Issue
EPL
Volume 77, Number 5, March 2007
Article Number 58004
Number of page(s) 5
Section Interdisciplinary Physics and Related Areas of Science and Technology
DOI http://dx.doi.org/10.1209/0295-5075/77/58004
Published online 21 February 2007
EPL, 77 (2007) 58004
DOI: 10.1209/0295-5075/77/58004

Self-organization of price fluctuation distribution in evolving markets

R. K. Pan and S. Sinha

The Institute of Mathematical Sciences, C.I.T. Campus - Taramani, Chennai, 600 113 India

sitabhra@imsc.res.in

received 21 June 2006; accepted in final form 16 January 2007; published March 2007
published online 21 February 2007

Abstract
Financial markets can be seen as complex systems in non-equilibrium steady state, one of whose most important properties is the distribution of price fluctuations. Recently, there have been assertions that this distribution is qualitatively different in emerging markets as compared to developed markets. Here we analyse both high-frequency tick-by-tick as well as daily closing price data to show that the price fluctuations in the Indian stock market, one of the largest emerging markets, have a distribution that is identical to that observed for developed markets (e.g., NYSE). In particular, the cumulative distribution has a long tail described by a power law with an exponent $\alpha \approx 3$. Also, we study the historical evolution of this distribution over the period of existence of the National Stock Exchange (NSE) of India, which coincided with the rapid transformation of the Indian economy due to liberalization, and show that this power law tail has been present almost throughout. We conclude that the "inverse cubic law" is a truly universal feature of a financial market, independent of its stage of development or the condition of the underlying economy.

PACS
89.65.Gh - Economics; econophysics, financial markets, business and management.
89.65.-s - Social and economic systems.
05.65.+b - Self-organized systems.

© Europhysics Letters Association 2007