Relative volume (RVOL)
Relative volume (RVOL) is a stock's trading volume divided by its typical volume for the same period, so a reading of 3.0 means three times the usual activity.
Last verifiedHow it is calculated
RVOL = Volume in the current period ÷ Average volume for the same period over a baseline window
The baseline is usually an average over a recent window, such as 30 trading days. The key choice is which period is being compared. Comparing a full day with a full day is straightforward. Intraday, a fair comparison uses the same time window: volume traded by 10:00 ET today against the average volume traded by 10:00 ET on past days, or premarket volume against past premarket volume.
Worked example
Hypothetical: Company X normally trades 40,000 shares in the premarket session (04:00 to 09:30 ET), averaged over the last 30 sessions. This morning it has traded 360,000 shares by 09:30. Premarket RVOL is 360,000 ÷ 40,000 = 9.0.
Comparing the same 360,000 shares with its average full-day volume of 1,200,000 would give 0.3, which compares a partial session with a whole day and understates how unusual the morning is.
Why it matters
RVOL flags when a stock is trading far more than usual, which often coincides with news, a filing, an offering or a halt. It puts raw volume in context: 500,000 shares is ordinary for one stock and extraordinary for another.
Limits of the measure
- Thin baselines. If a stock barely trades at a given time of day, a small amount of volume can produce a very large RVOL.
- New listings. A stock with little trading history has no meaningful baseline, so RVOL is not measured rather than zero or infinite.
- Splits. Reverse splits change share counts, so volume before and after a split should be compared on the same basis.
How to spot it
The Signal8 premarket screener shows RVOL for premarket movers. See Premarket RVOL.
Guides that use this term
- How to Trade Penny Stocks Without Getting DilutedA dilution-first guide to penny stocks. How new shares reach the tape, which SEC filings announce them, worked examples, and a 20-minute filing check.
- What Is an ATM Offering? At-the-Market Sales ExplainedWhat an at-the-market (ATM) offering is, how the sales agreement and 424B5 work, how fast an ATM can sell shares, and where its sales show up in later filings.
- Short Interest Explained: Days to Cover and BorrowHow short interest is reported to FINRA twice a month, how to calculate days to cover and short % of float, and how borrow fees and the Reg SHO list work.
- Short Interest vs Short Float: Which Number Matters for a SqueezeShort interest is a FINRA share count; short float is that count divided by a float. Why the two differ, which dates they carry, and how to read each.
- Relative Volume (RVOL) and Premarket Trading ExplainedHow relative volume (RVOL) is calculated, how the 4:00 to 9:30 a.m. ET premarket session works, and why the baseline behind an RVOL figure changes the reading.
Related terms
Check any ticker for dilution
DilutionScan reads each covered company's SEC filings and lists its warrants, convertibles, ATM programs, shelves and S-1s on one page, with a dilution rating and cash runway.
Definition from the Signal8 Academy glossary. Educational content only. DilutionScan and Signal8 are not broker-dealers or investment advisers, and nothing here is a recommendation to buy or sell any security.