Which event caused the 2020 stock-market crash to include four U.S. trading halts in March?

The COVID-19 pandemic caused the 2020 stock-market crash, which included four U.S. trading halts in March.

As the new coronavirus spread internationally, governments imposed travel restrictions, lockdowns, and other measures that sharply reduced economic activity. Investors also feared a prolonged recession and a collapse in corporate earnings. U.S. markets fell so rapidly that circuit breakers halted trading on 9, 12, 16, and 18 March 2020.

The crash was intensified by the March 2020 Russia–Saudi Arabia oil-price dispute, which briefly sent oil prices plunging after an agreement among major producers broke down. These shocks arrived together, but the pandemic was the defining global event behind the crash.

The market decline was unusually fast. After the initial fall, enormous fiscal and monetary support helped drive a powerful rebound. The 2020 crash should not be confused with the later inflation-driven market declines that occurred after the emergency pandemic period.