Field help: (2019) Do you want to record interim gains according to the Investment Tax Act (InvStG) 2004?
(line 29 of Form KAP-INV)

If you also want to enter interim gains according to the Investment Tax Act 2004, please select "yes".

In the case of old shares, the interim gains calculated as of 31.12.2017 are taxable at the time of the actual sale. Investment trusts were therefore notionally sold on 31.12.2017 and are thereafter considered as acquired again.

The notional sales profits must then be taxed when the investment shares are actually sold.