US stocks have suffered record losses and entered correction territory as fears around the spread of coronavirus mount.
The Dow closed 1191 points down overnight, or 4.4 per cent, the worst one-day drop in history.
The S&P 500 also closed down 4.4 per cent and finished the day below the 3000 point mark for the first time since October.
The Nasdaq Composite ended the day 4.6 per cent down to slump to its biggest one-day loss since 2011.
All three indexes are on track for their worst week since 2008, in the midst of the global financial crisis.
The losses came after the US Centres for Disease Control and Prevention confirmed an infection in California in a person who reportedly did not have relevant travel history or exposure to another known patient.
"In the recent week, markets have come to realise that the outbreak is much worse and are now realistically pricing in the impact of the virus on the economy," Philip Marey, senior US strategist at Rabobank, said.
"In that sense it's a bit of a catching up from the relative optimism that was there in the beginning when markets thought (the virus) will be contained to China with some minor outbreak outside."
Oil prices tumbled for a fifth day overnight to their lowest in more than a year over fears coronavirus could slow the global economy and erode demand for crude.
Brent crude dropped $US1.25, or 2.3 per cent, to settle at US$52.18 a barrel, off the session low of US$50.97 a barrel, the lowest since December 2018.
West Texas Intermediate (WTI) futures sank US$1.64, or 3.4 per cent, to US$47.09, after hitting their lowest since January 2019.
Trading in oil markets suggested investors expect a prolonged period of oversupply, with demand hurt as the virus has spread to large economies including South Korea, Japan and Italy.
Australian shares are expected to fall sharply when the market opens this morning.
Source: 9News https://www.9news.com.au/world/coronavirus-updates-dow-jones-worst-fall-in-history/517affc4-b86f-4099-a08a-c79ab30e8eaf