What is the ruling on dealing in the stock market, which involves forward online contracts on commodities and currencies, knowing that the profits are fixed and buying and selling are not done hand-to-hand?

Purchasing gold with dollars is considered a currency exchange (sarf), and it requires immediate, hand-to-hand possession, based on the Prophet Muhammad’s (peace be upon him) saying: “If it is hand-to-hand, then there is no harm; but if it is deferred, then it is not permissible.” Since this condition is often not met in the aforementioned stock exchange, and the company guarantees a known profit while immediate possession does not occur, participating in this system is not permissible.