Is it permissible to sell oil on the stock exchange with a broker who does not charge a commission on leverage or on holding overnight positions, knowing that registering the purchase contract in my name does not grant me full ownership rights over the commodity as its owner, but rather only authorizes me the freedom to dispose of it through buying and selling?

The mentioned transaction is impermissible because the intermediary stipulates that the trade must be conducted through him, and this combines a loan with a brokerage fee, which is prohibited based on the Prophet's (peace be upon him) saying: "It is not permissible to combine a sale and a loan." Thus, the intermediary would benefit from his loan, and every loan that brings benefit is prohibited usury (riba). Furthermore, since the original transaction is invalid, whatever is built upon it is also invalid. The inability to dispose of the goods except through buying and selling without taking possession of them makes what transpires illusory deals and a cover for gambling.