17. David Cheriton
Net Worth: $4.19 billion
Change from 2017 Ranking: ▲26.2%
Major company holdings: Arista Networks, Google
The Canadian-born Stanford computer science prof has quietly invested in nearly two dozen tech startups over the years—including Google, which is the origin of his fortune—but he appears to be taking a more active role in one of his portfolio’s firms. Cheriton is a founder and chief scientist at Apstra, which develops software for managing networking devices from multiple vendors.