Direct answer: EquiVolume plots each period as a box whose height is the period's price range and whose width is proportional to that period's trading volume, so wide, tall boxes flag high-volume, wide-range moves and narrow boxes flag low-volume periods; CandleVolume applies the same width-as-volume idea to candlestick-style boxes, keeping open/close coloring that plain EquiVolume boxes don't have.
How do EquiVolume and CandleVolume encode volume?
A standard price chart shows volume as a separate histogram panel underneath the price axis — you look at the candle, then look down at a bar to see how much volume traded during that period. EquiVolume, developed by market technician Richard Arms, removes that second panel by building volume directly into the geometry of each period's box on the price chart itself.
The encoding rule
Box height = period's price range (high − low)
Box width ∝ period's trading volume
Each period — a day, an hour, whatever interval the chart is built on — is drawn as a rectangle. The rectangle's vertical extent covers the same high-to-low price range a standard bar's wick would show. The rectangle's horizontal extent, its width, is scaled proportionally to that period's total trading volume: a period with twice the volume of its neighbor is drawn roughly twice as wide. A tall, wide box therefore represents a period that moved through a large price range on heavy volume — a high-conviction move by both measures at once. A short, narrow box represents a quiet period: a small range on light volume.
CandleVolume takes the identical width-as-volume rule and applies it to a candlestick-style box instead of a plain EquiVolume rectangle — meaning it keeps the open/close body coloring (typically one color for a close above the open, another for a close below) that a plain EquiVolume box doesn't carry, since EquiVolume itself doesn't distinguish open from close within the box.
Why this is useful
Because price range and volume are fused into one shape rather than split across two separate panel areas, a high-conviction move — a wide price swing that also traded heavy volume — is visually unmistakable at a glance: it's simply the biggest box on the chart. A trader scanning the chart doesn't have to mentally cross-reference a tall candle against a tall volume bar in a separate panel to notice they occurred on the same day; the fused box already tells that story in one shape.
Common mistake
The common mistake is assuming a wide EquiVolume box always means a bullish or important move. Width only encodes volume magnitude, not direction or quality — a wide box can just as easily represent a heavy-volume decline as a heavy-volume rally. Direction still has to be read from where the box sits relative to the prior box (EquiVolume) or from its open/close coloring (CandleVolume).
What is the tradeoff of encoding volume as width?
The same feature that makes EquiVolume useful — variable box width — is also its main limitation. Because each box's width depends on that period's own volume rather than a fixed time unit, the x-axis is no longer evenly spaced by time. A heavy-volume Monday might occupy noticeably more horizontal space on the chart than a light-volume Tuesday right next to it, even though both represent exactly one trading day.
That has two practical consequences. First, visually lining up a specific calendar date becomes harder than on a standard time-spaced chart, since the horizontal position of any given box depends on the cumulative width of every box before it, not on a fixed date grid. Second, comparing the overall shape of an EquiVolume chart against a standard time-spaced chart of the same instrument — or against a second EquiVolume chart covering a different period with different volume levels — is less direct, because the horizontal scale itself is a function of volume rather than a constant.
Common mistake
The common mistake is trying to eyeball elapsed calendar time from the horizontal distance between two points on an EquiVolume chart. That distance is a function of the volume in the boxes between those two points, not the number of trading days between them — the two only coincide by chance.
Worked Example: Four Synthetic Periods
Illustrative numbers — not live market data.
Assume four consecutive periods with the following high/low ranges and volume figures, and a chart where 1,000 shares of volume is drawn as one unit of relative box width.
| Period | High | Low | Price range (box height) | Volume (shares) | Relative box width |
|---|---|---|---|---|---|
| Period 1 | $52.00 | $50.00 | $2.00 | 1,200,000 | 1,200 units — wide |
| Period 2 | $52.60 | $52.00 | $0.60 | 300,000 | 300 units — narrow |
| Period 3 | $56.00 | $52.40 | $3.60 | 2,100,000 | 2,100 units — very wide |
| Period 4 | $56.30 | $55.80 | $0.50 | 250,000 | 250 units — narrow |
Period 1's box height is $2.00 (its $52.00 high minus $50.00 low), and its width comes from dividing its 1,200,000-share volume by the 1,000-share-per-unit scale, giving a relative width of 1,200 units — a fairly wide box. Period 2 barely moved ($0.60 range) on light volume (300,000 shares), so it draws as a short, narrow box — an unremarkable, low-conviction period sitting right next to a more active one. Period 3 is the standout: a $3.60 range on 2,100,000 shares produces the tallest and widest box of the four, immediately visible as the period where the most actually happened, combining both the largest price swing and the heaviest volume. Period 4 snaps back to a small $0.50 range on only 250,000 shares, drawing as the narrowest, shortest box in the sequence — a quiet consolidation period after period 3's wide move.
Laid out left to right, the sequence visually reads as: moderate box, thin box, one big box, thin box — a shape that immediately flags period 3 as the period worth a closer look, without needing to check a separate volume panel underneath.
Common mistake
The common mistake is assuming box width is measured in absolute currency or share-count units that translate directly across different EquiVolume charts. Width is relative to whatever scale a given chart or platform chooses (1,000 shares per unit in this example) — two EquiVolume charts of the same stock built with different width scales will show visually different box widths for the identical underlying volume.
How is EquiVolume different from Volume Profile?
EquiVolume and Volume Profile both put volume front and center, but they encode it along different axes entirely. Volume Profile bins traded volume by price level across a session, producing a horizontal histogram running alongside the price axis that shows which specific prices attracted the most trading activity, regardless of when during the session those trades happened. EquiVolume instead attaches each period's total volume to that period's own box width on a standard price-over-time layout, so it shows volume period by period across time, not aggregated by price level within a single session.
Put another way: Volume Profile answers "which prices did the most volume trade at during this session?" EquiVolume answers "how much volume, and how wide a price range, did each period on this chart involve?" They're complementary rather than competing views of the same underlying trade data, and a trader interested in both questions would typically use them side by side rather than choosing one over the other.
Misconceptions Versus Reality
| Misconception | Reality |
|---|---|
| A wide EquiVolume box always signals a bullish move | Width only encodes volume magnitude, not direction — a wide box can represent a heavy-volume decline just as easily as a heavy-volume rally |
| EquiVolume and CandleVolume are the same chart type | CandleVolume applies the identical width-as-volume rule but adds open/close body coloring, which plain EquiVolume boxes do not carry |
| Horizontal distance on an EquiVolume chart represents elapsed calendar time | Horizontal distance is a function of the volume in the boxes spanning that distance, not the number of trading days — the x-axis is not evenly time-spaced |
| EquiVolume and Volume Profile show the same information in different styles | Volume Profile bins volume by price level within a session; EquiVolume attaches volume to each period's box width across time — different axes, different questions answered |
Risks, Limitations, and Exceptions
- Box width is relative to a chosen scale (shares or volume units per width unit) that varies by charting platform — the same underlying volume can look visually wider or narrower depending on that setting.
- Because the x-axis is not evenly time-spaced, standard time-based tools (moving averages defined by calendar period, session-based comparisons) don't overlay onto an EquiVolume or CandleVolume chart the same way they do onto a standard time-spaced candlestick chart.
- Comparing the overall shape of two EquiVolume charts covering different date ranges or volume regimes is less direct than comparing two standard time-spaced charts, since each chart's horizontal scale is itself a function of the volume it contains.
- Plain EquiVolume boxes carry no open/close information, only price range and volume — CandleVolume addresses this specific gap but is a distinct variant, not the base EquiVolume method.
- The worked example in this guide uses small, clearly labeled, deterministic illustrative figures, not live market or volume data.
Frequently Asked Questions
How do EquiVolume and CandleVolume encode volume?
Both plot each period as a box rather than a thin bar. The box's height is the period's price range, from low to high, the same information a standard bar's high-low range shows. The box's width is proportional to that period's trading volume, so a high-volume period draws a wide box and a low-volume period draws a narrow one. CandleVolume adds open/close coloring on top of the same width-as-volume box, so it reads like a candlestick chart with volume built into each candle's width.
What is the tradeoff of encoding volume as box width?
The x-axis stops being evenly spaced by time, because each box's width depends on its own period's volume rather than a fixed time unit. A high-volume period takes up more horizontal space than a low-volume period even if both cover the same calendar day. That makes it harder to visually line up a specific date across the chart, and harder to compare the chart's shape directly against a different, evenly time-spaced chart of the same instrument.
How is EquiVolume different from Volume Profile?
They visualize volume along different axes entirely. Volume Profile bins traded volume by price level across a session, producing a horizontal histogram that shows which prices attracted the most activity regardless of when during the session they traded. EquiVolume instead attaches each period's total volume to that period's own box width on a standard price-over-time layout, so it shows volume period-by-period across time rather than aggregated by price level within one session.
Sources and Methodology
EquiVolume was developed by market technician Richard W. Arms Jr. and is documented in long-standing technical-analysis literature and charting-platform references. Key reference sources include:
- CME Group — Technical Analysis Resources: cmegroup.com/education — background on volume-weighted charting conventions.
- Nasdaq — Charting Education: nasdaq.com/market-activity — reference for standard chart-type terminology.
The worked example in this guide uses a clearly labeled, deterministic illustrative dataset, not live market or volume data. This content was reviewed by the Swoopr Editorial Team in August 2026.
Related Reading
- Alternative Chart Types — the parent hub for this content group, covering all non-standard chart methodologies.
- Volume Profile — a different approach to visualizing volume, binning it by price level across a session rather than encoding it into each period's box width.
- Heikin-Ashi Charts — a different price-smoothing transformation that averages open/close values rather than encoding volume into box geometry.