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,

Shares of some of UnitedHealth’s peers got a bump in the wake of Berkshire’s investment in the healthcare giant, and they all look cheaper based on price relative to expected earnings.

America’s largest health insurance company had fallen nearly 63% from a 52-week high of $630.73 before Friday’s surge

UnitedHealth shares surged Friday after Warren Buffett’s Berkshire Hathaway revealed a stake in the embattled healthcare giant. Monitor these major chart levels.

Berkshire Hathaway's $1.6 billion stake in UnitedHealth Group is helping to lift the Dow Jones Industrial Average to a new record as investors pile into healthcare sector funds.

Shares of UnitedHealth Group surged nearly 14% on Friday after billionaire Warren Buffett's Berkshire Hathaway bought 5 million shares of the company, providing a shot in the arm for investors who think the health conglomerate will turn around under its new CEO.

I would like to receive updates and special offers from Dow Jones and affiliates. I can unsubscribe at any time.

Buffett owned UnitedHealth shares before selling his stake in 2010, though his Berkshire Hathaway recently acquired shares.

Leveraged positions in the stock market jumped 18% in one month and topped $1 trillion for the first time. Increasing use of debt to invest can tell us a lot about investors' attitudes. And while this has always been the case,