Travis Kalanick — Uber

Travis Kalanick dropped out of UCLA and co-founded Uber, which peaked at a $120 billion valuation and transformed urban transportation globally. He had previously faced a $250 billion lawsuit from his first startup, Scour. Ousted as CEO in 2017 amid controversies, he cashed out $2.7 billion in stock sales. Uber's $120 billion peak is five times larger than Snapchat's IPO valuation (#7 Evan Spiegel), but Kalanick's exit strategy differs sharply from Spiegel's continued control. Still, his creation became a verb—'Uber' is in the dictionary—proving that even a dropout's disruption can reshape an industry.