WASHINGTON, July 5 (Reuters) - The dispute between Republican President Donald Trump and his main campaign financier Elon Musk took another fractious turn on Saturday when the space and automotive billionaire announced the formation of a new political party, saying Trump's "big, beautiful" tax bill would bankrupt America.

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.