Elie Ayache was trained as an engineer at l’École Polytechnique, Paris. He subsequently pursued a career as an option market maker on the floor of Marché à Terme International de France (MATIF, 1987–90) and London International Financial Futures and Options Exchange (LIFFE, 1990–95). He then turned to the philosophy of probability, by pursuing postgraduate studies at the Sorbonne, and to the technology of derivative pricing, by co-founding ITO 33, a financial software company, in 1999. Today, ITO 33 is the leading specialist in the pricing of convertible bonds, the equity-to-credit problem, and more generally the calibration and recalibration of volatility surfaces. Ayache has published numerous articles on the philosophy of contingent claims. He is the author of The Blank Swan: The End of Probability (2010) and The Medium of Contingency: An Inverse View of the Market (2015).