Tesla closed down 0.7% at $307.52 a share during official trading Thursday, and plunged 14% to $265.55 in after-hours trading on the news late Thursday.

A complaint filed by the SEC in a federal court in New York said that Musk “falsely indicated that, should he so choose, it was virtually certain that he could take Tesla private at a purchase price that reflected a substantial premium over Tesla stock’s then-current share price, that funding for this multi-billion dollar transaction had been secured, and that the only contingency was a shareholder vote.”

Am considering taking Tesla private at $420. Funding secured.

— Elon Musk (@elonmusk) August 7, 2018

The SEC maintains that those statements weren’t accurate. “In truth and in fact, Musk had not even discussed, much less confirmed, key deal terms, including price, with any potential funding source,” the complaint said. Musk, the SEC alleged, “knew or was reckless in not knowing” that his tweets weren’t in fact true.

Adding to mounting concerns surrounding Tesla in recent months, the SEC lawsuit is only one of several regulatory headaches for the company. The SEC is also looking into Tesla’s projections of car-production volumes, according to Bloomberg, while the Justice Department is also looking into whether Musk’s tweets misled investors.

In a press conference discussing the lawsuit, Stephanie Avakian, co-director of the SEC’s Enforcement Division, said Musk’s tweets led investors to think it was a “virtual certainty” that Tesla would be taken private at $420 a share. “We allege that he did not even discuss key deal details, including pricing,” with any potential investors who could help take Tesla private, she said.

The complaint says Musk chose the $420 a share price in an almost cavalier manner. Calculating that a 20% premium over Tesla’s price on Aug. 7 would value Tesla at $419 a share, Musk upped the figure by a dollar because of the significance of the number 420 to cannabis culture. Musk thought his girlfriend “would find it funny, which admittedly is not a great reason to pick a price,” he is quoted as saying in the complaint.

Musk’s false and misleading statements not only violated the 1934 Securities Exchange Act, the complaint alleged, but “unless restrained and enjoined [Musk] will violate again.” Asked by reporters about why the felt he would violate securities law again, SEC officials declined to offer any further comment.

In a statement issued by Tesla, Musk said he was “saddened and disappointed” by what he called an “unjustified action” by the SEC.