What is the ruling on divesting shares in a company, part of whose activity is unlawful, given that the share price has doubled? And is it obligatory to donate all of the profit or only a portion of it?

It is not permissible to buy shares of companies that engage in forbidden transactions, and this is what the resolutions of the Fiqh Academies have stipulated. Some have gone so far as to permit it, with the obligation to dispose of the percentage of profits related to forbidden transactions, in what is called "stock purification."

If the company has not yet engaged in betting, gambling, or other forbidden acts, there is no harm in benefiting from the operating profits. As for the profit resulting from selling the shares, if the reason for the increase in the share price is the entry of forbidden transactions into the company's activity, then the shares must be purified by extracting a percentage of the profit equivalent to what was caused by the existence of these forbidden activities.

And if the questioner only took his capital after selling the shares, he has acted with piety and caution, and this is better but not obligatory. Rather, he is only obliged to extract the purification percentage mentioned, along with repenting for buying shares that he knew beforehand were mixed.