Before the financial-sector meltdown, few people had ever heard of credit-default swaps (CDS). They are insurance contracts — or, if you prefer, wagers — that a company will pay its debt. As a founding member of AIG's financial-products unit, Cassano, who ran the group until he stepped down in early 2008, knew them quite well. In good times, AIG's massive CDS-issuance business minted money for the insurer's other companies. But those same contracts turned out to be at the heart of AIG's downfall and subsequent taxpayer rescue. So far, the U.S. government has invested and lent $150 billion to keep AIG afloat.