So how exactly do the 'better informed' cause the share price to...

So how exactly do the 'better informed' cause the share price to rise? Sit there with a gun to your head and tell you to press the buy button?

Talk about having your cake and eating it. If it does down it's because people 'in the know' want to load up on shares, if it goes up most of you would claim it's best news has leaked of a massive oil strike.

Given that your example is not bourne out in the real world- share prices can and do both rise and fall before announcements while drilling, I could well ask you if you're new to the oil and gas sector yourself.