The chances of a 'Santa rally' in US stocks just became a lot brighter, with Omicron worries subsiding and the economy looking strong

• The picture for US stocks brightened markedly Wednesday as Omicron jitters cooled and economic data improved.
• It means stocks could well be on track for a Santa rally after all, despite fears about coronavirus and inflation.

US stocks traditionally rise at Christmas time. Noone's exactly sure why, but the so-called Santa rally is an established phenomenon.

But in 2021, it looked like the Omicron coronavirus variant and inflation were going to be the Grinches who stole Christmas.

Yet the chances of Kris Kringle coming to Wall Street shot up Wednesday, as studies suggested Omicron is milder than Delta and a raft of strong economic data showed the US economic recovery was on track.

Santa rally is a long-running tradition

The Santa rally refers to the propensity of stocks to rise over the final five trading days of the year and the first two of the following year.

Since 1950, the S&P 500 has rallied 1.3% on average in these seven days, according to data from LPL Financial. And they've moved higher 79% of the time.

"Whether optimism over a coming new year, holiday spending, traders on vacation, institutions squaring up their books, or the holiday spirit, the bottom line is that bulls tend to believe in Santa," Ryan Detrick, chief market strategist at LPL, said.

Data on Omicron and economy brings Christmas cheer

Studies of data out of South Africa and Scotland on Wednesday showed people with Omicron are less likely to need to go to hospital than those who catch the Delta variant, according to early signs.

The studies cheered investors, who calculated that governments would be less likely to impose tough restrictions that hit global growth hard. The S&P 500 rose 1.02%, and the Dow Jones climbed 0.74%.

Markets also liked the look of economic data released Wednesday. The Conference Board found the consumer confidence index rose more than expected in December, with people feeling less worried about inflation.

Read more: Where to invest in 2022: Deutsche Bank lays out a bold forecast on which way stocks will go next year, and names 3 sectors to buy

Home sales picked up in November, data showed, while the Commerce Department upgraded its
estimate of third-quarter US GDP growth to an annual pace of 2.3%, up from 2.1%.

"Markets and investors will get their Santa/Christmas rally by the looks of it," Jeffrey Halley, senior market analyst at trading platform Oanda, said in a note.

"From here, we are probably going to need some more Omicron headlines along the lines of 'hospitalizations and deaths soar with total cases' to turn the markets from their central bank QE-induced perpetual 'buy-the-dip in everything' course," he added.

Yet investors are unusually uncertain

All this is not to say that stocks are nailed on to rally in the final days of this year.

Worryingly for many investors, China has responded to a new coronavirus outbreak by locking down 13 million citizens, giving a sense of how the virus might still knock the economy. Experts have also cautioned that Omicron's high transmissibility means it could still swamp hospitals.

And there are a number of uncertainties on the horizon, with the Federal Reserve set to start hiking interest rates next year and economists unsure about the path of inflation.

But traders will be hoping they can deal with all that next year, and that the tradition of the Santa rally continues.