Abstract
The research aimed to identify how to build models for selecting the optimal mix of investment portfolios, as well as presenting the stock returns of fifty-four companies listed on the Iraq Stock Exchange to facilitate investors' choice of the best investment alternatives by comparing stock returns with the financial market returns. Using monthly data spanning the period from March 2020 to May 2024, the research examined fifty-four companies listed on the Iraq Stock Exchange, covering all traded sectors. The research also demonstrated the importance of beta analysis (β) in classifying stocks into defensive and offensive, which helps investors build balanced financial portfolios that manage risks more effectively. The research reached several conclusions, the most important of which is that the pricing of capital assets depends on two important factors: the risk premium and the beta value. Consequently, any increase in either of these factors will be directly reflected in the prices of corporate assets.