The article investigates the history of securitization in order to analyze more general transformations in the social and political approaches towards various types of credit risks. The history of securitization reveals a long-term shift in the conventions addressed when dealing with risks. Socio-political conventions were gradually replaced by financialized, market-oriented conventions in which investors would take responsibilities and replace other actors, like the state or private corporations, which were previously involved. The first part of the article examines the epistemic and economic origins of securitization. In the second part, the analysis focuses on the golden age of securitization, from the 1980s to the mid-2000s, discussing decisive factors for its expansion. The third part reflects the role of securitization in the financial crisis of 2007/08 and debates the extent to which mathematical expertise can be made responsible for the collapsing securities market.