Fact checked by Vikki VelasquezWarren Buffett’s Berkshire Hathaway Inc. (BRK.A, BRK.B) is the single largest private holder of U.S. Treasury bills, surpassing even the Federal Reserve’s own holdings.

Berkshire Hathaway has resumed acquiring shares of Warren Buffett's favorite media stock. Other insider buyers are focused on three biotech stocks.

Little did they know that days after they had pushed Berkshire’s class A shares to a record, Buffett would announce he planned to step down as chief executive. Since then, the conglomerate’s high-vote A shares have fallen 14 per cent,