Efficient, inclusive, sustainable: these are only some of the concepts through which smart cities have been marketed globally, over the past fifteen years at least. But what has really driven smart city projects, governance, and economies? This book argues it is speculation: not merely finance, but a much broader technopolitical force seeking to calculate and shape the future. Smart cities have been testbeds for new technological products, governed through preemptive analytics, and fuelled by high-risk financial investments. Drawing on case studies from Kolkata and Cape Town, this book illustrates how smart city technologies speculate on the future to govern and monetise the present. Today, smart cities might have lost some of their hype already, but their legacies are here to stay, and their ethical and political implications appear more critical  than ever. This book offers insights into the speculative forces that undergird urban ‘smartness’, and into their implications on everyday life, spatial justice, and citizens’ rights.