Financial guaranty insurers are specialized, highly capitalized companies that traditionally have had the highest rating. The insurer’s high rating attaches to the bonds, lowering the riskiness of the bonds to investors. With their credit rating thus enhanced, municipalities can issue bonds that pay a lower interest rate, enabling them to borrow more for the same outlay of funds.
Over the years financial guaranty insurers have expanded their reach beyond municipal bonds and now insure a wide array of products, including mortgage-backed securities, pools of credit default swaps and other structured transactions. Recent problems in the credit markets have taken a toll on financial guaranty insurers, as they confront heavy losses related to these structured instruments.