Yang, 36; Filo, 38
Co-founders of Yahoo Inc.
Yang, 4.8 percent stake worth $2.1 billion; Filo, 6.4 percent stake worth $2.8 billion
How they started
The partners first began compiling a list of their favorite Web sites while they were electrical engineering graduate students at Stanford University. The directory first appeared a Web server named Akebano in honor of a Japanese sumo wrestler that Yang admired.
"In some ways, it feels like we have been doing this for as long as we can remember, but in other ways it feels like we are still at the beginning. Ten years from now, things are going to look vastly different." — David Filo.