Can it be stopped and how on earth can you monitor it and prove it.

On Friday, I watched a share on the ASX go up by nearly 5% in one day. It shot up in the early trades. Then at 11:18, an announcement was issued to the ASX about a new contract.

Can someone convince me that people in the "know" didn't know or were told about the announcement before it was given out. This happens all the time and the people that make the money out of it are the ones with money in the first place.