This section examines the concept of investment, the fundamental characteristics of investors, and the factors shaping investment decisions using a behavioral finance approach. Unlike the fully rational individual model assumed by classical finance, the investment process has a multidimensional structure shaped by psychological tendencies, cognitive biases, emotions, and social influences. In this context, investor types are categorized as individual and institutional investors, but it is emphasized that individual investors' decision-making processes are more susceptible to psychological factors.

Individual investor profiles are explained through their association with behavioral biases and risk perceptions. Personal, financial, and environmental factors influencing investment decisions are evaluated within the framework of variables such as knowledge level, expectations, income status, social environment, and cultural background. The impact of these factors on investment behavior, along with cognitive limitations and psychological tendencies, is explored to explain why investors make different decisions under similar circumstances.

Finally, basic financial investment instruments are introduced, and the reasons investors choose these instruments are linked to psychological tendencies. This demonstrates that the search for security, perception of uncertainty, and past experience are as important as economic returns in determining investment instrument selection.