How is the Zakat calculated for trade and saved money after a portion of it has been stolen, and is the stolen amount deducted from the Zakat of the original wealth?

It is not permissible to delay the distribution of zakat beyond its due time under the pretext of searching for the most deserving recipients. Rather, it is obligatory to hasten its disbursement to its rightful beneficiaries immediately. If the zakat money is stolen after it became due and you delayed its payment, then you are held liable for it and must pay an equivalent amount due to your negligence. As for debts that are not expected to be repaid, there is no zakat due on them until you receive them. Upon receiving them, you must pay zakat on them for the past years, according to the issued fatwa.