Version 1.8 · NinjaTrader 8 · English edition © 2026 TTW Trading Systems PTE. LTD. · Flow.42 Analytics · All rights reserved.
Context first. Pressure second. Execution last.
Table of Contents
- Overview
- What you see on the chart
- Aggressor volume: rolling vs projected
- Average liquidity
- Moving and arranging the panels
- Reading the meter
- Full parameter reference
- Quick start
- Troubleshooting
- Glossary
1. Overview
Flow.42 VolLiqMeter keeps two questions answered on your chart at all times: how much liquidity is resting in the order book right now, and how hard the tape is hitting into it. It is a context meter, not a signal tool: no arrows, no recommendations, just two clean panels you can read at a glance.
The value is in the pairing. Liquidity alone tells you how thick the book is; aggressor volume alone tells you how active the tape is. Together they tell you something neither can on its own. A thin book under heavy aggression means price can travel fast, with little resting size to slow it. A thick book under the same aggression means someone may be absorbing, and moves are likely to stall. VolLiqMeter puts both numbers side by side so that read takes one glance.
It works across futures, FX and crypto, formatting its numbers to suit each so the panels stay readable whether you trade contracts, lots or coins. Because it reads the live order book and the live tape, it is a real-time tool. The decisions it informs remain entirely yours.
2. What you see on the chart
VolLiqMeter draws two panels you can drag anywhere on the chart.
The Aggressor Vol. panel shows how much market-order volume is executing right now. A big Total number sits on top (bid plus ask), with the split below it: Ask is the volume that traded into the offer, buyers lifting it, and Bid is the volume that traded into the bid, sellers hitting it. The panel title carries the mode and the window on two lines, for example "Aggressor Vol. (last)" over "Period 30s". The "(last)" tag means a true rolling window; "(proj.)" means a projected rate (more on that next).
The Avg. Liquidity panel shows how thick the book is. A big Avg. Liquidity number on top is the average of the two sides, with Ask and Bid giving the average resting size on each across your chosen depth range. The title shows that range, for example "DOM Level 1 to 40".
By default the Bid figures are drawn in lime green and the Ask figures in crimson, so the panels read at a glance. Both colors, and everything else about the panels' look, are configurable.
3. Aggressor volume: rolling vs projected
VolLiqMeter reads the live tape and sorts each trade by where it printed relative to the current bid and ask: trades into the bid count as Bid (aggressive selling), trades into the offer count as Ask (aggressive buying). That gives you a practical "who is being aggressive right now" read without needing a footprint chart. Large iceberg fills that print as a burst of small trades at one price are grouped into a single entry, so the numbers stay clean rather than inflated.
How the window behaves is set by Use Rolling Window:
- On (recommended) gives you the true sum of the last N seconds, a genuine rolling window that feels like tape speed. The title shows "(last)".
- Off switches to projection: the meter measures the current rate and projects it out to a full period, giving a smoother, less jumpy number early in a period. The title shows "(proj.)".
The window length itself is Volume Period, anywhere from 1 to 300 seconds. A shorter period reacts faster and feels twitchier; a longer one is steadier. If the numbers feel too jumpy, lengthen the period or switch to projection mode.
4. Average liquidity
The liquidity panel reads live Market Depth and reports the average resting size per level on each side, across the depth range you choose. Level 1 is the top of book (the best bid and best ask), and the levels count deeper from there. With DOM Level from and DOM Level to you set the span that gets averaged: a narrow range near the top reflects what is immediately defending price, while a wider range reflects the broader book.
This panel depends on a Level 2 Market Depth feed. If your data feed does not deliver depth for an instrument, or depth is not enabled, the liquidity figures stay at zero while the aggressor panel keeps working from the trade feed.
5. Moving and arranging the panels
Both panels are draggable. Click and hold a panel, move it to where you want it, and release to set it. Positions are stored as relative chart coordinates, so they stay where you put them when you resize the chart. Arrange them once, then save your chart template or workspace to keep the layout.
To reset positions, the simplest route is to open the chart's Indicators dialog, select VolLiqMeter and reset it, or remove and re-add the indicator.
6. Reading the meter
VolLiqMeter is a quick context filter. A few common readings:
Breakout fuel. Aggressor volume rising while liquidity is thin: price can travel fast because there is little resting size to slow it down.
Absorption or stall risk. Aggressor volume rising but liquidity staying high: someone may be absorbing the flow. Expect more stop-and-go behavior.
Choppy rotation. Aggressor volume low with liquidity moderate to high: often a rotational market where moves struggle to extend.
High-activity battle. Aggressor volume high and liquidity high: strong participation on both sides. Watch for sudden liquidity pulls or a flip in the aggressor balance.
These are ways to frame what you are seeing, not trade signals. The meter gives you context; the decision is yours.
7. Full parameter reference
The settings appear in the NinjaTrader properties panel, grouped as you see them there. "Default" is the value the indicator ships with.
Parameter
| Setting | Default | What it does |
|---|---|---|
| DOM Level from | 1 | The starting depth level for the liquidity average. Level 1 is the top of book. |
| DOM Level to | 40 | The ending depth level for the liquidity average. |
| Volume Period (seconds) | 30 | The window length for aggressor volume, from 1 to 300 seconds. |
| Use Rolling Window | On | On gives the true sum of the last N seconds (recommended); off projects the current rate to a full period. |
Appearance
| Setting | Default | What it does |
|---|---|---|
| Panel Background Color | Black | The background color of both panels. |
| Panel Opacity | 60 | The panel transparency, from 0 (fully transparent) to 100 (fully opaque). |
| Border Color | White | The border color of the panels. |
| Border Thickness | 1 | The border width in pixels (0 to 5). |
| Show Border | On | Shows or hides the border around the panels. |
| Bid Color | LimeGreen | The color of the Bid figures. |
| Ask Color | Crimson | The color of the Ask figures. |
| Text Color | White | The color of titles and the total number. |
| Font Family | Arial | Any installed font name. |
| Text Size | 12 | The font size in points (8 to 24). |
Help & Hotkey
| Setting | Default | What it does |
|---|---|---|
| Show Help Panel | n/a | Shows or hides the Flow.42 help panel on the chart. |
| Enable Help Hotkey | n/a | Enables toggling the help panel with the Flow.42 hotkey. |
| Assigned Help Hotkey | CTRL + H | The shortcut that toggles the help panel. Read-only. |
| Help Panel Width (px) | n/a | The width of the help panel in pixels. |
| Help Panel Height (px) | n/a | The height of the help panel in pixels. |
| Help Panel Opacity (%) | n/a | The opacity of the help panel, from 0 to 100. |
8. Quick start
Add VolLiqMeter to a chart and, if you want the liquidity panel to update, make sure your data feed provides Level 2 Market Depth. The defaults are a good first read: a 30-second rolling window for aggressor volume and a DOM range of 1 to 40 for liquidity. Drag the two panels to where you like them, then save your chart template or workspace so the layout sticks.
From there, tune to taste. Lengthen the Volume Period if the numbers feel jumpy, narrow the DOM range if you care most about what is defending price right at the top of book, and set the colors and font to match your chart.
9. Troubleshooting
The panels do not show up. VolLiqMeter builds its panels once real-time data is flowing. Make sure you are connected to a data feed and the chart is running live rather than showing a static historical view.
Liquidity is always zero. The liquidity panel needs a Level 2 Market Depth feed. Your feed may not provide depth for that instrument, or it may need to be enabled. Some brokers require a separate market-depth entitlement. The aggressor panel will still work from the trade feed.
Aggressor volume is always zero. No live trades are arriving: a disconnection, a closed market, or an instrument that is not streaming. Note that liquidity does not replay historically, since depth is not available as history.
The numbers feel too jumpy. Increase the Volume Period (45 or 60 seconds, say), or switch Use Rolling Window off to use projection mode for a smoother reading.
The panels stop updating when the chart is hidden. This is by design: VolLiqMeter pauses its depth and tape processing when the chart window is minimized or hidden, to save resources. When you bring the chart back, the panels resume from the current moment; they do not backfill the gap. Keep the chart visible if you need continuous monitoring.
10. Glossary
Aggressor volume: the volume of market orders trading into the book, split by which side they hit.
Bid (aggressor): volume that traded into the bid: aggressive selling, sellers hitting the bid.
Ask (aggressor): volume that traded into the offer: aggressive buying, buyers lifting the offer.
Liquidity: the resting size sitting in the order book, waiting to be traded against.
DOM level: a depth level in the order book; level 1 is the top of book (best bid and ask), with deeper levels counting outward.
Rolling window: the true sum of activity over the last N seconds.
Projection mode: an estimate that takes the current rate and projects it to a full period.
Top of book: the best bid and best ask, the prices closest to the market.
Flow.42 VolLiqMeter is a context and visualization tool. It does not provide automated trade signals or trading advice. Trade less. Trade better. Trade with clarity.
© 2026 TTW Trading Systems PTE. LTD. · Flow.42 Analytics · All rights reserved.