Extended Stock Returns in Response to S&P 500 Index Changes

Our paper investigates extended abnormal returns for S&P 500 index changes in a comprehensive 1979-2015 sample. The literature’s depiction of longer window returns lacked both appropriate nuance and cross-sectional analysis. Solid evidence for reversion appears in the 2000s. Stocks no longer experience permanent shifts in investor demand when they are either added to or removed from the S&P 500. Received April 19, 2016; editorial decision January 23, 2017 by Editor Jeffrey Pontiff