In this first edition of Orrick’s quarterly series on PTAB trends and precedent, we provide statistics on the falling institution rate, relatively steady challenger success rate, and rapid increase in discretionary denials. Institution decisions in Q1 of 2021 suggest that the upward trend in discretionary denials may subside this year and lead to an increase in the overall institution rate, and we spotlight developments suggesting this potential change. We also spotlight recent developments in district courts’ application of IPR estoppel. On the one hand, for petitioners that receive adverse final written decisions, these developments will likely make mounting a district court prior use defense increasingly challenging, but, on the other hand, may provide an unlikely avenue to advance an invalidity defense based on printed publications despite estoppel.