Is Zakat due on shares of a food company that were purchased for speculation, then speculation on them ceased for four years and they lost 80% of their value? And how is their Zakat calculated for the past years if it is obligatory, knowing that a portion of the invested amount was a loan?

Zakat is obligatory on shares in two cases: first, if the company's activity is based on buying and selling; and second, if the shares are purchased with the intention of reselling them.

Since the questioner purchased the shares for speculation, Zakat is obligatory on their principal and any profit, if realized, and must be paid immediately.

He is required to pay Zakat for the past four years, at a rate of 2.5% of the value of the shares and their profit each year, after deducting any debt if he has no other money to cover it, provided that their value each year is not less than the Nisab (85 grams of gold or 595 grams of silver).