Is investing in a Bitcoin mining company that guarantees the return of the principal along with a predetermined profit, without any possibility of loss, considered usury (riba), and is it Islamically permissible?

It is not permissible to guarantee capital or stipulate a fixed profit in investment contracts, as this leads to usury and transforms the contract from a legitimate Mudarabah (profit-sharing) into an usurious loan. In addition, the company's field of work in cryptocurrency mining (Bitcoin) raises Shariah issues, as the International Islamic Fiqh Academy has indicated that the nature of these currencies and their Shariah ruling are still under consideration due to the significant risks, price fluctuations, and instability in dealing with them, and it recommends further research and study.