The Impact of Earnings Announcements on Stock Prices: An Event Study for the London Stock Exchange

Abstract

The period of 2010-2012 was characterized by information uncertainty and market volatility. Information uncertainty is a critical characteristic of financial market behavior. The ability to absorb and distribute information is central to financial market efficiency. Uncertain corporate earnings information causes stock price volatility which in turn impacts stock price equilibrium levels. An event study shows a picture in time of stock price impacts when information is released to financial markets. This picture can give indications of the levels of financial market efficiency. This event study focusses on the earnings announcements and investigates financial market efficiency, post earnings announcement drift and the presence of abnormal returns during the assessed period. This study seeks to add to the existing literature of event studies.

Keywords: Post earnings announcement drift, efficient market hypothesis, cumulative abnormal returns, event studies

JEL Classification: G14