The book's central theme is to develop a new theory of speculative capital related to other forms of capital, the world market, and the state. Unlike most Marxist and heterodox theories, the book distinguishes credit and fictitious capital from speculative capital to show its hegemony today in the capital markets. Speculative capital structures and also controls the so-called "real capital." The method is Marxist while also incorporating material from contemporary Marxist and heterodox authors like John Milios, Robert Meister, Tony Norfeld, Li Puma, Harald Strauß, Michael Heinrich, Suhail Malik, Bichler/Nitzan and Ellie Ayache. Offering a comprehensive study of the logic and mode of existence of capital in the 21st century, the book will be of interest to academics and students of monetary and financial economics alongside political economy.