Phase transition in the S&P stock market

Authored by Friedrich Wagner, Matthias Raddant

Date Published: 2016

DOI: 10.1007/s11403-015-0160-x

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Model Documentation: Other Narrative Mathematical description

Model Code URLs: Model code not found

Abstract

We analyze the returns of stocks contained in the Standard \& Poor's 500 index from 1987 until 2011. We use covariance matrices of the firms' returns determined in a time windows of several years. We find that the eigenvector belonging to the leading eigenvalue (the market) exhibits a phase transition. The market is in an ordered state from 1995 to 2005 and in a disordered state after 2005. We can relate this transition to an order parameter derived from the stocks' beta and the trading volume. This order parameter can also be interpreted within an agent-based model.
Tags
noise Risk Model Fluctuations Financial-markets Returns Matrices