Louis Bachelier

Louis Bachelier

French mathematician
Date of Birth: 11.03.1870
Country: France

Biography of Louis Bachelier

Louis Jean-Baptiste Alphonse Bachelier was born in Le Havre, France, on March 11, 1870. His father was a wine merchant, a scientist, and the vice-consul of Venezuela in Le Havre. His mother was the daughter of an important banker who was also a poet. After both of his parents passed away, Bachelier took on the responsibility of caring for his sister and three-year-old brother, as well as managing the family business.

During this challenging period, Bachelier gained practical knowledge of financial markets. His studies were temporarily interrupted due to military service. In 1892, Louis arrived in Paris to study at the Sorbonne. Historians report that Bachelier's dissertation topic initially did not receive much enthusiasm. However, his supervisor Henri Poincaré found some aspects of his work commendable. Poincaré described Bachelier's approach to studying Gauss's law of errors as "highly original" and expressed regret that Bachelier did not further develop this part of his dissertation.

In the end, Bachelier successfully defended his dissertation, 'The Theory of Speculation,' which was published in 1900 in the prestigious journal 'Annales Scientifiques de l'École Normale Supérieure.' This dissertation marked the first instance in history where advanced mathematics was applied to the study of finance. Many consider Bachelier a pioneer in the field of financial mathematics and stochastic processes.

In the following years, Bachelier continued to work on developing the theory of diffusion processes, and his scientific papers appeared in various academic journals. In 1909, he became a "freelance professor" at the Sorbonne, and in 1914, his book 'Games, Chance, and Randomness' was published, selling over 6,000 copies.

With the support of the Paris University Council, Bachelier secured a position as a permanent professor at the Sorbonne. However, his career was interrupted by the outbreak of World War I, and Bachelier was compelled to join the French army as a private.

His military service concluded on December 31, 1918. From 1919, Louis held the position of an associate professor at the University of Besançon until one of the regular faculty members returned in 1922. He married Augustine Jeanne Maillot in September 1920 but soon became a widower.

In 1922, Bachelier replaced another professor, this time in Dijon. By 1925, he had relocated to Rennes. Finally, in 1927, Bachelier became a permanent professor at the University of Franche-Comté, where he worked for ten years until his retirement.

Aside from the career difficulties caused by World War I, Bachelier faced opposition in 1926 when seeking a professorial position in Dijon. The problem arose from the "misinterpretation" of one of Bachelier's articles by the reviewing professor Paul Lévy, who had no knowledge of Bachelier's works or of Bachelier himself. This understandably sparked Bachelier's "righteous anger." However, Lévy later recognized his mistake and reconciled with Bachelier.

Bachelier's work, based on a mathematical model of random processes, was published five years before Einstein's famous work on Brownian motion.