Volume Chart Notes
A volume profile rotates the histogram onto the price axis and shows where, not when, the trading happened.
To build a profile, each interval's volume is distributed across the prices that interval touched, and the rows are summed sideways. The result hangs off the price axis like a sideways histogram: fat where business concentrated, thin where price barely paused.
The landmarks have stable names. The point of control is the longest single row — the most-traded price of the window. The value area brackets the prices containing the bulk of the volume, conventionally near seventy percent, bounded by a value area high and a value area low.
Beyond those, readers speak of high-volume nodes, the fat zones where the market lingered, and low-volume nodes, the thin zones it crossed in a hurry. The profile's shape — balanced, elongated, pinched in the middle — is a description of how the window's trading was arranged.
The vocabulary of acceptance and rejection attaches here. Prices that accumulated rows are described as accepted; prices that stayed thin are described as rejected. Both words are past-tense labels for the drawing, and the drawing changes with the window chosen.
That window dependence is the profile's main caveat. A session profile, a week profile, and a composite of months are different pictures built from the same trades, and none of them ranks one price as more valid than another — the profile maps history, it does not legislate it.
Further reading