Innovation processes are influenced by the dynamics of expectations. This paper addresses the question of what happens after a hype. It takes a closer look at the case of stationary fuel cells, for which a hype could be identified in 2001 followed by a clear downscaling of expectations and disappointment. Innovation activities, however, remained largely unaffected by the disappointment. We offer two explanations. First, only generalised expectations were adjusted after the hype, while overarching expectations (frames) remained stable and continued to legitimate the technology. Second, emerging institutional structures lead to increasing positive externalities thus stabilising ongoing innovation activities. These institutionalisation processes, again, were supported by a transformation of promises into requirements during the hype and the fact that the frames continued to legitimise the technology afterwards. We conclude with the proposition to differentiate disappointments according to which type of expectations changes after the hype.