Field guide / Relative volume
Put today’s volume in perspective.
Relative volume, or RVOL, compares trading activity with a historical baseline. Learn what the ratio measures, try the calculator, and see how Gapperz puts unusual participation into context.
By GapperzUpdated
Relative volume calculator
Try your own numbersCompare shares traded so far with the historical average through the same time of day.
Relative volume at time
3.00×
Formula: current volume ÷ average volume at the same time. A ratio of 3× means three times that average.
Illustrative inputs. This calculator measures a relationship between numbers; it does not forecast a stock’s next move.
- 01A 3× reading means three times the volume of the chosen baseline.
- 02For an intraday comparison, match the session and time of day.
- 03Read RVOL alongside absolute volume, price, and the spread.
The useful part is the comparison.
A volume number tells you how many shares traded during a period. Relative volume tells you how that number compares with a chosen average. The basic arithmetic is current volume divided by baseline volume.
If a stock has traded 1.2 million shares and its historical average through the same time is 400,000 shares, its RVOL is 3×. That describes unusually high activity relative to its own history. It says nothing by itself about whether the stock is rising or falling.
| RVOL | Relationship to the baseline | Example: baseline of 400,000 shares |
|---|---|---|
| 0.5× | Half the baseline | 200,000 shares traded |
| 1.0× | Equal to the baseline | 400,000 shares traded |
| 2.0× | Twice the baseline | 800,000 shares traded |
| 3.0× | Three times the baseline | 1,200,000 shares traded |
Use the calculator above to test the arithmetic. Enter share counts on the same basis: cumulative volume against a cumulative average, or a single period against a comparable period.
A morning number needs a morning baseline.
Suppose a stock has traded 600,000 shares at 10:00 a.m. Its average full-day volume is 2 million shares, but its average volume through 10:00 a.m. is 200,000. The same observed activity produces two different ratios.
| Comparison | Calculation | What it means |
|---|---|---|
| Against a full day | 600,000 ÷ 2,000,000 = 0.3× | 30% of an average full day has already traded. |
| Against the same time | 600,000 ÷ 200,000 = 3.0× | Three times the usual activity through 10:00 a.m. |
Both calculations can be mathematically correct. The second directly answers whether the stock is unusually active at that point in the session. A time-aligned baseline makes the comparison useful early in the morning as well as later in the day.
There is another distinction: cumulative volume counts from the session’s start, while bar volume counts only a particular interval. TradingView documents both calculation modes. Read the definition of the specific metric you are using.
How Gapperz calculates RVOL.
Gapperz compares today’s cumulative session volume with expected cumulative volume through the corresponding minute. The historical baseline uses 20 trading sessions, with minute buckets across the 4:00 a.m.–8:00 p.m. Eastern session.
Match the point in the session.
Identify the corresponding minute from the 4:00 a.m. Eastern session start. This aligns the current observation with the historical volume curve.
Add up expected volume through that minute.
The baseline contains historical average volume by minute. Summing those buckets gives the expected cumulative volume at the current point in the session.
Divide measured volume by expected volume.
The resulting ratio is displayed when the baseline has enough supported observations and a positive expected volume. The High RVOL scanner ranks measured ratios.
This is especially useful when researching a newly listed name. You can inspect its current price and volume while keeping the missing historical comparison visible. See our data methodology for the broader approach to sources and confidence.
Read the ratio beside the share count.
A 10× reading on 10,000 shares and a 3× reading on 1.2 million shares describe different conditions. The first is more unusual relative to its own baseline. The second represents much more observed volume. Neither number replaces the other.
Price and spread add two more dimensions. Check which direction price is moving, where it sits within the current range, and how far apart the bid and ask are. Relative activity, absolute participation, and current quotes work together as research context.
Also keep the baseline length and session scope in view. A platform using ten periods or regular-session-only data can show a different result from Gapperz’s 20-session extended-hours baseline. TradingView’s screener definitions provide a concrete example of why metric names alone do not establish an identical calculation.
Use High RVOL to focus your research.
Open Gapperz’s High RVOL scanner to find names trading above their usual pace. Read the measured ratio and total volume together, then open a result to inspect the chart and available catalyst.
Use the view that matches your next question. The premarket scanner organizes price gaps before the bell. The momentum workflow connects intraday movement with day-high proximity and participation.
Save a watchlist of the names you want to revisit and set a specific alert condition. That turns the ratio into a useful starting point for an ongoing research process.
A few useful answers.
What does 2× or 3× relative volume mean?
A 2× reading means the measured volume is twice the baseline; 3× means three times the baseline. For example, 600,000 shares against a 200,000-share same-time average is 3× RVOL. That is 200% above the average, not 300% above it.
What is a good RVOL for a stock scanner?
Start with the research question. A threshold above 1× narrows attention to activity above the selected baseline; a higher threshold creates a more selective list. Gapperz’s built-in High RVOL view uses a measured ratio of at least 1.5× alongside price, volume, and spread criteria. The threshold identifies activity, not an expected return.
Why do two platforms show different RVOL numbers?
They can use different historical lengths, cumulative or single-bar volume, session start times, eligible trades, and data coverage. Compare the numerator and denominator definitions, including the time window, before interpreting a difference as a data error.
What does an unavailable RVOL mean?
It means a supported comparison is unavailable, such as when there is insufficient history or a missing baseline. It is different from 0×, which would mean zero observed volume against a valid positive baseline. Gapperz keeps the distinction explicit.
Sources & editorial notes
Prepared by Gapperz using our scanner definitions and the primary references below. The examples are illustrative; the public methodology explains how we label data and research context.