Order book

The live list of buy and sell orders for a market at each price. It shows how much size is available where, and the gap between the best buy and sell is the spread.

Reading the order book tells you whether a Kalshi market is liquid enough to trade. A deep book lets you enter and exit near one price; a thin book means your order can move the price against you.

The order book is the live list of resting buy and sell orders for a market, organized by price. The bids show what buyers are willing to pay and the offers show what sellers will accept, each with the quantity available. The book is the real picture of supply and demand at that moment, far more informative than the last traded price alone.

Reading the book tells you the spread, the depth at each level, and how much size you can trade before moving the price. A book stacked with large orders near the current price signals liquidity and stability; a sparse book signals that even a modest order will walk the price and cost you slippage. Active traders check depth before sizing a trade.

Your own orders interact with the book in two ways. A limit order joins it as resting liquidity (you become a maker), while a market order consumes the existing orders from the best price outward (you are a taker). Understanding the book is what lets you predict your fill price rather than be surprised by it.