The wealth of 643 of US' richest billionaires rose from $2.95 trillion to $3.8 trillion between March 18 and September 15.
This marks a 29% increase over those six months.
That's according to a report by the Institute for Policy Studies and Americans for Tax Fairness said.
Tesla founder Elon Musk's wealth increased by 273% in the period to $92 billion.
Jeff Bezos wealth increased 64.8%, from $113 billion to $182.
Mark Zuckerberg's wealth increased from $54 billion to $100.