In connection with the Deutsche Wohnen acquisition, Vonovia raised €8.1bn of new equity by way of a subscription rights issue in December 2021. Every shareholder received subscription rights –relative to their shareholding- which are equal to a free bonus element, because they allowed shareholders to buy new shares at a discount (or sell the subscription rights).
This bonus element requires an adjustment of all historical per-share numbers (“TERP adjustment) to allow comparison with prior years because the new shares were issued to shareholders at a discount). International Accounting Standards (IAS 33) also require the adjustment of prior-year periods. All data providers like Bloomberg, Factset, Reuters etc. follow this approach as well.