UnitedHealth Group (UNH) stock is still down 40% YTD but has surged more than +20% this month following reports that Warren Buffett, and other billionaire hedge fund managers have taken a stake in the company.

This investment signifies Buffett's re-entry into UNH after liquidating his entire position back in 2010, indicating that he perceives significant value at

What Happened? Shares of health insurance company UnitedHealth (NYSE:UNH) fell 3% in the afternoon session after investors took some profits off the table as markets awaited signals on future monetary policy from the Federal Reserve's Jackson Hole symposium later in the week.