Impact investing is a dynamic field that has been recently been discussed as a supplemental funding source for addressing societal problems. The topic has generated significant interest and is presumed to achieve significant growth rates for the coming years. This book provides a refreshed yet comprehensive overview about the market, financial instruments and the associated impact assessment. Specifically, it covers the concept of impact investing within the broader field of social finance as well as the relevant (and new) actors, presents current financing instruments and the various tools to assess the impact of the investing strategy, and introduces valuation and fund modelling techniques which impact the investment decision of fund managers. This useful reference tool will be of interest to academics and researchers in the field of impact investing alongside students and practitioners in the space.