India, June 6 -- Elon Musk's clash with President Donald Trump appears to have backfired on him. The 53-year-old, who accused the president of being ungrateful, lost $15 billion on Thursday, and his company Tesla's shares tumbled as much as 9% during trading hours. According to Forbes' real-time billionaires list, Musk is worth $399.5 billion, down 3.63%.

Tesla slumped 8.9% amid Musk's criticism of Trump's 'Big Beautiful Bill'. This comes after the president lashed out at his former ally on Thursday, saying he was 'disappointed' by the billionaire's opposition to the sweeping tax-cut and spending bill that is at the heart of his administration's agenda.

"Look, Elon and I had a great relationship. I don't know if we will anymore. He said...