The forbidden bay ‘u al-gharar can best be translated as “trading in risk”. In the face of risk,any trade would involve some degreeof trading in risk,and thus jurists disagree over whether a specific  contract is forbidden or not based on their varying assessments of whether the amount of risk is substantial or small. Moreover,the prohibition is often overruled in cases where clear  economic benefit can only be served by a contract which includes substantial trading in risk.

We show that “trading in risk”is generally inefficient relative to other forms of risk sharing. Hence if a contract can attain its economic aim of increasing economic efficiency through either form of risk transfer,the prohibition of trading in risk should be applicable.

Cases where such a prohibition is moot because the risk trading instrument is not used do not affeect this general conclusion. In cases where trading in risk is integral to thecontract,but where the contract is important to meet economic needs (e.g.salam and ’istisn ¯a ‘), the analysis is still useful in two regards:(i)we can consider whether or not there is a risk sharing mechanism which can reduce part of the inherent trading in risk (e.g.financial vs.mutual insurance), and (ii)we should consider such alternatives if secondary tools for managing the resulting risk are sought.
 

 
 

An Economic Explication of the Prohibition of Gharar in
Classical Islamic Jurisprudence. - Mahmoud El-Gamal
Decision-Making under Uncertainty:
An Islamic Perspective - Sami Ebrahim Al-Suweilem
Towards an Objective Measure of Gharar in Exchange - Sami Ebrahim Al-Suweilem