Cross-correlation asymmetries and causal relationships between stock and market risk

PLoS One. 2014 Aug 27;9(8):e105874. doi: 10.1371/journal.pone.0105874. eCollection 2014.

Abstract

We study historical correlations and lead-lag relationships between individual stock risk (volatility of daily stock returns) and market risk (volatility of daily returns of a market-representative portfolio) in the US stock market. We consider the cross-correlation functions averaged over all stocks, using 71 stock prices from the Standard & Poor's 500 index for 1994-2013. We focus on the behavior of the cross-correlations at the times of financial crises with significant jumps of market volatility. The observed historical dynamics showed that the dependence between the risks was almost linear during the US stock market downturn of 2002 and after the US housing bubble in 2007, remaining at that level until 2013. Moreover, the averaged cross-correlation function often had an asymmetric shape with respect to zero lag in the periods of high correlation. We develop the analysis by the application of the linear response formalism to study underlying causal relations. The calculated response functions suggest the presence of characteristic regimes near financial crashes, when the volatility of an individual stock follows the market volatility and vice versa.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Commerce / economics
  • Commerce / statistics & numerical data*
  • Europe
  • Humans
  • Internationality
  • Investments / economics
  • Investments / statistics & numerical data*
  • Marketing / economics
  • Marketing / statistics & numerical data*
  • Models, Economic*
  • Risk
  • United States

Grants and funding

The host institution was Nordita, http://www.nordita.org/. This work was supported by Swedish Research Council grant VR VCB 621-2012-2983, http://www.vr.se/. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.