Anatomy of a CDO

Click the image for the original flash graphic, which illustrates quite clearly the re-bundling of securities. The process may sound technical, but in fact it appears the main variable is just an estimate of default probability and recovery fraction for various categories of mortgages. It will be interesting to see, when the dust settles, how much of the (massive) error in prediction came from outright fraud on the mortgage application (essentially, miscategorization) versus error in estimates of default probability by category.

WSJ: ... Mr. Ribotsky says the selling required little effort, as Merrill drummed up interest from its network of contacts. "That's what they get their fees for," he says.

Norma sold some $525 million in CDO slices -- largely the lower-rated ones with higher returns -- to investors. Merrill declined to say whether it kept Norma's triple-A rated, $975 million super-senior tranche or sold it to another financial institution.

Many investment banks with CDO businesses -- Citigroup Inc., Morgan Stanley and UBS -- frequently kept or bought these super-senior pieces, whose lower returns interested few investors. In doing so, they bet that the top CDO slices, which typically comprised as much as 60% of the whole CDO, were insulated from losses.

By September, Norma was in trouble. Amid a steep decline in house prices and rising defaults on mortgage loans, the value of subprime-backed securities went into a free fall. As increasingly worrisome delinquency data rolled in, analysts upped their estimates of total losses on subprime-backed securities issued in 2006 to 20% or more, a level that would wipe out most triple-B-rated securities.

Within weeks, ratings firms began to change their views. In October, Moody's downgraded $33.4 billion worth of mortgage-backed securities, including those which Norma had insured. Those downgrades set the stage for a review of CDOs backed by those securities -- and then further downgrades.

Mezzanine CDOs such as Norma were the hardest hit. On Nov. 2, Moody's slashed the ratings on seven of Norma's nine rated slices, three all the way from investment-grade to junk. Fitch downgraded all nine slices to junk, including two that it had rated triple-A.

Worse Performances

Other mezzanine CDOs, including some underwritten by other investment banks, have had worse performances. Around 30 are now in default, according to S&P. Norma is still paying interest on its securities. It is not known whether it has had to make payouts under the credit default swap agreements.

Ratings companies say their March opinions represented their best read at the time, and called the subprime deterioration unprecedented and unexpectedly rapid. "It's one of the worst performances that we've seen," says Kevin Kendra, a managing director at Fitch. "The world has changed quite drastically -- and our view of the world has changed quite drastically."

By mid-December, $153.5 billion in CDO slices had been downgraded, according to Deutsche Bank. Because banks owned the lion's share of the mezzanine CDOs, they bore the brunt of the losses. In all, banks' write-downs on mortgage investments announced so far add up to more than $70 billion.

For larger banks, holdings of mezzanine CDOs could account for one-third to three-quarters of the total losses. In addition to the $9.4 billion fourth-quarter write-down Morgan Stanley just announced it would take, Citigroup has projected its fourth-quarter write-down could reach $11 billion. UBS said this month it would take a $10 billion write-down after taking a $4.4 billion third-quarter loss.

Merrill, for its part, took a $7.9 billion write-down on mortgage-related holdings in the third quarter. Analysts expect it to write down a similar amount in the current quarter, which would represent the largest losses of any bank. News of the losses have led to the ouster of CEO Stan O'Neal and Osman Semerci, the bank's global head of fixed income. Mr. Margolis left this summer.