Despite predictions of a billionaire boom under Donald Trump, many of the world's richest people have seen their net worth tumble in recent weeks.

Tech billionaire Elon Musk admitted he is having “great difficulty” running his various businesses as he juggles an advisory role in the Trump administration and leads the Department of Government ...

On the barren outskirts of Abilene, Texas, traffic had snarled to a crawl: It was shift-change time at Project Stargate, and ...