He made nearly a billion hedging on dozens of events, and thousands upon thousands of trades. I bet you haven't read a single page of his actual published papers, just his poplit stuff.
It's built on OCaml because of functionality and langsec - contract code and implementations written in procedural/objective languages are immensely unstable which is also why ETH smart contracts keep getting hacked.
Consider that not even the fucking inventor of Ethereum himself can write a contract without massive exploits.