Hunting for Black Swans in the European banking sector using extreme value analysis

© Springer International Publishing Switzerland 2016. In financial risk management, a Black Swan refers to an event that is deemed improbable yet has massive consequences. In this communication we propose a way to investigate if the recent financial crisis was a Black Swan event for a given bank based on weekly closing prices and derived log-returns. More specifically, using techniques from extreme value methodology we estimate the tail behavior of the negative log-returns over two specific horizons: • Pre-crisis: from January 1, 1994 until August 7, 2007 (often referred to as the official starting date of the credit crunch crisis); • Post-crisis: from August 8, 2007 until September 23, 2014 (the cut-off date of our study). We illustrate this approach with Barclays and Credit Suisse data, and argue that Barclays can be considered as having experienced a Black Swan and Credit Suisse not. We then link the differences in tail risk behavior between these banks with capitalization and leverage indicators. We emphasize the statistical methods for modeling univariate extremes linked with graphical support.status: accepte