Summary: Research into the role of sovereign investments in a time of crisis is still unsatisfactory. This timely Research Handbook investigates the juridical foundation of sovereign wealth funds and investments and extends our frontier of understanding in this important area. Current research surrounding sovereign wealth funds is focused on investment flows and trends that are grounded in economics, neglecting to consider the role of law and governance in the investigation. From a legal perspective, the Handbook narrates a 'passive' side of sovereign wealth funds and state owned companies, exploring how and to what extent the legal constraints imposed by host States act as barriers to investments. Additionally, the 'active' side is also discussed and the influence of ethical principles, treaty re-negotiations and sovereign immunity practices on state investments considered. A comprehensive reference on a complex area of research, the Handbook will be a valuable addition to the library of scholars and students interested in investment law, central banks, international economics and governance