Abstract. The capital market is a reality today. The capital market has an important role to play in regularizing the surplus revenues available to the economic society. In this context, a number of portfolios may be placed on the capital market by investors, individuals or legal entities. The placement must take into account a number of aspects such as: the defined and reasoned market portfolio, the market and the factors acting on the market at a given time, the measurement of the performance of the placement of the portfolios on the capital market. In this article, the authors have studied and analyzed the methods of investigation that investors in the capital market must carry out before carrying out this operation. Asset portfolios are, in theory, within the reach of anyone, but a profitable investment must be based on a study that is well-developed enough to be able to capitalize on market developments influenced by a number of factors and subject to market risk in a future period. One by one, these aspects were analyzed, presented in the form of theories, statistical-econometric relations of calculation and graphical representations, which express more efficiently the way in which the portfolio in question is a real bearer of a performance and will result with a level of profitability thought by the investor. As a methodology, we used first of all a series of statistical quantities that characterize the evolution of the capital market, indicators that refer to the profitability (return) of asset portfolios, adequate graphical representations as well as comparative, structural analysis, leading to the proposed return (expected) by the asset portfolio investor.

Keywords: investors, portfolios, profitability, market, developments, risks.