TheStreet.com TV Recap: Off-Balance-Sheet Risks

"What happens is triple-A paper is reduced to a very low level piece of paper, although the ratings' agencies don't seem to understand this, when you attach a home-equity line of credit to it," he explained. If he could see exactly how much second lien mortgages the SIVs have against them, Cramer said he would be able to tell people how bad it was.

But the fact that he doesn't know this information is why calls Citigroup a black hole.

"I'm very jaundiced about everything I hear about the mortgage market because it all comes down to one thing: If housing prices go up, we're fine; if housing prices go down, it doesn't matter what the government does, it doesn't matter what the Fed does, short of cutting interest rates," Cramer said. "We have to make it so people want to buy a home again, and there isn't anything that's being done to make that happen."