On February 4, the Federal Circuit vacated and remanded a $1.1B damages award against Apple and Broadcom in litigation filed by the California Institute of Technology (Caltech), also trimming the underlying infringement verdict. While the reversal of such a large damages verdict is notable on its own, the Federal Circuit’s decision was also significant due to its expansion of inter partes review (IPR) estoppel—the statutory requirement that restricts petitioners from raising certain IPR validity arguments in subsequent district court challenges. In Caltech, the Federal Circuit resolved a district court split over the application of that requirement by overruling its 2016 Shaw Industries Group v. Creel Automated Systems decision, now holding that a petitioner is estopped not just from later asserting arguments actually raised in a successful petition, but also from including those arguments that they “reasonably could have” included.