The aim of this thesis is to explain the dynamics behind the increased level of price volatility and speculation in the oil market over the past three decades. In contrast to mainstream accounts, which typically invoke the notion of global oil shortage and so-called ‘peak oil’ arguments, this thesis suggests that price volatility and speculation in the oil market originate from a decades-long process of financialisation punctuated by recurring oil price shocks. This thesis examines the evolution of the international oil market with a view to investigate how, and to what effect, the process of financialisation has transformed the structure and dynamics of the global oil market between 1980 and 2010. In tracing this phenomenon to the contemporary oil market, and specifically to the context of the oil shocks, I identify three periods of financialisation: low (1980–1990), early (1991–2001), and advanced (2002–2008). My research suggests that the process of financialisation is both cause and proof of a profound change in the structure of the global oil market, insofar as the addition of financial actors has turned the triangle of producers, consumers, and mediators that characterised the oil market until the 1980s into a four-tier structure. Propelled by breakthroughs in technology and finance, this fourth player is found responsible not only for transforming the relationship between the oil industry and the financial sector, but also for reconfiguring the political economy of the international oil market.