> For the complete documentation index, see [llms.txt](https://870.gitbook.io/knowledgebase/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://870.gitbook.io/knowledgebase/how-do-options-work/reading-option-tables.md). # Reading Option Tables More and more traders are finding option data through online sources. While each source has its own format for presenting the data, the key components generally include the following variables: * Volume simply tells you how many contracts of a particular option were traded during the latest session. * The "bid" price is the latest price level at which a market participant wishes to buy a particular option. * The "ask" price is the latest price offered by a market participant to sell a particular option. * Implied Bid Volatility can be thought of as the future uncertainty of price direction and speed. This value is calculated by an option-pricing model such as the Black-Scholes model and represents the level of expected future volatility based on the current price of the option. * Open Interest number indicates the total number of contracts of a particular option that have been opened. Open interest decreases as open trades are closed. * Delta can be thought of as a probability. For instance, a 30-delta option has roughly a 30% chance of expiring in-the-money. Delta also measures the option's sensitivity to immediate price changes in the underlying. The price of a 30-delta option will change by 30 cents if the underlying security changes its price by one dollar. * Gamma is the speed the option is moving in or out-of-the-money. Gamma can also be thought of as the movement of the delta. * Vega is a Greek value that indicates the amount by which the price of the option would be expected to change based on a one-point change in implied volatility. * Theta is the Greek value that indicates how much value an option will lose with the passage of one day's time. * The "strike price" is the price at which the buyer of the option can buy or sell the underlying security if they choose to exercise the option. {% hint style="info" %} Buying at the bid and selling at the ask is how market makers make their living. {% endhint %} --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://870.gitbook.io/knowledgebase/how-do-options-work/reading-option-tables.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.