The conception of a concise and rational model for assets pricing in an efficient market’s context has been, for a long time, the axis of concern for the researchers of finance. This was warranted by the contributions of Sharpe 1964 Sharpe and Linter 1965 in their test to express the price of an asset by the systematic risk of this, last via the famous model of assets pricing known as the CAPM Capital Assets Pricing Model. The identification of the systematic risk is initially on some theoretical bases, that it is about the CAPM developed by Sharpe 1964, Sharpe and Lintner 1965 and Mossin 1966 or of the theory of the arbitrage pricing theory APT introduced by Ross 1976 and illustrated by Chen, Roll and Ross 1986.