Discussions about insider trading regulation veer between the poles of forbidding insider trading to protect market integrity and allowing insider trading to foster informational efficiency. We study traders’ preferences for regulation by offering them concurrent markets with different regulatory regimes in an experimental setting. We find that informed traders’ preference for the unregulated market causes both informed and uninformed traders to be more active in the unregulated market. This market, thus, sees more trading volume, lower spreads, and less mispricing. Nevertheless, uninformed traders suffer greater losses in unregulated markets, while informed traders profit from the absence of regulation.

Modern capital markets are subject to many interventions and regulations, some of which curtail the implementation of specific trading strategies in a market. While we understand much of these regulations’ individual effects, the picture is less clear about their joint effects. This paper considers the interaction of two regulations, namely rules limiting shorting of assets and cash, and rules limiting insider trading. For these regulations, prior research shows spikes in short-selling activity around the revelation of insider information, which different studies trace to different causes. Among other results, we find that both allowing short positions and allowing informed trading causes informed traders to increase their market activity and causes mispricing and spreads to diminish. Nevertheless, we find no evidence for significant interaction effects between the two regulations.