This paper explains exchange rate dynamics by linking financial customers’ foreign exchange order flow with their dynamic portfolio reallocation. For any currency pair in a particular period, one currency has higher assets return than the other and can be considered the high-return-currency (HRC). Financial institutions attempt to hold more HRC assets when they become more risk-loving or the relative return of the assets is expected to increase. Such a portfolio reallocation generates buy order toward the HRC and the currency appreciates. As the HRC changes over time, the direction that the relative return and risk appetite affect the exchange rate varies in different regimes.

This paper develops a new measure of comovement in the banking sector that takes into account the dynamic nature of interlinkages in the return on assets (ROA) and net chargeoffs (NCO) among different bank holding corporations by using a dynamic factor model with time-varying parameters and stochastic volatility. We find that the degree of comovement in ROA and NCO peaked during the 2008–2009 financial crisis, suggesting a significant increase in sector-wide stress. Using the least absolute shrinkage and selection operator (LASSO) methodology, we show that comovement and risk measures derived from our approach perform well when compared to other widely used measures of systemic risk in explaining real economic activity.