Beginnings In 1970, the US government-backed mortgage guarantor
Ginnie Mae created the first
mortgage-backed security (MBS), based on FHA and VA mortgages. It guaranteed these MBSs. This would be the precursor to CDOs that would be created two decades later. In 1971,
Freddie Mac issued its first Mortgage Participation Certificate. This was the first MBS made of ordinary mortgages. All through the 1970s, private companies began mortgage asset securitization by creating private mortgage pools. In 1974, the
Equal Credit Opportunity Act in the United States imposed heavy sanctions for financial institutions found guilty of discrimination on the basis of race, color, religion, national origin, sex, marital status, or age This led to a more open policy of giving loans (sometimes subprime) by banks, guaranteed in most cases by
Fannie Mae and Freddie Mac. In 1977, the
Community Reinvestment Act was enacted to address historical discrimination in lending, such as '
redlining'. The Act encouraged commercial banks and savings associations (Savings and loan banks) to meet the needs of borrowers in all segments of their communities, including low- and moderate-income neighborhoods (who might earlier have been thought of as too risky for home loans). In 1977, the investment bank
Salomon Brothers created a "private label" MBS - one that did not involve
government-sponsored enterprise (GSE) mortgages. However, it failed in the marketplace. Subsequently,
Lewis Ranieri (
Salomon) and
Larry Fink (
First Boston) invented the idea of
securitization; different mortgages were pooled together and this pool was then sliced into
tranches, each of which was then sold separately to different investors. Many of these tranches were in turn bundled together, earning them the name CDO (Collateralized debt obligation). The first CDOs to be issued by a private bank were seen in 1987 by the bankers at the now-defunct
Drexel Burnham Lambert Inc. for the also now-defunct Imperial Savings Association. During the 1990s the collateral of CDOs was generally
corporate and emerging market bonds and bank loans. After 1998 "multi-sector" CDOs were developed by Prudential Securities, but CDOs remained fairly obscure until after 2000. In 2002 and 2003 CDOs had a setback when rating agencies "were forced to downgrade hundreds" of the securities, but sales of CDOs grew—from $69 billion in 2000 to around $500 billion in 2006. Early CDOs were diversified, and might include everything from aircraft lease-equipment debt, manufactured housing loans, to student loans and credit card debt. The diversification of borrowers in these "multisector CDOs" was a selling point, as it meant that if there was a downturn in one industry like aircraft manufacturing and their loans defaulted, other industries like manufactured housing might be unaffected. Another selling point was that CDOs offered returns that were sometimes 2–3 percentage points higher than corporate bonds with the same credit rating.
Explanations for growth •
Advantages of securitization – Depository banks had incentive to "
securitize" loans they originated—often in the form of CDO securities—because this removes the loans from their books. The transfer of these loans (along with related risk) to security-buying investors in return for cash frees up the banks' capital. This enabled them to remain in compliance with
capital requirement laws while lending again and generating additional origination fees. •
Global demand for fixed income investments – From 2000 to 2007, worldwide fixed income investment (i.e. investments in bonds and other conservative securities) roughly doubled in size to $70 trillion, yet the supply of relatively safe, income generating investments had not grown as fast, which bid up bond prices and drove down interest rates. Investment banks on Wall Street answered this demand with
financial innovation such as the
mortgage-backed security (MBS) and collateralized debt obligation (CDO), which were assigned safe ratings by the credit rating agencies. The low yield of the safe
US Treasury bonds created demand by global investors for subprime mortgage-backed CDOs with their relatively high-yields but credit ratings as high as the Treasuries. This search for yield by global investors caused many to purchase CDOs, though they lived to regret trusting the credit rating agencies' ratings. •
Pricing models –
Gaussian copula models, introduced in 2001 by
David X. Li, allowed for the rapid pricing of CDOs.
Subprime mortgage boom File:Collateralized Debt Obligations.svg|thumb|450px|Source: Final Report of the National Commission on the Causes of the Financial and Economic Crisis in the United States, p.128, figure 8.1 In 2005, as the CDO market continued to grow, subprime mortgages began to replace the diversified consumer loans as collateral. By 2004, mortgage-backed securities accounted for more than half of the collateral in CDOs. According to the
Financial Crisis Inquiry Report, "the CDO became the engine that powered the mortgage supply chain", CDOs not only bought crucial tranches of subprime mortgage-backed securities, they provided cash for the initial funding of the securities. Between 2003 and 2007, Wall Street issued almost $700 billion in CDOs that included mortgage-backed securities as collateral. on the grounds that mortgages were diversified by region and so "uncorrelated"—though those ratings were lowered after mortgage holders began to default. The rise of "ratings arbitrage"—i.e., pooling low-rated tranches to make CDOs—helped push sales of CDOs to about $500 billion in 2006, with a global CDO market of over US$1.5 trillion. CDO was the fastest-growing sector of the structured finance market between 2003 and 2006; the number of CDO tranches issued in 2006 (9,278) was almost twice the number of tranches issued in 2005 (4,706). CDOs, like mortgage-backed securities, were financed with debt, enhancing their profits but also enhancing losses if the market reversed course.
Explanations for growth Subprime mortgages had been financed by
mortgage-backed securities (MBS). Like CDOs, MBSs were structured into tranches, but issuers of the securities had difficulty selling the more lower level/lower-rated "mezzanine" tranches—the tranches rated somewhere from AA to BB. Because most traditional mortgage investors are risk-averse, either because of the restrictions of their investment charters or business practices, they are interested in buying the higher-rated segments of the loan stack; as a result, those slices are easiest to sell. The more challenging task is finding buyers for the riskier pieces at the bottom of the pile. The way mortgage securities are structured, if you cannot find buyers for the lower-rated slices, the rest of the pool cannot be sold. To deal with the problem, investment bankers "recycled" the mezzanine tranches, selling them to underwriters making more structured securities—CDOs. Though the pool that made up the CDO collateral might be overwhelmingly mezzanine tranches, most of the tranches (70 to 80%) of the CDO were rated not BBB, A−, etc., but triple A. The minority of the tranches that were mezzanine were often bought up by other CDOs, concentrating the lower rated tranches still further. (See the chart on "The Theory of How the Financial System Created AAA-rated Assets out of Subprime Mortgages".) As journalist
Gretchen Morgenson put it, CDOs became "the perfect dumping ground for the low-rated slices Wall Street couldn't sell on its own." leading to "large capital inflows" from abroad helped finance the housing boom, keeping down US mortgage rates, even after the
Federal Reserve Bank had raised interest rates to cool off the economy. •
Supply generated by "hefty" fees the CDO industry earned. According to "one hedge fund manager who became a big investor in CDOs", as much "as 40 to 50 percent" of the cash flow generated by the assets in a CDO went to "pay the bankers, the CDO manager, the rating agencies, and others who took out fees." Moody's
operating margins were "consistently over 50%, making it one of the most profitable companies in existence"—more profitable in terms of margins than
ExxonMobil or
Microsoft. • Trust in rating agencies. CDO managers "didn't always have to disclose what the securities contained" because the contents of the CDO were subject to change. But this lack of transparency did not affect demand for the securities. Investors "weren't so much buying a security. They were buying a triple-A rating," according to business journalists
Bethany McLean and
Joe Nocera. Synthetic CDOs were cheaper and easier to create than original "cash" CDOs. Synthetics "referenced" cash CDOs, replacing interest payments from MBS tranches with premium-like payments from credit default swaps. Rather than providing funding for housing, synthetic CDO-buying investors were in effect providing insurance against mortgage default. If the CDO did not perform per contractual requirements, one counterparty (typically a large
investment bank or
hedge fund) had to pay another. As underwriting standards deteriorated and the housing market became saturated, subprime mortgages became less abundant. Synthetic CDOs began to fill in for the original cash CDOs. Because more than one—in fact numerous—synthetics could be made to reference the same original, the amount of money that moved among market participants increased dramatically.
Crash or downgraded to junk status), compared to a small fraction of similarly rated Subprime and Alt-A mortgage-backed securities. (source: Financial Crisis Inquiry Report) In the summer of 2006, the
Case–Shiller index of house prices peaked. In California, home prices had more than doubled since 2000 and median house prices in Los Angeles had risen to ten times the median annual income. To entice those with low and moderate income to sign up for mortgages,
down payments and
income documentation were often dispensed with and
interest and principal payments were often deferred upon request. As two-year "
teaser" mortgage rates—common with those that made home purchases like this possible—expired, mortgage payments skyrocketed. Refinancing to lower mortgage payment was no longer available since it depended on rising home prices. Mezzanine tranches started to lose value in 2007; by mid year AA tranches were worth only 70 cents on the dollar. By October triple-A tranches had started to fall. Regional diversification notwithstanding, the mortgage backed securities turned out to be highly correlated. (by the end of 2008 91% of CDO securities were downgraded), and two highly leveraged
Bear Stearns hedge funds holding MBSs and CDOs collapsed. Investors were informed by Bear Stearns that they would get little if any of their money back. In October and November the CEOs of
Merrill Lynch and
Citigroup resigned after reporting multibillion-dollar losses and CDO downgrades. As the global market for CDOs dried up the new issue pipeline for CDOs slowed significantly, and what CDO issuance there was usually in the form of
collateralized loan obligations backed by middle-market or leveraged bank loans, rather than home mortgage ABS.), and the
IMF's former chief economist
Raghuram Rajan warned that rather than reducing risk through diversification, CDOs and other derivatives spread risk and uncertainty about the value of the underlying assets more widely. During and after the crisis, criticism of the CDO market was more vocal. According to the radio documentary "Giant Pool of Money", it was the strong demand for MBS and CDO that drove down home lending standards. Mortgages were needed for collateral and by approximately 2003, the supply of mortgages originated at traditional lending standards had been exhausted. According to journalists Bethany McLean and Joe Nocera, no securities became "more pervasive – or [did] more damage than collateralized debt obligations" to create the
Great Recession. In the first quarter of 2008 alone,
credit rating agencies announced 4,485 downgrades of CDOs. At least some analysts complained the agencies over-relied on computer models with imprecise inputs, failed to account adequately for large risks (like a nationwide collapse of housing values), and assumed the risk of the low rated tranches that made up CDOs would be diluted when in fact the mortgage risks were highly correlated, and when one mortgage defaulted, many did, affected by the same financial events. They were strongly criticized by economist
Joseph Stiglitz, among others. Stiglitz considered the agencies "one of the key culprits" of the crisis that "performed that alchemy that converted the securities from F-rated to A-rated. The banks could not have done what they did without the complicity of the ratings agencies." According to Morgenson, the agencies had pretended to transform "dross into gold." Michael Lewis also pronounced the transformation of BBB tranches into 80% triple A CDOs as "dishonest", "artificial" and the result of "fat fees" paid to rating agencies by Goldman Sachs and other Wall Street firms. According to economist
Mark Zandi: "As shaky mortgages were combined, diluting any problems into a larger pool, the
incentive for responsibility was undermined." ==Concept, structures, varieties==