It's hard for me to imagine keeping the settlement details a secret for very long. How many people originally had knowledge of settlement details; 5, 10, more ? I'd guess more, considering the size of the executive and financial departments in each company involved.

If anyone of these original secret keepers told a friend, co-worker, or family member about the settlement how fast can that leak spread?

That doesn't mean the PPS decline is a result of the secret spreading. But it seems unlikely that details will remain a closely held secret for very long.

The Journal of Accounting Research published a study http://links.jstor.org/sici?sici=002... that seems to indicate there is a corrilation between how long a company waits to release info, and the impact there is on the PPS as a result of that formal release. The longer they wait the less impact the release has on PPS - suggesting that the info got to the market through other means.