[sebzim4500]

He'd certainly get much less than $100B, but he'd still get a lot. The share price of amazon is mainly driven by the revenue/expenses/growth opportunities of the company, which will not have changed just because bezos is cashing out, so it won't collapse completely.

That's not unique the the ultra rich, though. Many people have most of their wealth locked in a house. If they needed to sell at very short notice they would have to sell at a significant discount.