The S&P 500 was the principal U.S. stock index that fell about 34% during the COVID-19 crash in early 2020. From its February 19, 2020 record close to its March 23 low, the index declined approximately 34%.
The sell-off reflected the rapid spread of COVID-19, business closures, travel restrictions, and uncertainty about the economic effects of the pandemic. An oil-price dispute between Saudi Arabia and Russia added pressure to markets in March, while investors rushed toward cash and other perceived safe assets.
The 2020 crash was unusually fast. The S&P 500 entered a bear market in March, but extraordinary monetary and fiscal support, along with expectations for vaccines and economic reopening, helped produce a powerful rebound. The index returned to a record closing high by August 2020, although the effects on employment, public health, and individual industries remained uneven.