According to the general rules for Eurosystem monetary policy instruments and procedures, the outright purchase and sale of securities on the market (outright transactions) are considered standard open market operations within the Eurosystem’s monetary policy framework. However, such operations are intended to be applied within the Eurosystem only in order to adjust the structural liquidity position of the financial sector vis-à-vis the Eurosystem. As part of the non-standard monetary policy measures in response to the crisis as well as to complement its monetary policy toolkit, the ECB Governing Council decided to carry out additional monetary policy asset purchases with different monetary policy objectives.

The ECB’s main task in the monetary policy purchases is coordination, thereby safeguarding the singleness of the Eurosystem's monetary policy. The Eurosystem makes use of decentralised implementation. The Bundesbank consequently conducts a large share of the Eurosystem’s monetary policy asset purchases.