Shares of Tesla Inc (TSLA.O) tumbled 9% on Friday after Chief Executive Officer Elon Musk tweeted that the electric carmaker's high-flying stock was overly expensive.
"Tesla stock price is too high," Musk said on Twitter in one of several unusual messages, including ones quoting parts of the US national anthem and that he would sell almost all his physical possessions.
The subsequent share drop erased around $13 billion from Tesla's market value and nearly $3 billion from the value of Musk's stake. Still, shares remain up almost 50% from the start of April.
More than two hours after the tweets began, Tesla had not responded to requests for comment. Twitter declined to comment. The Wall Street Journal reported that Musk had responded to an email asking whether he was joking or whether his tweet was vetted by saying, "No".
Musk has a history of sending provocative tweets. In August 2018, he tweeted that he had secured funding to possibly take Tesla private at a big premium, which led a fraud case by the US Securities and Exchange Commission. Musk settled by agreeing to pay $20 million and have a Tesla lawyer pre-screen tweets with important information about the company.
Last month, a federal judge said Tesla and Musk must face a lawsuit by shareholders over the going-private tweet, including a claim that Musk intended to defraud them.