Warren Buffett's Berkshire Hathaway has created tremendous wealth for shareholders, and a key component of those returns stems from buying shares of strong businesses at attractive prices relative to their estimated worth. The company held an equity portfolio worth $271 billion in the third quarter, and one of its new buys was Domino's Pizza (DPZ -0.19%).It's a small position for Berkshire, making up less than 1% of the company's stock portfolio. Given the small stake, it was probably chosen by one of Buffe ...