What drives the market value of firms in the Defense industry ?.

This paper investigates the relative importance of different types of news in driving significant stock price changes of firms in the defense industry. We implement a systematic event study with a sample of the 58 largest publicly listed companies in the defense industry, over the time period 1995-2005. We first identify, for each firm, the statistically significant abnormal returns over the time period, and then we look for information releases likely to cause such stock price movements. We find that stock price movements in the defense industry are, in many ways, influenced by the same events as in other industries (key role of formal earnings announcements or analysts' recommendations) but this industry also has some specific features, in particular the influence of geopolitical events and the relevance and frequency of bids and contracts on stock prices.