Indeed, under normal circumstances, the ECB calibrates its liquidity provision in order to satisfy the liquidity deficit of the euro area banking sector under the assumption that banks as a whole prefer to fulfil their reserve requirements smoothly, i.e.
by holding – in aggregate terms – the same level of current account holdings with the central bank on each day of the reserve maintenance period. As a result, the ECB normally allots at the weekly main refinancing operations an amount of liquidity that is close to its “benchmark” estimate of the expected liquidity needs of the banking sector.