What is the ruling on profiting from the accredited financial markets index?

Gains based on an index vary in their forms, and each form has its own ruling:

1. Selling the index: This is considered prohibited gambling, as it is the sale of an imaginary thing that cannot exist. 2. Contracts for differences, options, and futures: These are prohibited because the subject matter of the contract is neither money nor a usufruct nor a financial right that can be compensated for. 3. Using an index as a guide to determine profit in a promise (Murabaha or Ijarah (definition) contracts): This is permissible if the profit is firmly determined at the time of the contract, such as using LIBOR or Prime Rate, as long as the index is consistent and known. 4. Relying on an index in long-term Ijarah to determine variable rent: This is permissible, provided that the rent is fixed for the initial period, and then changes in subsequent periods based on a consistent index that prevents disputes, with an upper and lower limit set for it.