The S&P 500 entered a bear market in 16 trading days during the 2020 coronavirus stock-market crash.
The index reached a record closing high on February 19, 2020, before rapidly falling as investors assessed the economic consequences of COVID-19. By March 12, it had declined at least 20% from that peak, the conventional threshold for a bear market.
The speed of the fall made the episode exceptional. Governments introduced restrictions to slow the spread of the virus, while businesses faced closures, supply disruptions, and sudden losses in revenue. Financial markets also experienced several days of extreme volatility and triggered temporary trading halts.
The 20% threshold describes the size of the decline, not its duration. The market continued falling after entering bear-market territory and reached its pandemic-era closing low on March 23. It then rebounded sharply as fiscal support, monetary easing, and expectations of economic reopening improved investor sentiment.