Trading Patterns, Time Deformation and Stochastic Volatility in Foreign Exchange Markets

Globalization of trading in foreign exchange markets is a principal sourceof the daily and weekly seasonability in market volatility. One way to mo del such phenomena is to adopt a framework where market volatility is tiedto the intensity of (world) trading through a subordinated stochastic pro cess representation. In this paper we combine elements from Clark (1973), Dacorogna et al. (1993) and Ghysels and Jasiak (1994), and present a stochastic volatility model for foreign exchange markets with time deformation.