In the mid-90s, “the total wealth or real net worth of the world’s billionaires” was about $1 trillion. By 2015, that number had surged to $5 trillion. Key factors: The rise of China and the Internet business. From CityLab: Understanding the rise of the global super-rich.

+ There are still plenty of dot com unicorns. Business Insider has a list of some of the youngest ones.