On-balance volume, and why the number is never shown

What it means

Every bar adds its volume to a running total when it closes higher than the last, subtracts it when it closes lower, and adds nothing when the close is unchanged.

The total depends entirely on where the series happened to start, so the value itself carries no information. Only its direction over a stretch of bars does, which is why no OBV figure appears anywhere on this site.

How we detect it

The engine compares the direction of the running total over the last twenty bars with the direction of price over the same twenty bars, and reports whether the two agree.

When they disagree it says so in those words. It does not say a reversal is coming, because a disagreement between two lines is not evidence about what happens next.

A market whose feed reports no volume gets no reading at all, and is told so.

When the read carries information

• The volume figures are real and comparable bar to bar, which is true of a single venue and often false of an aggregate.
• The window is long enough that one outsized bar does not decide the direction of the total.

When it misleads

• A single enormous bar can set the direction of the total for the whole window.
• On instruments where reported volume is a poor proxy for participation, the total describes the feed rather than the market.
• Agreement is the normal state. Reading every agreement as confirmation of something is how the indicator becomes noise.

How it reaches you

It appears only when a question asks about volume, and it is one line: the totals and price agree, or they do not.

A disagreement is never presented as a reason to expect a turn.