> No one has a billion in cash that I've ever heard of.
What's the biggest amount anyone has in treasury bonds or gold? You could easily liquidate a ton of that.
> but what happens when he only gets $70mil for it because the stock price tanked? Should he sell more, until he comes up with that original 20% of his "billion"?
If the stock tanks that much while he's selling, then the company is only worth about $300 million now, and the money he owes drops to $60 million.
Though I don't see why it would tank that much.
If owning stock (passively) all the sudden got taxed to any notable degree, you’ve just dramatically changed the value calculus for most of the world economy at this point. It would be shocking if the price didn’t crash.