The market dynamics of technology stocks in the late nineties has stimulated a growing body of theories that analyze the joint effects of short-sales constraints and heterogeneous beliefs on stock prices and trading volume. This paper examines implications of these theories using a unique data...

Commentaries on the credit bubble of 2003-2007 routinely equate it with earlier episodes like the Internet boom. While credits were over-priced like Internet stocks a decade before, we show, using a model based on disagreement and short-sales constraints, that this is where the similarity ends....