This legislation directs the Financial Crimes Enforcement Network (FinCEN) to develop and issue an advisory concerning the procurement of firearms and firearm accessories by homegrown violent extremists and other perpetrators of domestic terrorism. The advisory will also address how the United States firearms market is exploited to facilitate gun violence. To achieve this, FinCEN is mandated to request information from financial institutions within one year of the bill's enactment. Before requesting information, FinCEN must consult with the Director of the Federal Bureau of Investigation, the Director of the Bureau of Alcohol, Tobacco, Firearms and Explosives, and sellers of firearms and firearm accessories. Within 540 days, if FinCEN determines the collected information is sufficient, it must issue the advisory. If the information is deemed insufficient, FinCEN must submit a detailed report to congressional committees explaining the reasons and any barriers encountered. Additionally, FinCEN is required to promulgate rules within 90 days to define key terms such as "firearm accessory" and "homegrown violent extremist."