The first date in 2020 when New York Stock Exchange circuit breakers halted trading during the COVID-19 crash was 9 March 2020.
U.S. stocks opened sharply lower on 9 March after the rapid spread of COVID-19 combined with a collapse in oil prices. The S&P 500 fell enough to trigger its Level 1 circuit breaker, which pauses trading for 15 minutes after a decline of at least 7% from the previous close.
The halt was the first of four such U.S. market-wide halts during the 2020 crash. Additional interruptions occurred on 12 March, 16 March, and 18 March as investors reacted to worsening pandemic news and economic shutdowns.
The 2020 crash was unusually fast. The S&P 500 reached its pandemic-era closing low on 23 March 2020, then began a powerful recovery supported by fiscal measures, central-bank intervention, and expectations of vaccines and reopening.