A paper by Kim, Kim, and Rajgopal (2026) examines the effects of the Securities and Exchange Commission’s (SEC) 2022 amendments to Rule 10b5-1 on opportunistic insider trading. Kim, Kim, and Rajgopal provide compelling evidence that these amendments altered insider trading behavior. The paper’s research design is well suited to identifying whether opportunistic trading declined following the 2022 amendments. However, it leaves open an important question regarding the mechanism underlying these changes. Distinguishing among these mechanisms is important for both research and policy. If the observed effects arise primarily from the amended rule itself, the findings support greater reliance on ex ante trading constraints. If, instead, the amendments operated in part by inducing firms to strengthen their compliance programs and governance practices, the results underscore the importance of private ordering in implementing securities regulation. More broadly, understanding how legal reforms interact with firms’ internal governance systems may improve both the interpretation of empirical evidence and the design of future securities regulation.