The introductory chapter outlines the argument of the book and positions it both politically and intellectually. Politically, it challenges the naturalisation of financial assets as unproblematic objects with value in their own right and thus as just one more commodity that it is perfectly reasonable to buy and sell for profit. In reality they are nothing more than promises, and often highly tenuous promises, and their value depends circularly on the social construction of beliefs about their value. We must therefore doubt whether financial values bear any relation to the social value of financial products. Indeed, we are entitled to ask whether the buying and selling of financial instruments creates social value at all, or ultimately generates greater social costs than any benefits it may deliver. Intellectually, the book draws on recent work on valuation, but its explanatory framework depends on a critical realist understanding of causality and social structures.