How can the zakat on shares from 2005 be calculated for a merchant who has not paid the zakat on his shares since that year until 2010, knowing that he does not possess accounting records for 2005 and is currently experiencing a shortage of funds?

Zakat on shares differs based on their type and the buyer's intention. If they are fixed assets intended for benefiting from their returns, then Zakat is only on the profits when they reach the nisab. However, if they are for trading, then Zakat is on both the principal value of the shares and their profits. Their Zakat is calculated by giving one-quarter of one-tenth (2.5%) of their value if they reach the nisab (equivalent to 85 grams of gold or 595 grams of silver). If the value of the shares is unknown, one can refer to the company's financial statements or estimate based on probability. The obligatory Zakat does not lapse due to a collapse in share value, statute of limitations, or inability to pay it.