Cluster charts and TPO charts answer different questions about the same session. A cluster chart counts volume at each level and compares the two sides; a TPO chart counts how often a level appeared in successive time brackets. Configuring them well means keeping those two counting methods separate in your head, because the settings dialogs use similar words for different quantities.
What a Cluster Chart Counts
A cluster chart groups executions by level and by time bracket, then prints a compact cell for each intersection. The cell can show volume, trade count, or a derived value such as delta. A TPO chart replaces the volume inside the cell with a letter or block representing the bracket itself, so the chart records presence rather than size. Neither chart is more accurate than the other; they measure different things, and a session that looks balanced on one can look directional on the other.
The bracket length controls how many cells a bar occupies. A thirty-minute bracket produces fewer, wider columns than a five-minute bracket. Short brackets show the sequence of acceptance at a level; long brackets compress that sequence into a summary. When the bracket is changed, the chart rebuilds from stored trades, so the result is stable for a given data set.
Bracket Length and Session Alignment
Brackets should align with the session start, not with the moment the chart was opened. A chart opened at 10:07 with five-minute brackets will otherwise produce a first column covering three minutes, and every cumulative series derived from it will carry that irregularity for the rest of the session. The session template should define the anchor, and the chart should inherit it. If a template does not expose an anchor field, set the session start explicitly before building the chart.
Overnight sessions complicate alignment because the electronic session can begin on the previous calendar day. A chart anchored to midnight will split the overnight range into two columns that belong together. The practical fix is a session template that starts at the venue's electronic open and ends at its maintenance break, applied consistently to every panel in the workspace.
Value Area, Point of Control, and Single Prints
The point of control is the level with the greatest volume or the greatest TPO count, depending on the chart type. The value area is the contiguous band around that level that contains a chosen share of the total. Both are computed per profile, and both change when the profile's anchor changes. A composite profile spanning several sessions will produce a different point of control than the same data split by session, and that difference is often the point of the exercise rather than an error.
Single prints are levels visited by exactly one bracket. They are visually distinctive because they leave a one-cell column in an otherwise continuous shape. Many templates mark them with a separate color, and some traders treat an unfilled single print as a reference level for later sessions. Whether that interpretation holds is a matter of method, not of configuration; the chart's job is to display the single print accurately and consistently.
Cluster Metrics: Delta, Volume, and Trade Count
Delta is the difference between ask-side and bid-side volume for a cell or a bar. It is a signed quantity, so its cumulative form can drift far from zero over a session. Volume is unsigned and always positive. Trade count is a proxy for participation intensity and behaves differently from volume when order sizes vary. Showing all three in one cell is possible but rarely readable; choose one primary metric per chart and use a separate module panel for the others.
| Setting | Typical range | What changes |
|---|---|---|
| Bracket length | 5 to 30 minutes | Column count and the sequence detail visible per level |
| Primary metric | Volume, delta, trades | Which number occupies the cell |
| Value area share | 68 to 80 percent | Width of the highlighted band around the point of control |
| Single print mark | On or off | Visibility of one-bracket levels |
| Composite span | 1 to 10 sessions | Whether the profile is daily or rolling |
| Split profile | Session or bracket | Whether buying and selling halves are drawn separately |
Split Profiles and Composite Views
A split profile draws the two sides of the market as opposing shapes, which makes asymmetry obvious at a glance. The split can be by session or by bracket; the former summarizes the day, the latter shows how the balance shifted during it. Splitting increases the horizontal space a profile needs, so it works best on a wide panel or a dedicated column rather than squeezed beside a footprint chart.
Composite views stack several sessions into one profile and are useful for locating levels that matter across a week. The cost is that the composite hides the sequence: you can see that a level was heavily visited without seeing when. Pair a composite with a single-session cluster chart rather than replacing one with the other. The two views together answer both "where" and "when" without forcing either chart to do both jobs.
Reading a Cluster Chart Without Overreading It
A cluster chart shows where volume concentrated, not why. A large cell can represent a single participant or thousands, and the chart cannot tell you which. Treat the display as a description of executed activity and keep causal claims separate. When a level looks unusually heavy, the useful next step is to compare it with the same level on adjacent sessions, not to invent a narrative for the cell itself.
Consistency matters more than cleverness. A plain cluster chart with a fixed bracket, a fixed value area, and one primary metric will teach you more over twenty sessions than a rotating set of exotic overlays. Configure once, document the settings, and spend the remaining attention on the market rather than the dialog.