Drilling through the Allegheny mountains: liquidity, materiality and high-frequency trading

In 1999, Carruthers and Stinchcombe provided the classic discussion of 'the social structure of liquidity': the institutional arrangements that support markets in which 'exchange occurs easily and frequently'. Our argument in this paper is that the material aspects of these arrangements - and particularly the materiality of prices - need far closer attention than they normally receive. We develop this argument by highlighting two features of new assemblages that have been created in financial markets since 1999. First, these assemblages give sharp economic significance to spatial location and to physical phenomena such as the speed of light (the physics of these assemblages is Einsteinian, not Newtonian, so to speak). Second, they have provoked fierce controversy focusing on ultra-fast 'high-frequency trading', controversy in which issues of materiality are interwoven intimately with questions of legitimacy, particularly of fairness.