Market and limit orders
Place market and limit orders from the trade panel, choose how a market order fills and set when a limit order expires.
You place orders from the trade panel on the right of a market page. Pick the outcome at the top of the page (Yes or No, or the outcome names), then Buy or Sell, then the Market or Limit tab. The amount is in dollars on Buy and in shares on Sell. Split and Merge sit in the Pro ▾ menu next to the tabs.
The action button reads Login to trade until you sign in, and Preparing account for a moment right after. Rumor Predict adds no fee to your orders. On many markets Polymarket charges a taker fee when an order fills against the book; see fees.
Market order
A market order trades against the best prices in the order book and fills right away. Use it when you want to be filled now.
- Stay on the Market tab (the default) and enter the Amount.
- Check the summary, worked out from the live order book:
- Average price: your average fill price, walking through the book level by level.
- If you win (Buy): what your shares pay if the outcome resolves in your favor, $1 per share.
- You'll receive (Sell): what the shares sell for at current book prices.
- Click the action button. It names the outcome, e.g. Buy Yes or Sell No.
A market order takes whatever the book offers, so a large order on a thin book can fill well away from the best price. Check Average price and the order book first, or use a limit order to set the price yourself.
Limit order
A limit order rests in the order book at your target price and fills only when the market reaches it.
- Click the Limit tab and enter the Amount.
- Set the Target Price. The Market: X¢ button next to it sets the target to the best price available now: the best ask on Buy, the best bid on Sell.
- Optionally, turn on Expiration.
- Check If you win or You'll receive, then click the action button.
The order waits under Open Orders in your portfolio until it fills, you cancel it there or it expires. Your target is rounded to the market's tick size, its smallest price step.
If your target crosses the market (a Buy at or above the market price, a Sell at or below it), a warning says the order will execute immediately. Change the target if that isn't what you want.
A limit order can fill in parts: the filled part becomes your position, and the rest stays in the book.
Example
Yes trades at about 73¢ and you spend $100.
- Market buy: Average price reads
73.40¢, because your $100 takes the best ask and part of the next level. If you win reads$136.24(= $100 ÷ 0.7340). - Limit buy at 65¢: If you win reads
$153.85(= $100 ÷ 0.65), but the order rests in the book and fills only if Yes trades down to 65¢.
Execution: FAK vs FOK
Execution Type, in the collapsed row under the action button, decides what a Market order does when the book can't fill all of it at once. Limit orders don't have it.
| Mode | What it does | Use when |
|---|---|---|
| FAK (Fill And Kill), the default | Fills what the book offers now and cancels the rest | A partial fill is fine |
| FOK (Fill Or Kill) | Fills the whole order now, or cancels all of it | You want the exact size or nothing |
The choice resets to FAK when you reload the page. Quick Buy and the one-click Sell in your portfolio always use FAK.
Expiration
Expiration is for limit orders only. It cancels whatever is still unfilled at a time you choose.
- On the Limit tab, switch on Expiration below the target price.
- Pick 5M, 1H, 12H or 24H, or click the pencil and type a date and time as
MM/DD/YYYY HH:MM. - Place the order.
Times are local, on a 24-hour clock. A preset counts from when you click it, so click it again if you wait before placing. The time must be at least about a minute ahead, or the order isn't placed. Any part that fills before then stays in your positions.
Reserved funds
The Available to Trade row above the amount shows what you can use:
- Buy: your cash, minus the cash your open limit orders reserve.
- Sell: the shares of this outcome you hold, minus the shares your open sell orders reserve.
An open limit order sets aside what it needs until it fills, you cancel it or it expires.
If the amount is more than Available to Trade, the button reads Insufficient funds and is disabled. Lower the amount, or deposit funds.