Testing the CAPM: Evidences from Italian Equity Markets

The aim of the following work is to exploit principal econometric tecniques to test the Capital Asset Pricing Model theory in Italian equity markets. CAPM is a financial model which describes expected returns of any assets (or asset portfolio) as a function of the expected return on the market portfolio. In this paper I will first explain the meaning of the market risk and I will measure it via the estimation of beta coeffcients, which are seen as a measure of assets sensitivity to market portfolio fluctuations. The theoretical framework is based on the Sharpe (1964) and Lintner (1965) version of the CAPM and on the Pettengill's hypothesis (1995) over the relationship between betas and returns. Secondly, I will test the presence of specific effects which usually occur in financial markets; in particular, I will check the presence of the well-known January effect and detect the existence of structural breaks over the considered period of time.