SIPC is not backed by the government, is not a GSE, etc. A failure of a monoline--or even a downgrade by two agebcies of ABK orMBI will result in massive writedowns at major brokerages. CNBC is quoting a figure 00I assume including banks and pension funds--of $250 billion. SIP supports itself by assessing B/D's. So, all BD's would be assessed even if they have no exposure. My understanding is SIPC has only $1 bill in capital.