I started with: “How many unicorns were founded by people in their 30s? The biggest example I can think of is Larry Ellison” but it was easy to come up with so many more examples: Benioff, Reed Hastings, Bezos, Reid Hoffman.
Of course there are many examples of billionaires who founded companies in their 20s as well (Box, Dropbox, Airbnb, Stripe)… intuitively, I think there are a lot of factors (familial obligations being near the top, ahead of American “genius” bias) that tilt the scales towards younger founders.
I've heard that if you look at _successful_ startups, not necessarily unicorns but ones that grow into solid companies on a firm financial footing, the average age of the founders was in the middle 40s.
I would wager a guess that if you actually based success on revenue/employee, operating margins, and overall "healthy" business criteria, the number skews probably even higher.
As we were clearly made aware of in the last year, many unicorns of the last 5-10 years were little more than good marketing and a Tier 1 VC footing the bill.
Of course there are many examples of billionaires who founded companies in their 20s as well (Box, Dropbox, Airbnb, Stripe)… intuitively, I think there are a lot of factors (familial obligations being near the top, ahead of American “genius” bias) that tilt the scales towards younger founders.