To a casual eye, the London trading desk of GFI, one of the world’s leading interdealer brokers, seems the last place in the world where religion would crop up. Amid a bank of computer screens, dozens of men – and the occasional woman – sit hunched at their phones, scrambling to make as much money as possible.

However, this winter, Islam is entering the trading floor: GFI recently became the first interdealer broker in the world to set up a desk to trade so-called Islamic bonds, or sukuk. The desk is tucked between sections dedicated to other, non-religious financial instruments, such as credit derivatives or energy futures.