It is not permissible for the middleman to ask the customer for the price of the item, or ask for a down payment or a payment in advance before taking possession of the item, so as to avoid coming under the Islamic prohibition on selling what one does not possess.

1. There is nothing wrong with dealing in shares, on condition that they are clean, not mixed or haraam. 2. It is haraam to deal in options contracts, whether the option is for the seller or the buyer. For more details, please see the long answer.

It is prohibited to trade by buying and selling after the call to Jumu‘ah prayer. This prohibition includes every interaction that will distract one from Jumu‘ah and does not apply only to ordinary trading. Based on that, being distracted by digital trade at the time of Jumu‘ah is haraam. Seeing that the times of prayer vary from one city to another, it is a good idea to put a note on your website stating that purchasers – if they are among those for whom Jumu‘ah prayer is obligatory – should pay attention to the sanctity of the time for Jumu‘ah prayer and not make any purchases at that time.