This cracks me up because of all the times I've seen that NOT happen. The stock drops actually drops big time after the announcement.

Sometimes the news is "good" but doesn't meet expectations, so the stock drops. Maybe it was already priced in. Sometimes the news is "bad", but better than expected, so the stock goes up. Maybe that was already priced in, too.

Either way "just looking at stocks before a major announcement" isn't going to get you anywhere fast.