Anomalous daily seasonality in Ireland?

Abstract

Substantial evidence exists to indicate that a negative Monday, or in some case Tuesday, mean return is achieved by stock market indices. In contrast to these and to previous Irish studies, this paper finds that there is no negative Monday or Tuesday return, there being a persistent and positive Wednesday return. This is seen across two indices and over a number of sub-periods. It is also seen, using a GARCH-M specification, that this ‘Wednesday effect’ cannot be attributed to systemic daily variation in risk.