An investigation to determine the differences in magnitude and timing of price changes associated with three levels of voluntary disclosure. It is discovered that, when subsequent disclosure is about-as-expected, the Finnish market reacts on the day of the interim announcement and achieves its maximum degree of reaction two days after the announcement. When the level of disclosure is lower than expected, this whole process is delayed by one day. When the level of disclosure is greater-than-expected, the process is delayed by three days.