The main objective of the paper is to present the solution to the problem of possibilities’ reliability management, which is an important problem of uncertainty (risk) economics. Also, the paper aims to propose adequate methods of stochastic optimization and reveal their broad implementation possibilities. Along with that, the concept of utility function is being disclosed, when we take into account not only the possibilities of prices and costs, but also their reliability, in order to achieve the highest value added in this process. The original methods of stochastic optimization are used, while searching for the optimal allocation of invested capital among the investment assets. Adequate investment portfolio is treated as theoretically sound and practically effective instrument for investment decision-making in capital and currency markets, as well as for other problems related with optimal resource allocation. The adequate portfolio supplements the modern portfolio by adding the third portfolio parameter – the reliability of return. Also, the utility function based on return, reliability and risk is used to find the optimal investment possibility for particular investor. The formed portfolio solutions were tested in the markets of NYSE, UK and France.