[jevgeni]

CDO's are huge and complicated deals. All the little details are documented in the prospectus. Granted it's 700 pages long on average, but maybe people shouldn't be buying 2-3 billion USD securities if they don't have the capacity to understand and model them properly.

[shrewduser]

there aren't many humans who can grok that kind of info and truly understand it, that's why they were supposed to be rated accurately by ratings agencies.