UnitedHealth Group, the largest for-profit health insurer, saw its executives, including the chairman, sell approximately $102 million in stock just before the public disclosure of a federal antitrust investigation. These sales, which occurred over four months last year, did not appear to be part of any scheduled trading plans, according to filings. This has raised concerns about the timing of the sales relative to the investigation. Additionally, UnitedHealth is facing challenges from a recent cyberattack on its Change Healthcare unit and ongoing margin pressures on Medicare Advantage players, contributing to its shares being down for the 13th week out of the last 15. The company's performance and the impact of these issues will be closely watched in its upcoming first-quarter earnings report next Tuesday.