Ordinarily the gain will be calculated (in EUR) based on the difference between the net proceeds and the ‘base cost’ for the shares sold from a company, although you can also deduct certain costs of sale or acquisition (for example, broker fees, etc.). It should be the calculated separately the capital gain that arises per each entity.
To calculate the acquisition value, it will be necessary to calculate the acquisition price following FIFO “first in, first out” mechanism, based on the value of the share at the time of purchase.
The general rule is that any profit made from the sale of property is subject to capital gains tax. However, capital gains obtained in the transfer of the taxpayer's habitual residence may be exempt, when the total amount obtained from the transfer is reinvested in the acquisition of another habitual residence or in the rehabilitation of that residence that will have such a character.
The reinvestment of the amount obtained in the sale must be carried out, in one go or successively, in a period not exceeding two years, counted from date to date, which may be not only the subsequent ones but also the previous ones to the sale of the previous habitual residence.
If you are over 65 years old, the sale of your primary residence may be exempt from capital gains tax, regardless of whether you reinvest the proceeds or not. This exemption applies if the property has been your primary residence for at least three years.