"I am passionate about the challenge of making this become a real business," says John Casaudoumecq, head of global commodities at Citi. "We started with very little. Seeing the plan executed successfully is all you need to stay motivated."

In April, Casaudoumecq's passion for the business led him to relocate to London, after spending most of his career in North American offices of the Citi family and its predecessors Salomon Brothers. His locations included Toronto, New York and his native San