Financial markets have been reacting to news of the virus' spread because of the potential impact of the outbreak on the global economy.
U.S. and German bond yields resumed their fall while gold prices rose.
Health officials in New York's Nassau County said on Wednesday that they were monitoring 83 people who visited China and may have come in contact with the coronavirus, but Governor Andrew Cuomo said the state has had no confirmed cases so far.
"We need to (get) more information before markets have a further correction or get comfortable things won't escalate further," said Jason Draho, head of Americas asset allocation at UBS Global Wealth Management in New York.
"Markets will be very jumpy until there's increasing confidence the virus is abating and that it won't be a global pandemic," he said.
On Wall Street, the Dow Jones Industrial Average fell 123.77 points, or 0.46%, to 26,957.59, the S&P 500 lost 11.82 points, or 0.38%, to 3,116.39 and the Nasdaq Composite added 15.16 points, or 0.17%, to 8,980.78.
The S&P rose more than 1.7% at its session high.
Emerging market stocks lost 1.25%. Brazil's Bovespa index tumbled 7%, catching up with the selloff after a long carnival holiday. Brazil confirmed the first case of coronavirus in Latin America on Wednesday.
Argentina's S&P Merval fell 5.65%.
Nikkei futures rose 0.77%.
Oil prices fell after hundreds of new coronavirus cases were reported in Europe and the Middle East. The New York state report added to concerns that energy demand would decline.
"It's still all about the virus here," said Bob Yawger, director of energy futures at Mizuho in New York. "It's going to be hard for risk assets to gather momentum."
U.S. crude fell 2.38% to $48.71 per barrel and Brent was last at $53.41, down 2.8% on the day.
The benchmark yield on 10-year U.S. notes touched a fresh record low of 1.301% and last fell 4/32 in price to yield 1.342%, from 1.33% late on Tuesday. The 30-year bond matched its Tuesday record low and last fell 21/32 in price to yield 1.8301%, from 1.803%.
The dollar ticked up from a two-week low hit the previous session, though moves in major currencies were muted for the most part as investors remained cautious. Sterling gave up Tuesday's sharp gains.
The dollar index rose 0.126%, with the euro up 0.02% to $1.0881.
The Japanese yen weakened 0.23% versus the greenback at 110.47 per dollar, while sterling was last trading at $1.2904, down 0.77% on the day.
Spot gold added 0.3% to $1,639.76 an ounce. Copper lost 0.43% to $5,660.50 a tonne.
By Rodrigo Campos