Interestingly, there are just seven industry or sectors with at least one millennial billionaire. : Millennials are apparently more conscious about building wealth than their previous generations. That too, they want to make money fast, thanks to the illustrative list of their peers who have made millions, and even billions, at a very young age in industries ranging from technology, finance, fashion and healthcare to property. Interestingly, there are just seven industry or sectors with at least one millennial billionaire, according to research by PhysicalGold.com.