Is it permissible to agree with a speculator on a specific profit or loss percentage (1-5%), and anything exceeding that is for him or against him?

The described form of Mudarabah is not permissible, because it is not allowed for the owner of the capital (Rabb al-Mal) to stipulate that the Mudarib (agent) guarantee all or part of the capital. Loss should only be borne by the capital, unless there is negligence or misconduct on the part of the Mudarib. Similarly, it is not permissible for the owner of the capital to stipulate for himself a fixed percentage of the capital as a profit due to him in any case. Rather, an agreement must be made on a shared percentage for the distribution of profits between the owner of the capital and the Mudarib, if profits are generated.