Amends the Antitrust Criminal Penalty Enhancement and Reform Act of 2004 to: (1) extend until June 22, 2020, provisions of that Act limiting civil damages in antitrust enforcement actions involving conduct covered by antitrust leniency agreements; and (2) revise the timeliness requirements applicable to an antitrust leniency applicant for cooperating in an antitrust enforcement proceeding, including the timeliness of cooperation after a stay or protective order has expired or terminated. Directs the Comptroller General, within one year after the enactment of this Act, to submit to the congressional Judiciary Committees a report on the effectiveness of the Antitrust Criminal Penalty Enhancement and Reform Act of 2004, both in criminal investigation and enforcement by the Department of Justice (DOJ), and in private civil actions. Requires such report to include a study of the appropriateness of the addition of qui tam proceedings to the antitrust leniency program and of creating anti-retaliatory protection for employees who report illegal anticompetitive conduct. Provides for compliance with the Statutory Pay-As-You-Go Act of 2010.