Polymarket order types explained for bot builders: Fill-or-Kill (FOK), Fill-and-Kill (FAK), Good-til-Cancelled (GTC), and limit-vs-market trade-offs. With production-grade decision rules.
Polymarket order types explained for bot builders: Fill-or-Kill (FOK), Fill-and-Kill (FAK), Good-til-Cancelled (GTC), and limit-vs-market trade-offs. With production-grade decision rules.
By Harley Young, lead writer at Polymarkets.co.il. Last reviewed: May 2026.
What this chapter covers
This is chapter 10 of our 32-part series on building a Polymarket trading bot. We cover the topic in depth across the sections below. Body content for each section is being written and rolled out chapter-by-chapter; FAQ answers and references are already complete and reflect production experience from running our own trader.
Quick decision tree
FOK: when you must fill or skip
FAK: when partials are acceptable
GTC: when you want to rest on the book
Limit vs market and the spread tax
Our production defaults (FOK buys, GTC sells]
Code: place each order type
Quick decision tree
This section is in active development. Want to be notified when it goes live? Contact us or watch the authors page.
FOK: when you must fill or skip
This section is in active development. Want to be notified when it goes live? Contact us or watch the authors page.
FAK: when partials are acceptable
This section is in active development. Want to be notified when it goes live? Contact us or watch the authors page.
GTC: when you want to rest on the book
This section is in active development. Want to be notified when it goes live? Contact us or watch the authors page.
Limit vs market and the spread tax
This section is in active development. Want to be notified when it goes live? Contact us or watch the authors page.
Our production defaults (FOK buys, GTC sells]
This section is in active development. Want to be notified when it goes live? Contact us or watch the authors page.
Code: place each order type
This section is in active development. Want to be notified when it goes live? Contact us or watch the authors page.
Frequently asked questions
What is FOK on Polymarket?
Fill-or-Kill. The order must fill in full immediately or it is cancelled - no partial fills, no resting on the book. We use FOK by default for buys in our production trader because it eliminates phantom-fill ambiguity (the order is either fully filled or fully gone, never half-stuck).
What is FAK on Polymarket?
Fill-and-Kill (also called IOC, Immediate-or-Cancel). The order takes whatever liquidity is available immediately and cancels the unfilled remainder. Useful when you accept partial fills but never want a rest. Faster than FOK in fragmented order books.
What is GTC on Polymarket?
Good-til-Cancelled. The order rests on the book until filled or you cancel it. GTC is what you use to be a maker (provide liquidity), earn rebates, and avoid taker fees. We use GTC for sells in our production setup so we capture the spread on exits.
Should my bot use limit orders or market orders?
Limit orders almost always. Market orders pay the taker fee (0.75% to 1.80%) and the spread; limit orders earn the maker rebate (20-25% of taker fees). The only good reason to use a market order is when news has hit and the price is about to move beyond the spread before your limit can fill.
Does Polymarket support stop-loss orders natively?
No. Stop-loss is a client-side concept: your bot watches the price, and when the trigger condition is met, places a market or FAK sell order. The exchange has no native stop primitive, so you must build the logic in your bot.
What are the order minimums?
Market orders: 1 USD minimum notional. Limit orders: 5 shares minimum. Some thin markets reject very small orders - the SDK returns a specific error code you can detect and re-size against.
عام سوالات
What is FOK on Polymarket?
Fill-or-Kill. The order must fill in full immediately or it is cancelled - no partial fills, no resting on the book. We use FOK by default for buys in our production trader because it eliminates phantom-fill ambiguity (the order is either fully filled or fully gone, never half-stuck).
What is FAK on Polymarket?
Fill-and-Kill (also called IOC, Immediate-or-Cancel). The order takes whatever liquidity is available immediately and cancels the unfilled remainder. Useful when you accept partial fills but never want a rest. Faster than FOK in fragmented order books.
What is GTC on Polymarket?
Good-til-Cancelled. The order rests on the book until filled or you cancel it. GTC is what you use to be a maker (provide liquidity), earn rebates, and avoid taker fees. We use GTC for sells in our production setup so we capture the spread on exits.
Should my bot use limit orders or market orders?
Limit orders almost always. Market orders pay the taker fee (0.75% to 1.80%) and the spread; limit orders earn the maker rebate (20-25% of taker fees). The only good reason to use a market order is when news has hit and the price is about to move beyond the spread before your limit can fill.
Does Polymarket support stop-loss orders natively?
No. Stop-loss is a client-side concept: your bot watches the price, and when the trigger condition is met, places a market or FAK sell order. The exchange has no native stop primitive, so you must build the logic in your bot.
What are the order minimums?
Market orders: 1 USD minimum notional. Limit orders: 5 shares minimum. Some thin markets reject very small orders - the SDK returns a specific error code you can detect and re-size against.
