> For the complete documentation index, see [llms.txt](https://docs.lighter.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.lighter.xyz/trading/binary-options.md). # Binary Options Binary options on Lighter are markets with two possible outcomes. Each market asks a single question with a fixed end time, for example "Will the BTC price at 14:15 UTC be at least the BTC price at 14:00 UTC?", and settles to one of the two answers once that time has passed. The first binary options on Lighter are **Up/Down** markets on crypto prices. Each series covers one asset and one window length (for example BTC, 15 minutes), and a new market opens for every window of the series. ### How it works * Every market has one order book. Prices are quoted in USDC between `0.01` and `0.99` and are the price of one **Up** share. * An Up share pays **1 USDC** if the market settles Up and **0** otherwise. A Down share pays the opposite. * The price of a share can be read as the market's implied probability of that outcome: an Up price of `0.62` implies a 62% chance of Up and costs `0.38` for the Down side. * Positions are fully collateralized in USDC. There is no leverage, no funding and no liquidation: the most you can lose on a position is what you paid for it. * You can close a position at any time while the market is open by trading the other side, or hold it until settlement. ### Up/Down markets
ItemDescription
UnderlyingCrypto price, for example BTC or ETH
Price sourceChainlink Data Streams
WindowThe series duration, for example 15 minutes. Its start and end define the question.
Start priceUnderlying price at the start of the window
Settlement priceUnderlying price at the end of the window
OutcomeUp if the settlement price is greater than or equal to the start price, Down otherwise
Payout1 USDC per winning share, paid in USDC to your account
Market symbol<ASSET>-UPDOWN-<DURATION>-<WINDOW START>, for example BTC-UPDOWN-15M-1792168200 (window start in Unix seconds)
Markets of a series are listed ahead of time, so you can trade a window before it starts. Trading stops at the end of the window, and the market settles shortly after. ### In this section * [Fee Structure](/trading/binary-options/fee-structure.md): how trading fees are charged on binary options and how they are discounted. * [Discovering and Trading Markets](/trading/binary-options/discovering-and-trading-markets.md): how to find markets, read their state and trade them. --- # 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 by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.lighter.xyz/trading/binary-options.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. 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.