Abstract:
Many researchers have tested whether the seasonal anomalies are present in the stock markets. Those
studies have been carried out in the stock markets both in the developed and developing economies.
Existence of seasonal anomalies let the investors to earn abnormal returns by trading on past information.
Most common seasonal anomalies are day of the week effect, month of the year effect, holiday effect,
Monday effect and Friday effect. Although information technology and regulatory mechanisms are much
stronger than ever, there are strong evidences to support that seasonal anomalies exist in stock exchanges
both in developing and developed countries. Furthermore, Colombo Stock Exchange has been named
recently as one of the stock exchanges with higher returns in the world. Thus, it is of paramount importance
identify how those returns are made of. Abnormal returns gained from anomalies cannot be justified from a
risk-return standpoint. Yet it remains as an important element of stock returns. This study attempts to
examine whether the month of the year effect and January effect are present in the Colombo Stock
Exchange based on data from January 2002 to December 2011. For the purpose of analysis, non linear
GARCH model is employed along with other techniques due to its strong capability to detect such
anomalies. Results provide evidence to support the claim that both the month of year effect and January
effect exist in the Colombo Stock Exchange despite its use of modern information technology infrastructure
and regulatory developments.