Ilgalaikių investicijų portfelių diversifikavimo galimybių vertinimas apsisaugant nuo nesisteminės rizikos / ; Assessment of long-term portfolio diversification benefits and its protection from non-systemic risk.

It has been approximately seven decades, after the first try to distinguish investment portfolio diversification and determine the optimal number of stocks. However, scientists agree only on one thing, investment portfolio diversification is vitally important in reducing investment risk and ensuring investment gains. Opinions on optimal stock number in the portfolio varies from less than ten up to hundreds of stocks. By diversifying their assets, investors trying to achieve two goals, decrease the risk of the portfolio and gain maximum returns. The problem with this is, that these two usually does not go together, and one of them has to be sacrificed. That is why it is essential to determine the optimal number of assets in the investment portfolio. By doing so, it is possible to distinguish the boundary, after which investor can expect most of the value with decreased risk. The main object of the paper is the resistance of non-systemic risk of diversified investment portfolios valuing through investment gains and risks measures. The main purpose is to evaluate means of diversification valuing their resistance to non-systemic risk and gains in long term investment horizon. In the first part of the paper, the main focus is literature analysis, in which the research oriented to diversification risks are reviewed. It is stated, that investment risks are influenced by the chosen market, how investment is distributed and how often if at all they are rebalanced. Also, ETF’s are distinguished as a good alternative to diversified portfolio formation. In the second part of the paper, reviews the theories and methods related to investment portfolio diversification. This part analyzes the differances between small and large investment portfolios and the advantages and disadvantages of diversification in foreign markets. It is generally accepted that the number of securities in an investment portfolio is strongly determined by commissions, the chosen region and the investment period. Finally, an analysis of the methods used ...