Reminds me of a (not great) book I read about a secretive trading firm that build an AI to maximize profits except it gained enough awareness to take things int

Reminds me of a (not great) book I read about a secretive trading firm that build an AI to maximize profits except it gained enough awareness to take things into its own hands, by hiring mercenaries and assassins to drive the market and ever increase its portfolio. After, of course, killing everyone at the firm.