Stocks have been selling off around the world all week as investors fret about the spread of the virus.

Stocks are still some ways away from a bear market, which is defined as 20% or more below the most recent peak.

Worries about the coronavirus outbreak mounted this week, with the US Centers for Disease Control and Prevention saying it expects cases in the United States to rise. The virus has now infected more than 82,000 people worldwide, with the vast majority of cases in China.

"What's even more disconcerting is that the news headlines haven't been all that bad yet," said Paul Hickey of Bespoke Investment Group. "Right now, it's the fear of what could happen that's driving the markets rather than what is actually happening."

Still, safe haven investments like gold are up on Thursday and the 10-year US Treasury yield is sitting little changed near its all-time low. Bond yields and prices move in opposition to each other.

In the energy space, US oil prices fell yet again as investors worries about a drop in demand. US oil futures were down 3.5% at $47.05 a barrel.