Prince William broke the record for the largest foreign currency trade when he joined his father to take part in the ICAP fancy-dress charity day on Wednesday. He joked with one bank: "I have got Batman and Robin standing either side of me... They are very slow here. I have had to come and give them some help." There was loud applause when the prince eventually completed the deal, which saw Barclays trade €17bn (£14.2bn) with Credit Suisse based on the projected currency value for Wednesday and Thursday.