Warren Buffett (Trades, Portfolio)'s conglomerate Berkshire Hathaway (BRK.A)(BRK.B) bought approximately $1 billion worth of shares in leading gaming firm Activision Blizzard ( ATVI , Financial) during the fourth quarter of 2021. The stock traded for an average share price of $68 during the quarter, which made the market cap at the time of purchase just $50.4 billion.