Purpose – The purpose of this paper is to examine an entrepreneur’s attempt to gain legitimacy and change institutions in a multiple institutions setting. Design/methodology/approach – The authors conducted a qualitative case study to track an entrepreneur’s efforts to create a new financial instrument and get it accepted and traded on the New York Stock Exchange. Findings – The authors introduce the concept of institutional judo, analogous to the martial art where a fighter uses his opponent’s forces against him. While institutional theory has focussed on how institutional pressures force actors to conform, the term judo refers to an actor using institutional pressures to their advantage in changing those very institutions. Research limitations/implications – This qualitative research involves a single case study, but is most suited to revealing extensions of theory and subtle processes. Practical implications – The approach allowed the authors to provide a nuanced look at the actual change efforts by an entrepreneur to gain legitimacy. Social implications – This study provides a nuanced look at actual attempts to change institutions. Originality/value – Institutional judo offers a new change mechanism within institutional theory.