What is the method and amount of zakat due on shares that are gradually acquired over four years, with their full profits received starting from the first year, and what is the ruling on zakat if the value of all shares is paid in advance but they cannot be sold until after the prescribed period has elapsed?

A Muslim must seek to apply Islamic law in his dealings. It is not permissible for him to invest in a company whose transactions are Islamically prohibited. Similarly, it is not permissible to sign a contract that prevents the buyer from disposing of the sold item; if such a condition is stipulated, the condition is void, but the sale remains valid. Contracting on shares that are not Muslim (Islamicly permissible) and whose price is deferred (a sale of deferred for deferred, bay' al-kali' bi al-kali') is forbidden. If you contract on these shares, they are considered your property from the date they are written in your name, and you must pay zakat on them as trade goods.