3. Mark Zuckerberg, Facebook, $69.9 billion
Facebook CEO Mark Zuckerberg speaks about "News Tab" at the Paley Center, Friday, Oct. 25, 2019 in New York. The new feature in the Facebook mobile app will display headlines — and nothing else — from the Wall Street Journal, the Washington Post, BuzzFeed News, Business Insider, NBC, USA Today and the Los Angeles Times, among others.(AP Photo/Mark Lennihan)