Calendar anomalies in the Gulf Cooperation Council stock markets

We examine calendar anomalies in Gulf Cooperation Council (GCC) stock markets and document a Friday-type effect that occurs on the last trading day of the week and which we call “Wednesday effect”, since Wednesday is the last day before the weekend in the leading market for the region. This effect, however, is more pronounced outside the month of Ramadan. We also find a statistically significant positive December effect, contrary to the January effect documented in Western countries. The presence of such anomalies may provide money managers with opportunities to optimally time their trades based on daily and monthly price fluctuations.