Sub-Prime Market

A few weeks ago, John Mauldin had a good explanation of the potential problems in the sub-prime lending market:

Let me give you a preview of a coming scandal, just to illustrate the chase for yields. In the US, about 25% of the mortgages on new homes are what is known as sub-prime mortgages. These are mortgages that are slightly less creditworthy and therefore offer higher interest rates. In the beginning this was a good thing, as first-time owners and those just starting out in life were given an opportunity to own their own homes.

But then came a world of liquidity looking for yield. Investors demonstrated a large appetite for these mortgages. Investment banks would buy those high-yielding sub-prime loans and package them into something called Residential Mortgage Backed Securities. Now, a sub-prime loan is not considered an investment-grade security. But when you put a group of them together into a pool and break them up into various sub-groups or tranches, through the alchemy of high finance, you turn lead into gold. You create high-grade bonds from sub-prime debt. In fact, 80% of those grouped together get a AAA rating, because that tranche gets the first monies paid back to the debt pool. And it probably is pretty safe money. No problems yet.

Then the investment bank starts slicing smaller parts of the pool and eventually ends up with the final 4% getting a below-investment-grade BBB rating. Again, this is all a good thing as it allows investors to buy the risk they want and makes for a more liquid real estate market. But then we start to get cute with alchemy. Not content with turning lead into gold, we start trying to do the magic on sewage.

Investment banks pool all these BBB tranches into yet another pool called a Collateralized Debt Obligation or CDO. The rating agencies have sophisticated models which tell them that with the increased diversification, 87% of these former BBB bonds can now be sold as AAA or AA investment-grade bonds. Only 4% is considered actual BBB debt. So we have taken an original security that is not investment-grade and turned all but less than 1% into an investment-grade bond.

Again, if all those mortgages pay off like they have in the past, then not too much problem. But recent research suggests that as many as 20% of these mortgages sold in 2005 and 2006 are going to default or foreclosure. But the CDOs assume that less than 1% will default. If the number of defaults is even half of that predicted, then someone is not going to get their full capital back, let alone the interest. And we are seeing home foreclosures at record levels in every part of the United States due to the large number of sub-prime mortgages.

Why such a growing default rate? Because investors kept throwing money at mortgage bankers, who found out they could sell mortgages with little documentation. For instance, you could get a loan without actually having to prove your income. So the bankers said, "Let's take the fees and run. Bonuses all around for selling more mortgages." Now there is anecdotal evidence that a small but significant portion of these low-documentation loans had some items that were misrepresented. You know, little things like whether you were actually going to occupy the home.

Since then there has been quite a bit of fallout, and for those interested, I've found this site to be a good way to keep track of the events as they unfold.