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Last updated: August 2026

Polymarket Order Types Explained

Polymarket runs a central limit order book, so the two orders that matter are the same as on any exchange. A market order fills immediately against whatever is resting on the book, paying the spread. A limit order posts your own price and waits, which costs nothing extra but may never fill. In markets as thin as most prediction markets, that choice moves your returns more than most people expect.

01.How the order book works here

Prices are quoted in cents from 0 to 100, representing the implied probability of an outcome. Buying YES at 34c means paying 34 cents for a contract that pays a dollar if the event happens. Every trade has a counterparty taking the other side at that price — the venue is not one of them, which is what separates an exchange from a bookmaker.

  • Prices run 0-100c and read directly as implied probability.
  • A YES at 34c and a NO at 66c are the same trade seen from opposite sides.
  • Your counterparty is another trader, not the platform.

02.Market orders: certainty of fill, uncertainty of price

A market order takes the best available price and keeps taking until filled. On a deep market that is fine. On a thin one — which most prediction markets are away from the headline questions — your order can walk several cents up the book, and the average price you paid can differ noticeably from the quote you clicked. Always look at depth, not just the top of book.

  • Fills immediately, at whatever the book offers.
  • On thin markets, slippage is the dominant cost, not fees.
  • Check depth before sending size, not just the displayed price.

03.Limit orders: your price, no guarantee

A limit order posts at a price you choose and sits until someone crosses to you. You avoid paying the spread and may collect it instead. The risk is straightforward: the market moves without you and your order never fills, which on a fast-moving news market is exactly when you most wanted the position.

  • You set the price; you may capture the spread rather than pay it.
  • No fill is guaranteed, and unfilled is worst precisely when news breaks.
  • This is the default tool for anyone providing rather than taking liquidity.

04.Selling before resolution

Positions are tradable, so you are never locked in until the event settles. Selling means posting on the other side of the book and finding a buyer at your price. This is what makes prediction markets tradable instruments rather than bets — most active traders close well before resolution, taking the move rather than the outcome.

  • Exit any time by selling into the book at the going price.
  • What you actually get depends on depth, same as entering.
  • Trading the move and holding to resolution are genuinely different strategies.

Related Pages

Polymarket Tools for BeginnersTrading TerminalsPolymarket Market Making ToolsPolymarket Risk Management Tools

Frequently Asked Questions

What order types does Polymarket support?▼
It runs a central limit order book, so the core types are market orders, which fill immediately against resting orders, and limit orders, which post at your chosen price and wait. Client libraries expose these through the CLOB API.
What do the prices on Polymarket mean?▼
Prices run from 0 to 100 cents and read directly as implied probability. Buying YES at 34c means paying 34 cents for a contract worth one dollar if the event occurs — the market is pricing it at roughly 34% likely.
Should I use market or limit orders?▼
Market orders when getting the position matters more than the price, typically on breaking news. Limit orders otherwise. On thin markets slippage from a market order usually costs more than any fee, so limit orders are the default for anything not urgent.
Can I sell before the market resolves?▼
Yes. Positions are tradable at any time by selling into the order book. What you receive depends on current depth. Most active traders exit before resolution rather than holding to settlement.
What is slippage on Polymarket?▼
The gap between the price you saw and the average price you actually paid, caused by your order consuming more than the top level of the book. It is the main hidden cost on thin markets and is avoided by using limit orders or checking depth before sizing.