I assume most of it was in stock options if certain metrics were met
I believe you are correct. And there is “no limit” in the sense that if he drives the stock price from $50 to $500 he makes $450 per share in his options. If he drives the price from $50 to $45 he makes nothing.
“I assume most of it was in stock options if certain metrics were met”
That sounds correct. Most of his money is tied up in SpaceX and Tesla.
He ends up selling shares in order to have the cash to pay the IRS since they don’t accept TSLA shares as payment.