Tesla shares fell over 3% on Monday, under pressure from investor concerns about the focus of boss Elon Musk after he announced he would form a new U.S. political party, marking a new escalation in his feud with President Donald Trump.

Elon Musk said in a post on X Saturday that he had set up the “American Party” to compete against the Republican and Democratic parties.

President Donald Trump blasted Elon Musk’s bid to start a new political party, as the intensifying feud between the former allies deepens concerns among investors over the implications for Tesla Inc.