Do investors trade too much? A laboratory experiment

TL;DR

This experimental study shows that investors tend to trade excessively, which harms their wealth, and highlights how risk preferences influence trading activity and market synchronization without major crashes.

Contribution

The paper provides experimental evidence on excess trading, market impact, and synchronized trading behavior, contributing new insights into investor behavior and market dynamics.

Findings

Excessive trading reduces traders' wealth.

Risk aversion correlates with higher trading activity.

Traders synchronize entry and exit points without causing crashes.

Abstract

We run experimental asset markets to investigate the emergence of excess trading and the occurrence of synchronised trading activity leading to crashes in the artificial markets. The market environment favours early investment in the risky asset and no posterior trading, i.e. a buy-and-hold strategy with a most probable return of over 600%. We observe that subjects trade too much, and due to the market impact that we explicitly implement, this is detrimental to their wealth. The asset market experiment was followed by risk aversion measurement. We find that preference for risk systematically leads to higher activity rates (and lower final wealth). We also measure subjects' expectations of future prices and find that their actions are fully consistent with their expectations. In particular, trading subjects try to beat the market and make profits by playing a buy low, sell high strategy. Finally, we have not detected any major market crash driven by collective panic modes, but rather a weaker but significant tendency of traders to synchronise their entry and exit points in the market.