Peer Pressure: Social Interaction and the Disposition Effect

Abstract

Social interaction contributes to some traders' disposition effect. New data from an investment-specific social network linked to individual-level trading records builds evidence of this connection. To credibly estimate causal peer effects, I exploit the staggered entry of retail brokerages into partnerships with the social trading web-platform and compare trader activity before and after exposure to these new social conditions. Access to the social network nearly doubles the magnitude of a trader's disposition effect. Traders connected in the network develop correlated levels of the disposition effect, a finding that can be replicated using workhorse data from a large discount brokerage.

Keywords: Individual Investors, Disposition Effect, Behavioral Biases, Social Networks, Causal Peer Effects