Clearly Irrational Financial Market Behavior: Evidence from the Early Exercise of Exchange Traded Stock Options

摘要

This paper analyzes the early exercise of exchange-traded options by different classes of investors over the 1996 to 1999 period. A large number of exercises are identified as clearly irrational without invoking any model of market equilibrium. Customers of discount brokers and customers of full-service brokers both engage in a significant number of irrational exercises while traders at large investment houses exhibit no irrational early exercise behavior. Rational and irrational exercise is triggered for discount and full-service customers by the underlying stock price attaining its highest level over the past year and by high returns on the underlying stock.