The Dow Jones fell 1.23% to 34,932.16 points, the Nasdaq index, 1.24% to 14,980.94 points, and the broader S&P 500 index, 1.14%, to 4,568.02 points.

"Uncertainty about the ultimate impact of the Omicron variant remains," Schwab analysts summed up in a note.

If the intensity of the virus seems relatively moderate, as expected, its speed of spread has nonetheless led the authorities in several countries to put in place health restrictions.

The Omicron variant "adds to the uncertainty over interest rates," said Sam Stovall, chief investment officer at CFRA.

Omicron's spread poses the risk of an economic slowdown, but one that would arguably be accompanied by inflation as it worsens supply chain disruptions.

"The Fed (American central bank) is a bit stuck", considers the analyst, "because inflation will be a problem in both cases", if the economy picks up or if it is permanently disturbed by the new variant, "and that could force her to hike rates" no matter what.

To the pandemic has been added the setback suffered by President Joe Biden in Congress, whose massive plan of social and environmental measures seems close to failure.

The moderate Democratic senator Joe Manchin, in fact, indicated on Sunday that he would not vote for the text, while his voice was able to tip the scales favorably for Joe Biden.

However, several media reported on Monday that the West Virginia senator had not yet closed the door definitively.

"Mr. Manchin's persistent willingness to trade gave the market some hope of seeing a deal," Briefing.com analysts said, allowing the indices to limit their losses during the session.

Bond rates rose slightly at the end of the day, with the yield on 10-year US government bonds rising to 1.42% from 1.40% on Friday.

Among the values ​​in the spotlight on Monday, the American software publisher and remote computing giant (cloud), Oracle, was sanctioned (-5.15% to 91.64 dollars) after the announcement of the he acquisition of Cerner (+ 0.80% to $ 90.49), a company specializing in IT services to the medical sector, for an enterprise value of $ 28.3 billion.

The biggest capitalisations of Wall Street, Apple (-0.81%) and Microsoft (-1.20%), continued to fall, handicapped by profit taking at the end of a good year.

Also in reverse, Tesla (-3.50%) and the new stars of electric transport, from Rivian (-7.90%) to Lucid (-5.05%), growth stocks shunned by investors who have them raised to higher valuations than those of automotive giants.

Novavax slipped (-7.07% to 201.95 dollars) despite the green light, Monday, from the European Medicines Agency (EMA) to the marketing of its anti-Covid vaccine.

Nuvaxovid is based on a more traditional technology, similar to that used for vaccines against hepatitis B or pertussis.

Novavax's competitor, Moderna, also unscrewed (-6.25% to $ 276.38) despite the publication of the results of a clinical study which shows that a booster of its anti-Covid vaccine made with one dose complete, compared to half a dose currently, further increases its effectiveness against the Omicron variant of the coronavirus.

The movie theater chain AMC did well (+ 1.99% to $ 29.70) after the announcement that the film "Spider-Man: No Way Home" had grossed $ 253 million at the box- North American office this weekend, the third best release of all time, pandemic or not.

Italian fashion house Ermenegildo Zegna made an encouraging start on Wall Street (+ 5.92% to $ 10.74), where it entered through a financial vehicle from European group Investindustrial, becoming the leading brand Italian fashion to be listed in New York.

© 2021 AFP