This week has seen global coronavirus cases rise by over 500,000 for the first time, with France and Germany preparing fresh lockdowns.
Underwhelming outlooks and results from some of Wall Street's largest companies further soured the mood and dragged U.S. stocks lower. The S&P 500 was on track for its largest weekly drop since March and its second-consecutive monthly decline.
"There is a big sell-off in those big tech names because they didn't live up to the hype and people are really worried about next week's election," said Kim Forrest, chief investment officer at Bokeh Capital Partners in Pittsburgh.
Ahead of the last campaign weekend, Republican President Donald Trump trails Democratic challenger Joe Biden in national opinion polls, as he has done for months, partly because of widespread disapproval of Trump's handling of the coronavirus. Opinion polls in the most competitive states that will decide the election have shown a closer race, though still favoring Biden.
The Dow Jones Industrial Average fell 331.45 points, or 1.24%, to 26,327.66, the S&P 500 lost 54.12 points, or 1.63%, to 3,255.99 and the Nasdaq Composite dropped 303.96 points, or 2.72%, to 10,881.63.
The S&P was on track to fall over 6% this week and more than 3% in October.
The pan-European STOXX 600 index % and MSCI's gauge of stocks across the globe <.MIWD00000PUS> shed 1.47%. Emerging market stocks lost 1.64%.
Oil prices fell for the fourth time this week, weighed by demand concerns as COVID-19 cases swelled globally and fresh lockdowns were to start in Europe's two largest economies.
U.S. crude recently fell 2.49% to $35.27 per barrel and Brent was at $37.39, down 0.69% on the day. Both were on track to fall over 10% this week alone.
The oil weakness led to a broad sell-off of commodity-linked currencies, including the Russian rouble, Norwegian crown and Canadian dollar.
The dollar index, measuring the greenback against a basket of peers, was little changed on the day and was on track for only its second weekly gain of over 1% in more than six months as its safe-haven appeal shone this week.
The dollar index <=USD> rose 0.113%, with the euro down 0.16% to $1.1655.
Societe Generale FX analyst Kit Juckes said that given the recent imposition of a fresh lockdown in France, the positive growth data there - an 18.2% quarter-on-quarter jump - was not enough to outweigh virus concerns.
The Japanese yen strengthened 0.01% versus the greenback at 104.58 per dollar, while the British pound was last trading at $1.2937, up 0.09% on the day.
A risk-on revival after the U.S. election could see the dollar resume its slide from the March highs.
"Our month-end models show a backdrop that would favor a slightly weaker dollar," said Mazen Issa, senior currency strategist at TD Securities in New York.
(Graphic: Stocks and oil vs. coronavirus cases )
Treasury yields were little changed, with benchmark 10-year notes last down 6/32 in price to yield 0.8552%, from 0.836% late on Thursday.
Spot gold added 0.7% to $1,879.66 an ounce. Silver gained 1.18% to $23.55.
(Reporting by Rodrigo Campos; additional reporting by Simon Jessop, Shadia Nasralla, Marc Jones and Olga Cotaga in London, Medha Singh and Shivani Kumaresan in Bengaluru, and Gertrude Chavez-Dreyfuss and Kate Duguid in New York; editing by Jonathan Oatis)
By Rodrigo Campos