NetBank's deposits was taken over by ING when FDIC moved in and closed NetBank. Over a weekend, accounts moved to ING - that's all. The scenario would doubtless differ for each bank failing, but since FDIC insures $100k per depositor, you are good. Problem arises for all funds above $100k - the receiver of the failed bank (FDIC) needs to see if they have money to pay everyone - if not, what % would be made available to all depositors that had more than 100K. This takes time