In particular, the overall envelope was rescaled from the initial € 750 billion to € 1,350 billion in June 2020 and € 1,850 billion in December 2020 in line  with re-evaluations of the likely duration of the pandemic, the scale of pressure on the bond market and size of the pandemic inflation gap.
With its emphasis on maintaining favourable financing conditions (following the flattening of the yield curve in autumn 2020), the December 2020 decision allowed for two-sided flexibility: relative to the € 1,850 billion envelope, the overall expected stock could be revised down if financing conditions eased or the projected inflation shortfall declined; in the other direction, the overall expected stock could be revised up if financing conditions tightened or the projected inflation shortfall increased.