Slack Technologies, Peloton Interactive, Roku and SmileDirectClub - all of which are unprofitable - were among the stock market's strongest gainers.

With people across the United States told to work from home and avoid large social gatherings to slow the spread of COVID-19, office messaging app seller Slack jumped 18%, while stationary exercise bike company Peloton jumped 19%.

Video streaming service Roku rallied nearly 10%, while SmileDirectClub, which sells orthodontic braces online, surged 24%.

Slack, Peloton and SmileDirectClub were among a wave of unprofitable companies that held highly anticipated stock listings in 2019, and their shares have been volatile since then.

Broadly, the S&P 500 soared 5.1%, rebounding from Monday's 12% loss, which was the worst one-day decline since 1987.

(Reporting by Noel Randewich; Editing by Alistair Bell)

By Noel Randewich