Trump also singled-out Mr Musk in his victory speech, spending several minutes praising his rocket firm, Space X. Mr Musk's association with the president-elect also boosted the share price of his electric car maker Tesla - and, with it, his net worth, which now stands at an estimated $290bn.

The world’s richest man gave his money and time in campaigning for the president-elect and now is putting in his requests for a friendlier regulatory environment.

Trump could appoint the world’s wealthiest man to fire workers and make drastic cuts in spending. He says economic ‘hardship’ will follow, Alex Woodward reports