Creating flows of interpersonal bits: the automation of the London Stock Exchange, c. 1955-90

This article deals with the concept of market information. In particular, it argues that references to the so-called conduit metaphor, which represents markets as a series of information flows, hide the localized, historically contingent and materially mediated practices of the economy. Following the tradition of the performative theory of social institutions, this article argues that the specific meaning of ‘market information’ and its concrete manifestations (e.g. prices) depend on the sociotechnical character of the calculative practices through which market participants orient their economic actions. The point is illustrated through a historical reconstruction of the introduction of price and quote dissemination technologies in the London Stock Exchange between 1955 and 1990. By highlighting the historical and technological contingency of prices, the case of the London Stock Exchange shows that it is impossible to provide a universally and temporally invariant definition of market information.