Number one on this list of youngest by a wide margin is Mark Zuckerberg, whose Facebook shares and net worth soared to new heights. He is now worth $50 billion, up $2.9 billion from a year ago. That’s $40 billion-plus more than the next person, his Facebook cofounder Dustin Moskovitz.
In their place comes a star-studded class of celebrities and athletes. Newcomers to the 2016 ranks include NBA stars Kobe Bryant and LeBron James and boxer Floyd Mayweather as well as pop star Beyonce and actress-turned-consumer products marketer Jessica Alba. The latter are the only two women among the top 40 under 40. All five of these superstars have net worths that range from $275 million to $350 million, meaning they made the cut this year in part thanks to the lower net worth cutoff.