Microscopic origin of non-Gaussian distributions of financial returns
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Data
2008-03-01
Autores
Biro, T. S.
Rosenfeld, Rogério [UNESP]
Título da Revista
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Editor
Elsevier B.V.
Resumo
In this paper we study the possible microscopic origin of heavy-tailed probability density distributions for the price variation of financial instruments. We extend the standard log-normal process to include another random component in the so-called stochastic volatility models. We study these models under an assumption, akin to the Born-Oppenheimer approximation, in which the volatility has already relaxed to its equilibrium distribution and acts as a background to the evolution of the price process. In this approximation, we show that all models of stochastic volatility should exhibit a scaling relation in the time lag of zero-drift modified log-returns. We verify that the Dow-Jones Industrial Average index indeed follows this scaling. We then focus on two popular stochastic volatility models, the Heston and Hull-White models. In particular, we show that in the Hull-White model the resulting probability distribution of log-returns in this approximation corresponds to the Tsallis (t-Student) distribution. The Tsallis parameters are given in terms of the microscopic stochastic volatility model. Finally, we show that the log-returns for 30 years Dow Jones index data is well fitted by a Tsallis distribution, obtaining the relevant parameters. (c) 2007 Elsevier B.V. All rights reserved.
Descrição
Palavras-chave
stochastic volatility, Born-Oppenheimer approximation, power-law distribution of returns
Como citar
Physica A-statistical Mechanics and Its Applications. Amsterdam: Elsevier B.V., v. 387, n. 7, p. 1603-1612, 2008.