You need to ask the right question to get the right answer. The wrong question that I see most of the foolish out there asking: Is the market random? And, they're thinking primarily about using price to predict the future price. Their thinking about the market in a very limited way. Better questions to ask: What's influencing the market right now? Where is the market going tomorrow? You see something can be predictable but not be dependent on the historical price data. Look at the big dude, what was his name Pauslon? who shorted the housing market. There was nothing in the price that told him to short. All the scientist would say well nothing here: just pure random. But, there was something. There was something that allowed him to predict something that had never occurred which was the ability to anticipate correctly how the market was going to react in the future. He had the ability the model possible future scenarios. I do believe price data can be predictive. But, it can so much more predictive when you can anticipate using hypothesis based reasoning to go with it. In other words, if you can anticipate something happening then you can also monitor to see if it is happening. Most losers are looking backwards while the leaders are looking forward. They are anticipating. Sometimes they anticipate too far ahead which is why every trader has to manage risk. One trader here asked about tape reading as a means too know when the big trader is making a move. Well, if you know what the big trader is looking at and you know how he's going to make his decisions then you can move before he even makes his trade. You can be the big trader. Or you can combine such a hypothesis with the ability the ability to read the market and that's powerful stuff.