The 2007–2009 financial crisis has led to considerable debate about the role of financial industry actors in global regulatory processes. This article seeks to contribute to this debate by assessing when and why financial industry actors mobilise in order to influence securities markets regulations. Do these mobilisation patterns suggest undue influence by a small set of powerful industry actors, or do they reflect the engagement of a more diverse set of actors representing broader public interests? It is argued that variation in mobilisation patterns is a function of: (1) institutional opportunity (the openness and accessibility of regulatory politics); and (2) demonstration effects (how crises increase the salience of regulatory issues). Empirical analyses suggest that the financial crisis diminished the diversity of mobilising actors. This trend, however, is reversed when the news media disseminate information about the costs of weak financial regulation and thereby increase the salience of regulatory issues.