U.S. SECURITIES AND EXCHANGE COMMISSION

Litigation Release No. 26573 / June 24, 2026

Securities and Exchange Commission v. Casey Muggleston, No. 1:26-cv-00744 (D. Del. Filed June 24, 2026)

SEC Charges Nuclear Engineer with Insider Trading

Today, the Securities and Exchange Commission filed charges against Casey Muggleston, a nuclear engineer formerly employed by Constellation Energy Corporation, for allegedly insider trading in Constellation's securities based on confidential information he obtained during his employment.

According to the SEC's complaint, in 2024, Muggleston was an engineering manager at Constellation. In that role, Muggleston allegedly had access to material nonpublic information relating to Constellation's confidential project to potentially restart its nuclear power plant at Three Mile Island, which Constellation referred to as "Project Tetris." Also according to the complaint, Muggleston breached the duty he owed to Constellation and violated the federal securities laws when he used material nonpublic information about Project Tetris to trade in the company's securities in advance of Constellation's September 20, 2024, announcement that it had entered into a 20-year power purchase agreement with Microsoft Corporation that would pave the way for Constellation to restart the nuclear power plant. The complaint alleges that Muggleston's illegal trading generated profits of approximately $1,400,000.

The SEC's complaint, filed in the United States District Court for the District of Delaware, charges Muggleston with violating the antifraud provisions of Section 10(b) of the Securities Exchange Act of 1934 and Rule 10b-5 thereunder. The complaint seeks an injunction, disgorgement with prejudgment interest, and a civil penalty.

Today, in a parallel criminal action, the United States Attorney's Office for the District of Delaware announced an indictment charging Muggleston with securities fraud.

The case originated from the SEC Market Abuse Unit's Analysis and Detection Center, which uses data analysis tools to detect suspicious trading patterns. The SEC's investigation was conducted by Jeffrey Oraker, Patrick McCluskey, and Danielle R. Voorhees of the Division of Enforcement's Market Abuse Unit, under the supervision of Market Abuse Unit Chief Joseph G. Sansone, with the assistance of trial counsel Sharan Lieberman and supervisory trial counsel Gregory A. Kasper of the SEC's Denver Regional Office. The SEC's litigation will be led by Ms. Lieberman. The SEC appreciates the assistance of the FBI and the United States Attorney's Office for the District of Delaware.