Credit Default Swaps and All That:

In Michael Lewis's fascinating essay on "The End" of Wall Street, he mocks the alchemy of how Wall Street could take a bunch of junk mortgages and convert them into AAA rated paper and sell it over and over. But while he mocks, he doesn't really explain what was going on.

I just came across a really interesting article in Wired that explains how the alchemy of credit default swaps worked--and why it failed in the end. A really accessible introduction to an extremely complicated subject.