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.
The YES/NO model
Every market on Polymarket US has two sides: YES and NO. They always add up to $1.00. If YES is priced at $0.60, NO is priced at $0.40.
You don’t trade YES and NO as separate things. There’s only one instrument per market — the YES side. To trade against an outcome, you sell YES (which is the same as buying NO).
| What you want to do | How you do it |
|---|
| Trade on the outcome happening | Buy YES |
| Trade on the outcome not happening | Sell YES (equivalent to buying NO) |
| Close a winning YES position | Sell YES |
| Close a losing NO position | Buy YES back |
Order types
| Type | How it works |
|---|
| Limit order | You set a price. The order sits on the book until someone trades against it, or you cancel it. |
| Market order | Fills immediately at the best available price. You get instant execution but pay the spread. |
Time in force
When you place a limit order, you choose how long it stays active:
| Option | What it means |
|---|
| Good till cancel (GTC) | Stays open until it fills or you cancel it |
| Good till date (GTD) | Stays open until a specific time, then cancels automatically |
| Immediate or cancel (IOC) | Fills whatever is available right now, cancels the rest |
| Fill or kill (FOK) | Must fill completely or not at all — no partial fills |
What happens after you place an order
Your order goes through a lifecycle:
- Pending — the exchange has received your order
- Open — it’s resting on the book, waiting for a match
- Partially filled — some of your order has matched, the rest is still open
- Filled — your entire order has matched
- Canceled / Expired / Rejected — the order didn’t fill
Positions
Once your order fills, you have a position. A position is simply the contracts you hold in a market.
- A long position means you own YES contracts — you profit if the outcome happens
- A short position means you’ve sold YES contracts — you profit if the outcome doesn’t happen
Your buying power is the cash you have available to open new positions. When you buy contracts, your buying power decreases. When you sell or a market settles in your favor, it increases.
Closing a position
You can close a position at any time by taking the opposite action:
- If you’re long (bought YES), sell YES to close
- If you’re short (sold YES), buy YES to close
You don’t have to wait for the market to settle. If the price has moved in your favor, you can lock in a profit early.
