``Disorder-induced volatility'' (DIV) describes the enhanced fluctuations of collective behaviors exhibited by bistable systems in the presence of a rapidly fluctuating external signal. At the DIV resonance, a defining characteristics is that the response of the system becomes uncorrelated with...

Krugman (1991)'s target zone model has become the reference of a large part of this literature. Despite its simplicity and elegance, empirical evidence has been lacking. Deriving from Krugman's model analytical expressions for the conditional volatility and density distribution close to the...

The statistical estimate of the branching ratio η of the Hawkes model, when fitted to windows of mid-price changes, has been reported to approach criticality (η = 1) as the fitting window becomes large. In this study -- using price changes from the EUR/USD currency pair traded on the...

We inspect the price volatility before, during, and after financial asset bubbles in order to uncover possible commonalities and check empirically whether volatility might be used as an indicator or an early warning signal of an unsustainable price increase and the associated crash. Some...

The endo-exo problem lies at the heart of statistical identi fication in many fields of science, and is often plagued by spurious strong-and-long memory due to improper treatment of trends, shocks and shifts in the data. A class of models that has shown to be useful in discerning exogenous and...

We introduce a new measure of activity of financial markets that provides a direct access to their level of endogeneity. This measure quantifies how much of price changes are due to endogenous feedback processes, as opposed to exogenous news. For this, we calibrate the self-excited conditional...