Low interest rates as well as high cash levels. The whole point of markets is to raise cash then pay it off. Not to tank the price and rip off investors. Also

Low interest rates as well as high cash levels. The whole point of markets is to raise cash then pay it off. Not to tank the price and rip off investors. Also, buying back shares keeps stock prices high, makes each outstanding share worth more (less dilution), so more value for the remaining owners.