Prices and orders — odds, spreads and order types
How to read a price on Polymarket, what the bid–ask spread is, and the difference between market and limit orders.
#The price is the probability
A winning share is worth $1 and a losing one $0, so the price reads as the market's probability: 62¢ means the market puts it at about 62%.
#From price to payoff
Buy at price p (in dollars) and you make 1 − p per share if you're right, and lose p per share if you're wrong.
| Buy price | Win per share | Loss per share | Back if you win |
|---|---|---|---|
| 10¢ | 90¢ | 10¢ | 10× your stake |
| 50¢ | 50¢ | 50¢ | 2× |
| 90¢ | 10¢ | 90¢ | about 1.11× |
You don't have to wait for settlement: you can sell at the current price any time before.
#Bid, ask and the spread
The order book has two prices:
- bid: the most someone will pay — what you get if you sell now;
- ask: the least someone will sell for — what you pay if you buy now.
The gap is the spread. Popular markets usually have a tight spread; quiet markets and in-play games are wider. BOOPOLY's order book shows both sides and their sizes live.
#Market and limit orders
| Market order | Limit order | |
|---|---|---|
| How it fills | Right away, at the best price on the book | Rests at your price until someone takes it |
| Price | The book's, with an acceptable-slippage setting | Yours |
| Fill guaranteed | Yes, if there are orders to take | No; cancel any time |
| Fee | Taker fee | None when it fills as a maker |
Step by step: Placing a trade. Rates: Fees & Costs.
#Minimum order
Every order needs at least 5 shares and $1.
#Let the tools place orders for you
To enter and exit by fixed rules, set your parameters in Automated trading and let it place orders 24/7; to follow a trader's orders, use Copy trading.