In the three months ended Sept. 30, Berkshire bought 1.3 million shares of the pizza chain worth about $550 million, according to a filing with the Securities and Exchange Commission released Thursday.
Dominos stock popped 6% in pre-market trading Friday.
The sprawling Omaha, Nebraska-based conglomerate grew its cash pile to a whopping $325.2 billion last quarter, selling a total of $36.1 billion of stock, including considerable chunks of some of its long-held investments.