Forbes' annual US 400 rich list came out yesterday, with a recorded combined wealth of $2.34 trillion (£1.5 trillion), and the highest average net worth to date of $1.7bn - the bar to be included.
One thing it shows is America's billionaires are getting young: this year there were 17 under-40s on the list, unsurprisingly most of them were techies. So, without further ado (and ranked in age order), here are the 10 youngest billionaires in America:
1. Evan Spiegel
The youngest billionaire is Snapchat’s Spiegel, who at age 25 has a net worth of $2.1bn.
2. Bobby Murphy
At 27 years old, Murphy, the co-founder of Snapchat with Spiegel, is worth $1.8bn.
3. Julio Mario Santo Domingo, III
Santo Domingo inherited his grandfather's 15 per cent stake in the world's second largest brewer, SAB Miller (which is expecting a takeover offer from its rival AB INBev). AT 30 years old, he's worth $23bn.
4. Mark Zuckerberg
At 31, Facebook founder Zuckerberg made it into the top 10 for the first time ever, ranking seventh, with a net-worth of $40.3bn.
5. Dustin Moskovitz
Moskovitz, 31, is one of Facebook's co-founders. He's since left the company and founded his own software firm Asana. Worth $8.4bn.
6. Elizabeth Holmes
Holmes, also 31, is the youngest woman on the list. Worth $4.5bn, she's developed a new blood-testing technology, and founded her company Theranos to help detect a range of diseases.
7. Scott Duncan
Duncan, 32, inherited his father', Dan Duncan's Texas oil pipeline fortune and is now worth $5bn. He was left Enterprise Products Partners in 2010 alongside his three siblings, but is not involved in the business.
8. Nathan Blecharczyk
Aged 32, Blecharczyk is the youngest of the co-founders of Airbnb, which is now valued at more than $25bn, and chief technology officer for the company. He is worth $3.3bn.
9. Brian Chesky
The 34-year-old former body-builder Chesky is the chief executive and co-founder of Airbnb, and is worth $3.3bn. He recently published the seven rejection letters he received when first looking for Airbnb funding.
10. Joe Gebbia
Gebbia, 34, also made his $3.3bn fortune from Airbnb. He is another co-founder and the chief product officer.
Lastly, special mention to Microsoft’s Bill Gates, 59, who remains in the top spot for the 22nd year running, worth $76 billion, a drop of $5bn.
See the full Forbes 400 list here.