Relative Volume (RVOL)
// today's volume divided by the average volume at the same time of day
Relative Volume (RVOL) is the ratio of today's cumulative share volume to the average cumulative share volume at the same time of day over a recent lookback window. RVOL of 2.0 means today is running at twice the typical pace.
- Time-of-day-aware. RVOL at 10:00 ET compares against the typical 10:00 ET cumulative volume, not the typical close-of-day total.
- Standard lookback is 20 sessions (one trading month). Some scanners use 10 or 30.
- RVOL above 2.0 in the first hour is a common gappers-and-movers screener filter. Above 5.0 is unusual.
How it is calculated
The cumulative-volume comparison is what makes RVOL useful. Comparing absolute share count at 10:00 ET against the daily total for the prior 20 sessions would always look small; comparing against the 10:00 ET running total gives a regime-comparable number. The lookback excludes today.
What traders use it for
- Day-trading scanners. RVOL >= 2.0 with a price move identifies names trading hotter than typical at the same point in the session.
- News-flow confirmation. A headline that prints with RVOL barely above 1.0 is being faded; RVOL of 4 or 5 is the market acting on the headline.
- Volume-weighted entry confirmation. A breakout on declining RVOL is a low-conviction breakout; on rising RVOL it is participation.
Worked example
Suppose at 10:30 ET the cumulative TSLA volume is 18.4M shares. The 20-session average cumulative volume at 10:30 ET is 6.1M shares. RVOL prints 18.4 / 6.1 = 3.02. As of 2026-05-02 10:30 ET. The session opened on a +4.2% earnings gap; an RVOL of 3.0 in the first hour is consistent with institutional reposition rather than a fade.
Live data: /stocks/TSLA.
Common pitfalls
- Lookback choice matters. A 20-session lookback that includes a prior earnings event distorts the average; some scanners drop the highest and lowest sessions.
- Pre-market volume is not always included. Tapeboard's RVOL is regular-hours-only by default; pre-market gappers can show RVOL near 1.0 at the open even if pre-market activity was extreme.
- Low-float names compute RVOL on a small denominator. A nano-cap with average daily volume of 50,000 shares can print RVOL of 20 on a 1M-share day; the absolute liquidity remains thin and the metric overstates the move.
- RVOL is a measurement, not a prediction. High RVOL says the tape is moving; it does not say which direction.
Where this metric appears on Tapeboard
RVOL renders on /scanner (sortable column), on every `/stocks/{T}` ticker page, and as a screener-preset filter (e.g., "Top RVOL gappers" preset).
Tapeboard surfaces this metric as a first-class screening filter. See the comparison pages at all Bloomberg alternatives for how Tapeboard's relative volume (rvol) surface compares against Koyfin, Finviz, TradingView, and Unusual Whales.
Related terms
- Options Flow: OPRA is the consolidated US options price-reporting authority; every executed options trade reports to OPRA in real time.
- Gamma Exposure (GEX): Aggregate dealer-position gamma across an option chain. Positive GEX implies dealers buy dips and sell rips (volatility-suppressive); negative GEX implies the reverse (volatility-amplifying).
- Dark Pool Print: Dark pools are SEC-registered Alternative Trading Systems regulated under Reg ATS. Trades execute off-exchange but post to FINRA TRF in real time after execution.
Primary sources cited
- SEC EDGAR full-text search documentation: US-equity consolidated tape volume is reported through the Securities Information Processor (SIP) per Reg NMS. https://www.sec.gov/edgar, retrieved 2026-05-04.
Methodology last reviewed 2026-05-04 by Marcus Reilly, Editor at Tapeboard. Every claim on this page has a row in the citation registry. Glossary terms reverify on the Jan 15 / Apr 15 / Jul 15 / Oct 15 cron and any time the underlying primary-source publishes a methodology change. See methodology for the full fact-check process and corrections for the public correction log.
Disclaimer. This page is for educational and informational purposes only. Nothing on Tapeboard is investment advice. See the full risk disclaimer.