And tomorrow there'll be three.
There are more than 1,600 billionaires in the world, but only four of them are in their twenties. And probably the only one of these you've heard of turns 30 today.
That's right: Mark Zuckerberg will leave his Facebook co-founder, Dustin Moskovitz, as the richest man in his age decade. That is, for a grand total of 8 days, until Moskovitz hits the milestone.
In honor of occasion, we're taking a look at the quickly shrinking billionaires under 30 list.
Zuckerberg doesn't have much to 'unlike,' though. He's staying on a list that's only slightly less exclusive, Forbes' Youngest Billionaires list, which has now dwindled down to 29 under 40.
On top of that, this year he grew his wealth faster than anyone on the planet. Who else can't wait to see what Zuckerberg does with his next decade?