The main objective of this research is to optimize the stock portfolio of investment companies operating in the field of petrochemical and refining industries through minimizing risk with respect to the expected return. In this regard, first of all, the compositions of sample firm's portfolios were investigated during 2013 to 2016 and high-weight industries were selected. Then, the risk of retu...

modern portfolio theory is based on harry markowitz's 1952 work on mean-variance portfolios. he stated that a rational investor should either maximize his expected return for a given level of risk, or minimize his risk for a given expected return. in this study the markowitz model with cardinality constraints was studied. we extend the standard model to include cardinality constraints that...

In this paper, we develop a dynamic investment model maximizing the expected “utility” of excess return relative to a benchmark portfolio. Following the standard setting of continuous time framework for the securities market developed by Merton (1971) and others, we obtain an explicit formula for the optimal portfolio policy for a utility function ofHyperbolic Absolute Risk Aversion (HARA). Unl...

In this paper, we discuss a multiperiod portfolio selection problem with fuzzy returns. We present a new credibilitic multiperiod mean semi- absolute deviation portfolio selection with some real factors including transaction costs, borrowing constraints, entropy constraints, threshold constraints and risk control. In the proposed model, we quantify the investment return and risk associated with...

Information asymmetry in stock market can increase the risk of investment which in turn increases the capital cost of firms. Bhattacharya (1979) proposed a hypothesis that states dividend can act as a powerful signal in order to solve information asymmetry problem. We measured information asymmetry by lack of earnings transparency. Therefore we examine the effect of earnings transparency on cap...

stock selection criteria play a key role in contrarian portfolio construction. the usual approach is applying cumulative return as stock selection criteria however applying this criterion leads to ranking stocks without considering investment risk. in this study, we analyze contrarian strategies that are based on reward–risk stock selection criteria in contrast to ordinary contrarian strategies...

portfolio selection is considered a critically significant decision, firms have to make. as such, much research has been focused on the selection of a portfolio with a controlled level of risk and high expected return. this paper uses a new definition of risk for portfolio selection whereby risk taking is taken as a curve instead of a specific value. in this paper, a genetic algorithm is presen...

recently, the economic crisis has resulted in instability in stock exchange market and this has caused high volatilities in stock value of exchanged firms. under these conditions, considering uncertainty for a favorite investment is more serious than before. multi-objective portfolio selection (return, liquidity, risk and initial cost of investment objectives) using minmax fuzzy goal programmin...

return maximization or risk minimization is goal in portfolio optimization based on mean variance theory. the structure of correlation matrices and individual variance of each asset are two main factors in optimization with risk minimization object. it’s necessary to use appropriate variance and correlation coefficient for time series with clustering volatilities feature, too. in this research,...