A.I.G. does business with virtually every financial institution in the world. Most important, it is a central player in the unregulated, Brobdingnagian credit default swap market that is reported to be at least $60 trillion in size.
Nobody knows this market’s real size, or who owes what to whom, because there is no central clearinghouse or regulator for it. Credit default swaps are a type of credit insurance contract in which one party pays another party to protect it from the risk of default on a particular debt instrument. If that debt instrument (a bond, a bank loan, a mortgage) defaults, the insurer compensates the insured for his loss. The insurer (which could be a bank, an investment bank or a hedge fund) is required to post collateral to support its payment obligation, but in the insane credit environment that preceded the credit crisis, this collateral deposit was generally too small.
