On Exchange Rate Predictability and Adaptive Market Hypothesis in South Africa

This study sets out to explore the predictability of global foreign exchange rates vis-à-vis the South African rand using daily nominal exchange rates from January 2010 to February 2018. The estimation techniques include automatic portmanteau test, wild bootstrap variance ratio test, Dominguez-Lobato test for martingale difference hypothesis, and generalized spectral tests. We investigate the time-varying predictability by employing the fixed-length rolling window approach. The full sample results indicate significant predictability of some exchange rates while some suggest no predictability. The rolling window approach established that all the foreign exchange markets go through episodes of significant predictability and episodes of unpredictability. The currency investment space is dynamic and that makes it imperative for market participants to be adaptable.