The price of oil has dropped below $50 in New York trading for the first time since December as concerns that Opec’s output cuts are failing to restrain record US stockpiles triggered the biggest slump in more than a year.

Some predicted a win for Trump would spook the markets but Tom Metcalf and Jack Witzig found the prospect of a businessman in the White House just helped the rich grow richer.

The ex-wife of multi-billionaire energy tycoon Harold Hamm plans to appeal a court ruling that awarded her nearly $1bn (€790,000m) in a divorce settlement, according to her attorney.