The number of contracts traded today. It reflects activity right now, and a rise points to growing interest.
What it counts
Volume (Volume) is the number of contracts that changed hands during the current session. It starts at zero every morning and builds trade by trade, so it is the pulse of activity right now. Open interest is different: it measures the stock of positions still outstanding.
Volume without context is a meaningless number
A thousand contracts in a quiet symbol is an event; in a big index it is noise. So volume is measured against its norm: today's volume divided by its average. Relative volume (RVOL · Relative Volume) is what separates exceptional activity. A sharp jump in it with trades all leaning one way is the basis for spotting unusual activity.
Volume with open interest
Comparing the two tells the story. Heavy volume today with open interest rising tomorrow means new positions were built. Heavy volume with open interest falling means positions were closed out. Volume alone cannot tell an entry from an exit. The pair can.
Hypothetical example
A call with average daily volume of 300 contracts printed 4,800 contracts today, mostly at the ask (active buying), and its open interest rose the next day: a clear new position came in. This is the pattern the flow tools look for.
Common mistake
Reading every huge volume as a directional bet: much of it is legs of multi-leg strategies, hedges and position rolls. The direction of execution (at the Ask or the Bid) and the context of the whole chain are more reliable than the bare number.
Why it is always read relatively
Raw volume with no reference says nothing. A million shares is sleepy for a giant and an earthquake for a mid-cap. Its ratio to that asset's own average is what turns it into a signal, which is why scanners rank by relative volume, not raw volume.
Where to see it on the platform
The options chain shows each contract's volume, the trade radar spots sharp jumps in relative volume, and the flow tools classify the direction of execution.
The symbol card compares today's volume with its usual curve, and scanners rank by relative volume.
