The purchase of government securities by the European Central Bank aims to safeguard the monetary policy transmission mechanism, by giving support to the market segments considered as crucial for the financing of the financial sector and banks in particular.
The EMS was designed as a symmetric system of fixed but adjustable rates. It allowed member currencies to float within bands of 2.25% above and below bilaterally fixed central exchange rates. Symmetric intervention obligations aimed at stabilising the 1  BIS Review 133/1999  exchange rates of members within the bands were part of this exchange rate mechanism.