Fractal structures and naive trading systems: Evidence from the spot US dollar/Japanese yen

Abstract

This study investigates whether daily logarithmic returns on the spot US dollar/Japanese yen (USD/Yen) for the period 3 March 1987 to 8 September 1993 displayed an underlying fractal structure. The analysis employed a rescaled range (R/S) technique, and revealed USD/Yen persistence which favoured continued depreciation of the USD. The results suggest the presence of time or memory effects in the currency. These effects were arbitrageable by speculators who by holding long Yen positions were able to earn positive returns.