It has shown that the root of the problems was the gradual build-up of common risks within the system. It is now widely acknowledged that such crystallisation of risk, linked to major shifts in the correlation between financial products and markets, requires more systemically-focused oversight and regulation.
To use the professional jargon, microprudential control, the preserve of the supervisory authorities, must be complemented by macroprudential oversight, resorting to the expertise of central banks.