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…
