We simulate the impact on the nonbank liabilities of banks in a multiplex interbank environment arising from changes in currency exposure. Currency shocks as a source of financial contagion in the banking sector have not, so far, been considered. Our model considers two sources of contagion: shocks to nonbank assets and exchange rate shocks. Interbank loans can mature at different times. We demonstrate that a dominant currency can be a significant source of financial contagion. We also find evidence of asymmetries in losses stemming from large currency depreciations versus appreciations. A variety of scenarios are considered allowing for differences in the sparsity of the banking network, the relative size and number of banks, changes in nonbank assets and equity, the possibility of bank breakups, and the dominance of a particular currency. Policy implications are also drawn.

A general measure of asset market interdependence based on higher order comoments is developed and applied to studying weekly U.S. and eurozone equity returns from 1990 to 2017. A new test of independence is also developed. The empirical results show that interdependence peaks during the global financial crisis with the covariance and covolatility comoments being the dominant factors. Conditioning the interdependence measure on volatility does not change the overall qualitative results. Implications of the results for constructing diversified portfolios reveal economic benefits from portfolios based on higher order comoments than the usual assumption of bivariate normality, especially during the GFC. The empirical results also provide evidence that European Union membership led to higher interdependence than did the adoption of the common currency.