"Just one set of numbers, from the University of California, Berkeley, economist Gabriel Zucman:

The 400 richest Americans — the top .00025 percent of the population — now own more of the country’s riches than the 150 million adults in the bottom 60 percent of wealth distribution. The 400’s share has tripled since the 1980s."

https://www.nytimes.com/2019/11/11/opinion/billionaires-warren-wealth-tax.html