Note, though, that Buffett has two lieutenants, Ted Weschler and Todd Combs, who also make many investment decisions. So any given purchase or sale may have been directed by any of the three. In its last reported quarter, which ended on Sept. 30, here were Berkshire's top holdings:

Warren Buffett has recently engaged in a significant sell-off of stocks while amassing a substantial cash reserve. Learn how investor wariness can impact hiring.

Warren Buffett is stockpiling cash. His Berkshire Hathaway holding company continued to sell more than it bought in the third quarter when it offloaded a quarter of its stake in Apple, regulatory filings revealed Thursday.