Relative Volume
Definition
Relative volume (RVOL) compares a stock's current trading volume to its average volume for the same time of day, expressed as a multiple — a stock with 5x RVOL is trading five times more actively than normal, signaling unusual interest and making it a priority candidate for day trading setups.
Example
“My scanner showed RVOL at 8.3x at 9:45 AM — eight times the normal volume for that time of day. Something was clearly happening. I pulled up the news, found an upgrade, and started watching for a clean setup.”
Detailed Explanation
Relative volume is arguably the most important single filter a day trader can apply when scanning for opportunities. The logic is simple: if a stock is trading at 10x its normal volume, the market is telling you something unusual is happening. That something might be news-driven (earnings, upgrade, merger announcement), catalyst-driven (a sector move, a regulatory decision), or technically driven (a breakout at a key level attracting attention). Whatever the cause, elevated RVOL means there are active buyers and sellers at current prices — which translates to momentum potential and, crucially, enough liquidity to enter and exit cleanly.
The time-adjusted comparison is what makes RVOL more useful than raw volume during the session. A stock that trades 1 million shares by 10 AM normally trades 200,000 shares by 10 AM on average — that's 5x RVOL. Simply looking at 1 million absolute shares tells you nothing without the context of what's normal. Most professional scanning platforms calculate RVOL automatically, updating in real time throughout the session. The thresholds most traders use: above 2x is notable, above 3x is significant, above 5x is strong — anything above 10x demands immediate attention and investigation.
RVOL decays throughout the day as more volume accumulates in the denominator. A 10x RVOL reading at 9:45 AM might normalize to 3x by noon even if the stock keeps trading actively — because average all-day volume is higher than average early-morning volume, so the denominator grows. This means RVOL readings are most dramatic and actionable in the first 30-60 minutes of the session, when the morning catalyst is freshest and the volume relative to the quiet early-morning average appears most extreme. By midday, relative volume naturally compresses, which is one reason morning setups have better momentum characteristics than afternoon setups.