Not only did the wealth of billionaires grow, but so did their numbers: in March of last year, there were 614 Americans with 10-figure bank accounts; this August, there are 708. Their $1.8 trillion of increased wealth alone over 17 months, which will not be taxed unless they sell their assets.

https://ips-dc.org/u-s-billionaires-62-percent-richer-during-pandemic/