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.

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.

During a feud with President Trump, Tesla Chief Executive Elon Musk announced plans to start his own political party. Shares for his company fell more than 6% Monday.