We consider the dynamic relationship between trader emotions and asset market behavior. We create experimental asset markets with the structure first studied by Smith, Suchanek and Williams (1988), which is known to generate price bubbles and crashes. To track traders’ emotions in real time, we analyze participants' facial expressions with facereading software before and while the market is operating. We find that a positive emotional state correlates with purchases and overpricing. Fear correlates with low prices, price decreases, and selling. The experiment confirms the intuition that emotions and market dynamics are closely related.​