Analysis of modern approaches to the formation of the portfolio investor shares stock

The object of research is an investment portfolio consisting of a set of investment instruments (securities, assets, projects, etc.) in which the investor's finances are distributed. The main purpose of forming an investment portfolio is its maximum return, but income is always directly proportional to risk. The paper proposes an approach in which the user can manage the values of profitability and risk, and thus determine for himself the optimal composition of the investment portfolio. This is achieved by using a combination of financial asset valuation methods.The study used models that are the basis of portfolio theory and include the choice of investment assets and the optimization of the composition of the portfolio, methods for assessing the investment qualities of assets and the effectiveness of portfolio investment. In particular, Markowitz, Sharpe and Tobin models are used to ensure greater efficiency in making investment decisions in the stock market, including those related to the formation and management of the share portfolio. And in assessing the investment qualities of financial assets.Tests of the method and models on real investment assets have confirmed their effectiveness. In particular, when forming a portfolio of shares, it is determined that the maximum profitability is ensured in the investment portfolio, which is characterized by the maximum risk. Compared to other variants of portfolios with average and minimum returns, it is determined that the value of risks differ by 3–5 %. This is due to the fact that the proposed method is based on a combination of models that take into account various aspects of the stock market. Thus, an optimal portfolio is formed that provides the investor with the desired level of profitability at a fixed level of risk.The results obtained in this work allow to propose a general methodology for the formation of an optimal investment portfolio containing various shares of the most reliable and attractive financial assets in the conditions of modern uncertainty and volatility of the Ukrainian stock market.