What is the ruling on Mudarabah with a foreign company operating in currency trading under the mentioned conditions, with no capital guarantee and a fluctuating profit percentage? Is it permissible for the company to pay an estimated profit percentage without commitment, or to supplement it from reserves without a condition?

Trading currencies online is permissible if constructive possession is achieved and the transaction is free from overnight fees and leverage. For the speculative partnership (mudarabah (definition)) to be valid, the stipulated profit must be a known percentage of the profits, not of the capital. Stipulating a percentage of the capital invalidates the contract. Informing the company of your expected profit does not harm the validity of the contract. However, regarding the company's voluntary guarantee of profit or assumption of loss, there is a difference of opinion among scholars.