Relative Volume (RVOL)

Relative volume (RVOL) is a ratio: the volume traded in a security over some period divided by an average of its volume over comparable past periods. An RVOL of 2× means twice the baseline. Because it is scaled to each security’s own history, it puts a heavily traded stock and a thinly traded one on the same footing.

There is no single standard definition. Tools differ in the period measured (a full session, the session so far, a single minute), in the baseline (the past 10, 20 or 50 sessions, the same time of day on past sessions, or the preceding bars) and in whether extended-hours trading is included. Two RVOL figures are comparable only when they use the same method. RVOL describes participation relative to a baseline; it does not say why volume changed or which way a price moved.

Volume Ratios in TradeAI News

TradeAI News shows two different ratios. On each ticker page, the “What changed” block compares a session’s total daily volume with its 20-session average, and the page notes that daily volume includes pre- and post-market trading. As of the close on Oct 16, 2026, AAPL traded 60.2M shares, 1.56× its 20-session average of 38.5M (source: TradeAI News, from daily volume; see the AAPL page).

The dashboard’s Unusual Volume module uses an intraday window instead: the volume of a ticker’s latest one-minute bar against the average of its last 20 one-minute bars, that bar included, taken when the event is detected. The two ratios measure different things and are not interchangeable.