Fresh from his tour of the Caribbean, Prince Harry stepped out on Wednesday to attend the ICAP charity day on behalf of his organisation, Sentebale.
The Prince was tasked with playing broker for the day at the Liverpool Street, London offices.
Harry did his best at the fundraising event, using his wit and humour to seal deals.
"50 million, done," he was heard saying on the phone.
Negotiating another deal he quipped, "We'd like a bit more than that," prompting laughter from the trading floor.
Staff had donned fancy dress for the occasion, and Harry was faced with a sea of funny costumes including Where's Wally? characters.
The 32-year-old, who had just come fresh off the plane from Toronto where he was visiting his girlfriend Meghan Markle, commented on the fancy dress.
"I'm not entirely sure what country we're in," he joked.
The sporty royal helped kick off a cycling race, and poked fun at the participants as he watched them sweat.
He had a go on the life-size Operation game manned by the London Air Ambulance and managed to play for just 30 seconds before "killing" the plastic patient.
The Prince was in high spirits carrying out the engagement for his charity, showing no signs of fatigue or jet lag.
He was joined by Prince Edward's wife the Countess of Wessex, who was there to raise money for the children's hospice Shooting Star Chase.
Despite admitting that she didn't know what she was doing, Sophie later cheered: "Yes! That was so easy. What did it all mean?"
Honey G was among the celebrities invited to the event.
Mollie King also stepped out to show her support for the event...
...as did Jodie Kidd.