Adani Group Chairman Gautam Adani, with $135 billion in wealth, has slipped to the fourth spot on Forbes' list of the world's richest billionaires. At the time of writing, Elon Musk topped the list with $263.2 billion in wealth. He was followed by Bernard Arnault & family with $142.1 billion in wealth and Jeff Bezos with $141.4 billion in wealth.