Is buying shares for capital gain permissible or forbidden, and is it permissible to sell them on the day following the purchase, knowing that the shares are transferred electronically after two days but you become responsible for their risks immediately upon purchase?

It is permissible to trade in shares for the purpose of profit, provided that the shares are pure, belonging to a company with permissible activities that does not deal with usury. As for mixed or forbidden shares, it is not permissible to deal with them.

It is not permissible to sell shares before taking possession of them and their entry into the portfolio or account, in accordance with the saying of the Messenger of Allah, peace and blessings be upon him, to Hakim ibn Hizam: "If you buy something, do not sell it until you take possession of it," and his prohibition, peace and blessings be upon him, against selling goods until merchants take possession of them and move them to their places.