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.

Ross Gerber, a longtime Tesla investor and vocal Musk critic, didn’t hold back online, writing in his own post that, “no one wants the Elon first party,” accusing the company’s board of being “Elon vampires sucking the blood of Tesla equity.”