In the 2020 stock-market crash, what global health emergency prompted the rapid worldwide sell-off?

The COVID-19 pandemic prompted the rapid worldwide sell-off known as the 2020 stock-market crash.

As the disease spread internationally in early 2020, governments introduced travel restrictions, lockdowns, and other measures that disrupted factories, airlines, restaurants, offices, and supply chains. Investors rapidly revised expectations for corporate earnings and economic growth. Major indexes around the world entered bear-market territory in March.

The crash was intensified by an oil-price dispute between Saudi Arabia and Russia, which briefly caused an additional shock to energy markets. Central banks cut interest rates or expanded asset-purchase programs, while governments introduced large fiscal support packages. The U.S. Federal Reserve also established emergency lending facilities. The market decline was unusually fast, but the recovery was also rapid compared with many earlier crashes. COVID-19 is caused by the SARS-CoV-2 virus; SARS was a different coronavirus disease identified in 2003. The term “crash” describes the financial-market event, not the pandemic itself.