When you look at how Jobs quit Apple and sold his shares, the fact that he's even a billionaire is pretty impressive. He made all the money from NeXTSTEP and Pixar.
He bought Pixar, and founded Next, from the money he made at Apple.
Next was actually acquired on a down valuation--according to Wikipedia, Canon's investment gave them a $600 million valuation in 1989, whereas they were acquired by Apple for $429 million in 1996.
