UnitedHealth Group , whose stock has been in a tailspin amid a tumultuous period for the health-care giant, saw some of its insiders step in and purchase declining shares this week. Kristen Gil, a director at the firm, bought 3,700 shares worth roughly $1 million on Thursday, while Timothy Patrick Flynn and John Noseworthy, also directors, scooped up about 1,500 and 300 shares , respectively, on Wednesday, according to InsiderScore, which tracks regulatory filings from corporate insiders. Shares of UnitedHealth plunged nearly 11% to $274.35 on Thursday following a report in The Wall Street Journal that the Department of Justice is conducting a criminal investigation into possible Medicare fraud. The stock rebounded 6% Friday, cutting its weekly losses to 23%. UNH 5D mountain UnitedHealth The reported investigation also follows the surprise exit of UnitedHealth Group CEO Andrew Witty, who will be replaced by the company’s former longtime chief executive Stephen Hemsley. Shares of UnitedHealth Group are down roughly 43% this year following a string of setbacks for the company. The company has been grappling with a historic cyberattack, higher-than-expected medical costs and a torrent of public blowback after the murder of UnitedHealthcare CEO Brian Thompson.