Warren Buffett is known for making billions by investing in public companies. Buffett prefers to buy companies that other investors have ignored and are "cheap." However, Buffett also looks to buy shares of a company with a great CEO leading the charge.

One such company and person Buffett's Berkshire Hathaway has put billions behind ($14 billion to be exact) is American Express and CEO Kenneth Chenault. Chenault has been CEO of the company since 2001. Despite being American Express's largest shareholder, Buffett is extremely trusting of Chenault's judgement. In 2010, Chenault said "Warren has given me his proxy. And he is, I think, a very satisfied shareholder and has been very supportive of the Company and management." In the following video, Motley Fool analyst David Hanson explains why Buffett is able to have such confidence in the American Express management team and why Buffett does not try to control the company's operations from the board room. David also discusses why American Express's business may still have room to run even after years of impressive growth.

Warren Buffett doesn't worry about AmEx, but this scares him
At the recent Berkshire Hathaway annual meeting, Warren Buffett admitted this emerging technology is threatening his biggest cash-cow. While Buffett shakes in his billionaire-boots, only a few investors are embracing this new market which experts say will be worth over $2 trillion. Find out how you can cash in on this technology before the crowd catches on, by jumping onto one company that could get you the biggest piece of the action. Click here to access a FREE investor alert on the company we're calling the "brains behind" the technology.

David Hanson owns shares of American Express and Berkshire Hathaway. The Motley Fool recommends American Express and Berkshire Hathaway. The Motley Fool owns shares of Berkshire Hathaway. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.