You can skip this beginning part if you know what a CDO is or know a mezzanine tranche from junk:
By now, almost everyone knows that most mortgages are no longer held by banks until they are paid off: They are packaged with other mortgages and sold to investors much like a bond. In the simple version, each investor owned a small percentage of the entire package and got the same yield as all the other investors. Then someone figured out that you could do a bigger business by selling them off in tranches corresponding to different levels of credit risk. Under this arrangement, if any of the mortgages in the pool defaulted, the riskiest tranche would absorb all the losses until its entire investment was wiped out, followed by the next riskiest and the next. With these tranches, mortgage debt could be divided among classes of investors. The riskiest tranches -- those with the lowest credit ratings -- were sold to hedge funds and junk bond funds whose investors wanted the higher yields that went with the higher risk. The safest ones, offering lower yields and Treasury-like AAA ratings, were snapped up by risk-averse pension funds and money market funds. The least sought-after tranches were those in the middle, the "mezzanine" tranches, which offered middling yields for supposedly moderate risks.
Stick with me now, because this is where it gets interesting. For it is at this point that the banks got the bright idea of buying up a bunch of mezzanine tranches from various pools. Then, using fancy computer models, they convinced themselves and the rating agencies that by repeating the same "tranching" process, they could use these mezzanine-rated assets to create a new set of securities -- some of them junk, some mezzanine, but the bulk of them with the AAA ratings more investors desired. It was a marvelous piece of financial alchemy, one that made Wall Street banks and the ratings agencies billions of dollars in fees. And because so much borrowed money was used -- in buying the original mortgages, buying the tranches for the CDOs and then in buying the tranches of the CDOs -- the whole thing was so highly leveraged that the returns, at least on paper, were very attractive. No wonder they were snatched up by British hedge funds, German savings banks, oil-rich Norwegian villages and Florida pension funds.
Here is the money paragraph:
What we know now, of course, is that the investment banks and ratings agencies underestimated the risk that mortgage defaults would rise so dramatically that even AAA investments could lose their value. One analysis, by Eidesis Capital, a fund specializing in CDOs, estimates that, of the CDOs issued during the peak years of 2006 and 2007, investors in all but the AAA tranches will lose all their money, and even those will suffer losses of 6 to 31 percent. And looking across the sector, J.P. Morgan's CDO analysts estimate that there will be at least $300 billion in eventual credit losses, the bulk of which is still hidden from public view. That includes at least $30 billion in additional write-downs at major banks and investment houses, and much more at hedge funds that, for the most part, remain in a state of denial.
...and the rest: it's bad, going to get worse.
As part of the unwinding process, the rating agencies are in the midst of a massive and embarrassing downgrading process that will force many banks, pension funds and money market funds to sell their CDO holdings into a market so bereft of buyers that, in one recent transaction, a desperate E-Trade was able to get only 27 cents on the dollar for its highly rated portfolio. Meanwhile, banks that are forced to hold on to their CDO assets will be required to set aside much more of their own capital as a financial cushion. That will sharply reduce the money they have available for making new loans. And it doesn't stop there. CDO losses now threaten the AAA ratings of a number of insurance companies that bought CDO paper or insured against CDO losses. And because some of those insurers also have provided insurance to investors in tax-exempt bonds, states and municipalities have decided to pull back on new bond offerings because investors have become skittish.
If all this sounds like a financial house of cards, that's because it is. And it is about to come crashing down, with serious consequences not only for banks and investors but for the economy as a whole. That's not just my opinion. It's why banks are husbanding their cash and why the outstanding stock of bank loans and commercial paper is shrinking dramatically. It is why Treasury officials are working overtime on schemes to stem the tide of mortgage foreclosures and provide a new vehicle to buy up CDO assets. It's why state and federal budget officials are anticipating sharp decreases in tax revenue next year. And it is why the Federal Reserve is now willing to toss aside concerns about inflation, the dollar and bailing out Wall Street, and move aggressively to cut interest rates and pump additional funds directly into the banking system.
This may not be 1929. But it's a good bet that it's way more serious than the junk bond crisis of 1987, the S&L crisis of 1990 or the bursting of the tech bubble in 2001.
I told you so: here is a post of mine from 2005 predicting that things would end in tears in credit derivative markets.
Repeat five times: it's not a black swan event, it was predictable; it's not that statistical modeling and correlations are useless, but rather how they are used; don't blame the quants; the incentive structures were all wrong; traders selling naked puts; blah blah blah.