> ## Documentation Index > Fetch the complete documentation index at: https://docs.polymarket.us/llms.txt > Use this file to discover all available pages before exploring further. # Glossary > Glossary of common Polymarket terms ## Market Structure & Hierarchy | Term | Definition | | -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | **Category** | Broadest classification level organizing instruments by event type (e.g., Sports, Politics, Crypto, Culture). | | **Series** | More specific classification within a category, such as a sports league or topic (e.g., NFL, NBA, US Presidential, Bitcoin). | | **Event** | A specific occurrence with multiple possible outcomes. Each event consists of one or more instruments representing the complete set of tradable outcomes. | | **Product** | The type of contract structure used to format instruments (e.g., Athletic Event Contract, Election Winner Contract, Total Score Contract). | | **Instrument** | The tradable symbol representing a specific outcome for an event. Follows consistent naming conventions for easy identification. Also called a market. | | **Market** | Same as an instrument. A tradable outcome with defined resolution criteria and sources. | | **Contract** | An instance of an instrument. You trade contracts in quantities (e.g., buying 100 contracts). Each contract settles at \$1.00 if the outcome occurs and \$0.00 if it does not. | ## Trading Basics | Term | Definition | | ---------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Long position** | Buying contracts of an instrument, trading on the outcome occurring. You pay the current price per contract and receive \$1.00 per contract if the outcome happens. | | **Short position** | Selling (shorting) contracts of an instrument, trading on the outcome not occurring. You receive the current price per contract but must cover potential losses if the outcome happens. | | **Order** | A request to buy or sell contracts at a chosen price. | | **Order book** | List of bids and asks showing available prices and size at each level. | | **Bid** | Highest price buyers are willing to pay. | | **Ask** | Lowest price sellers are willing to accept. | | **BBO (Best Bid and Offer)** | The best bid and ask prices currently available in the order book - the tightest spread at the top of the book. | | **Spread** | Gap between the bid and the ask. | | **Size** | Number of contracts available to buy or sell at a given price. | | **Liquidity** | How much size is available to trade at listed prices. | ## Order Execution | Term | Definition | | -------------------------- | ----------------------------------------------------------------------- | | **Fill** | When your order completes, fully or partially. | | **Partial fill** | When only part of your order fills. | | **Execution price** | The price at which your order fills. | | **Fill price** | Average price you receive when your order fills across multiple levels. | | **Marketable limit order** | An order that fills at the best available price shown on your screen. | | **Price impact** | How much your fill price changes because of limited liquidity. | | **Slippage** | Difference between expected and actual execution price. | | **Maker** | Trader who adds liquidity by placing an order on the book. | | **Taker** | Trader who removes liquidity by filling an existing order. | ## Positions & Account | Term | Definition | | ------------------------ | ---------------------------------------------------------------------------------------------------------- | | **Open position** | Contracts you currently hold. | | **Closed position** | A position you no longer hold because you sold it or the market resolved. | | **Position value** | Real-time dollar value of your open positions. | | **Cash balance** | Funds in your account not tied to open positions. | | **Buying power** | Cash available to open new positions after margin is applied. | | **Instant buying power** | Part of your deposit that becomes available to trade immediately. | | **Margin** | Funds locked to cover the maximum possible loss of a short position. Equal to \$1.00 per contract shorted. | | **Max gain** | The most you can earn on a position. | | **Max loss** | The most you can lose on a position. | ## Market Lifecycle | Term | Definition | | ----------------- | ----------------------------------------------------------------------------------------------- | | **Clarification** | Extra context added to explain how rules should be understood. | | **Resolution** | When Polymarket determines the final outcome of a market using the sources listed in the rules. | | **Settlement** | Final payout of \$1.00 for winning contracts and \$0.00 for losing contracts. | ## Fees & Display | Term | Definition | | ---------------- | ---------------------------------------------------------------------- | | **Fees** | Trading or platform fees applied to executed orders. | | **Odds display** | How prices are shown, such as price, percent chance, or American odds. | | **Open order** | An order waiting on the book to be filled. | | **Order status** | Whether an order is open, filled, or partially filled. | | **History** | Section showing your past filled orders and closed positions. |