Polymarket Order Types Explained: GTC, GTD, FOK & FAK
Choosing the right order type controls whether your order rests, expires, or must fill instantly. It is a small detail that meaningfully affects fills, costs, and how cleanly a strategy executes.
What “time in force” means
Time in force tells the exchange how long an order stays active and what to do if it cannot fully fill right now. Polymarket's CLOB supports several types, each suited to a different intent.
GTC — Good-Til-Cancelled
Rests on the order book until it fills or you cancel it. The default for passive strategies like market making where you want to earn the spread rather than cross it.
GTD — Good-Til-Date
Like GTC but expires automatically at a time you set. Useful when an order should only stand for a defined window — for example, around a specific event — without you having to remember to cancel it.
FOK — Fill-Or-Kill
Must fill completely and immediately or it is cancelled entirely. Ideal for arbitrage, where a partial fill on one leg leaves you exposed. All-or-nothing, right now.
FAK — Fill-And-Kill (IOC)
Fills as much as possible immediately, then cancels the remainder. Use it when you want whatever liquidity is available now without leaving a resting order behind.
Choosing the right type
| Goal | Best order type |
|---|---|
| Post passively, earn the spread | GTC |
| Stand only until an event | GTD |
| All-or-nothing instant fill | FOK |
| Take available liquidity now | FAK / IOC |
How bots select dynamically
A good bot picks the order type per situation: FOK or FAK for an arbitrage leg or an aggressive entry, GTC for resting quotes. Hardcoding one type for everything leaves performance — and money — on the table.
Order-type names and exact behavior can vary slightly over time; confirm details in Polymarket's current API documentation before relying on them in code.
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Frequently Asked Questions
Disclaimer: This article is for educational purposes only and is not financial, investment, or legal advice. Prediction-market trading carries a real risk of loss. Automation does not guarantee profit, and past performance never guarantees future results. Only trade funds you can afford to lose, and confirm that Polymarket is available and legal in your jurisdiction before trading.