As the strange business of slicing and reslicing mortgage loans into collateralized debt obligations (CDOs) boomed in 2005 and 2006, JPMorgan Chase stood on the sidelines, its executives watching in bewilderment as rivals Citigroup, Merrill Lynch and UBS churned out hundreds of billions of dollars' worth of the securities. As Gillian Tett told the story in her 2009 book Fools Gold, the JPMorgan derivatives team, which had effectively invented the CDO, thought the risks of mortgage CDOs were too high, and the bank's new chief executive, Jamie Dimon, agreed. This caution hurt JPMorgan's profits at the time but paid off in spades in 2009, as the bank earned $8.5 billion in the first three quarters of the year while most of its rivals continued to flounder.