AltFin seeks to better understand regional economic development at the interface of alternative economy approaches, here circular economy (CE), and sustainable finance, in order to comprehend mechanisms that will guide regional transitions towards sustainable development. Fundamentally, transitions as directed, yet open-ended, social processes require institutions to adapt and change. Thus, AltFin scrutinises in particular regional institutions in the three neighbouring countries France, Germany and Luxembourg, where national and regional initiatives have started to support CE endeavours. CE is indeed a prominent example of broader alternative economy approaches with particular – long-term – financing needs. At the same time, powerful financial firms, mainly embedded in international financial centres (IFCs) to serve global circuits of capital, have started to shift parts of their business towards sustainable finance. For example, large investment funds seek to invest in projects and assets that not only generate financial returns but also ecological and/or social benefits (impact investing). CE is an area that potentially matches these investment criteria, but, so far, the majority of financial firms anchored in IFCs invest much more on a global than on a national/regional level. Further, finance is a powerful player and may promote change in a different direction than that intended by CE agents. The proposed project builds on preliminary evidence from Luxembourg that although there is strong demand for financing CE projects on a national level, financial firms in Luxembourg’s IFC – which has heavily specialised in green bonds and green investment funds – primarily invest in extra-European regions and, there, mainly in climate finance projects. We hypothesise that one reason for this organisational, financial and geographical mismatch is a corresponding mismatch in Luxembourg’s institutions that are currently unable to (re-)align local finance needs in regional alternative economic projects with global finance supply in IFCs. We seek to investigate empirically in a comparative manner the power-induced relationships between sustainable finance designed in the IFCs Frankfurt, Luxembourg and Paris, and alternative economic activities in the three regional economies. Ultimately, AltFin seeks to develop a new framework of institutional change and its key mechanisms and practices at the interface of sustainable finance and alternative economies to strengthen regional economies and their sustainable development.