Silicon Valley's unicorn elite create wealth like never before

With money flooding into Silicon Valley and the likes of Uber Technologies and Airbnb becoming household names, America’s start-ups are creating wealth like never before. And the rise of unicorns—the once-rare class of private companies valued at more than $1 billion—means their founders have huge stakes worth astonishing amounts. If only on paper.
 

Among closely held US venture-backed companies, the 10 most valuable stakes owned by founders are worth $60 billion, based on ownership data compiled by EquityZen, which helps investors trade start-up shares. That would rank more than a dozen of the founders as paper billionaires, according to calculations