Keep in mind that his income is probably not what he lives on. He probably gets loans with the stock. That 500 mill bump probably got him a large loan.

He probably doesn't need more stock borrow against if he has billions of dollars of equity already and a seven digit annual compensation. His stock transfers and sales are public information so you can look that up if you want. A cursory search shows that he sold at least 50 million dollars worth, which should cover some daily expenses