This book defines investors' sentiments as investors' attitude and opinion towards investing in the stocks. Investors' sentiment has been a serious subject of study in the finance literature for a number of years. The research in behavioural finance is comparatively less in India. It is not possible for all retail investors to make a successful investment decision at all times. A better undertaking of behavioural process and outcomes is important for financial planners, investors and others. It is good to study periodically the investors' sentiment to find out what really influence them. An attempt has been in this book to develop and validate a comprehensive model based on investors' sentiment in Tamil Nadu. In short, this book explains how investment attitude is influenced by a variety of factors.