Global coronavirus cases rose by over 500,000 for the first time this week, with France and Germany preparing fresh lockdowns while a record surge of U.S. cases is pushing hospitals to the brink of capacity and killing up to 1,000 people a day.
Underwhelming outlooks and results from some of Wall Street's largest companies, including Apple and Facebook, further soured the mood and dragged U.S. stocks lower.
"There is a big selloff 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, still favoring Biden.
The Dow Jones Industrial Average fell 157.51 points, or 0.59%, to 26,501.6, the S&P 500 lost 40.15 points, or 1.21%, to 3,269.96 and the Nasdaq Composite dropped 274.00 points, or 2.45%, to 10,911.59.
The S&P fell 5.6% this week and nearly 3% in October.
The pan-European STOXX 600 index edged up 0.18% on the day but also lost 5.6% this week. MSCI's gauge of stocks across the globe <.MIWD00000PUS> shed 1.16% on Friday and lost 5.3% this week. Emerging market stocks posted a weekly 3% decline.
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.
"Many nations with high oil consumption across the world are seeing infection levels that they didn't have even during the first wave," said Paola Rodriguez-Masiu, Rystad Energy's senior oil markets analyst.
"These infection levels are destined to bite oil demand, as traffic will be curbed to a minimum during the coming lockdowns."
U.S. crude fell 1.38% to $35.67 per barrel and Brent was at $37.45, down 0.53% on the day. Both fell over 10% this week alone.
The oil weakness led to a sell-off of some commodity-linked currencies, including the Russian rouble.
The dollar index, measuring the greenback against a basket of peers, ticked up for the day and posted its second weekly gain of over 1% in more than six months as its safe-haven appeal shone.
On the day, the dollar index <=USD> rose 0.152%, with the euro down 0.25% to $1.1645.
The Japanese yen weakened 0.05% versus the greenback at 104.68 per dollar, while the British pound was last trading at $1.2953, up 0.21% on the day.
A risk-on revival after the U.S. election could however 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.
Longer-dated Treasury debt sold off, steepening the yield curve to the widest since June, as investors anticipated the deluge of supply that would come from a post-election stimulus package.
The 30-year bond last fell 28/32 in price to yield 1.6633%, from 1.625% late on Thursday.
Benchmark Treasury yields ticked up, with 10-year notes last down 12/32 in price to yield 0.8754%, from 0.836%. The 2-year note was little changed on the day.
Spot gold added 0.6% to $1,877.90 an ounce. Silver gained 1.53% to $23.63.
(Reporting by Rodrigo Campos; additional reporting by Simon Jessop, Marc Jones and Olga Cotaga in London and Stephanie Kelly, Gertrude Chavez-Dreyfuss, Herbert Lash and Kate Duguid in New York; editing by Jonathan Oatis, Ken Ferris and Tom Brown)
By Rodrigo Campos