But depending on the distribution of payment flows throughout the day, even with large ES balances, some banks may still need to borrow at the end of the trading day to ensure their ES balances remain positive. [4] It is worth remembering that the banking system as a whole has to hold the level of ES balances supplied by the Reserve Bank.
So while any individual bank may try to lend their excess ES balances, at the end of the day, some bank in the system has to hold them.