Central bank money is mainly provided through open market operations, a weekly tender being offered with a maturity of two weeks and a monthly one with a maturity of three months. Through the institution of two standing facilities, the movement of the overnight money rate is curbed by an interest-rate corridor, i.e. a ceiling and a floor to the overnight money rate.
The Eurosystem also has a wide range of fine-tuning instruments. Owing to the buffer function of the minimum reserve system, however, a comparatively steady development of the money-market rates is assured, so that the Eurosystem has not had to intervene in the market with fine-tuning measures even once since the start of monetary union.