I've taken some time to read through market-profile books and from what I've managed to extract by skimming through the relevant books, the essential of the whole approach is: (1) The time-frame of the participants is the most essential feature in relation to their behavior; (2) The amount of time spent in a range is more likely to be an accurate indication of market-perceived value than volume. That's it. Two other things I thought were just interesting: Responsive-Initiative Distinction Responsive is when a participant is reacting to price moving below or above perceived value; Initiative, as defined here, is trying to capture a participant reacting to value moving away from price; It's a bit slippery and vague, but basically I think what is being capture here is that sometimes people can put on or unwind a position without much consideration for price. And the only reason it might help you to make that distinction is to be able to keep in mind that the market can go much further than you're used to, especially if you're microscopically staring at intra-day charts and the DOM. Market Time-Calendar Time Distinction Essentially this distinction captures that calendars and measures of time can sometimes be arbitrary measures for a market. A day captures relationships between planets. If because of this a market has an imposed open/close time and no overnight session, then it may have some impact on the behavior of a market. There are other reasons it may also, of course. But the point is that sometimes that's irrelevant, and the thing the matters might be an event unfolding over days, or weeks, which is has much more weight than the calendar time and affects market behavior over that period. ... The rest, I can't see why any of it is relevant. And a lot of it seems just like the arbitrary logical deductions of (some) philosophers.