What Is Relative Volume and Why Scan for It?
Relative volume (RVOL) compares today’s traded shares to average volume at the same clock time—or full-day average for end-of-day scans. RVOL of 2 means twice normal participation. Unusual volume often precedes or accompanies institutional activity, news absorption, and sustained trends. Percent change alone misleads: a 5% move on double volume differs from 5% on half volume. RVOL scanners prioritize participation-confirmed movers over thin air pumps.
Use time-of-day adjusted RVOL intraday—raw volume at 9:30 always looks elevated versus noon.
What RVOL Thresholds Do Traders Use?
Day trade momentum: RVOL above 2 by 10:00, rising. Breakout confirmation: RVOL above 1.5 on the breakout bar. Swing unusual activity: full-day RVOL above 1.5 before the close. Thresholds vary by universe—liquid ETFs rarely hit 4 RVOL; small caps often do on news. Combine a minimum average share volume so RVOL on a tiny average name does not flag illiquid traps.
Rising RVOL on pullbacks in uptrends flags accumulation—worth a dedicated scan preset.
How Do You Build a Relative Volume Scanner?
Base liquidity: price above $5, average volume above 1,000,000 shares. RVOL greater than 2, percent change aligned with strategy direction. Optional: price above VWAP for long bias. Sort by RVOL (and average volume) for impact. Alert on cross—RVOL newly above 2—not static membership. Intraday refresh every one to three minutes. Pair with a sector filter when one group leads the market. Export the top ten to a watchlist for chart pattern review.
Add a maximum float filter when hunting sustained trends—extreme RVOL on low float often mean reverts fast.
How Does RVOL Confirm Other Setups?
Breakout scans require an RVOL spike on the break bar. Gap continuation needs RVOL holding above 1.5 in the first 30 minutes. Pullback entries want RVOL contraction on the dip and expansion on the bounce. Reversal fades want declining RVOL into resistance. RVOL is a participation lens layered on price structure—not a standalone entry. The chart must still show a clear level and stop.
When price makes a new high but RVOL diverges lower, tighten stops—the move may lack sponsorship.
What Mistakes Do Traders Make With RVOL Scans?
Using full-day average at 9:30 without time adjustment. Ignoring average share volume on low-float RVOL spikes. Chasing RVOL after the move is extended. Treating RVOL as a buy signal without a price setup. Running an RVOL scan without a direction filter on strong bear days. RVOL scanner strategies work when thresholds match your style and every alert still passes chart qualification.
Compare RVOL to sector peers—leadership within a hot group matters more than isolated RVOL in a dead sector.