On this episode of Ropes & Gray’s Antitrust Insights podcast series, seasoned antitrust partners and former FTC and DOJ prosecutors Jonathan Klarfeld and Samer Musallam discuss significant changes—and their substantial impact on businesses—to the Hart-Scott-Rodino (“HSR”) rules, which went into effect on February 10, 2025, with private equity transactions partner Chau Le. The discussion covers expanded data and disclosure requirements, enhanced business and competition documents, and increased scrutiny of prior acquisitions. They also offer practical advice on navigating these new rules, emphasizing the importance of early engagement with antitrust counsel and diligent compliance efforts. *Since the recording of this podcast, the new FTC Chair, Andrew Ferguson, has publicly endorsed the new HSR rules.