We looked at MRK, had time to cancel, but because the indication was so low, we decided to keep the order in. We had two good chances to get out ( I missed the highest print, but still made 35 cents.
This type of thing is a judgement call. We use the "buy on rumor, sell on news" theory most of the time when it comes to "news items" etc. This is usually a good time to stay in...since it is usually the last "bump up" --- we use examples in class that reflect the expanded opening prices and how they can relate when "upgrades" and all that other nonsense kick in....which usually mean good opportunities.
Hope this helps everyone....