Market Capitalization Changes For S&P 500 Inclusions And Exclusions

Research Paper from the year 2015 in the subject Business economics - Investment and Finance, grade: 9.0/10, Maastricht University, language: English, abstract: Previous research has already proven that firms which get included in or excluded from the S&P 500 index experience stock price changes that ultimately result in market capitalization changes. The causes of these changes has extensively been examined, but a consensus on the true cause has not yet been reached. In this paper the market capitalization effect is examined by making a distinction between the reasons for inclusions and exclusions. It is argued that expected events, like bankruptcy and index-downgrading, have lower price effects than unexpected events, which include mergers and acquisitions. By usage of a regression analysis it is concluded that there is no difference in price effects between the individual reasons for inclusions and exclusions. However, when the reasons are grouped into unexpected and expected events there is a significant effect for the inclusions. Firms which expectedly enter the index experience lower market capitalizations changes than firms which unexpectedly entered the index. This effect could not be proved for exclusions.