An open question is what happened to the 15,625 shares that he received when he exercised his options in 1996?

If he had held on to those, they would be worth even more than the additional 9,375 shares he was entitled to -- about $1.7 billion using the same numbers in the post.

My guess is that he probably sold them when they were worth a lot less then they are now, and would have done the same with the additional shares too.