So if WSJ has a headline that X is in talks to buy Y, that's pretty much that. Also you could eliminate most of your risk by placing a limit order based upon the last trade prior to the news coming out. The market will either a) confirm that you are one of the first people to understand what has happened by filling your order at a price that doesn't reflect the news, locking in profits, or b) your limit order won't be filled because the price already is already above your limit, in which case you have assumed no risk.
[1] https://www.google.com/#q=site:wsj.com+%22in+talks+to+buy%22
Is there a timestamped archive of DowJones Newswire articles? I found it difficult to find archived news articles the last time I was looking for them.