A single cumulative volume line. There is no fixed scale — only its direction and its agreement or disagreement with price matter. Rising OBV means volume is favoring up-bars; falling OBV means it is favoring down-bars.
OBV (On-Balance Volume) is a single running line built from volume. It adds the bar's volume on up-closes and subtracts it on down-closes, so the line rises when buyers are pressing and falls when sellers are. Traders watch whether OBV confirms or diverges from price.
How it works
Starting from a running total, each bar adds its volume if the close is higher than the previous close, subtracts its volume if the close is lower, and leaves the total unchanged if the close is flat. The result is a cumulative line whose direction reflects whether volume is flowing into up-bars or down-bars.
Connects to
Feeds into
Examples
Confirm an uptrend: require OBV to be making higher highs along with price.
Spot a warning: flag bars where price makes a new high but OBV does not (a bearish divergence).
Common mistakes
Reading the absolute OBV value — only its slope and divergence versus price carry information.
Comparing OBV levels across different symbols or sessions, since the running total has no common baseline.