"Is there money to be made from reading announcements then buying if the news is positive? Or do people already know and have sold by then?"
Generally speaking if the "good" news is expected then the price will go down as large holders sell into the buying depth resulting from the news.
However, if the news is unexpected the SP will most likely rise , like RMX saying hey we just found a stack of gold last week.
You really have to research though if there has been a recent cap raise and "unexpected" good news comes out somebody might have found out before you and be ready to sell knowing there's a big difference between finding gold and making money.
Like Sandy says you have to take your time, get the feeling when is the best time to buy & sell.
It's a tough game and you won't win everytime with all the expereience and research all you can do is tilt the odds of a profit slighty in your favour.
