He won't sell it all at once. Bill Gates used to own lots of Microsoft stock. Over time he sold it off and diversified, to the point that it's now only about 25

He won't sell it all at once. Bill Gates used to own lots of Microsoft stock. Over time he sold it off and diversified, to the point that it's now only about 25% of his net worth. The key thing is that over time, Microsoft transitioned to a point where Bill Gates wasn't running things day-to-day and investors became comfortable with him not having any control. At that point, him selling shares was no big deal. At the other end of the extreme would be someone like Elon Musk, where Tesla's stock price is almost entirely dependent on him being at the helm. If he were to walk away now, the shares would tank in value. Jeff Bezos is somewhere in between. Clearly, Amazon would run okay without him, but he still has some involvement. He certainly can't sell all of his shares, but if he sells over time and makes it clear (and credible) that he is selling in order to use his money elsewhere (rather than trying to time the market because he thinks the stock is overpriced), the share prices of Amazon should hold up just fine.