Hi Vespasian, Here is a interview that if you read and listen carefully to what Adam Wasserman says you will get the idea of tape reading and how it works. Even though it says it does not apply to Level2 quotes, it does. Please understand that it is reading stock behavior and not a exact science. It is like recognizing someones emotions. Some people hide them better and some people don't. You need to recognize their mood. That is what tape reading is. Finding the signs of a buyer or seller. http://www.tradingmarkets.com/recent/wasserman_interview-656624.html This is legitimate information from a guy who makes millions of dollars a year tape reading with his own money. I know this for a fact because I and another elite trader member Maverick74 all sat next to each other back in the late 90's at a firm named WorldCo LLC. This stuff still works and always will. As for people complaining about the HFT and tape reading does not work anymore. That is just another excuse to justify their losses!