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Relative Volume (RVOL)

today's running volume divided by the average volume at the same time of day

Relative Volume (RVOL) is the ratio of a stock's cumulative volume so far today to its average cumulative volume at the same time of day. An RVOL of 2.0 means the stock is trading at twice its usual pace for this point in the session.

In short
  • Time-of-day-aware. RVOL at 10:00 ET compares against the typical 10:00 ET running total, not the typical end-of-day total.
  • Tapeboard's 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 movers screener filter. Above 5.0 is unusual even on news names.
How its calculated

How is Relative Volume (RVOL) calculated?

RVOL(t) = cumulative_volume_today(t) / avg(cumulative_volume(t)) over lookback N sessions

t is the current time of day.
N is the lookback in sessions (Tapeboard default: 20, lookback excludes today).

The cumulative comparison is what makes RVOL useful. Comparing the share count at 10:00 ET against the prior 20 sessions' full-day totals would always look small; comparing against the 10:00 ET running total gives a number comparable across sessions and times of day.

What traders use it for

What do traders use Relative Volume (RVOL) for?

  • Real-time scanners. RVOL of 2.0 or more with a price move identifies names trading hotter than typical for 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.
  • Breakout confirmation. A breakout on declining RVOL is a low-conviction breakout; on rising RVOL it is participation.
Worked example

Worked example

Worked example: $TSLA
RVOL on $TSLA after an earnings gap

Suppose at 10:30 ET the cumulative TSLA volume is 18.4M shares and 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 repositioning rather than a fade.

Live data: /stock/TSLA.

Common pitfalls

What are common pitfalls of Relative Volume (RVOL)?

  • 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; a pre-market gapper 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 50,000 shares of average daily volume can print RVOL of 20 on a 1M-share day while remaining absolutely thin.
  • RVOL is a measurement, not a prediction. High RVOL says the tape is moving; it does not say which direction.
Where it appears on Tapeboard

Where this metric appears on Tapeboard

RVOL renders on /scanner (relativeVolume is a sortable column and a filter), on every /stock/{T} ticker page, and in the hits feed that powers alert rows.

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

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.
  • Momentum Scanner: It ranks the present, not the past. The sort key is current momentum (for Tapeboard, 5-minute price momentum), refreshed continuously in market hours.
Primary sources

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 2026-10-24.
See it live

See it live

The Momentum Now scanner preset ships RVOL as a live column: every row shows relative volume next to 5-minute momentum, refreshed continuously during market hours.

Page review

Methodology last reviewed 2026-10-24 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.