A plunge in Wall Street's three key stock averages prompted a 15-minute trading halt yesterday.
The S&P 500 closed 7.6% lower, the Nasdaq was down 7.29% and the Dow Jones Industrial Average lost 7.79%.
Reuters noted it was Wall Street's biggest one-day loss since the 2008 financial crisis, with the S&P 500's close about 19% below its all-time high set on February 19, and yesterday's drop occurring on the day marking the current bull market's 11th year.
Around the world, London's FTSE 100 lost 7.69%, Australia's S&P/ASX200 fell 7.9% yesterday and in Canada, the S&P/TSX Composite Index plunged 10.3%.
Futures were indicating another day of losses.
"Markets were already anxious about the impact of COVID-19 on the global economy, and have reacted negatively at the prospect of a war for market share between the world's major oil producers in an environment where oil demand shows severe signs of weakness," the Economist Intelligence Unit lead analyst energy Peter Kiernan said.
The gold price has also softened, to US$1,669 an ounce on the spot market.
Among the mining majors, Glencore (LSE: GLEN) shed more than 12% yesterday, Barrick Gold (TSX: ABX) lost 4.4% and Freeport-McMoRan fell 12.7%.
