SEC filings show billionaire Warren Buffet’s Berkshire Hathaway investment company has bought $1.07 billion worth of Apple stock as of March 31. The news sent Apple’s stock up more than two dollars per share as of Monday morning, seeming to quiet concerns raised by billionaire investor Carl Icahn’s public dumping of his position in Apple last month. Icahn expressed doubts over Apple’s ability to expand its business into China after the country suddenly halted iTunes Movies and iBooks sales. Icahn had expressed a willingness to to buy back into Apple if the situation in China “was basically steadied.” For its part, Apple shows no signs of slowing its expansion in China, last week announcing a $1 billion investment in Chinese ride-hailing service Didi Chuxing.