By slapping AAA seals of approval on large portions of even the riskiest pools of loans, rating agencies helped lure investors into loading on collateralized debt obligations (CDOs) that are now unsellable. Corbet ran the largest agency, Standard & Poor's, during much of this decade, though the other two major players, Moody's and Fitch, played by similar rules. How could a ratings agency put its top-grade stamp on such flimsy securities? A glaring conflict of interest is one possibility: these outfits are paid for their ratings by the bond issuer. As one S&P analyst wrote in an email, "[A bond] could be structured by cows and we would rate it."