Non-extensive Behavior of a Stock Market Index at Microscopic Time Scales

A. A. G. Cortines; R. Riera

doi:10.1016/j.physa.2006.10.099

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arXiv · physics/0607167

Non-extensive Behavior of a Stock Market Index at Microscopic Time Scales

A. A. G. Cortines·R. Riera

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Abstract

This paper presents an empirical investigation of the intraday Brazilian stock market price fluctuations, considering q-Gaussian distributions that emerge from a non-extensive statistical mechanics. Our results show that, when returns are measured over intervals less than one hour, the empirical distributions are well fitted by q-Gaussians with exponential damped tails. Scaling behavior is also observed for these microscopic time intervals. We find that the time evolution of the distributions is according to a super diffusive q-Gaussian stationary process within a nonlinear Fokker-Planck equation. This regime breaks down due to the exponential fall-off of the tails, which in turn, governs the transient dynamics to the long-term macroscopic Gaussian regime. Our results suggest that this modeling provides a framework for the description of the dynamics of stock markets intraday price fluctuations.

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A. A. G. Cortines, R. Riera. 2006-07-18. Non-extensive Behavior of a Stock Market Index at Microscopic Time Scales. https://doi.org/10.1016/j.physa.2006.10.099

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