operate undetected.

The SDNY prosecutors are not treating the case as a one-off. The parallel SEC civil action against 21 individuals signals that securities regulators intend to use the case to reset expectations for how law firms monitor their own deal rooms. Any firm that names a partner to a deal team now faces the question of whether its internal controls would have caught Nourafchan’s activity — and whether they would catch it today.

The defendants face charges including securities fraud, wire fraud and conspiracy. Nourafchan and Yadgarov did not respond to requests for comment. Weil Gotshal, Sidley Austin, Latham & Watkins, Goodwin Procter and the other firms named in the charging documents either declined to comment or did not respond.