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The rapid onset of concerns about the Omicron variant of the coronavirus has ushered in a period of fresh market anxiety as investors wait for more information about what it could mean for the trajectory of the pandemic.

But what if the variant turns out not to be so bad for markets and the economy after all? That’s one view getting tentatively shopped around by some on Wall Street.

Much more data from scientists is clearly needed before any conclusions can be drawn. But some investors are highlighting the possibility that Omicron leads to milder illness than the Delta variant, which caused global cases to spike earlier this year. That could generate a positive outcome for stocks, they argue.

“A thought. While it is too early to have definitive data, early reported data suggest that the Omicron virus causes ‘mild to moderate’ symptoms (less severity) and is more transmissible,” hedge fund billionaire Bill Ackman tweeted over the weekend. “If this turns out to be true, this is bullish not bearish for [stock] markets.”

Ackman is no Covid denier. In March 2020, he warned companies that “hell is coming” and called on former President Donald Trump to shut down the country for 30 days.

And he’s not alone in spotting a potential “upside.” A team of strategists at Goldman Sachs have examined four scenarios for the economy. One of them is based on the chance that “Omicron is slightly more transmissible but causes much less severe disease.” This could boost global growth as restrictions are eased and facilitate a quicker comedown in inflation.

The investment bank said it will not make any Omicron-related changes to its economic forecasts “until the likelihood of these scenarios has become somewhat clearer.” It also included two scenarios in which the effects of the Omicron variant are negative.

A big caveat: Wall Street analysts are not infectious disease specialists. Dr. Angelique Coetzee, chair of the South African Medical Association and one of the doctors treating patients with the Omicron variant, told CNN Tuesday that the majority of cases of the variant that she has seen have been mild, but it’s still early days.

The World Health Organization, for its part, has deemed Omicron a “variant of concern” and said that “preliminary evidence suggests an increased risk of reinfection.” Scientists are emphasizing that it could be weeks until they have answers to three important questions: Do Omicron’s mutations make it more transmissible? Is it more severe or deadly than other variants? And is it more resistant to vaccines?

But the range of calls peppering the investment community — buy, sell, do nothing — underscores the depth of uncertainty markets are now facing. That will make stocks exceptionally susceptible to news in the coming days and weeks.

See here: Markets are pulling back again on Tuesday following a warning from Moderna’s CEO that current vaccines will struggle with Omicron. It’s far from definitive — but for investors, it’s a headline to trade on.

“There is no world, I think, where [the effectiveness] is the same level . . . we had with [the] Delta [variant],” Stéphane Bancel said in an interview with the Financial Times published on Tuesday. “I think it’s going to be a material drop. I just don’t know how much because we need to wait for the data. But all the scientists I’ve talked to  … are like, ‘This is not going to be good.’”

Jack Dorsey steps down as CEO of Twitter

For years, Jack Dorsey has been the public face of Twitter (TWTR), steering it through the controversies of the Trump years and criticism of social media.

Now, he’s stepping down. On Monday, the company announced that Dorsey — who co-founded Twitter — would leave his role, effective immediately, and hand the reins to Parag Agrawal, Twitter’s chief technology officer.

“I’ve decided to leave Twitter because I believe the company is ready to move on from its founders,” Dorsey said in a statement. “My trust in Parag as Twitter’s CEO is deep. His work over the past 10 years has been transformational. I’m deeply grateful for his skill, heart, and soul.”

Dorsey told employees that the decision to leave was his own, and was a “tough one.”

Remember: Dorsey returned to the chief executive role in 2015 to help turn around the social network’s business. During his tenure, Twitter achieved profitability, posted its first $1 billion quarter and began testing and releasing a wide range of features to draw in users.

But like its peers, Twitter has also had to confront the challenge of content moderation, as well as growing scrutiny from lawmakers and the public, my CNN Business colleague Brian Fung notes.

While much smaller than rivals like Facebook, Twitter has been central to debates over the responsibilities of social media platforms to curb hate speech, violent rhetoric and misinformation on their sites.

Dorsey has had to navigate these issues while also serving as CEO of Square, the payments company he co-founded. Activist hedge fund Elliott Management pushed for changes, including possibly removing Dorsey, as recently as last year, but he survived the bid for a shake-up.

Investor insight: Shares of Twitter gained more than 30% from the beginning of 2015 through Friday’s close. They finished Monday down 2.7%.

Facebook-owner Meta has been ordered to sell Giphy

Meta (FB) has been ordered to unwind its recent acquisition of Giphy by regulators worried about the deal’s impact on competitors — a blow to the Facebook owner and a warning to Big Tech as the industry faces antitrust scrutiny.

The latest: The UK’s Competition and Markets Authority said on Tuesday that Meta’s control of the popular search engine for GIFs — short, looping videos and animations — would reduce competition between social media platforms and had already removed one potential rival in the advertising market, my CNN Business colleague Mark Thompson reports.

Facebook, as Meta was then known, bought Giphy, reportedly for $400 million, in 2020. It was intending to integrate the service with Instagram, making it easier for people to find relevant GIFs for their stories and direct messages.

In its announcement of the deal, Facebook had vowed to grant third parties the same level of access to Giphy’s content as before. Less than a month after the acquisition was announced, however, the CMA said it was looking into it.

In its initial findings published in August, the regulator said that Facebook’s control over Giphy could allow it to cut off other social media sites’ access to GIFs. Giphy’s services currently integrate with platforms such as Twitter, Snapchat, Apple’s iMessage and Slack.

Meta said Tuesday it disagreed with the CMA and was considering “all options, including appeal.”

Why it matters: Although far from the largest deal Meta has ever done, the Giphy acquisition is the company’s first high-profile deal that government officials have tried to unwind. Is this a harbinger of more aggressive action to come?

Up next

Salesforce (CRM) reports earnings after US markets close.

Also today:

Coming tomorrow: Day two of Powell and Yellen’s testimony in front of Congress, this time before the House Financial Services Committee.