What volume is counting
Every unit traded had a buyer and a seller. Volume does not tell you which side was keener — that is a myth worth dropping early. What it counts is participation: how many people cared enough to transact in that period.
That makes it a measure of conviction behind a move, not direction of it. A rise on heavy volume and a rise on light volume look identical in price. They are not the same event.
Expansion and contraction
The most useful pattern in the whole subject is also the simplest. In a healthy trend, volume expands when price moves in the direction of the trend and contracts during pullbacks against it.
The logic is plain. A pullback on thin volume means very few people are willing to sell into it — the people who own the thing are sitting still. A push on heavy volume means new participants arriving. Together they say: the crowd is still on one side.
Volume is the only thing on a price chart that is not price. That is precisely what makes it worth looking at.
The reverse is just as informative. When price keeps making new highs but each new high arrives on less volume than the last, the move is running on fewer and fewer participants. It does not mean a reversal is due. It means the thing driving the move is thinning.
When volume is a warning
Occasionally volume arrives in a single enormous bar, several times anything around it, usually with a long wick and a close far from the extreme. This is a climax: a moment where everyone who was going to panic did so at once, and somebody on the other side absorbed all of it.
The interesting part is what it implies. If that much stock changed hands at those prices and price did not stay there, the supply that had been pressing was exhausted into willing hands.
Where volume misleads
- Expiry days and index rebalancing produce volume that has nothing to do with opinion. Somebody is rolling a position, not forming a view.
- Holidays and half-days depress volume across the board. A thin bar on a thin day says nothing.
- Comparing across instruments is meaningless. Volume is only readable against its own recent history.
- Volume without price context is noise. The bar matters because of the candle above it, never on its own.
Treating a single heavy bar as a signal. One bar is an event, not a pattern. What carries information is the relationship between volume and price across a stretch of candles — expanding with the move, contracting against it, or the opposite.
Read it yourself
Price and volume together. Say what the volume is telling you at each stage.
- What happens to volume during the first pullback, and what does that suggest?
- Compare the volume on the second push higher with the first. What changed?
- What is happening to volume in the last three candles, and why is that worth noticing?
Show answers
1. It falls to the lowest on the chart. Very few sellers — the pullback is a lack of buying rather than an arrival of selling.
2. The second advance reaches a similar high on noticeably lighter volume. Same price progress, fewer participants behind it.
3. Volume expands sharply as price falls. Through the whole rise, the heaviest bars had come with advances; now they come with declines. That is the participation switching sides, and it is visible before any level breaks.
Terms used
- Volume
- Units traded in a period. A measure of participation, not of direction.
- Expansion
- Volume rising relative to its recent average.
- Contraction
- Volume falling relative to its recent average.
- Climax
- An outsized volume bar with a long wick, marking exhaustion of one side.
- Divergence
- Price and volume moving in opposite directions over a stretch of candles.