We investigate investor behaviors before and during the global financial crisis of 2007-2008 using complex network theory. We find that investor networks have different structures between pre-crisis and crisis periods with statistical significance. Moreover, we observe the herding tendency and...

We introduce various network similarity measures that can capture the topological changes of investor networks over time. We use them to study the joint dynamics of investor networks and stock price time series. We find that the network changes are positively correlated with volatility while...