Financial firms used to only do so called boring things like lending to businesses. Now their profits come from selling complex products, which could threaten the economy.

Banking used to be a laid-back profession involving long lunches and the odd loan approval to a business. Over the last few decades that has all changed as financial institutions focus increasingly on selling products to the public and thinking up ever more complicated money making schemes for the world markets. This process - often described as financialisation - has meant increased profits for the banks but is also seen as a threat to the rest of the economy. Authors Rana Foroohar and Joshua Ryan-Collins argue that some financial institutions may once again repeating old mistakes.

Presenter: David Grossman

Producer: Matthew Chapman