Structural Evolution of Stock Networks

In this study, we report the changes and evolution of non-overlapping yearly stock networks (asset graph) in time period from 2000 to 2012. Thirteen annual non-overlapping windows are created by Bonferroni correction of p-values used to estimate a partial-correlation threshold for portfolio of 60 stocks belonging the SP100 index. We analyze each network structure by applying tools from Information Theory and descriptive quantifiers from complex networks to quantify and compare evolving network's topologies. We have found that stock network structure drastically changed after the year 2006, and network has higher level of randomness in the structures of year 2008 and year 2011.