Warren Buffett's Berkshire announces surprise stake in embattled UnitedHealth

Core Insights - Berkshire Hathaway, led by Warren Buffett, has acquired 5 million shares in UnitedHealth Group, resulting in a 7% increase in the health insurer's stock during extended trading [1][3][5] - This investment marks a return for Buffett, who previously held approximately 1.18 million shares from 2006 to 2009 before selling his entire stake in 2010 [1][3] Company Challenges - UnitedHealth is currently facing significant challenges, including soaring medical costs, ongoing federal investigations, the aftermath of a top executive's murder, and a cyberattack that occurred last year [2][5] - The company has issued a new profit forecast that is considerably lower, anticipating billions in additional costs in the upcoming quarters [2] Stock Performance - Despite the recent investment news, UnitedHealth's shares have declined by 46% so far this year [5]