Read the volume profile
Find where trading activity concentrated, then put today’s price in context.
In this article 8 sections
Where did the activity happen?
Candles show how price moved through time. A volume profile groups activity by price: a longer horizontal bar means more volume was assigned to that price area.
This gives you a starting point for a useful question: is price trading near the session’s busiest area, or moving away from it? Prism’s example is an estimate from minute bars; the chart below makes that method visible.
Where did activity concentrate?
QQQ · Sep 11, 2026 · 9:30 a.m.–4 p.m. ET
4,254,650 recorded shares · XNAS minute-close estimate
Choose a reference to highlight its price bin.
Point of control · $716.04
The busiest estimated price bin. Its longer bar shows where the most recorded volume was assigned during this session.
This bin: 702,837 shares · 16.52% of recorded session volume.
POC and VAH share a price bin in this session. They describe different features of the same profile.
For a later-session or swing review
Use this completed range as context when reviewing subsequent sessions: does price spend time back inside it or build activity elsewhere? This one-day estimate cannot tell you the next move.
How this estimate is built · source & limits
Source: Databento XNAS.ITCH · venue OHLCV, not consolidated SIP volume. All 390 recorded 1-minute bars are used, totaling 4,254,650 shares. This profile becomes available after the session closes.
Each minute’s entire volume is assigned to the nearest $0.36 price bin using its closing price. POC is the largest occupied bin; ties choose the lower price. Starting there, the value area grows toward the next occupied bin with more volume (upward on ties) until it includes at least 70%. Here it contains 73.91%.
The bin width is 0.05% of the first minute’s close, rounded to a cent with a one-cent minimum. Bin assignment and width use nearest-even rounding. VAH and VAL show the centers of the highest and lowest included bins.
This is an app-derived approximation, not trade-by-trade volume at price, consolidated market volume, or a time-at-price (TPO) Market Profile. It does not reproduce a Dalton method and is not available in advance.
Archive fingerprints
- resource-case-study-census.json
af9379d9eb6802044356957fd6cf9a96b203eb57bddafd844c2d56ebf679de85 - cycles.parquet
cb31c638974f19aea8cd9bc5b0bc0366f088e49ed69369d72f131823138b742f - contracts-QQQ.parquet
7d0c5c93cc5fd95b5e70865e74765fb3c33b8cbaee4d88be42da9f2ec7ba7c62 - QQQ-preview.json
c7650ac0a1d9b5d4fc8cb3e66df8d5c07b578067a54f9874b5b36d0a161a9471
Three labels, one simple map
The value area is a range around the busiest price, expanded until it contains about 70% of the profile’s volume. Here, “value” describes activity; it does not mean the investment is cheap or fairly valued.
| Label | What it marks | What to notice |
|---|---|---|
| POC · Point of control | The price bin with the most estimated volume. | Is price returning to this busy area or spending time away from it? |
| VAH · Value area high | The upper edge of the estimated value area. | Does trading continue above the range or return inside it? |
| VAL · Value area low | The lower edge of the estimated value area. | Does trading continue below the range or return inside it? |
Observe the response
Traders use “acceptance” for sustained activity around a price area, and “rejection” for an excursion that returns away from it. One candle touching a line establishes neither.
For a repeatable observation, decide your timeframe first, then record how long price remains beyond the area and whether it returns inside. These are questions to test, not a promise that the next move will follow a pattern.
Useful beyond a day trade
If you hold for days, compare completed sessions alongside your daily or weekly chart. Is each session’s busy area moving higher, lower or overlapping? This organizes your review without requiring you to watch every minute.
Dalton’s published routine begins with monthly, weekly and daily context before reviewing the latest profile. In Prism, start with the three sample dates. An old profile is a dated reference; reassess it when price, news or your holding period changes.
Sources: Jim Dalton Trading: Jim Reveals His Daily Trading Routine.
How this sits in a plan you already have
The value area maps where activity concentrated. Use it to locate a plan you already have. It does not predict the next auction, it does not mean the ETF is cheap, and it does not choose an entry for you.
- Wait for price at the value area instead of chasing through the middle of the range.
- Place the stop beyond VAH or VAL instead of an arbitrary tick count.
- Confirm the profile belongs to the session you mean before treating those edges as the session edges.
- If the data clock is not current, stand down. A completed-session profile was not known at that session’s open.
How Prism estimates this profile
The example assigns each recorded XNAS one-minute bar’s entire volume to the bin containing that minute’s closing price. It finds the busiest bin, then expands toward neighboring bins until at least 70% of the volume is included.
The source covers the Nasdaq venue, not consolidated trading across every venue. A minute’s trades may occur at many prices, so this estimate can differ from a trade-by-trade volume profile. The completed session’s POC, VAH and VAL were not known at its open.
The Dalton connection
James “Jim” Dalton coauthored Mind Over Markets with Eric T. Jones and Robert B. Dalton. Its updated edition explains volume and time-based value-area calculations separately in Appendix 1, pages 331–333. Markets in Profile develops the broader auction and timeframe perspective.
Traditional Market Profile counts time-price opportunities, or TPOs: whether a price traded during each time bracket. Volume profile measures traded quantity. Dalton discusses both and favors including time; Prism’s minute-close estimate is a different implementation. These sources provide conceptual background, not endorsement of Prism or evidence of a trading advantage.
Sources: Wiley — James F. Dalton, Eric T. Jones and Robert B. Dalton: Mind Over Markets, updated edition (2013), Appendix 1: Value-Area Calculation, pp. 331–333; Jim Dalton Trading: TPO vs Volume Profile; Wiley — James Dalton, Robert Bevan Dalton and Eric T. Jones: Markets in Profile: Profiting from the Auction Process (2007).
Sources and editorial notes
Read the primary references and editorial policy
Published by GEXfreak. Prism by GEXfreak is the product described in these guides. Definitions reference the primary sources below; examples and tool-selection checklists are GEXfreak’s own illustrations. This is product education, not independent investment research.
These sources explain market auctions, time-based Market Profile, and volume profiles. Prism’s minute-close estimate uses a different calculation; these references do not endorse the product or establish predictive performance. Book edition years and undated web pages are identified below.
- Mind Over Markets, updated edition (2013), Appendix 1: Value-Area Calculation, pp. 331–333 — Wiley — James F. Dalton, Eric T. Jones and Robert B. Dalton. Published 2013. Checked .
- TPO vs Volume Profile — Jim Dalton Trading. Publication date not stated. Checked .
- Jim Reveals His Daily Trading Routine — Jim Dalton Trading. Publication date not stated. Checked .
- Markets in Profile: Profiting from the Auction Process (2007) — Wiley — James Dalton, Robert Bevan Dalton and Eric T. Jones. Published 2007. Checked .
For the product’s calculation and data boundaries, read Prism’s methodology.
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