Skip to content

Reaction-Diffusion-Branching Models of Stock Price Fluctuations

Lei-Han Tang, Guang-Shan Tian

cond-mat.stat-mecharXiv:cond-mat/9811114

Abstract

Several models of stock trading [P. Bak et al, Physica A 246, 430 (1997)] are analyzed in analogy with one-dimensional, two-species reaction-diffusion-branching processes. Using heuristic and scaling arguments, we show that the short-time market price variation is subdiffusive with a Hurst exponent H=1/4. Biased diffusion towards the market price and blind-eyed copying lead to crossovers to the empirically observed random-walk behavior (H=1/2) at long times. The calculated crossover forms and diffusion constants are shown to agree well with simulation data.

Create a lesson