Abstract Using comprehensive time stamp data on earnings announcements collected from newswires, we show that earnings news announced within trading hours results in approximately 50% smaller immediate reaction compared to similar earnings announced outside trading hours. Negative news tends to be announced during trading hours, which, together with the reduced response, may allow for managerial opportunistic behavior. We also provide evidence that announcement timing is affected by internal corporate governance. Recent regulations that tightened firms’ governance are associated with a significant shift to announcing outside trading hours, especially for firms with better corporate governance. Our surveys of corporate managers corroborate these results.

Using combinations of weekdays and times of day (before, during, and after trading hours) of earnings announcements, we examine whether managers attempt to strategically time these announcements. We document that the worst earnings news is announced on Friday evening and find robust evidence that only Friday evening announcements represent managers’ rational opportunistic behavior. Friday evening announcements are followed by insider trading in the direction of earnings news and the largest post-earnings announcement drift. Managers also attempt to reduce interaction with investors and hide more than just earnings news by announcing on Friday evening. We find that Friday evening announcements occur later in the evening than announcements on other evenings, firms have a reduced propensity to hold conference calls, and major firm restructuring events are relatively more likely to occur after Friday evening announcements.

Abstract Open market share repurchase announcements are commonly associated with equity undervaluation, but their signal about firm value can often be misleading. We conjecture that executives who buy shares of their firm before an announcement add credibility to the undervaluation signal. Consistent with this hypothesis, we find that announcement returns are positively related to past insider purchases, especially for firms that are priced less efficiently. Firms whose insiders bought more shares are also more likely to complete their repurchase plans. Finally, we find that insider purchases predict post-announcement stock returns.

We report reduced market response to Friday announcements of dividend changes, seasoned equity offerings, share repurchases, earnings, and mergers, which is seemingly consistent with the notion of investor inattention on Fridays. However, we show that these findings are an outcome of selection bias. Firms that make announcements on Fridays experience reduced market response on any weekday and have common unobserved characteristics across announcement types. After correcting for selection bias, there is no evidence that investors pay less attention to announcements made on Fridays. The method introduced here is applicable to other studies in which an exogenous factor influencing firm performance can actually be associated with firm characteristics.