In the case of complete markets, such as in the classical Black–Scholes case, perfect hedging, which eliminates all randomness in the evolution of the portfolio, is (theoretically) possible. This, of course, is not (even theoretically) possible in an incomplete market. Nevertheless, it is possible to hedge the risk that is correlated with the tradables – partial hedging is possible. So the goal is to have a formula that will coincide with the Black–Scholes formula when the market is complete, while hedging all the risk that is correlated with the available tradables when the market is incomplete. Moreover, the goal is to have a formula applicable to any financial engineering model, i.e., applicable in the context of simple economies, and to be applicable for hedging of any portfolio of contracts.