July 7–8, 2025: The first trading day since Musk’s weekend announcement, Tesla shares tumbled, and Musk’s personal fortune dropped by as much as $15 billion, according to the Bloomberg Billionaires Index. As of July 9, it stands at $349 billion with Tesla shares broadly unchanged.

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.

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.