Evan Spiegel — Billionaire at 25 (Snapchat)

Spiegel dropped out of Stanford three credits short of graduating, rejected Mark Zuckerberg's $3 billion cash offer for Snapchat in 2013, and took the company public in 2017 at a $24 billion valuation. He became a billionaire at 25 and the youngest billionaire CEO on a major exchange. He married Miranda Kerr, lives in a $120 million Bel Air estate, and Snap now has 800+ million monthly active users. The kid who said no to $3 billion from the guy who said no to $1 billion — it's turtles all the way down in Silicon Valley rejection economics.