On-Balance Volume (OBV): Tracking Smart Money
On-Balance Volume adds or subtracts volume based on price direction to reveal where the "smart money" is positioning. Learn the OBV formula and how to read it.
On-Balance Volume (OBV): Tracking Smart Money
Price tells you what. Volume tells you who. OBV connects the two — and lets you follow the smart money.
On-Balance Volume (OBV), created by Joseph Granville in the 1960s, is a cumulative volume indicator. It adds the day's volume when price closes up and subtracts it when price closes down. The running total is meant to capture whether "smart money" is accumulating or distributing before price confirms it.
The formula
If Close > Previous Close: OBV = Previous OBV + Volume
If Close < Previous Close: OBV = Previous OBV − Volume
If Close = Previous Close: OBV = Previous OBV (no change)
OBV is a running total, so the absolute number is meaningless — only its slope and divergence from price matter.
Worked example:
| Day | Close | Volume | Direction | OBV |
|---|---|---|---|---|
| 1 | $50 | 1,000 | — | 0 |
| 2 | $51 | 1,200 | Up | +1,200 |
| 3 | $50 | 800 | Down | +400 |
| 4 | $52 | 1,500 | Up | +1,900 |
Price ended day 4 at $52, but OBV rose to +1,900 — a much bigger rise in volume than in price. That's the kind of quiet accumulation OBV is designed to catch.
What OBV tells you
| OBV behaviour | Meaning |
|---|---|
| Rising OBV, rising price | Healthy uptrend — volume confirms |
| Rising OBV, flat/falling price | Accumulation — potential bullish breakout |
| Falling OBV, falling price | Healthy downtrend — volume confirms |
| Falling OBV, flat/rising price | Distribution — potential bearish reversal |
| OBV divergence from price | Trend in doubt — watch for reversal |
The core idea: confirmation
Granville's central claim: volume precedes price. When institutions quietly accumulate, OBV rises even if price is still flat. When they distribute, OBV falls. By the time price breaks out, the move is already underway.
OBV divergence
The most powerful OBV signal:
- Bullish divergence — price makes a lower low, but OBV makes a higher low → accumulation under the surface
- Bearish divergence — price makes a higher high, but OBV makes a lower high → distribution under the surface
Pair this with RSI divergence for a stronger signal.
How to use OBV
- Confirm trends — require OBV to slope with price. No volume confirmation = weak trend.
- Spot breakouts early — OBV breaking out before price is a leading signal.
- Detect divergence — disagreement between price and OBV is a warning.
- Trade the trend — when OBV and price agree, ride the trend.
Common mistakes
- Reading the absolute value — meaningless; only slope and divergence matter
- Using OBV alone — always pair with price action and a trend indicator
- Ignoring the higher timeframe — daily OBV is far more reliable than 5-minute
- Forgetting gaps — OBV ignores gap size, just counts up/down days
How to start
- Add OBV below a daily chart
- Compare its slope to price over the last few months
- Flag any divergence as a watch-list item
- Confirm breakouts with rising OBV before entering
- Set stops with the stop loss calculator and size with the position size calculator
Summary
OBV turns volume into a single line you can read like price. When OBV and price agree, the trend is healthy; when they diverge, smart money may be repositioning. It's a leading indicator of accumulation and distribution — exactly what trend traders want to see confirmed before committing.