Claudia Winkleman, Ross Kemp, Mel C and Nicole Scherzinger were among the stars who picked up the phone at a charity event to honour those killed in the September 11 attacks.
The annual event at brokerage firm BGC Partners also hosted famous faces including Sarah, Duchess of York, Ryan Giggs and Olly Murs.
The firm lost 658 employees in the attack on the World Trade Centre in 2001 and now hosts a charity day in commemoration every year, during which all profits from trades are donated to good causes.
They include the Cantor Fitzgerald Relief Fund and dozens of other charities around the world.
The event is now in its 14th year and since its inception has raised approximately $147 million (£113 million) globally.
Strictly Come Dancing star Winkleman attended to support charity Child Bereavement UK, while Kemp wore a t-shirt bearing the logo of male cancer charity Orchid.
Comedian Jimmy Carr made himself comfortable on the trading room floor by putting his feet up on the desk.
Wales manager Giggs attended the event in support of Make-A-Wish, which grants wishes to seriously ill children, while the Duchess of York wore a badge supporting charity Street Child.
Former X Factor star Murs hit the phones at the event in honour of charity Brainwave, which helps children with disabilities and additional needs.