U.S. markets triggered their Level 1 circuit breaker four times during the 2020 COVID-19 market crash.
The S&P 500 fell at least 7% from its previous close on 9, 12, 16, and 18 March 2020. Each decline activated the Level 1 circuit breaker, which pauses trading for 15 minutes during the regular session when the threshold is reached before 3:25 p.m. Eastern Time.
The sell-off reflected rapidly changing expectations about the coronavirus pandemic, economic shutdowns, corporate earnings, and energy markets. On 9 March, an oil-price dispute between Saudi Arabia and Russia added further pressure. The Federal Reserve and other central banks later introduced major support measures.
The circuit breakers did not stop the crash permanently; they briefly slowed trading and gave market participants time to absorb information. The 2020 event is also called the coronavirus crash, but it was distinct from the 2008 financial crisis and the 1987 crash.