At the height of the housing boom, the 26th floor of Goldman Sachs’s former headquarters on Broad Street in Lower Manhattan was the nerve center of Goldman’s fast-growing mortgage trading business.

Hundreds of employees worked closely in teams, devising mortgage-based securities — billions of dollars’ worth — that were examined by lawyers, approved by management, then sold to investors like hedge funds, commercial banks and insurance companies.

At one trading desk sat Fabrice Tourre, a midlevel 28-year-old Frenchman who was little known not just outside Goldman but even inside the firm. That changed three years later, in 2010, when he achieved the dubious distinction of becoming the only individual at Goldman and across Wall Street sued by the Securities and Exchange Commission for helping to sell a mortgage-securities investment, in one of the hundreds of mortgage deals created during the bubble years.  Read more