Since becoming chairman of Berkshire Hathaway (NYSE:BRK-A)(NYSE:BRK-B) in the 1960s, Warren Buffett has trounced the market by an almost two-to-one ratio over those 60 years. By looking for great companies trading at fair prices,

Berkshire Hathaway's sixth-largest holding. Don't get me wrong: Occidental Petroleum appears to be a well-run company. Buffett has expressed several times in the past that he has high confidence in the company's management team.

Investors love to follow the portfolio moves of Warren Buffett, given his incredible track record compounding capital as CEO of Berkshire Hathaway. There are dozens of stocks the conglomerate owns. One such business dominates the credit card space,