The impact of index reconstitutions: Evidence from the FTSE 100
No Thumbnail Available
URL
Journal Title
Journal ISSN
Volume Title
School of Business |
Master's thesis
Authors
Date
2024
Department
Major/Subject
Mcode
Degree programme
Finance
Language
en
Pages
57+5
Series
Abstract
This thesis examines the impact of FTSE 100 Index reconstitution events on stock performance, focusing on both short-term and long-term effects. Using data from 2004 to 2024, the thesis investigates abnormal returns, share turnover, and changes in index ownership for stocks added to or deleted from the index. Key findings reveal significant short-term abnormal returns for additions driven by the price pressure hypothesis, while deletions show immediate negative returns followed by long-term reversals consistent with the imperfect substitutes hypothesis. Over the observation period, short-term effects have diminished, and the timing of price reversals has shifted from around the effective date to immediately following the announcement date. This suggests that by the latter years of the study, reconstitution events were increasingly priced into stock values by the announcement date. Furthermore, the study identifies a diminishing long-term return effect for additions, while long-term reversals for deletions emerge and intensify over time, providing theoretical support for deletion-based investment strategies. Further analysis shows a sharp spike in trading turnover one day before the effective date, reflecting index fund rebalancing. While index ownership trends persist — increasing for additions and decreasing for deletions — regression analysis indicates no significant relationship between ownership changes and cumulative abnormal returns. These findings highlight the role of demand pressures and market dynamics, offering nuanced insights into the broader implications of index reconstitution events.Description
Thesis advisor
Lof, MatthijsKeywords
FTSE 100 index, index reconstitution, stock performance, index ownership