What the Four Flow Volume Fields Mean
On the Option Flow page, volume is grouped by strike and expiration. The labels describe whether trades were classified as buyer-initiated or seller-initiated for calls and puts.
Buy Call Vol
Call contracts traded on buyer-initiated prints. Often interpreted as upside participation or call demand, especially when concentrated near or above spot.
Sell Call Vol
Call contracts traded on seller-initiated prints. It may reflect call selling, closing long calls, covered-call style supply, or one leg of a spread.
Buy Put Vol
Put contracts traded on buyer-initiated prints. It may reflect downside protection, bearish speculation, or hedge demand around a key strike.
Sell Put Vol
Put contracts traded on seller-initiated prints. It may reflect put premium selling, closing long puts, or one leg of bullish or neutral structures.
Large Volume Is a Clue, Not a Prediction
A large volume spike tells you that activity is concentrated at a strike. It does not tell you with certainty whether the trader is opening, closing, hedging, spreading, or rolling a position.
How Multi-Leg Options Trades Can Appear
Many SPX trades are spreads or multi-leg structures. A single strategy can create volume on more than one strike and more than one option side, so large flow should be interpreted as a structure map rather than a simple bullish or bearish vote.
| Structure | Possible Legs | How It May Show Up |
|---|---|---|
| Call Debit Spread | Buy lower call, sell higher call | Buy Call Vol at one strike and Sell Call Vol at another strike. |
| Put Debit Spread | Buy higher put, sell lower put | Buy Put Vol and Sell Put Vol can appear together across nearby strikes. |
| Iron Condor | Sell call spread and sell put spread | Sell Call Vol, Buy Call Vol, Sell Put Vol, and Buy Put Vol may all appear in one structure. |
| Roll or Adjustment | Close one strike, open another | Large volume can show at old and new strikes without a clean directional message. |
Reading Top Flow Strikes
The Top Flow Strikes panel ranks the three largest strikes for each flow type within the selected expiration. Use it to find concentration, then compare those strikes with spot, GEX Heatmap, gamma walls, and market direction.
Better Context
Risk Reminder
Buyer-initiated and seller-initiated classifications are estimates based on trade prints. They can be noisy, especially during fast markets, wide spreads, and complex institutional order execution.
Recommended English Videos
These YouTube videos help explain option volume, open interest, bid-ask context, and unusual options flow. They are external educational resources and are not trading recommendations.