"Mr. Icahn quietly amassed a Twitter stake of well over $500 million in the past few months" Absolute reason why Icahn is a billionaire but I can't even get to

"Mr. Icahn quietly amassed a Twitter stake of well over $500 million in the past few months" Absolute reason why Icahn is a billionaire but I can't even get to a million. I was sure Musk would have to buy the stock at a premium of what it was trading for. I did nothing about it. Yet, Icahn bet $500 mil. Icahn is just different.