Documentation Index
Fetch the complete documentation index at: https://docs.polymarket.us/llms.txt
Use this file to discover all available pages before exploring further.
Prices are probabilities
Every contract on Polymarket US is priced between $0 and $1. The price represents the market’s collective belief about how likely an outcome is.
| Price | What it means |
|---|
| $0.25 | The market thinks there’s roughly a 25% chance |
| $0.50 | Coin flip — the market is undecided |
| $0.75 | The market thinks it’s likely (75% chance) |
The order book
Polymarket US runs a central limit order book. Prices aren’t set by Polymarket — they come from traders placing buy and sell orders against each other.
The order book has two sides:
| Side | What it means |
|---|
| Bids | Buy orders — the prices traders are willing to pay |
| Asks (offers) | Sell orders — the prices traders are willing to accept |
How trades happen
When you place a market order, it fills immediately at the best available price on the other side of the book. You’re a taker — you’re taking liquidity.
When you place a limit order at a specific price and it doesn’t fill immediately, it sits on the book waiting. You’re a maker — you’re providing liquidity for others to trade against.
If your limit order’s price crosses the best available price on the other side, it fills immediately (like a market order). Otherwise, it rests on the book.
Settlement
When a market resolves, every contract settles at either $1.00 (YES won) or $0.00 (NO won). The exchange handles this automatically — winning contracts are credited to your balance, losing contracts go to zero.
Market states
A market goes through different states during its lifecycle:
| State | What it means |
|---|
| Open | The market is accepting orders and actively trading |
| Pre-open | The market exists but trading hasn’t started yet |
| Suspended | Trading is temporarily paused |
| Halted | Trading has been stopped |
| Expired | The market has ended and settled |
