First, in view of expected lower market liquidity in the summer and towards the year-end, the Eurosystem frontloaded APP purchases, raising them above the target for a number of months, while reducing them below target in August and December. Second, in the day-to-day implementation of the programme, bond purchases are also responsive to signs of scarcity of individual bonds.
To be more transparent about key factors influencing the monthly gross purchase volume, the Eurosystem recently started to publish the expected monthly redemption amounts for the APP. This decision reflects the increasing relevance of reinvestments, given the higher redemption amounts that will be seen in 2018.