The combined wealth of America's billionaires, including Amazon.com Inc founder Jeff Bezos and Tesla Inc chief Elon Musk, increased nearly 10 per cent during the ongoing Covid-19 pandemic, according to a report published by the Institute for Policy Studies (IPS).

The wealth surge of America's richest men happened during a period that also saw as many as 22 million Americans filing for unemployment benefits, Reuters reported.

Even as the broader economy faced a recession, tech and stay-at-home stocks like Zoom have rallied in recent weeks, due to a surge in usage of video conferencing and remote work technology, thus boosting the net worth of billionaire founders with holdings in those companies.

"This is the tale of two pandemics, with very unequal sacrifice," said Chuck Collins, a co-author of the report.

During the period between January 1 to April 10 this year, 34 of the nation's wealthiest billionaires have seen their net worth increase by tens of millions of dollars, the report said.

According to the IPS report, eight of these billionaires including Bezos, Zoom Video Communications Inc founder Eric Yuan and Musk saw a $1-billion jump in their total net worth.

Musk holds an 18.5 per cent stake in Tesla shares, which has soared over 73 per cent since the beginning of the year as traders looked beyond the short-term impact of the coronavirus pandemic.

Bezos owns about 15.1 per cent in Amazon stock, which has gained nearly 31 per cent this year as online orders on its platform have surged due to people staying indoors.

In the last decade, wealth of US billionaires jumped over 80.6 per cent adjusted for inflation, the report added.