X-Capm Revisited: the Institutional Extrapolative Capital Asset Pricing Model (i-X

Abstract

This study constructs and tests a consumption-based asset pricing model in which someinvestors form beliefs about future price changes in the stock market by extrapolating past pricechanges, while other investors hold fully rational beliefs. The contribution of the present work isthe inclusion of institutional investor bias. As such it extends theory. But it also conductseconometric tests by using daily survey data on individual and institutional investors’ sentimenton the current economic situation and their future expectations. Empirical findings may implythat institutions’ sentiment reverts quicker to the equilibrium price than individual sentiment, atleast with regard to their beliefs on future economic outlook. If studied further with a biggerdataset, it may imply that institutional investors are closer to the rational-decision makingmechanism compared to individual investors. The theoretical framework rests on prospecttheory. The market studied is the US equity market, however findings and suggestions can beapplied to global markets and various financial instruments.