The S&P 500 recorded its largest one-day percentage loss of the 2020 COVID-19 market crash on March 16, 2020.
The index fell 11.98% that day as investors reacted to the accelerating global pandemic, travel restrictions, business shutdowns, and extraordinary uncertainty about economic activity. The decline followed a 7.60% drop on March 9 and an 8.38% fall on March 12.
The Federal Reserve announced major emergency measures around this period, but monetary support did not immediately calm markets. U.S. exchanges also used temporary circuit breakers to pause trading after severe declines.
March 23 marked the S&P 500’s closing low for the bear market, not its largest daily percentage loss. That distinction explains why March 16, March 23, and the earlier March 9 sell-off are sometimes confused in summaries of the crash.