How is zakat calculated for losing stock market shares that originated from an unfulfilled investment debt, and is it permissible to pay it in installments due to the inability to pay it as a lump sum?

Every Muslim must learn the rulings of Zakat. Whoever delays it due to ignorance must repent and make it up, for it is a debt that does not fall away due to ignorance or delay. Shares are subject to Zakat even if they are at a loss, according to the majority of scholars. Zakat for past years is calculated through diligence and investigation if it is difficult to determine its value each year. Debt exempts the obligation of Zakat on internal wealth such as gold, silver, cash, and trade goods. If no nisab remains after deducting the debt, there is no Zakat, unless the person owing Zakat has wealth not subject to Zakat that exceeds their needs, in which case they should use it to cover the debt. Zakat must be paid immediately or in installments if one is unable to pay it all at once.