Turn-of-the-month effect, FX influence, and efficient market hypothesis: new perspectives from the Johannesburg stock exchange

Abstract

ABSTRACT This paper examines the Turn of the Month (TOM) effect in the highly capitalized emerging South African stock market. We use data from the FTSE/JSE Afr8ica All Shares Index (JALSH) and the USDZAR FX market for the period 31.12.1998-31.12.201. We provide empirical evidence that TOM is present in the S. African stock market, but there is a non-TOM anomaly in the FX market. Thus, the S. African stock market enables us to gain new perspectives on the study of the TOM effect. Specifically, using an optimization algorithm, we are able to identify the optimal intra-month period in the JALSH by examining it in both the local currency (ZAR) and in USD. Moreover, we show that the performance in the USDZAR FX market has an impact: (a) on the domestic stock market’s performance (JALSH in ZAR), and (b) on the TOM effect. Finally, we present some practical investment strategies based on the TOM effect which can outperform the stock market and prove beneficial for investors trading in USD.