Relative volume (RVOL): unusual participation measured against normal.

What RVOL is trying to measure

Relative volume compares current trading activity with a normal baseline. A value above 1 means activity is above that reference level; a value below 1 means it is below. The important part is how the platform defines the baseline.

Why time-of-day adjustment matters

Intraday volume is naturally concentrated near the open and close. A useful intraday RVOL implementation compares current activity with what is normally expected around the same time rather than simply comparing partial-day volume with a full-day average.

Trade Ideas has a specific premarket limitation

Trade Ideas says its Relative Volume filter compares current volume with average volume for the same time of day, but the filter does not calculate during premarket. Setting a minimum RVOL above 1 can therefore suppress premarket alerts and Top List results.

This is a good example of why scanner definitions matter more than the indicator name.

RVOL is context, not a complete setup

High RVOL can tell you attention is elevated; it does not tell you whether price will continue, reverse, or remain tradable. Combine participation context with a defined event and the rest of your strategy rules rather than treating RVOL as a standalone signal.

Use RVOL to reduce noise

The best scanner use is often exclusionary: avoid spending time on symbols with ordinary participation when your strategy requires unusual activity. Then let a separate price/event condition determine when the candidate deserves attention.

Common RVOL mistakes

• Comparing a time-of-day-adjusted RVOL value from one platform with a simple daily-volume ratio from another as though they are identical.
• Using the same threshold in premarket even when the platform does not calculate RVOL there.
• Assuming high RVOL determines direction rather than participation.
• Adding RVOL to every scan without testing whether it actually reduces noise for the intended setup.

Treat the metric definition as part of the strategy. If you change platforms, re-check how RVOL is calculated before assuming an old scan translates directly.