When did U.S. stock-market circuit breakers first trigger during the COVID-19 crash?

U.S. stock-market circuit breakers first triggered during the COVID-19 crash on March 9, 2020.

Trading on the New York Stock Exchange halted for 15 minutes after the S&P 500 fell 7% shortly after the opening bell. The trigger was activated as investors reacted to the coronavirus outbreak and a collapse in oil prices caused by a dispute between major producers.

The halt was designed to slow panic selling and give market participants time to process information. It did not end the broader decline: similar Level 1 halts occurred on March 12, March 16, and March 18.

These modern circuit breakers replaced older arrangements after the 1987 crash. The March 9 halt was the first such U.S. marketwide trading stop since 1997.