Which wealth? Your capital in the banking system?
Discussion
Your € in the bank, your Shares and any other assets.
They are even discussing including the house you live in. So you will pay wealth tax on the house you live in as if it is a income.
But the roi of your € in the bank do not need to estimated. The bank sends an exact report of your capital earnings, doesn't it?
Taxing other assets like homes or imposing any other not realised gains tax is becoming quite common, I'm afraid. States are broke, and they are picking up the theft pace.
They assume 4% ROI. So it is not triggered by a sale as capital gains. Let us say you have €100k above the minimum threshold in the bank. They assume you made €4k and will tax you 30% over that.
If they included your house equity as they want then you will be hit really hard.