The S&P 500 reached its pandemic-era closing low on March 23, 2020, during the 2020 stock-market crash.
The index had entered a sharp decline as investors reacted to the spread of COVID-19, restrictions on economic activity, uncertainty about corporate earnings, and a collapse in oil-market negotiations. From its February 19 record close to the March 23 low, the S&P 500 fell about 33.9%.
The speed of the decline was remarkable. The S&P 500 entered a bear market in March after taking only 16 trading days to fall at least 20% from its peak. Governments and central banks then introduced extensive fiscal, monetary, and public-health responses.
The market rebounded quickly compared with many earlier crashes, although the broader economic effects were severe. The March 23 low should not be confused with the first emergency trading halt, which occurred earlier, on March 9.