At first, the index only tracked the 20 richest people in the world, and then expanded to 100, 200, 400 and later 500 in October 2016.

At its launch in 2012, Mexican telecommunications tycoon Carlos Slim was in the top spot, with an estimated $65.8 billion net worth. Beginning in May 2013, Microsoft co-founder Bill Gates was the world's top billionaire. Amazon CEO Jeff Bezos