Jon Deane remembers his boss at JPMorgan screaming across the commodities trading floor as Lehman Brothers, the US bank, plunged towards bankruptcy in January 2008.

Deane and his trading colleagues watched in horror as shares in other US banking groups Morgan Stanley, Citi, and Bank of America, began to crumble. Investors around the world were learning that these top-shelf banks were all invested in a raft of toxic financial products that were fast becoming worthless.