Shares of some of UnitedHealth’s peers got a bump in the wake of Berkshire’s investment in the healthcare giant, and they all look cheaper based on price relative to expected earnings.

Berkshire Hathaway has built up sizable investments in a handful of companies, according to a filing released on Thursday.

Shares of UnitedHealth Group surged nearly 14% on Friday after billionaire Warren Buffett's Berkshire Hathaway bought 5 million shares of the company, providing a shot in the arm for investors who think the health conglomerate will turn around under its new CEO.