For some time now, the insider trading enforcement regime in the United States has been criticized by market participants, scholars, and jurists alike as lacking clarity, theoretical integrity, and a coherent rationale. One problem is that Congress has never enacted a statute that specifically defines “insider trading.” Instead, the current regime has been cobbled together on an ad hoc basis through the common law and administrative proceedings. As the recent Report of the Bharara Task Force on Insider Trading puts it, the absence of an insider trading statute “has left market participants without sufficient guidance on how to comport themselves, prosecutors and regulators with undue challenges in holding wrongful actors accountable, those accused of misconduct with burdens in defending themselves, and the public with reason to question the fairness and integrity of our securities markets.”

Congress appears to be responding, and a number of bills that would define insider trading and otherwise reform the enforcement regime are receiving bipartisan support. But it would be a mistake to pass new legislation without first taking the time to get clear on the economic and ethical reasons for regulating insider trading. This is particularly true in light of the fact that the general…