Bachelier

Bachelier is a surname of French origin. It is an occupational surname, derived from the Old French word "bachelier," which referred to a young man, a bachelor, or a knight of lower rank. The term itself is believed to have originated from the word "bac," meaning a horse, implying a rider or a young man who could afford to keep a horse, a sign of some social standing. Over time, it evolved to describe a young man, often unmarried, and later became a title for a holder of a bachelor's degree in universities.

The surname Bachelier can be found primarily in France and has spread to other parts of the world through migration. Notable individuals with this surname include Louis Bachelier, a French mathematician whose work in probability theory laid the foundation for modern financial mathematics. His 1900 thesis, "Théorie de la Spéculation" (Theory of Speculation), introduced the concept of a random walk now known as the Bachelier process, which describes the random movements of stock market prices. While his contributions were significant, they were largely overlooked during his lifetime and only gained wider recognition much later. The surname is not exceptionally common but is present across various regions and professions.