March 9, 2020, was the first 2020 U.S. stock-market crash date to trigger a market-wide circuit breaker.
The S&P 500 fell 7% shortly after trading began on March 9, 2020, activating a Level 1 circuit breaker and halting trading for 15 minutes. The sell-off reflected rapidly worsening fears about the COVID-19 pandemic and an oil-price shock caused by a dispute between major producers. It was the first such U.S. halt since the circuit-breaker system was revised after the 2010 Flash Crash.
Trading halts also occurred on March 12, March 16, and March 18 as the pandemic’s economic consequences became clearer. The system is based on percentage declines in the S&P 500, not on a fixed number of index points, so its numerical thresholds change as the index level changes.
A circuit breaker pauses trading; it does not permanently stop the market or guarantee that prices will recover. The 2020 episode is therefore distinct from the broader COVID-19 stock-market crash, which unfolded over several weeks.