> ## Documentation Index > Fetch the complete documentation index at: https://docs.kairos.trade/llms.txt > Use this file to discover all available pages before exploring further. # The Order Book > Understanding bids, asks, the spread, and how to read an order book A market price isn't a single number handed down from somewhere — it's the result of buyers and sellers posting what they'll accept. This chapter shows you where to read that: bids, asks, the spread, and depth. ## What Is an Order Book? An order book is a live list of everyone who wants to buy and everyone who wants to sell. Think of it like an auction house — buyers shout out what they're willing to pay, and sellers shout out what they're willing to accept. ![Frogs at the auction](https://imagedelivery.net/Hias1rvxalFDFzbgXzaBJg/5c4dd477-a46d-4e60-950f-2357048f7b00/public) ## Bids and Asks There are two sides to every order book: | Term | Who | What They Want | | - | - | - | | **Bid** | Buyers | "I'll pay up to this price" | | **Ask** | Sellers | "I'll sell for at least this price" | The **best bid** is the highest price any buyer is willing to pay. The **best ask** is the lowest price any seller is willing to accept. ## The Spread The **spread** is the gap between the best bid and the best ask. The bid-ask spread between the best bid and the best ask ## Reading the Order Book Here's what a simple order book looks like: An example order book with ask rows above and bid rows below the spread Reading this: * The cheapest you can **buy right now** is \$0.55 (80 shares available) * The most you can **sell for right now** is \$0.52 (someone wants 120 shares) * The spread is \$0.03 ## Depth — How Much Is Available The numbers next to each price are the **quantity** — how many shares are sitting at that price. This is also called **depth** or **liquidity**. More depth = easier to trade large amounts without moving the price. If you want to buy 300 shares and only 80 are available at $0.55, you'd need to buy the rest at higher prices ($0.57, \$0.58). This is called **walking the book** — more on that in the execution chapter. ## Why It Matters The order book tells you: * **What price you'll get** — look at the best bid/ask * **How much you can trade** — look at the depth * **How active the market is** — look at the spread * **Where support/resistance sits** — large quantities at certain prices ## Think of It Like a Farmer's Market Imagine you're at a farmer's market buying apples: * Several sellers have signs showing their prices * The cheapest seller has apples at \$0.55 each, but only 80 left * The next cheapest has them at \$0.57 * Meanwhile, other buyers are offering to buy at \$0.52 The "order book" is just all of these offers written down in one list. You can see exactly what's available before you decide to buy or sell. **Next:** [Order Types](/learn/order-types) — how to place an order against this book. This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.