where yt = log(pt/pt−1) and pt
is the closing price at day t, Dti is the indicator variable for day i and ϵt
is the error that was
assumed to follow five different GARCH models. The estimates of the λ’s are shown in Table 1. The results indicated that
there was a significant negative Thursday effect for the daily composite index at closing for the period of December 25, 1995
to July 7, 2006 [3].