This thought-provoking book introduces a financial economics perspective to the topic of eco-innovations and, more generally, sociotechnical transitions. It develops a model that illustrates how financial constraints can prevent the development of eco-innovations within companies and hinder the transition process towards a more sustainable regime. Edgardo Sica presents a review of the state of the art, as well as new data from original surveys aimed at testing the impact of financial constraints on eco-innovative decisions at radical and niche levels. He proposes a definitive conceptualisation of eco-innovations while stressing the relevance of the environmental performance of innovations, rather than the environmental motivation of the innovators. Through the use of a unique multilevel perspective model, the book critically analyses the extent to which financial constraints can hinder eco-innovative decisions, thereby crucially filling a gap in the current literature on eco-innovations. Firms, Finance and Sustainable Transitions will prove a stimulating read for academics, researchers and experts within the fields of eco-innovations, sustainable development, financial and environmental economics, and green finance.