This book deals with the investors' behavior and stock prices variations for the period 1998-2008 in Karachi Stock Exchange (KSE), Pakistan. The first chapter comprises on working and performance of the KSE. The second chapter presents the results of surveys which are conducted in summer 2007 in KSE. Participants were asked to share the importance of twenty macro-economic, firm-specific accounting variables and other risk factors by marking only five boxes on the questionnaire with their top most priority whenever they do investment in the stock market. Based on the institutional investors' preferred variables, there has been developed a statistical relationship for determining the stock prices by applying the approaches of Nicholson (1960), Amoako-Adu and Smith (2002), Gordon and Shapiro (1956), Gordon (1959) and Kothari and Zimmerman (1995) in the third, fourth and fifth chapters. These empirical findings have the ability to evaluate the stocks and guide to investors for making better investment decisions. These empirical findings may help out the investors to choose optimal portfolio, to monitor efficiently and manage financial risks.