While portfolio diversification can be a way for investors to reduce their exposure to risk, it's clear that Berkshire Hathaway CEO Warren Buffett isn't a big fan of the strategy. In fact, the Oracle of Omaha has said that "Diversification is protection against ignorance. It makes little sense if you know what you are doing."

Right now, roughly 74% of Berkshire's $366 billion stock portfolio is spread across its five largest holdings. Even more striking, its top-two largest positions account for 54.5% of the investment conglomerate's total stock holdings.

Read on to see why Buffet has bet so heavily on these two industry-leading companies. 

Continue reading

Source Fool.com