Oil, also called black gold, is considered as the commodity which has the greatest impact on the world's economy, and it has been studied in terms of its relationship and effects on macroeconomic variables such as Gross Domestic Product (GDP), inflation, trade balance, exchange rate and some...

Modern portfolio theory is one of the most important investment decision tools in finances. In 1952 Harry Markowitz set the foundations of the Modern portfolio theory, since than this theory was a backbone of many studies that dealt with investment decisions. This research applies mean-variance...