Herding behaviour and sentiment: Evidence in a small European market

This work studies herding behaviour in a small European market, by analysing the stocks that constituted the Portuguese stock PSI-20 index, for the period between 2003 and 2011. The two different approaches used to measure herding intensity led to different results, suggesting that measurements of the herding phenomenon are sensitive to the method used. Consequently, there is a need for further research into the methodology used to test this phenomenon. Additionally, the study analyses the relationship between herd behaviour and investor sentiment, an area that has been little explored. In applying causality tests to the impact of sentiment on herd behaviour, only weak evidence is found that sentiment influences herding.