H.R. 4619 would require the Securities and Exchange Commission (SEC) to issue rules that prohibit market makers from “trading ahead,” using nonpublic information provided by customers to trade securities. The bill would establish civil penalties, which are recorded as revenues, for employees of market makers who violate the bill’s prohibitions. CBO estimates that enacting H.R. 4619 would not affect direct spending and would have an insignificant on revenues over the 2023-2032 period. CBO has not estimated the discretionary costs of implementing the bill. The bill would impose a private-sector mandate as defined in the Unfunded Mandates Reform Act that would not exceed the annual threshold of $184 million in 2022 (adjusted annually for inflation). The bill contains no intergovernmental mandates.