This book attempts to provide insight into role of some of the underlying reasons and biases that causes some investors to behave irrationally and often against their best interests. This study will give them an edge when it comes to making decision of investment particularly in Equity market. Researchers developed a hypothetical model based on literature review .Investments of Pakistani stock were chosen for the study. The data was drawn together from 84investors.The impact was measured with a tool and the analysis showed varying responses while taking investment decision. Glamour stocks and sin/faith based stocks are the major driving forces to the final choice.