like if reddit is buzzing about certain stock you can predict with rather high probability that it will spike when forums are chatting up and the stock ticker gets mentioned more and more often
or if you see certain pattern develop you can predict with certain probability that the stock will follow through with the pattern because most people read same books and recognise same patterns. what you cant predict is people who will purposely break the pattern because they also know that many people are about to make a certain move since thats what the books seminars and web gurus taught them to do with this pattern.
Granted this is true. How are you going to take advantage of these opportunities?