The South Sea Bubble of 1720 was Britain’s first modern financial crisis. This chapter uses digital tools to study the development, during the early eighteenth century, of a conceptual framework describing bubbles in the financial market. It traces the emergence of the phrase ‘South Sea Bubble’ in the months and years after the crisis, alongside the more complicated patterns of evolution in what that phrase describes, ultimately arguing that there is little resemblance between the ‘South Sea Bubble’ of the 1720s and that of the present-day historical imagination. The chapter’s final claim is that the conceptual framework underpinning how we understand present-day financial crises has its origins in the latency of the words used, at the time, to describe the emerging and interlinked crises of 1720.