This article explores the trajectory of so-called guaranteed social housing in the Czech Republic as an example of penetrating financial instruments into the public policy realm. The project, promoted by the government’s Agency for Social Inclusion, was intended to encourage private landlords to rent their properties to people in need through commercial insurance against the risk of rent defaults. Using policy documents, media and interviews with governmental officers, the article describes the performative strength of financial instruments in the sphere traditionally occupied by the welfare state. In financialisation literature, the proliferation of financial instruments is often described as a one-way process in which these instruments colonise public domains. However, the empirical case discussed in the article shows that this process is much more complex and contingent, and financial instruments are not used as the best option but rather as a last resort in a situation marked by weak policies.