My research centres on economic sociology, especially new developments within algorithmic finance (including high-frequency trading). I have a long-standing interest in how particular forms of knowledge, in the form of scholarly semantics, have political effects. I have examined this in studies of crime semantics (my PhD) and crowd semantics, the latter culminating with my award-winning book, The Politics of Crowds: An Alternative History of Sociology (Cambridge UP, 2012). My most recent book is Social Avalanche: Crowds, Cities and Financial Markets' (Cambridge UP, 2020). In addition to this, I am interested in architecture and urban sociology, in particular in issues relating to atmospheres and atmospheric politics. I am also the PI of the ERC-funded project Algorithmic Finance.