Appian's CEO walked away from millions—twice—but the risk paid off: Now he's now worth over $4 billion.

(Credit: Courtesy of Fleishman Hillard)

Appian’s CEO, Matt Calkins, turned down the chance to be a multimillionaire twice—the first time was when he was just 26 years old.

Calkins was the youngest director at MicroStrategy when he left the company to launch Appian in 1999 with his three friends, Michael Beckley, Robert Kramer, and Marc Wilson. It meant walking away from his shares, which had just ballooned thanks to the company’s IPO one year prior.