Derivatives, Derivatives, Derivatives...

"The credit agencies, therefore, need to compete for business based at least in part on the ratings they are willing to give these tranches. As a result, they will only downgrade when forced to by experienced losses; not rising default rates, not a worsening economy, but only actual, experienced losses. Even more disturbing, they will be most reluctant to downgrade the riskiest tranches (the equity tranches) since those continue to be owned by the issuers even after the deal is sold."