More than a month after their initial social media bluster, Elon Musk has announced the formation of a new U.S. political party in response to U.S. President Donald Trump signing his sweeping tax and spending bill into law.

Tesla investors hoping that CEO Elon Musk would stay out of politics after leaving his position in the Trump administration are going to be sorely disappointed—again. Disappointment is rarely good for stock prices.

"The America Party is formed to give you back your freedom," Musk said, days after Trump debated deporting him.