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.