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.

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.”