This thesis analyses the reactions of business interest groups following an external shock: the global financial crisis. This challenging moment allows to analyze how business interest groups adapt to moments which tend to be characterized by in­ creasing issue salience and legitimacy threats. Specifically, I look at the strategies applied by business interest groups during both higher and lower issue salience along with conflicts and coalition formation within the business interest group community. The emphasis of this thesis is on Switzerland which is an intriguing case given the centrality of business interest groups in decision-making, as well as the prominence of the financial industry. Concretely, I employ an embedded case study to investigate three specific public policies related to the financial crisis: financial regulation, corporate governance, and tax policy. Firstly, I apply a theory-testing process-tracing to examine the underlying mechanisms linking the global financial crisis with the reaction of business interest groups. Secondly, in order to examine coalitions and conflict within the business interest groups community, I apply a mixed-method approach in which I combine a quantitative text analysis method with a thematic analysis. Finally, concerning the general strategies, I rely on semi-structured inter­ views and documents. The results show that the increasingly unfavourable opinion of financial institutions and transnational companies had a significant impact on the policies investigated - although in different ways - and on the preferences and strategies of business interest groups. This thesis illustrates how crucial perceived legitimacy of business interest groups is and how, when this is missing, the business interest group community adapts.