Which event caused the 2020 global stock-market crash when COVID-19 spread worldwide?

The COVID-19 pandemic caused the 2020 global stock-market crash as the disease spread worldwide.

The sell-off accelerated in February and March 2020 as governments introduced travel restrictions, lockdowns, and other measures to slow transmission. Investors feared a sharp interruption to business activity, employment, trade, and consumer spending. Energy markets also suffered as expectations for fuel demand collapsed.

The S&P 500 entered a bear market on March 12, 2020, and reached its low on March 23. Major central banks and governments responded with interest-rate cuts, asset purchases, emergency lending, and large fiscal programs. Markets then recovered rapidly, although economic damage and uncertainty continued.

The crash is often called the coronavirus crash or the COVID-19 crash. It differs from the 2010 Flash Crash because it was a broad, sustained repricing over several weeks rather than a minutes-long algorithmic dislocation.