Musk, who also runs SpaceX and a number of other companies, has been known to make big often exaggerated promises. For example, he once called the Hyperloop, which was never built, the "fifth mode of transport" and famously promised to take Tesla private in a Twitter post, saying he had secured financing that he didn't have.

Musk, who last year said “things that inhibit freedom of exchange or distort the market are not good,” became $11 billion poorer Monday.

Investors are betting on Elon Musk and his company Tesla making a fortune under US President Donald Trump even as threats mount. View on euronews

Elon Musk's control of a federal payment system is raising concerns about funding for programs like Social Security and the safety of personal data.

Elon Musk is rapidly consolidating control over large swaths of the federal government with President Donald Trump ’s blessing, sidelining career officials, gaining access to sensitive databases and dismantling a leading source of humanitarian assistance.

Elon Musk will work under President Donald Trump as a “special government employee,” designating Musk as an unpaid employee of the federal government with fewer restrictions than full-time employees, according to the White House, as Musk’s so-called Department Of Government Efficiency has involved itself in multiple federal agencies in recent days.

Musk, who has promised "mass head-count reductions" across the federal bureaucracy, has drawn wide scrutiny in recent days as his team has been given access to or has taken contro

At a signing ceremony in the Oval Office on Feb. 3, President Trump said that Elon Musk "won't do anything" without his administration's approval.