The news for Facebook couldn’t have been better.

On Monday, a US judge dismissed two complaints that accused the company of holding a monopoly on social media — a major setback for regulators that are increasingly looking for ways to break up Silicon Valley’s top players.

Facebook’s shares soared more than 4%, pushing the company’s market value above $1 trillion for the first time.

But CEO Mark Zuckerberg may want to hold off popping the champagne.

The judge said the Federal Trade Commission did not do enough to back up its assertion that Facebook controls at least 60% of the social media market. The FTC had alleged that Facebook violated the nation’s anti-monopoly laws by acquiring nascent startups like Instagram that it perceived as a threat to its dominance, and by preventing others from plugging into Facebook’s services.

Facebook’s daily double: Judge tosses antitrust case, giant tops $1 trillion in value

However, the agency can still file an amended complaint. An FTC spokesperson said it’s closely reviewing the decision.

The dismissal may also serve to harden the resolve of US lawmakers, who are pursuing a parallel track to rein in Big Tech with new legislation.

“The FTC should do everything it can to pursue its case against Facebook. But the ruling shows why our antitrust laws need to be updated after years of bad precedent,” Sen. Amy Klobuchar, a Democrat, tweeted after the decision. “We can’t meet the challenges of the modern digital economy with pared down agencies & limited legal tools.”

“Agreed,” Rep. Ken Buck, a Republican, said in response.

Plus, Facebook is still under the microscope outside its home country. Earlier this month, European regulators announced two separate antitrust investigations that will probe whether the social network’s use of data gives it an unfair advantage in online advertising.

Big picture

The dominant narrative for months has been that investors are brushing off regulatory risks to tech stocks. Clearly, looking at the bump Facebook got after the US judge’s ruling, that’s not entirely true.

It’s a reminder for investors to watch what’s happening closely. Given Big Tech’s clout — Facebook, Amazon, Apple, Alphabet and Microsoft now make up almost 23% of the market value of the S&P 500 — there could be big consequences if critical regulators ultimately find even limited success.

“The temptation is to believe that tech will remain all powerful in a post-pandemic world. However, history cautions against this automatic assumption,” JPMorgan strategists Jan Loeys and Shiny Kundu wrote in a note to clients late last week.

Loeys and Kundu focus on the potential for the “start of a political movement against mega companies” that would likely center on Big Tech. If it gains traction, that could end the era of US stocks outperforming other regions market dominance, they warn.