Relative Volume, often times called RVOL, is an indicator that tells traders how current volume is compared to past trading volumes over a given period. It is kind of a like a radar for how “in-play” a stock is. The higher the relative volume is the more in play it is.
Relative Volume is displayed as a ratio. So if it is showing 3.5 relative volume, that means it is trading at 3.5 times its normal volume.