Relative Volume
Also called: relative volume, rvol, relative volume meaning, how to compare todays volume, is todays volume high.
How it is read
Its whole value is in comparing like with like. Take forty thousand shares traded by 10 a.m. Measure that against a full-day average of one hundred thousand. That gives 0.4. The number says almost nothing. A morning cannot be judged against a whole day. Now measure it against a like-for-like average instead. That is the average cumulative volume by the SAME time in earlier sessions of the same kind. That figure is twenty thousand. The ratio is then 2.0. Those two ratios answer different questions. Only the second says whether this morning is busy for a morning.
What it does not tell you
There is no standard definition across platforms. So two sites can publish different numbers for the same day. Neither of them is wrong. A missing reference average must be shown as unavailable. It must not be shown as a ratio of zero. A zero reference leaves the ratio undefined. A high ratio shows unusual activity. It does not show a direction. It does not show a cause. It does not show who was trading. Holiday-shortened and special sessions need their own handling. They must not enter an average until that is done.
Related concepts
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