Technical analysis · Intermediate

On-Balance Volume (OBV)

OBV is a running total that adds volume on up-closes and subtracts it on down-closes. Read the shape of the line, never its value.

Last reviewed 15 September 2026 by the MarketPro research desk · Editorial policy

In short

On-Balance Volume is a cumulative line that adds a period's entire volume when price closes higher and subtracts it when price closes lower. The idea is that sustained buying or selling pressure shows up in the volume record before it is obvious in price. Because the total has no fixed starting point, its absolute value is meaningless, so OBV is read through its slope and its structure relative to price.

What to remember

OBV ignores the size of the move entirely. A one-pip higher close adds the same volume as an 80-pip higher close, which is why it is read as a shape.
The absolute value means nothing because the total depends on where your chart history starts. Only the slope and the structure carry information.
Draw trendlines and swing points on OBV the same way you draw them on price, then compare the two. Disagreement is the useful output.
In forex, OBV inherits every tick-volume limitation, so it is a weaker tool on a currency pair than on an exchange-traded instrument.

Lesson 15 of 26 in Technical analysis

PreviousVolume Analysis Basics NextIchimoku Cloud Basics

OBV turns volume into a single running line

On-Balance Volume is a cumulative total. When a period closes higher than the previous close, the whole of that period's volume is added to the running total. When it closes lower, the whole of that period's volume is subtracted. Flat close, no change. The result is one line that rises when up-closes carry the volume and falls when down-closes do.

Notice how crude the rule is. A candle that closes one pip higher on enormous volume adds the same full amount as a candle that closes 80 pips higher on the same volume. OBV does not weight by the size of the move at all. That bluntness is deliberate, and it is why OBV is read as a shape rather than as a number.

The idea behind it

The premise is that volume leads price: sustained accumulation or distribution should register in the volume record before it becomes obvious in the price chart. When large participants build a position over several sessions, the argument goes, the buying shows up in the cumulative total even while price is still going sideways.

Treat that as a plausible mechanism rather than a proven one. It is more defensible in a centralised market with real exchange volume than in forex, where the input is tick volume from your own broker. On a currency pair, OBV is a smoothed picture of how many price updates accompanied up-closes versus down-closes, which is a weaker claim than the theory implies.

Reading the slope, not the value

Because OBV is cumulative and has no starting reference, its absolute value is meaningless. A reading of 4.2 million says nothing on its own. What matters is the direction of the line, the slope relative to price, and whether it is making higher highs and higher lows in the same places price is.

The practical method is to draw the same structure on OBV that you draw on price. Trendlines, swing highs, ranges. Then compare the two structures. Where they agree, the price move has participation behind it. Where they disagree, you have a question worth asking, and questions are the useful output of a secondary indicator.

10 more sections in MarketPro

The three readings

Confirmation. OBV rising alongside price says the advance is happening on candles that carried participation. It adds nothing new, but it removes a reason for doubt.
Divergence. Price makes a new high while OBV fails to exceed its previous high. The latest push happened on candles that carried less of the activity, which suggests thinner backing.
Breakout in OBV before price. The cumulative line pushing through its own range while price is still consolidating is the reading the theory is built on, and the one worth watching for.

When OBV and price disagree

A pair ranges between 1.0850 and 1.0950 for three weeks. Price is going nowhere, but OBV climbs steadily through that period, because most of the sessions closing higher arrived with heavier tick activity than the sessions closing lower.

You have learned something the price chart did not show: within a flat range, the up-closes carried more of the activity. That is a bias, not a trade. The trade still requires price to break 1.0950, and the stop still sits beneath the range, and the position size still comes from that distance through the position size calculator. What OBV changed is which direction of break you were prepared for, and being prepared for the right one is worth a great deal at the moment it happens.

The limits of a cumulative line

The all-or-nothing rule is crude. A one-pip close decides the sign of the entire period's volume, so a market closing marginally higher and marginally lower in alternation produces a noisy line for no real reason.
Divergences persist. OBV can fail to confirm new highs for months while the trend carries on. It flags a condition, not a date.
It inherits every tick-volume problem. Broker-specific input, thin sessions, feed gaps. Garbage in the volume series becomes a permanent kink in a cumulative line.
Starting point affects appearance. Where your chart history begins changes the line's level and visual slope, so two traders can see the same OBV looking quite different.

Keep it as a second opinion

Keep OBV as a second opinion rather than a trigger. It is at its best answering one specific question: did the move I am looking at happen on the candles that carried the activity, or on the quiet ones? That question is worth asking before a breakout entry, and it costs nothing to ask.

Do not stack it with three other volume tools. OBV, volume histogram, a volume oscillator and a running pip tally are all reading the same underlying series, and agreement between them is not confirmation, it is repetition. One volume-based view per chart is enough, and the strategy guide covers how to keep a chart from turning into a dashboard.

Finish this lesson in MarketPro

The rest of On-Balance Volume (OBV), a quiz that checks it landed, and your place kept in the curriculum.

10 more sections of this lesson
All 320 lessons, with no cap and no paywall
Free on any account, including a free one

In your browserContinue on webor continue on web

Same account as the app · No install · Free to start

Or scan with your phone camera to get the MarketPro app.

Download on theApp Store Get it onGoogle Play

Free account, no card needed.

Not investment advice. Past performance is not indicative of future results.

Run the numbers while this is fresh

Work it through on your own position size. Nothing leaves your browser and there is no sign-up: Pivot points calculator, Fibonacci calculator.

Written and reviewed by the MarketPro research desk

MarketPro is a trading-signal and trading-education app operated by Harajuku Holdings LTD (Cyprus). Our signal desk publishes and tracks every trade idea in-app, and every page here is checked against the app's live behaviour before publishing. Last reviewed 15 September 2026. How we produce signals and content · About MarketPro

FAQ

On-Balance Volume (OBV): questions

What does OBV divergence mean?

OBV divergence is when price makes a new high or low that the OBV line does not confirm. A new price high with a lower OBV high suggests the latest push happened on candles carrying less participation than the previous one. It flags a condition rather than a date, since a cumulative line can disagree with price for months without anything happening.

Is a high OBV value bullish?

The value itself carries no information. OBV is a running total with an arbitrary starting point determined by how much history your chart loads, so two traders can see very different numbers for the same market. What matters is whether the line is rising or falling and whether its highs and lows line up with the highs and lows in price.

Does OBV work in forex?

It can be used, but with lower confidence than on an exchange-traded market. Forex charts feed OBV with tick volume, a count of price updates from one broker rather than actual lots traded, so the cumulative line inherits every quirk of that feed. Read it as a relative comparison on your own chart and treat conclusions as tentative.

Trade · Learn · Earn

The whole academy is free in MarketPro

All 320 lessons, 12 guided paths, quizzes and a daily streak. Free on every account, in the app or your browser, with vetted free signals alongside it.

In your browserContinue on webor continue on web Download on theApp Store Get it onGoogle Play

Same account as the app · No install · Free to start

Not investment advice. Past performance is not indicative of future results.