Up/down Volume

What is Up/down Volume?

Up/down volume is a breadth measure that splits a session's total exchange volume by direction: up volume is the combined volume of advancing issues, down volume the combined volume of decliners, summed across a universe such as the NYSE or Nasdaq. The difference between the two (the VOLD spread on many platforms) shows where the volume actually went, which issue counts alone cannot: two thousand advancers on thin volume is a weaker statement than fifteen hundred advancers carrying the day's heaviest turnover. A running total of the daily net figure is the Cumulative Volume Index, the volume-weighted cousin of the advance/decline line covered under advance/decline internals.

Extreme one-sided days matter most. Sessions where up volume overwhelms down volume by roughly nine to one, a threshold Martin Zweig studied, feed several breadth thrust definitions, while equally lopsided down-volume days mark liquidation pressure.

How traders use it

• As an intraday conviction gauge: day traders watch the running up/down volume spread alongside the TICK; a spread that grinds steadily in one direction supports trend-day tactics, while a spread oscillating around zero argues for range tactics.
• As confirmation for index moves: a new high backed by strong net up volume is better supported than one where up volume barely exceeds down volume, and a persistent divergence between price and cumulative volume breadth is a classic warning, though it can run for a long time before it matters.
• As a thrust and washout detector: clusters of nine-to-one up-volume days after a decline are read as initiation evidence, and nine-to-one down days as capitulation candidates, with the caveat that a single extreme day reverses nothing by itself.