This study analyzes the effects of six different credit rating announcements on systematic and unsystematic risk in Spanish companies listed on the Electronic Continuous Stock Market from 1988 to 2010. We use an extension of the event study dummy approach that includes direct effects on beta...

When evaluating the significance of calendar effects, such as those associated with Monday and January, it is necessary to control for all possible calendar effects to avoid spurious results. The downside of having to control for a large number of possible calendar effects is that it diminish...

This paper focuses on one of the heavily tested issue in the contemporary finance, i.e. efficient market hypothesis (EMH). However, we try to find the answers to some fundamental questions basing on the analysis of high frequency (HF) data from the Warsaw Stock Exchange (WSE). We estimate model...

This paper focuses on one of the heavily tested issue in the contemporary finance, i.e. efficient market hypothesis (EMH). However, we try to find the answers to some fundamental questions basing on the analysis of high frequency (HF) data from the Warsaw Stock Exchange (WSE). We estimate model...

This paper focuses on one of the heavily tested issues in the contemporary finance, i.e. efficient market hypothesis (EMH). The existing evidence in the literature is ambiguous. For some markets, the departure from efficiency is observed only when High Frequency (HF) data are analysed....