This publication is first and foremost an observation, conducted during ten weeks of lockdown in France, which started on 13 March 2020. As such, it is a logbook, completed as the days and weeks passed. It is also a theoretical endeavour to interpret, explain or recount the eruption of the crisis ― it is these very first weeks which are of interest, as they contain the maximum intensity of the real, financial and psychological shock, in the form of a DNA for what follows. This theoretical endeavour makes it possible to test, against the reality of the crisis, a certain number of hypotheses made in earlier works and to consolidate and refine our tool box. The COVID-19 crisis offers a unique case-study for a theory which is concerned with the analogy between the circulation of viruses and that of money, images and narratives. This period also reveals a notable gap, which is rapidly described as irrational, between the traditional, accepted view of fundamentals and the prices observed on the financial markets. The term "irrational" is used to denote a difficulty or failure to understand a certain idea of posited rationality, especially when defined ex ante. This may be due to an imperfect or incorrect interpretation of a relevant subject. Or, on the contrary, it may indicate that the matter under consideration is not relevant. It is, therefore, necessary to reformulate the fundamentals, as a function of subjective value and narration.
