The volume bars under a normal chart answer one question: when did the
trading happen? Volume profile rotates that histogram ninety degrees and
answers a more useful one: at what prices did the trading happen?
The rotation that changes the picture
Take every trade in a session and, instead of stacking volume under its
time-slot, stack it beside its price. The result is a sideways histogram
along the price axis: long bars at prices where huge volume changed hands,
stubby bars where price only passed through.
Three features of that shape carry names you will meet everywhere:
- POC (Point of Control) — the single price with the most traded volume.
The session's busiest shelf. - Value area — the price band around the POC containing the bulk
(conventionally ~70%) of the session's volume. Where the market spent its
day doing business. - HVN / LVN (high & low volume nodes) — local bulges and gaps in the
profile. An HVN is a price the market kept returning to; an LVN is a price
it rejected quickly, in either direction.
How traders read the shape
The profile is read as a map of acceptance and rejection:
- Heavy-volume shelves (HVNs, the value area) are prices the market
accepted — both sides transacted comfortably there. When price revisits
such a shelf, trading often slows and two-sided battle resumes. - Thin zones (LVNs) are prices the market rejected — it moved through them
fast because one side overwhelmed the other. Revisits often move quickly
through the same thin air again. - A session closing far outside its value area is telling you the day's
business failed to hold price; a session building value steadily higher
tells a different story than one spiking on thin volume.
None of this is prediction. It is context: where the crowd transacted, where
it refused to, and where today's price sits relative to both.
The honest caveats
- The window defines the profile. A session profile, a weekly profile and
a composite of months over the same stock look different and imply
different shelves. Any reading must state its window. - Shelves are zones, not lines. Treating a POC as a to-the-tick level
misuses a distribution. - Profiles describe the past. A heavy shelf can be sliced through on any
news candle; thin zones fill in eventually. The map updates; it does not
promise. - Illiquid names produce lumpy, unreliable profiles — a single block
trade can fake an HVN.
Where to watch this live
Torpedo, Ticker Lab's streaming-analytics product, builds this view
continuously from live minute candles: open the Profile (VP) tab and you
get the session's volume-by-price histogram with its POC and value area
marked — the high- and low-volume shelves plain to see in the histogram's
shape — updating as the day trades, next to Torpedo's
Structure and S/R views so the profile sits in its market context. The same
acceptance-and-rejection map from this post, drawn from live NSE data,
interpretation left where it belongs: with you.
Questions or a different read? Tell us on X
@tickerlabHQ — or through the Ideas board if
you're a member.
Informational, not advisory. Ticker Lab explains how market data is read;
it does not provide investment advice or trading calls.