Sure it's insured............we will all be repaid with inflated worthless dollars! Do you feel better? Why do you think there is no more M3?
SIPC only covers your holdings up to 500k, of which it will only cover 100k that you have in cash that's bearing interest. In other words, any money in excess of 100k that's not invested in equities IS NOT COVERED in the event of a bankruptcy or other involuntary liquidation by a brokerage firm.
http://mbtrading.com/accountProtection.asp My firm, MB Trading, has excess SIPC insurance of $200,000,000 with up to $900,000 in cash covered.