Billionaires Warren Buffett and David Tepper and "Big Short" Investor Michael Burry Just Bought UnitedHealth Group Stock. Should You? Buffett, Tepper, and Burry bought shares of UnitedHealth Group in Q2. The stock is popular with these wealthy investors because of its attractive valuation.

So while we should always try to assess where a stock or sector is headed, the better way to trade is with a simple framework: Any stock can go up and thus be a source of profits. However, owning each stock comes with different levels of risk,

TheStreet. Warren Buffett is arguably the most successful investor of all time. He's amassed an amazingly massive net worth by buying and usually holding stocks for the long haul. Trained under legendary value fund investor Benjamin Graham,