What is the ruling on buying company shares on the Egyptian Stock Exchange, and what are the Shariah controls for that, especially if the shares are for companies that deal with usury or whose activities are impermissible (haram), and what should I do regarding my current portfolio that contains such shares?

What the doctor said regarding the permissibility of purchasing company shares without distinguishing their type or activities is incorrect. Dealing in usury, selling alcohol, and pork are forbidden by Islamic law. A shareholder in such companies is considered a participant in sin, thus repentance is necessary, and the funds must be withdrawn from them. Money earned from a permissible activity that becomes mixed with an unlawful one, then the permissible part is lawful. As for money earned directly from an unlawful activity, it must be disposed of by spending it on charitable causes and public welfare for Muslims, with the intention of getting rid of it, not as charity. If it is difficult to distinguish between lawful and unlawful, then caution must be exercised.

And Allah knows best.