[ahnuld]

There are alot of informational effects that the market appears to not correctly value immediately. I came across a study that in the past 30 years one could have made abnormal returns by buying companies which gave positive signals to the market such as dividend increases or stock buyback and shorting the opposite signals. Your example is pretty similar to those types of actions. But the thing is just because those trends occured in the past is no indication that those trends will continue in the future, especially since it is widely known by the time you know.