The use of dynamical networks to detect the hierarchical organization of financial market sectors
Two kinds of filtered networks: minimum spanning trees (MSTs) and planar maximally filtered graphs (PMFGs) are constructed from dynamical correlations computed over a moving window. We study the evolution over time of both hierarchical and topological properties of these graphs in relation to market fluctuations. We verify that the dynamical PMFG preserves the same hierarchical structure as the dynamical MST, providing in addition a more significant and richer structure, a stronger robustness and dynamical stability. Central and peripheral stocks are differentiated by using a combination of different topological measures. We find stocks well connected and central; stocks well connected but peripheral; stocks poorly connected but central; stocks poorly connected and peripheral. It results that the Financial sector plays a central role in the entire system. The robustness, stability and persistence of these findings are verified by changing the time window and by performing the computations on different time periods. We discuss these results and the economic meaning of this hierarchical positioning.
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- 3.J.-P. Onnela, M.Sc. Thesis, Department of Electrical and Communications Engineering, Helsinki University of Technology (2002)Google Scholar
- 16.A planar graph is a graph that can be represented on an Euclidean plane with no intersections between edgesGoogle Scholar
- 17.T. Di Matteo, T. Aste, International Journal of Theoretical and Applied Finance 5/1, 107 (2002)Google Scholar
- 20.J. Eisner, Manuscript, University of Pennsylvania (1997)Google Scholar
- 22.G. Caldarelli, Scale-Free Networks. Complex Webs in Nature and Technology (Oxford University Press, 2007)Google Scholar
- 23.S.N. Dorogovtsev, J.F.F. Mendes, Evolution of Networks. From Biological Nets to the Internet and www (Oxford University Press, 2003)Google Scholar