At Berkshire Hathaway’s annual meeting earlier this year, Warren Buffett showed just how much of a fan he is of Apple’s CEO, Tim Cook. “Tim Cook has made Berkshire a lot more than I have made Berkshire,” Buffett said to laughter in the room. It was funny, but considering that Apple is Berkshire’s largest holding, I don’t think it was hyperbole.

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

Investing in index funds or exchange-traded funds is often simpler and more straightforward than buying individual stocks. Each fund may contain dozens or even hundreds of stocks,

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

Berkshire purchases often boost stocks. Shares of the steel maker traded as high as $151.32 on Friday, but closed at $145.48, up 0.8%. The S&P 500 fell 0.3%. The Dow Jones Industrial Average rose 0.1%.

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,

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

Berkshire Hathaway revealed three new investments Thursday in steelmaker Nucor and two of the nation's biggest homebuilders — Lennar and DR Horton — but none of the investments are big enough to ensure that legendary investor Warren Buffett handled them.