Listed corporations achieve effectiveness through segmentation of investors. Categorization of like- minded investors diminishes goal incongruence. This thesis aim to examine an Investor models accuracy, provided by a Professor Emeritus in Economic Psychology in 2001. This model segments investors as active, passive, speculative and naive investors. This thesis has a demarcation to private investors on the Swedish stock market. It has a deductive and qualitative approach as the purpose is to study the Investor model.