Central banks usually fulfil the function of ‘lender of last resort’. To ensure financial stability, the central bank provides emergency credit to financial institutions that are struggling financially and near collapse, for example if they no longer have other available means of borrowing, and where their failure to obtain credit would dramatically affect the economy. An example of when this is needed is if bank account holders withdraw funds at a level and in a timespan which means the bank cannot liquidate assets fast enough to match the demand, creating what is known as a ‘run on the bank’.