Relative Volume (RVOL)
Relative volume (RVOL) is a stock's volume divided by its own average volume, so 3 means three times the usual participation. It measures how unusual activity is, and says nothing about direction.
MadStockAlerts Research · Updated October 2, 2026
What to Take Away
- Relative volume divides the shares traded today by the stock's own average, so 2 means twice the usual participation.
- An intraday figure has to be compared with what normally trades by that time of day, or it climbs mechanically through the session.
- A high reading says participation is unusual. It carries no information about which way price will go.
- Small caps read jumpy because a large multiple of a thin average can still be very few shares.
- No threshold is correct. Readings of 1.5 and 2 are screening conventions that the data itself does not single out.
MAD Academy Training Video · 0:54
When Relative Volume Misleads
One ratio that spots unusual activity quickly, and three ordinary ways it gives the wrong impression.
This lesson is part of a MAD Academy plan.
What relative volume measures
Relative volume, or RVOL, compares the number of shares of a stock traded today with the number that normally trade. A reading of 1 is an ordinary day, 2 is twice the usual participation and 0.5 is half. Because each stock is measured against its own history, a mega cap and a small cap land on one comparable scale.
That last property is the reason the measure exists. Raw trading volume cannot be compared across securities: ten million shares is a quiet morning for one company and a record for another. Dividing by each stock's own baseline removes the size of the company from the number and leaves only how unusual the day is.
relative volume = volume traded so far today / average daily volume over the last n sessions
- n is commonly 10, 20, 30 or 50 completed sessions
- the average is taken over completed sessions, so today's activity does not dilute its own baseline
- a reading above 1 means more participation than usual, below 1 less
Why the time of day changes the reading
US equity volume is not spread evenly through the session. The first half hour and the last half hour each carry a large share of the day, with the closing auction the single largest event, and the middle of the day is quiet. A stock that has traded a fifth of its usual daily volume by 10 a.m. is having a busy morning.
Scroll the chart sideways to see all of it.
- Twice the usual pace
- A typical day
There are therefore two versions of the measure in common use. The unadjusted version divides volume so far by the full-day average, which is simple and comparable at the close but understates every reading taken earlier. The time-adjusted version divides by the volume the stock normally trades by that minute of the session, which is comparable at any hour but needs an intraday history to compute.
Any platform reporting relative volume intraday should say which version it shows. An unadjusted figure that reads 0.8 at 11 a.m. can describe a day that will finish at 2.0, and the two versions disagree most in exactly the morning hours when traders are reading them.
What a high reading says, and what it does not
A high reading says that more participants than usual are transacting. Something has usually changed: an earnings release, a filing, an analyst action, a sector move, an index event or a halt and reopening. It also says liquidity is temporarily deeper than normal, which affects the bid-ask spread and how much can trade without moving price.
It does not say which way price is going. Every share traded has a buyer and a seller, so heavy volume on a decline produces the same ratio as heavy volume on an advance. Nor does it say whether the activity will persist into tomorrow, or what caused it. The cause is a separate question, and usually the more important one.
A common question is what counts as a good relative volume for day trading. The honest description is that there is no such number. Scanners aimed at intraday activity often filter at 1.5 or 2 because that removes most ordinary sessions, and higher cutoffs return fewer, more event-driven names. Each cutoff is a trade-off between how many names a list returns and how unusual each one is.
Why small caps read differently
The ratio hides the size of the base. Five times a 20,000-share average is 100,000 shares, which can be a handful of orders. Five times an eight-million-share average is forty million shares and a market-wide event. Reading relative volume beside average volume, or beside dollar volume, restores what the ratio removes.
- Thin averages swing on single orders, so a small cap can print a large multiple from one block trade.
- A low float concentrates trading in fewer available shares, which makes large multiples more common.
- A newly listed stock has no baseline at all, and a short one makes every reading unstable.
- A single extreme day inside the averaging window inflates the baseline for as long as it stays in, and every later reading looks quieter until it drops out.
That last effect produces a jump with nothing new happening. When a 40x day leaves a 30-session window, the average falls and the next day's ratio rises on identical volume.
Sessions that distort the ratio
| Session | What happens to relative volume |
|---|---|
| Index rebalance days | Closing auction volume swells across every affected stock at once |
| Monthly options expiration | Volume rises on hedging flows, with no news about the company required |
| Half-day sessions | A full-day average makes the shortened day look quiet |
| The day after a split | The share count changes, so a baseline that is not split-adjusted is wrong |
| Earnings days | Heavy volume is expected, so a high reading is ordinary for that day |
How MadStockAlerts uses this
The free scanner carries an RVOL column on its movers and volume presets, defined as today's volume against the 30-session average. It is the unadjusted version, so early in the session it reads low by construction and rises as the day goes on. The Unusual Volume preset lists names above 2x and shows the average volume beside the ratio, because the same multiple on a thin stock and on a heavily traded one describes very different amounts of activity.
Sort any preset by relative volume, with average volume beside it, on the free scanner. It runs on data that is not real-time.
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