Early in the new millennium, as they surveyed the wreckage of the global technology boom and the burst stock market bubble that it had produced, the world’s leading financiers marvelled at the resilience of the 21st-century financial system.

Despite heavy losses in telecommunications and the collapse of large companies such as Enron and Parmalat in other sectors, no big financial institution had run into serious difficulty. This, bankers and regulators argued, was because banks had embraced techniques such as securitisation and the use of derivatives to pass on risks that they would previously have held in their entirety.