March 29, 1900, is considered by many to be the day mathematical finance was born. On that day a French doctoral student, Louis Bachelier, successfully defended his thesis Theorie de la Speculation at the Sorbonne. This book provides a translation of Bachelier's seminal work. "Louis Bachelier's thesis is a seminal work, and to have it readily accessible will be a most valuable contribution to the field. This book represents a timely look back at the scientific origins of the enormously important modern-day finance industry."-Chris Rogers, University of Cambridge, coauthor of Diffusions, Markov Processes and Martingales, Volumes 1 and 2