The Duke of Sussex successfully closed a £1 billion deal on a financial trading floor, helping to raise £50,000 for charity.
He managed to keep his cool and seal the deal, all whilst juggling three phones and having traders barking orders at him.
A portion of the money raised will go to the Invictus Games, of which Prince Harry is a patron.
The annual event is staged by BGC Partners brokerage at its offices in London’s Docklands, commemorating the 658 Cantor Fitzgerald staff and 61 EuroBrokers employees who died in the attack on the World Trade Centre in New York on September 11, 2001.
At the Gilts desk, which trades in Government debt, Harry completed the huge trade under the watchful eye of Ryder Brown, co-head of the department.
Mr Brown said the Duke had done the difficult job of closing a £1 billion trade in 10-year gilts.
He added: “I thought he was excellent.
"It was very nerve-wracking but he handled the pressure well and closed the trade.
“That was the hard bit, to close the trade.
"He picked the telephone up and managed to do it – it’s like old-style trading.”
The Duke was one of a host of celebrities including comic Jimmy Carr, Game Of Thrones star Kit Harrington, London Mayor Sadiq Khan, former England football manager Sam Allardyce and England World Cup-winning cricket captain Eoin Morgan taking part in the BGC charity day.