D.R. Horton, Lennar, and other home builder stocks were rising Friday after Warren Buffett’s Berkshire Hathaway purchased shares.

The biggest immediate changes will be that different people will be in control of the company's stock portfolio, and Abel will have power over Berkshire's $344 billion cash hoard. However, portfolio managers Ted Weschler and Todd Combs have been managing more of Berkshire's investments as the years have progressed.

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

Warren Buffett's Berkshire Hathaway has acquired 5 million shares in UnitedHealth Group , a regulatory filing showed on Thursday, sending the health insurer's stock up 7% in extended trading.

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,