S&P 500 in ugly close as first U.S. omicron case rattles markets; European markets close higher amid tumultuous week; Stoxx 600 up 1.8% 
The S&P 500 closed lower Wednesday, after cutting its intraday gains as the U.S. confirmed its first case of the new Omicron Covid-19 strain, triggering a fresh wave of uncertainty across on Wall Street.   
The S&P 500 fell 1.2%, and had been more than 1% higher intraday. The Dow Jones Industrial Average fell 1.3%, or 462 points, and the Nasdaq slipped 1.8%. 
U.S. health officials confirmed Wednesday that the first case of the Omicron variant of Covid-19 was identified in California.  
Moderna (NASDAQ:MRNA), meanwhile, slumped more than 11% after losing an appeal against a court ruling on patents – used in the making of its Covid-19 vaccine – held by Arbutus Biopharma (NASDAQ:ABUS). Arbutus surged 44%, but was well off its session highs.  
In energy, Exxon Mobil (NYSE:XOM) was in focus after the oil major forecast a doubling of earnings and cash flow by 2027 amid plans to lower capital expenditure. 
Twitter (NYSE:TWTR), meanwhile, fell more than 2% even as Cathie Wood revealed that ARK purchased 1.1 million shares of the social media company on Tuesday, amid optimism about the future of the company under the leadership of new Chief Executive Parag Agrawal. 

The pan-European Stoxx 600 provisionally closed up by 1.8%, with autos and travel and leisure stocks jumping more than 3% to lead gains as all sectors and major bourses entered positive territory. 
In terms of individual share price action, Hungary’s Wizz Air jumped 7% to lead the broad advance for travel stocks. Lufthansa added 5%. 
Source: CNBC, Investing.com