Tesla shares fell nearly 8% on Monday after CEO Elon Musk's plans to launch a new U.S. political party reignited concerns about his commitment to the company's future as it struggles with declining sales.

Tesla shares sank Monday after CEO Elon Musk announced he would form a new political party in an escalation of his feud with President Donald Trump.

Coming into Monday trading, Tesla stock was up 25% since the Nov. 5 election, down 22% year to date, up 17% since news that Musk was likely to leave DOGE in early April, and down 8% since a spat broke out between Trump and Musk on social media in early June.