New elements on Jules Regnault’s Calcul des chances et philosophie de la bourse [Calculation of the Chance and Philosophy of the Stock Market]: a very well diffused book and new connections with Louis Bachelier

It is nowadays well-known that the first publication about the random character of stock market prices date back to 1863 with Jules Regnault’s Calcul des chances et philosophie de la bourse [Calculation of the Chance and Philosophy of the Stock Market]. This book is the first work in modern finance we know today. Unfortunately, to date, we did not have significant information about the diffusion of this book and its influence. Recently several new elements have been discovered that change markedly what we thought we knew about Jules Regnault and about the dissemination and application of his ideas. This article presents and analyzes these new elements. It shows that this author grew up in an intellectual environment in Brussels closely associated with some of the most influent academics and mathematicians at this time. This article also shows that this book was largely diffused and more importantly it circulated among the most important French mathematicians interested in the application of the calculus of probability to finance and social issues when Louis Bachelier started his doctoral studies. This article sheds new light on the early history of financial economics and provides clear connections between Jules Regnault and Louis Bachelier