Is Zakat obligatory on the difference in the price of company shares whose value has increased, knowing that the purpose of owning these shares is the annual yield and not trading them, and given the existence of shares of other companies whose value has not increased or has decreased?

Zakat is obligatory on the income of shares if they are fixed assets, and the income reaches the nisab and a hawl (a lunar year) has passed on it. However, if the shares are trade goods, zakat is obligatory on the capital and profit, provided the conditions of nisab and hawl are met. The decrease or stability of shares does not waive zakat from the profits or assets on which zakat is due.