The following analysis measures how the market behaved after pre-announcements since January 2000. First, the study tracked whether pre-announcements in the first month of each quarter (January, April, July, and October) accurately indicated the strength or weakness of estimates for the entire quarter. For instance, if pre-announcements in January beat analysts’ expectations, did the remaining pre-announcements for the quarter follow suit?

The analysis also looks at how the quality of pre-announcements affected the S&P 500 index’s quarterly performance. For example, if pre-announcements were strong in January, how did the S&P 500 perform in February and March?

The quality of pre-announcements in a quarter’s first month turned out to be an accurate indicator of whether all pre-announcements beat, missed, or matched analysts’ expectations, but the S&P 500 didn’t react as you might expect to these positive and negative reports.