The traders at my firm knew him for Alameda. Straight quote: "It's crazy to think a couple of years ago we were just chatting with this dude and he seemed like a normal guy and now he's got billions of dollars. Guy timed it hella right."

AFAIK he seemed a decent fellow (but that's 2nd hand) and about par for the trading space. But that was then. Obviously now in hindsight, he seems to have been different in some intangible ways.