Empirical evidence shows that macroeconomic fundamentals have little explana-tory power for nominal exchange rates. On the other hand, the recent “microstruc-ture approach to exchange rates” has shown that most exchange rate volatility at short to medium horizons is related to order flows....

Recent episodes (October 2008, May 2010, August 2011) have witnessed huge spikes in equity price risk (implied volatility). Apart from their large size, several features characterize these risk panics. They are global phenomena, shared among a broad set of countries. There is substantial...

There has been a long debate about whether speculators are stabilizing or not. We consider a model where speculators have a stabilizing role in normal times, but may also provoke large risk panics. The very feature that makes arbitrageurs liquidity providers in normal times, namely their...

Recent crises have seen large spikes in asset price risk. We propose an explanation for such panics based on self-fulfilling shifts in beliefs about risk. A negative link between the current level and the future risk of an asset price leads to a circular relationship between the stochastic...