What it means
A monoline insurer does not sell home, car or life cover. Its product is a financial guarantee: for a fee, it promises to pay the interest and principal on a bond if the issuer cannot, which allows the bond to be sold at a lower interest rate because it carries the insurer's strong credit rating.
The model relied on the insurer's top credit rating. Investors treated an insured bond as safe because the guarantor was safe, so the insurer earned a premium for lending its rating to the issuer, usually a municipality or a structured finance vehicle.
Concentration is the catch. Because a monoline does nothing but insure financial risk, a downturn in credit markets can hit its whole portfolio at once, and its high leverage, meaning a small capital base supporting a very large amount of insured debt, leaves little room for error.
That is what happened in the 2007 to 2009 crisis. Several monolines had also insured complex mortgage-linked securities, losses mounted, the insurers lost their top ratings, and the bonds they had wrapped lost the benefit of the guarantee.
Outside insurance, the word is used for specialist lenders such as credit card companies or mortgage originators that offer a single product. They can be very efficient and well informed in their niche, but they have no other income to fall back on if that market weakens.
When assessing a monoline, investors look at capital relative to insured exposure, the quality and diversification of the insured portfolio, and the strength of the rating. Those factors determine whether the guarantee can be relied on.
In practice
Real-world examples.
Example
A city issues $50,000,000 of bonds backed by a financial guarantee from a highly rated monoline. Investors accept a lower interest rate, and the city saves money over the life of the bonds. The saving is paid for by the premium, which is far smaller than the interest saved.
Example
A specialist credit card company lends only to consumers and funds itself in the bond market. When consumer defaults rise, it has no other business lines to offset the losses.
Example
A bond investor reads that a monoline guarantor has been downgraded. She re-prices her insured bonds on the strength of the underlying issuer alone, because the guarantee is now worth less.
Formula
Calculation
Guarantee premium = Insured amount x Premium rate
Insured leverage = Total insured exposure / Claims-paying resources
A monoline insures a $100,000,000 municipal bond for an upfront premium of 0.6%, which is $100,000,000 x 0.006 = $600,000. The insurer has total insured exposure of $4,000,000,000 and claims-paying resources of $200,000,000, so its insured leverage is $4,000,000,000 / $200,000,000 = 20 times. If losses wiped out 5% of insured exposure, or $200,000,000, the entire claims-paying capital would be gone.Case study
Seen in the real world.
Bayridge Guaranty is an illustrative, fictional monoline insurer that wrapped city and school district bonds for decades without a major loss. Wanting to grow, it began to guarantee pools of consumer loans, which paid higher premiums but carried more risk.
When consumer defaults rose sharply, Bayridge faced claims much larger than its model had assumed. Its capital of $300,000,000 supported $9,000,000,000 of guarantees, a leverage of 30 times, so even modest losses became threatening.
Rating agencies cut Bayridge's rating, which meant the bonds it guaranteed lost value overnight and the company could no longer write new business. The fictional lesson was that a narrow business with high leverage cannot afford to stray into riskier products. The fictional board later restricted the company to simple, diversified guarantees.
Watch out
Common mistakes.
- Assuming an insured bond is risk-free, when it depends on the guarantor's strength as well as the issuer's.
- Treating a monoline as a diversified insurer, when all of its risk sits in one correlated area and losses tend to arrive together.
- Ignoring leverage, which can turn a modest loss into a threat to survival when capital is thin compared with insured exposure.
Questions
People also ask.
What is a monoline insurer?
It is a company that provides financial guarantees for bonds and similar obligations and does not sell other types of insurance. It earns premiums for lending its credit rating, and the premium is often paid upfront when the bond is issued.
Why did monolines get into trouble in the financial crisis?
Some insured complex mortgage-linked securities, and when defaults rose, losses exceeded their capital and they lost their ratings. Bonds that investors had treated as top quality then fell in value.
Is monoline always about insurance?
No, the term can describe any financial firm that focuses on one product, such as a specialist lender. The risk of concentration is the same, since a single weak market can damage the whole business.
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