; (4) identifies the major digital asset trading platforms in the United States, the number of customer accounts with each platform, and the annual trading volume of each platform; (5) estimates the number of United States citizens who use United States registered digital asset trading platforms compared to foreign digital asset trading platforms; (6) estimates the amount of tax revenue which was not received by the United States Treasury due to under reporting by United States taxpayers each year between 2016 and 2020; and (7) makes legislative and regulatory recommendations regarding changes which would improve reporting and collection of taxes on digital assets so it would be closer to reporting and collection of taxes on securities holdings. (b) Specified committees In this section, the term specified committees means— (1) the Ways and Means Committee of the House of Representatives; (2) the Finance Committee of the Senate; (3) the Committee on Financial Services of the House of Representatives; (4) the Committee on Banking, Housing, and Urban Affairs of the Senate; (5) the Committee on Agriculture of the House of Representatives; and (6) the Committee on Agriculture, Nutrition, and Forestry of the Senate. 502. Report on ransomware and digital assets (a) Report Not later than 270 days after the date of enactment of this Act, the Department of Justice, Department of Homeland Security, Department of the Treasury, and Board of Governors of the Federal Reserve System shall jointly submit a report to the appropriate committees that— (1) summarizes the number and size of recent ransomware attacks in the United States and the world; (2) discusses the frequency of ransomware hackers requesting payment in digital assets and identifies the most common digital assets which are demanded; (3) discusses the use of mixing and tumbling services and money mules to help obscure audit trail for the digital assets involved