Banks have exposure the financial guarantors through banks' holdings of insured municipal securit1es and structured securities, through derivative transactions for which the guarantors are a counterparty, and through loans and lines of credit they have extended to the guarantors. Banks also have significant exposures to the financial guarantors through the liquidity support that banks provide for certain types of municipal securities and structures, including variable-rate demand obligations (VRDOs) and tender-option bonds (TOBs), as wen as some asset-backed commercial paper conduits. Reduced confidence in the financial guarantors could lead some investors to exercise options to put these securities back to the liquidity providers. Moreover, money market funds, who are major investors in these securities, can be required to put the securities back to the liquidity providers if the financial guarantor is downgraded significantly. Thus, banks could be required to bring a sizable volume of assets, especially municipal securities, onto their books.