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Volume & Open Interest
Two numbers, two different stories
Every strike on the options board carries two counters that beginners constantly confuse:
| Volume | Open Interest (OI) | |
|---|---|---|
| Measures | Contracts traded today | Contracts currently held open |
| Tells you | Where the action is right now | Where positions are entrenched |
| Resets | Every day | Only when positions close |
| Metaphor | Gunfire | Fortifications |
A strike with huge volume but little OI is a day-trading battleground. A strike with huge OI is a structural position that dealers have been hedging for a while — and will defend.
The Point of Control (POC)
The Volume POC is the strike where the most volume has traded today — the session's "fair value" in the eyes of the market:
- Spot above the POC → the POC acts as a shelf (support). Price pulling back to it often finds buyers who remember it as fair.
- Spot below the POC → it acts as a lid (resistance).
Price has a well-documented tendency to revisit the POC during the session — it is a magnet, not a wall.
High-gravity strikes
When a single strike accumulates both heavy volume and heavy OI, it becomes the day's dominant magnet — the level price is most likely to gravitate toward as expiration approaches, because that is where the most hedging interest lives. The platform highlights this strike for you on the levels dashboards.
The Put/Call ratio
Comparing put volume to call volume gives a fast sentiment read:
- Put-heavy tape — fear. At extremes, often a contrarian bottom signal: panic put-buying frequently marks lows.
- Call-heavy tape — greed. At extremes, often marks tops as latecomers chase.
- Balanced tape — no edge from sentiment; lean on structure instead.
The platform normalizes this ratio to a symmetric scale so bullish and bearish imbalances are directly comparable, and tracks it in short rolling windows (1, 5, 15 minutes) so you can see momentum waves as they build rather than after the fact.
Air pockets
Just as important as where OI is, is where it isn't. Price crossing a zone with very little open interest has nothing to slow it down — moves through these air pockets tend to be fast and slippery. If your trade's path to target crosses one, expect acceleration; if your stop lives inside one, expect slippage.
How you'll see it on the platform
Volume and OI profiles are on every dashboard, the POC and dominant-gravity strike are marked on the level maps, and the live put/call gauges show flow momentum in real time. The whale-flow tools go one step further and isolate the institutional share of that volume — see the Institutional Tape app.
Next: Market Regimes — putting GEX and DEX together into a daily playbook.