The task of control from the position of mathematical tools application is discussed, economic statement and mathematical model of optimization problem are formulated, the sequential realization of the research aim - the mechanism of optimal portfolio management strategy formation - is presented. The results of dynamic optimization of decisions made at each step form the optimum law of the portfolio management. Scientific novelty of the study consists in the fact that the constructed portfolio takes into account the real incompleteness of the initial data on the processes of change in the yields of securities; there is no need to build a set of effective portfolios and indifference curves that characterize the risk appetite of investors; private characteristics are not used as the main criteria that determine the structure of the optimal portfolio of securities.