The significance of Graham in Buffett‟s career and the role of a mentor he would have in future deserve a few words to be mentioned about his teachings. Benjamin Graham is known as “the father of value investing”. He stressed the importance of trading on the market as one would trade with a business partner that offers you the chance to buy you or sell you his interest on a daily basis. This imaginary partner, to whom he referred as Mr. Market, would sometimes offer fair deals but often his price would be either undervalued or overvalued given the characteristics of a specific business, which created the possibility of speculation. For him having a margin of safety on an investment, meaning to buy a stock only if its price is lower than the conservative value of he business, was essential. In this way he ensured any investment from fluctuations on the negative side. For this purpose an investor has to determine the intrinsic value of a company. In his believes a company that was well managed and firm in its belief about the value of its product could and should prosper as an investment. The mathematical simplicity of Graham‟s methods appealed much to Warren‟s feeling of numbers.