Tesla shares took a nose-dive Friday morning after a post from chief executive Elon Musk’s Twitter account said the company was overvalued.

“Tesla stock price is too high imo,” Musk wrote in a tweet, using shorthand for “in my opinion.”

Corporate executives are supposed to refrain from issuing market-moving statements while trading is happening. That is especially pressing for Musk, who struck an agreement to have his public messaging vetted by lawyers with the Securities and Exchange Commission last year stemming from a fraud settlement.

That didn’t stop Musk from issuing his opinion Friday, in a tweetstorm that included him expressing that he planned to get rid of most physical possessions, including his home, and reiterating his opinion that the country should do away with widespread shelter-in-place orders amid the novel coronavirus pandemic.

The stock was down more than 11 percent by about noon Eastern time, trading at about $693 from a morning opening of $755.

The tweet could create new problems for Musk, who cost himself and Tesla $20 million each after tweeting that he had secured funding to take the company private at $420 a share in 2018. It led to the SEC settlement and an institution of a chaperone system where his tweets would be vetted. After alleging he broke the agreement in early 2019, the SEC came to an agreement with Musk defining nine categories of information that must be screened, including Tesla’s “financial condition, statements, or results, including earnings or guidance.”

Tesla and the SEC did not immediately respond to requests for comment.

Jeffrey A. Sonnenfeld, a senior associate dean at the Yale University School of Management who has closely followed Musk, said that unless there was prior clearance, Musk’s tweet explicitly violated the tenets of the 2018 consent decree that ordered the CEO’s tweets to be vetted. It could trigger steep penalties — beyond a financial slap on the wrist.

“There’s no ambiguity, nothing gray about it, is a direct 100 percent violation of the SEC’s language,” he said. “He’s not supposed to be able to comment on material information without it being cleared.”

To get out of the bind, he said, the company and its board will have to explain the statement that triggered the sharp drop more thoroughly.

“They’ll have to demonstrate that this is an official message of the company: that they think its stock price is overvalued,” he said. “They have a lot of explaining to do here.”

Tesla reported better-than-expected first-quarter results on Wednesday, turning a narrow profit as the first impacts of the coronavirus outbreak began to be felt. The results were overshadowed by a profanity-laced rant during the earnings call, where Musk called the country’s stay-at-home orders “fascist.”