March 9, 2020, was the day the New York Stock Exchange triggered its first U.S. market-wide circuit breaker since 1997. The S&P 500 fell 7% shortly after opening, activating a Level 1 trading halt.
The decline reflected escalating fears about the COVID-19 pandemic and a collapse in oil prices after Saudi Arabia and Russia disagreed over production cuts. The sudden combination of health, economic, and energy shocks caused investors to sell risky assets worldwide.
The 2020 crash produced additional U.S. circuit-breaker halts on March 12, March 16, and March 18. The Federal Reserve and governments later introduced major support measures, while many economies imposed restrictions to slow the virus.
March 9 is sometimes confused with March 12 or March 16 because all were exceptionally severe sessions. March 12 produced a larger percentage S&P 500 loss, but March 9 was the first U.S. market-wide halt in more than two decades.