Elon Musk regained his spot as world's richest person, hours after Larry Ellison ended his 300-day streak. Ellison now is the world's second-richest person with a $383-billion net worth, according to Bloomberg, followed by Mark Zuckerberg ($264 billion), Jeff Bezos ($252 billion) and Larry Page ($210 billion). Sergey Brin ($196 billion) and Steve Ballmer ($172 billion) rank sixth and seventh.