# Options flow glossary: the tape, translated > Options scanners compress a lot of market structure into short labels. This plain-English glossary explains the terms traders encounter in an options flow feed and the caveats that keep those labels from becoming misleading signals. - Canonical page: [https://caymanbot.com/options-flow-glossary](https://caymanbot.com/options-flow-glossary) - Content type: guide - Last reviewed: 2026-08-19 - Publisher: CaymanBot, LLC ## Quick answer Options scanners compress a lot of market structure into short labels. This plain-English glossary explains the terms traders encounter in an options flow feed and the caveats that keep those labels from becoming misleading signals. ## Key points - **Trade terms:** Understand sweeps, blocks, premium, bid/ask execution and multi-leg activity. - **Contract context:** Review volume, open interest, moneyness, expiration and implied volatility. - **Risk language:** Learn delta, gamma, theta, vega, GEX and why no label proves direction by itself. ## Options flow and execution terms **Options flow:** A stream of options transactions organized to expose contract details, size and execution context. Flow describes what traded, not the full intent of the participant. **Sweep:** An order routed across multiple exchanges to fill quickly. Sweeps can suggest urgency, but they can also be hedges or part of a complex position. **Block:** A large negotiated transaction generally executed as one print. Size thresholds vary by product and scanner. **Premium:** The option price multiplied by the contract multiplier and number of contracts. For standard U.S. equity options the multiplier is usually 100. **Bid-side / ask-side:** A description of where the print occurred relative to the quoted market. Trades near the ask are often labeled buyer-initiated and trades near the bid seller-initiated, but quote changes and complex orders can make that inference wrong. **Mid-market:** The price halfway between the displayed bid and ask. A midpoint execution provides less directional evidence than an aggressive trade at one side of the spread. **Multi-leg order:** Two or more related option or stock legs executed as one strategy. Reading one leg without the others can reverse the apparent directional meaning. ## Contract and positioning terms **Call:** A contract giving the holder the right, but not the obligation, to buy the underlying at the strike before or at expiration, depending on exercise style. **Put:** A contract giving the holder the right, but not the obligation, to sell the underlying at the strike. **Strike price:** The price at which the contract can be exercised. **Expiration:** The date after which the option ceases to exist. Short-dated options react differently to price, volatility and time than longer-dated contracts. **Volume:** The number of contracts traded during the current session. **Open interest:** The number of contracts that remained open after the prior clearing cycle. Same-day volume is not immediately included, so volume above open interest does not prove every trade is opening. **In the money (ITM):** A call with strike below spot or a put with strike above spot. **At the money (ATM):** A contract whose strike is near the current underlying price. **Out of the money (OTM):** A call with strike above spot or a put with strike below spot. **0DTE:** An option expiring on the current trading day. Its sensitivity and risk can change extremely quickly. ## Volatility and Greek terms **Implied volatility (IV):** The volatility input consistent with an option’s market price under a pricing model. IV reflects supply, demand and expected uncertainty; it is not a direct forecast of direction. **Delta:** An estimate of how much an option’s price changes for a one-unit change in the underlying, all else equal. Delta also changes as conditions change. **Gamma:** The rate at which delta changes as the underlying price changes. **Theta:** An estimate of option value lost with the passage of time, holding other inputs constant. **Vega:** Sensitivity to a change in implied volatility. **Gamma exposure (GEX):** A modeled estimate of aggregate gamma positioning and the hedging sensitivity it may create. **Vanna exposure (VEX):** A model of how delta may change as implied volatility changes. **Charm:** A measure of how delta changes as time passes, holding other inputs constant. ## Signal and risk terms **Unusual options activity:** Trading that stands out relative to normal size, premium, volume, strike, expiration or execution behavior. **Whale:** Informal shorthand for a participant placing a relatively large trade. The label says nothing certain about skill or information. **Bullish flow / bearish flow:** A scanner’s directional classification based on observable execution and contract details. It is an inference, not knowledge of the complete position. **Opening / closing:** Whether a trade creates a new position or offsets an existing one. This is often uncertain in real time without account-level data. **Liquidity:** The ability to trade size with limited price impact. Quoted spread, displayed size, trade frequency and open interest can all provide partial clues. **Slippage:** The difference between an expected price and the actual execution price. **Assignment:** The obligation imposed on an option seller when the holder exercises. **Defined risk:** A position whose maximum loss can be bounded in advance under its structure, though execution and assignment still require attention. ## Frequently asked questions ### What is the most important number in options flow? There is no single most important number. Premium, volume, open interest, strike, expiration, liquidity, execution location and surrounding market context work together. ### Does volume greater than open interest mean a new position? Not necessarily. Open interest is generally updated after clearing, and the day’s volume can contain both opening and closing transactions. The comparison is a clue, not proof. ### Are sweeps always bullish? No. A sweep only describes how an order sought liquidity. It can involve calls or puts, buying or selling, hedging or one leg of a larger strategy. ### How should beginners use options flow? Use it to discover activity for research, then check the contract, liquidity, catalyst, chart, volatility and risk. Paper testing can help build a process before risking capital. ## Related CaymanBot resources - [How to read live options flow](https://caymanbot.com/how-to-read-options-flow) - [Live options flow scanner for unusual activity](https://caymanbot.com/options-flow) - [Find unusual options activity in live options flow](https://caymanbot.com/unusual-options-activity) - [Turn dealer gamma exposure into a readable market map](https://caymanbot.com/gex-heatmap) - [Test an options idea before turning it into an alert](https://caymanbot.com/options-backtesting) Market data, modeled analytics, calculators and public-filing summaries are informational. Verify time-sensitive data and original filings before making decisions.