We have not such a tax rule in Belgium and I guess not in other European countries.If I understood it right you have to fill in the loss and gains you have during a year on the tax document .So in certain circumstances it's better to sell some shares with a loss to lower tax rates.

About this

C'est sympathique d'avoir des membres de tous les pays sur ce forum!

I have the same feeling.It would be interesting if we know from which country each member is?