Global stocks mostly fell Monday, along with oil prices and the pound, as a highly infectious strain of coronavirus in Britain had traders seeking shelter.
European equities were hammered as more than two dozen countries from India to Argentina suspended flights from Britain in the wake of the latest twist in the coronavirus saga.
While experts say there is no evidence the UK variant of the virus -- one of several mutations -- is more lethal or will affect the impact of vaccines, it may be up to 70 percent more transmissible, according to early data.
Travel-related shares were broadly lower, with US equities Expedia, Marriott International and United Airlines all off more than one percent.
Worries about the British outbreak highlight "the familiar concern about the virus' effect on the economy" and "travel-related stocks are taking it on the chin," TD Ameritrade's JJ Kinahan said in a note.
Fears about the new Covid-19 strain blunted the boost from the deal hammered out by US legislators on a $900 billion relief package after months of wrangling between Democrats and Republicans.
The package will include a new but smaller round of pandemic relief payments. US Treasury Secretary Steven Mnuchin said the $600 checks will go out as early as next week.
"The US got its stimulus package through but it seems that was largely priced in and investors are more concerned with the new strain of Covid-19," Oanda analyst Craig Erlam told AFP.
"Coming at a time when another Brexit deadline has been missed... it's no surprise to see sentiment taking a big hit."
- Vaccine hopes -
At the weekend, US authorities also gave the green light to another vaccine, this one produced by Moderna, paving the way for it to be rolled out this week.
"We expect the New Year wish of many market participants to be that the arrival and initial distribution of coronavirus vaccines now signals light at the end of a very tiring and debilitating tunnel," said Simon Ballard at First Abu Dhabi Bank.
The prospects for post-Brexit trade deal meanwhile remained uncertain, with UK-EU talks edging ahead after missing another deadline, overshadowed by the transport chaos caused by the new virus variant.
Back in the US, several leading banks were higher after the Federal Reserve on Friday approved share repurchases with some limitations. JPMorgan Chase and Bank of America both gained more than three percent.
But Tesla dropped 6.5 percent after its long-awaited addition to the prestigious S&P 500 index. Shares had rallied aggressively leading into the shift, which took effect Monday.
- Key figures around 2145 GMT -
New York - Dow: UP 0.1 percent at 30,216.45 (close)
New York - S&P 500: DOWN 0.4 percent at 3,694.92 (close)
New York- Nasdaq: DOWN 0.1 percent at 12,742.52 (close)
London - FTSE 100: DOWN 1.7 percent at 6,416.32 (close)
Frankfurt - DAX 30: DOWN 2.8 percent at 13,246.30 (close)
Paris - CAC 40: DOWN 2.4 percent at 5,393.34 (close)
EURO STOXX 50: DOWN 2.7 percent at 3,448.68 (close)
Tokyo - Nikkei 225: DOWN 0.2 percent at 26,714.42 (close)
Hong Kong - Hang Seng: DOWN 0.7 percent at 26,306.68 (close)
Shanghai - Composite: UP 0.8 percent at 3,420.57 (close)
West Texas Intermediate: DOWN 2.8 percent at $47.74 per barrel
Brent North Sea crude: DOWN 2.6 percent at $50.91 per barrel
Pound/dollar: DOWN at $1.3436 from $1.3523 at 2200 GMT Friday
Euro/pound: UP at 91.00 pence from 90.64 pence
Euro/dollar: DOWN at $1.2229 from $1.2257
Dollar/yen: UP at 103.32 yen from 103.30 yen