To what extent would an investment portfolio be affected by different variables in terms of Markowitz and Index model?

Abstract

Portfolio Theory has been widely used in the securities market. Investors expect to maximize the return of the portfolio based on a given level of risk. By using naive diversification, investors can partly reduce the portfolio's risk by reducing the firm-specific influences. However, due to the macro-economic factors (inflation, interest rates, exchange rates, etc.), the risk cannot be eliminated entirely. Based on two popular models, the Index and Markowitz models, we chose seven stocks as one portfolio and set five constraints to simulate a real stock market.  Even though results are very similar between Markowitz and Index model, the Markowitz model is more suitable than the index model in terms of circumstances we faced. And with any additional constraints added to the "free market," our portfolio return can only be negatively or non-affected. The purpose of this paper is to determine how the portfolio performance would be affected by different factors and how these two models would be used based on our comparative analysis of our portfolio in the index model and Markowitz model.