In a competitive information market, a single information source can only dominate other sources individually, not collectively. We explore whether earnings announcements constitute such a dominant source using Ball and Shivakumar's (2008) R2 metric: the proportion of the variation in annual...

Earnings announcement days on average provide more information to the stock market than any other days in each quarter. In particular, the proportions of the variation in annual returns explained by returns on days with dividend announcements, management forecasts, preannouncements, or 10-K and...