A federal jury in San Francisco, California, ruled on Friday that tech billionaire Elon Musk provided false information to Twitter shareholders, leading to a drop in the company’s stock price during his preparations to acquire it for $44 billion.

The verdict came in a class-action securities lawsuit. It could force Musk, currently the world’s richest person, to pay billions in damages as determined by the jurors.

Musk’s legal team quickly responded, telling AFP that he plans to appeal the decision, calling it a “setback.”

The outcome followed a three-week trial in federal court in San Francisco, during which Musk gave in-person testimony.

The jury specifically found that two tweets Musk posted in May 2022 included false statements. These statements directly caused Twitter’s share price to decline.

Investor Giuseppe Pampena filed the lawsuit on behalf of shareholders who sold their Twitter stock between mid-May and early October 2022. Musk finalized the acquisition in late October 2022 and later renamed the platform X.

Jurors determined that Musk violated securities laws by making false or misleading statements that harmed stock prices. The plaintiffs’ lawyers estimated potential damages at about $2.6 billion.

Musk, who frequently posts on X, did not immediately comment on the ruling. The decision marks an uncommon legal defeat for him, often called “Teflon Elon” for avoiding consequences in past cases. His attorneys noted that on the same day, a Texas court cleared him in a separate defamation lawsuit.

In 2023, a San Francisco federal jury quickly acquitted Musk on similar allegations from Tesla shareholders related to his 2018 tweets about taking the company private.

The civil complaint claimed Musk deliberately manipulated Twitter’s stock price. He aimed to renegotiate the purchase terms or escape the deal, resulting in losses for shareholders who sold during that period.

During the acquisition talks, Musk tweeted that the deal was temporarily on hold pending verification of the proportion of automated accounts, or “bots.” Plaintiffs argued this formed part of a strategy to pressure Twitter’s board into a lower price, especially as Tesla’s stock fell and increased the shares Musk needed to sell to finance the purchase.

Musk eventually dropped efforts to end the acquisition in late 2022 after Twitter pursued legal enforcement of the contract. Since then, he has integrated the platform with his xAI venture and SpaceX.

Forbes estimates Musk’s net worth at $839 billion, primarily from stakes in Tesla, SpaceX, and other ventures.