Sparseness and roughness of foreign exchange rates
An accurate multiaffine analysis of 23 foreign currency exchange rates has been performed. The roughness exponent H-1 which characterizes the excursion of the exchange rate has been numerically measured. The degree of intermittency C-1 has been also estimated. In the (H-1,C-1) phase diagram, the currency exchange rates are dispersed in a wide region around the Brownian motion value (H-1 = 0.5, C-1 = 0) and have a significantly intermittent component (C1 not equal 0).
multiaffine analysis currency exchange rates brownian motion arch modeling temporal correlations stationarity