Paul Poet

Oh man, CPDOs. CPDOs! Why was I not aware? This Australian court decision is like 3,000 pages long but it is riveting; if you built a CPDO, email me, I will buy you a drink and you can tell me all about it. My God it’s so beautiful.

The story is that ABN Amro invented a structured-credit monstrosity called a constant proportion debt obligation, got it rated AAA by S&P, and sold it to some people; it ended up in the hands of some Australian regional councils, and then it chewed their hands off. As well it might have! It was monstrous. Anyway the councils sued S&P (and others) and today they won their lawsuit, which is bad news for S&P, though they kind of deserved it.

To simplify enormously the CPDO deal was:

  • You are a ten-year pool of money
  • You make a levered investment in some 5-year investment grade credit indices
  • Every six months you roll that investment into the next 5-year index
  • If credit has widened, you have lost money and therefore lever your investment more, to try to make your money back
  • If credit has tightened, you have made money and therefore ratchet down your leverage, hoping to get out in one piece
  • If you keep winning you take more money off the table until you end up with your money in Treasuries for the remainder of the 10 years
  • If you keep losing you run out of money and just give up, with your investors losing everything

This is obviously a martingale gambling strategy and the analogy is made extensively in the opinion but don’t worry about that now. Worry about the purity of the ratings arb here. It is breathtaking. Here is the core trick of it: S&P rated structured credit products based solely on the probability that they would pay off less than 100% of their principal plus interest, and not at all based on the expected loss if that happened. A triple-A rating required a <0.728% probability of defaulting. What this means is that: Read more »