New York | Shares in former president Donald Trump’s social media company have fallen so much that his onetime $US6 billion ($8.9 billion) stake is now worth about $US2 billion.

The stock price of Trump Media & Technology Group closed on Wednesday (Thursday AEST) at $US16.98, and is down more than 74 per cent from the high-water mark it hit after Trump Media’s merger in March with a publicly traded shell company.