Barely a year after serving as student body president at the NYU Stern School of Business, a junior analyst at RBC Capital Markets was charged by federal prosecutors with insider trading.

Bill Tsai, 23, is accused by the government of trading ahead of the April 15 announcement that private equity firm Siris Capital Group would acquire the digital printing technology company Electronics for Imaging, or EFI. The Securities and Exchange Commission also filed a related civil lawsuit in New York Aug. 12.

“Tsai learned of the impending acquisition through his work” at the firm, which the government identifies as Investment...