This theme issue originates from an invitational workshop on the spatiality and diversity of markets, convened at the Karl Polanyi Institute of Political Economy in Montreal in 2017. Workshop participants, regardless of their disciplinary backgrounds and diverse research interests, shared a conviction that markets should be analysed in their plural and hybrid forms, as social and political constructs always 'in making'. In contrast to more orthodox conceptions of markets as free-standing entities, discrete institutions or ideal types, this was translated into an imperative to centre 'marketization', along with attendant processes of market re/construction. While this was interpreted as a positive research programme, if a challenging and quite radically open one, there was also an underlying concern. The concern was that critical approaches to the study of markets, which foreground and problematize their variegated character, seem to have reached something of an impasse. A gulf has opened up between those orthodox market purists who seem to see little beyond the abstract market prescribed by the neoclassical model (a self-regulating system of rational buyers and sellers) and the heterodox sceptics who, if they do not sidestep the market altogether, focus instead on an unruly plethora of real markets, criticizing the neoclassical market model as an idealized and ideological construct. As we point out elsewhere (Peck et al., 2020), the problem with these polar(ized) positions is that, notwithstanding their philosophical and normative differences, they all tend to work with, or against, a received reading of the capital-M Market as advanced by standard economic theory, indexing to this analytical yardstick in either positive or negative terms. On the heterodox side, the sway of the neoclassical, capital-M Market is manifest across a range of perspectives. Political-economic accounts, for instance, tend to invoke an understanding of the market as a destructive juggernaut.