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.