In the current era of strong worldwide market couplings the global financial village became highly prone to systemic collapses, events that can rapidly sweep through out the entire village. Here we present a new methodology to assess and quantify inter-market relations. The approach is based on...

We analyze the stock prices of the S&P market from 1987 to 2012 with the covariance matrix of the firm returns determined in time windows of several years. The eigenvector belonging to the leading eigenvalue (market) exhibits in its long term time dependence a phase transition with an order...

In this paper we analyze transitions in the stock markets of the US, the UK, and Germany. For all this markets we find that while the markets were focused on stocks from the IT and technology sector around the year 2000, this focus has vanished and the markets have mostly moved towards a focus...

Properly estimating correlations and understanding how they change under different economic conditions plays a key role in asset pricing models, risk management, and many econometric models. In this paper we introduce a robust framework to identify a meaningful correlation relationship, address...

Understanding correlations in complex systems is crucial in the face of turbulence, such as the ongoing financial crisis. However, in complex systems, such as financial systems, correlations are not constant but instead vary in time. Here we address the question of quantifying state-dependent...

The impacts of the Subprime Financial crisis resulted in generally similar decline and volatility in both developed and emerging stock markets. However, in the aftermath of the crisis, the performance of emerging economies was stronger. To investigate this phenomena, this paper seeks to gauge...

We develop networks of international stock market indices using information and correlation based measures. We use 83 stock market indices of a diversity of countries, as well as their single day lagged values, to probe the correlation and the flow of information from one stock index to another...