The index revision party

This paper examines the annual revision of the AEX index in the Netherlands. This particular index is interesting because the revision rules enable investors to anticipate changes in both constituents and index weights long in advance. Our results suggest that attention and temporary price pressure play a role in the observed revision effect. A portfolio containing those stocks expected to benefit from the index revision is showing an outperformance of up to 7% in the weeks before the revision, while losers are unaffected. Around the revision day, we find indications of temporary price pressure for winners as well as losers.