Microsoft logo is seen on a smartphone placed on displayed Activision Blizzard logo in this illustration taken January 18, 2022. REUTERS/Dado Ruvic/IllustrationHedge funds, which make profits by speculating on precarious takeovers, got a treat this week when Microsoft Corp (MSFT.O) agreed to buy "call of duty" maker Activision Blizzard (ATVI.O) for US$68.7 billion dollars in cash.