What is the ruling on dealing with banks by opening an account for buying and selling currencies, metals, and stocks, taking advantage of margin facilities that allow purchasing at a value exceeding the amount available in the account, knowing that buying and selling are instantaneous?

There are two main scenarios for buying and selling through banks: The first is within the limits of one's capital, which is permissible under certain conditions. The second is through margin facilities, which is a loan from the bank.

If the bank charges interest on the loan, it is forbidden usury (riba).

If the bank charges a service fee for buying and selling operations, it is permissible.

The buying and selling must be for an existing commodity that can be owned and possessed, and the exchange and delivery must take place; otherwise, the transaction is invalid.