At a glance
The short version
The volume profile turns a chart sideways: instead of price over time, it shows volume at each price across everything on screen. The longest row is the point of control; the band holding 70% of the volume is the value area. Traders lean on both — fade the edges, target the POC, trade the break of value — and every one of those ideas can be counted on CRTLAB's replay, where the profile only ever knows the candles you have already seen.
How CRTLAB's profile works
It is a visible-range profile: it covers exactly the candles on screen, so zooming out to a week gives you the week's profile and zooming in to a session gives you the session's. During replay it updates on every new candle, easing to the new shape rather than jumping.
Rows are split on clean price steps (up to 40, adapting to the range so each row stays readable), up and down volume are drawn in two colours, the value area is shaded stronger than the rest, and the POC is drawn in red with its own price tag. Row count, value area %, width, side and every colour are editable, and templates save your setup.
Volume is real traded volume, not tick counts: for indices, forex, gold, silver and oil it is the matching futures contract's exchange volume, minute by minute; for crypto it is exchange volume (Coinbase); for US stocks it is the exchange's trades in regular hours.
Volume profile ideas to put numbers on
The 80% rule. When price opens outside yesterday's value area and then trades back into it for two periods, it is said to cross to the other side most of the time. Mark yesterday's value, wait for the condition, and count how often it is true on your market.
POC as a magnet. How often does price revisit the prior session's POC, and how far does it run first? A level that gets revisited 70% of the time is a target; one revisited 30% of the time is a story.
Low-volume nodes. Do breaks through thin parts of the profile travel to the next high-volume node, and how fast?
Why replay matters more for profiles than for anything else
A volume profile drawn on a finished chart already contains the move you are trying to predict — the POC sits where it does because of what happened later. Studying profiles on completed history therefore shows you levels that look magical and are not. In replay, the profile only contains the past, so the level you trade is the level you would have had.
Frequently asked questions
Is the volume profile free?
CRTLAB is free to try. You get the real-volume profile on every market, with every tool the product has, for your first 10,000 candles of replay — roughly two hours of stepping through a chart, no card needed. After the sample, unlimited replay is $14.99 a month, cancel any time.
Is it real volume or tick volume?
Real traded volume. Forex, indices, metals and oil use the matching futures contract's volume; crypto uses exchange volume; US stocks use exchange trades.
Can I change the value area percentage?
Yes — value area %, row count, width, left or right side and every colour are editable, with saved templates.
Does the profile repaint during replay?
It updates as each new candle is revealed, and only ever includes candles up to the replay cursor, so it never shows volume from the future.