Mathematical Finance Seminar
May 2, 2002 , 5:30 PM to 7:00 PM
H. E. Stanley, Boston University
Understanding Large Movements in Stock Market Activity
After a very short introduction to some of the most recent results
obtained in the field of econophysics we consider the problem of ``rare
events'' of the stock market price dynamics. It is becoming widely
appreciated that even extremely large movements in stock market activity
may not be ``outliers'' but rather may conform to newly-uncovered
empirical laws, such as the (i) power law distribution of returns with
exponent 3, outside the Levy-stable regime, (ii) power law distribution
of trading volume with exponent 1.5 [1]. We discuss these new empirical
laws, and also discuss how one interdisciplinary ``economist/physicist''
collaboration is beginning to gain theoretical insight and understanding
of these new empirical laws using concepts drawn from both the economics
and physical sciences [2-5].
The research reported was done primarily in collaboration with X. Gabaix
MIT Economics Dept), P. Gopikrishnan (now at Goldman Sachs), and
V. Plerou (Boston University) and has been supported by NSF and BP.
[1] R. N. Mantegna and H. E. Stanley, Introduction to Econophysics:
Correlations and Complexity in Finance (Cambridge University Press,
Cambridge, 2000).
[2] V. Plerou, P. Gopikrishnan, X. Gabaix, and H. E. Stanley,
``Quantifying Stock Price Response to Demand Fluctuations'' cond-mat
0106657 (preprint).
[3] V. Plerou, P. Gopikrishnan, and H. E. Stanley, ``Critical Threshold for
Symmetry Breaking in Stock Demand'' (preprint) cond-mat/0111349.
[4] X. Gabaix, P. Gopikrishnan, V. Plerou, and H. E. Stanley, ``A Simple
Theory of Asset Market Fluctuations, Motivated by the Cubic and Half
Cubic Laws of Trading Activity in the Stock Market'' (preprint).
[5] V. Plerou, P. Gopikrishnan, B. Rosenow, L.A.N. Amaral, T. Guhr, and
H. E. Stanley, ``A Random Matrix approach to Financial
Cross-Correlations'' Phys. Rev. E (in press) cond-mat/0108023.