A sweeping federal insider-trading prosecution in Boston took a significant step forward on June 1, when 15 defendants pleaded not guilty in a case prosecutors say spanned roughly a decade and touched nearly 30 merger transactions. The U.S. Attorney’s Office in Boston has charged 30 people overall, alleging that lawyers and financial professionals improperly shared confidential deal information that was then used to trade ahead of market-moving announcements.

The case stands out both for its scale and for the professional roles allegedly involved.

Federal prosecutors in Boston and the SEC have unsealed a closely watched insider-trading case alleging that confidential merger information was funneled from lawyers at elite law firms into a wider trading network. The government’s allegations center on Nicolo Nourafchan and Robert Yadgarov, and reportedly tie the flow of nonpublic deal information to attorneys associated with Goodwin Procter and Latham Watkins.

What makes this case stand out is not just the scale of the alleged trading scheme, but the source of the information.

The SEC has settled insider-trading charges against Weizheng Zeng in an administrative proceeding arising from the acquisition of Chimerix, Inc. by Jazz Pharmaceuticals plc. In SEC v. Weizheng Zeng (File No. 3-22627), the agency alleged that Zeng traded Chimerix stock while participating in due diligence work connected to Jazz’s acquisition of the company, before the deal was publicly announced on March 5, 2025.

According to the SEC, those trades generated roughly $69,011 in illicit profits.