Direct Answer
Down volume is the volume of bars in which the price closed below the prior close. Whole-bar volume is assigned to the down side based on the bar's price change, regardless of trade direction inside the bar. Down volume that clearly exceeds up volume shows that more activity occurred on declining bars.
Down Volume: Formula, Meaning, Signals, Examples and How to Use It
How Is Down Volume Calculated?
Down volume is the volume of bars in which the price closed below the prior close. Whole-bar volume is assigned to the down side based on the bar's price change, regardless of trade direction inside the bar.
Formula: Down Volume = sum of Volume over bars where Close < prior Close
Inputs:
- Bar closes
- Bar volumes
- Look-back window to sum over
Worked example. Three down-closing bars with volumes of 0.90M, 1.30M and 0.70M shares give a down volume of 2,900,000 shares. The inputs are illustrative numbers, not market data.
Reading it. Down volume that clearly exceeds up volume shows that more activity occurred on declining bars. Market-wide versions sum the volume of declining stocks and are used in breadth and trin-style measures.
Limits. The label comes from the close-to-close change, not from who initiated the trades, so it differs from sell volume. Bars with an unchanged close fall in neither group, and the split is coarser on long bars than short ones.
What is Down Volume?
Down volume is the volume of bars in which the price closed below the prior close. Whole-bar volume is assigned to the down side based on the bar's price change, regardless of trade direction inside the bar.
How to use Down Volume
Down volume that clearly exceeds up volume shows that more activity occurred on declining bars. Market-wide versions sum the volume of declining stocks and are used in breadth and trin-style measures. A reading alone is never a buy or sell signal; it needs context from price structure, volume, volatility and the broader market regime.
Strengths
- Because each bar goes to one side, up and down totals plus unchanged bars always sum to total volume, so nothing is lost or double counted.
- Using close-to-close change makes the label consistent with how returns are measured, so it lines up with the return series.
- Reproducible when the formula and data convention are fixed.
Weaknesses and limitations
- Reversal bars that trade heavily at both ends receive one label, so the down total can include volume that was mostly buying.
- The down total depends on the prior close definition, and sessions with extended-hours trading may define it differently between data sources.
- Correlated indicators can create false confidence by repeating the same underlying information.
Editorial and risk note
This page is educational content, not individualized investment advice. It should not imply guaranteed prediction, accuracy or outperformance.
Frequently Asked Questions
Is Down Volume a buy or sell signal?
No. Down volume that clearly exceeds up volume shows that more activity occurred on declining bars. The label comes from the close-to-close change, not from who initiated the trades, so it differs from sell volume. A trade built on it still needs a trigger, an invalidation rule, a position size and realistic execution assumptions.
What is the best setting for Down Volume?
Down Volume takes these inputs: bar closes; bar volumes; look-back window to sum over. There is no universal best setting for the tunable ones, so test them across instruments, regimes and out-of-sample periods and favor stable parameter regions over one historical winner.
Can Down Volume be used by itself?
The label comes from the close-to-close change, not from who initiated the trades, so it differs from sell volume. Bars with an unchanged close fall in neither group, and the split is coarser on long bars than short ones. For that reason it is read next to measures of direction, participation, valuation, liquidity and risk, not alone.
Does Down Volume work on every timeframe?
The calculation can be run on any bar size, but behavior is not portable: a reading on a five-minute chart describes a very different market window from the same reading on a daily chart. Validate the exact timeframe before relying on it.
Why does Down Volume give false signals?
Reversal bars that trade heavily at both ends receive one label, so the down total can include volume that was mostly buying. The down total depends on the prior close definition, and sessions with extended-hours trading may define it differently between data sources. Lag, noise and regime changes add to this, because market participants react to new information after the reading is calculated.
How should Down Volume be backtested?
Rebuild Down Volume from bar closes using point-in-time data, write the rules before testing, include delisted securities where relevant, model realistic fills and costs, reserve a validation sample and compare with a simpler baseline.