Robert Waldmann of Angry Bear has a fascinating post exploring the possibility that sharp movements in the value of Lehman senior debt could be explained by the possibility that Lehman had sold Credit Default Swaps on itself. Since a CDS is insurance against the possibility of default on debt, this is a no-lose bet for Lehman. If the firm survives, they collect the premiums and pay nothing and, if it doesn’t the losses are borne by the creditors. And, as Waldmann points out, it’s not crazy to buy such a CDS, since it will retain some value in bankruptcy. If you’ve already sold a lot of Lehman CDS yourself, there’s a significant hedging benefit. So both parties benefit, and the losers are the existing bondholders. Waldmann has an interesting optimization exercise to show that optimal (for Lehman) use of the CDS option could explain the collapse in the value of Lehman bonds.
Thinking about this, I’m more and more convinced that Warren Buffett’s description of derivatives as financial weapons of mass destruction applies in spades to CDSs.