Is any value from the stock's values subject to purification, and is the purification applied to the market value of the stocks if the speculator is required to purify?

Not all stocks require purification; some are inherently forbidden, such as those of usurious banks. It is not permissible to purchase them, and whoever has purchased them is only entitled to their principal, while the forbidden profit must be disposed of. There are also permissible stocks that do not require purification. Purification applies to stocks of institutions where unlawful elements have entered their activities at certain percentages. Purification—which is the removal of the forbidden percentage—is done from the profit and is spent on Muslim welfare or given to the poor and needy. This purification is not the obligatory zakat on wealth.