Order Types, Expiry, Maker & Taker
How Polymarket order types work in Polycopy: Limit with expiry, Fill and Kill, Fill or Kill, Good-Til-Cancelled, and why maker vs taker affects fills, fees, and price.
Start with the Polymarket order book
Polymarket uses a central limit order book, often called the CLOB. You sign an order with a price, size, side, and order behavior. If your order can match existing liquidity, it trades. If it cannot, a limit-style order can rest on the book until another trader matches it, you cancel it, or it expires.
Limit order with expiry (GTD)
This is the default behavior for most Polycopy copy-trading flows. Polycopy places a limit order on Polymarket at your protected price and lets it rest for up to 10 minutes. If another order matches it during that window, it fills. If not, it expires automatically. This can improve fill quality because you are not forced to cross the spread immediately, but it can leave an order open until the expiry window ends.
Fill and Kill (FAK)
Fill and Kill tries to trade immediately against available orders on the book. It fills whatever size is available at your limit price or better, then cancels the unfilled remainder. This is useful when you want quick execution and do not want a stale order sitting open, but you may get a partial fill or no fill if liquidity is thin.
Fill or Kill (FOK)
Fill or Kill is stricter than FAK. The whole order must fill immediately at your limit price or better, or the entire order cancels. It avoids partial positions, but it is easier to miss trades in thin or fast markets because one missing share can cause the full order to fail.
Good-Til-Cancelled (GTC) and expiry
Polymarket also supports Good-Til-Cancelled limit orders. A GTC order stays open until it fills or you cancel it. A GTD order is the expiring version: it stays open only until a specific expiry time. In Polycopy, Limit usually means GTD with a 10-minute expiry, while some close-position or advanced screens may show GTC. Expiry matters because open orders reserve balance and can fill later if the market returns to your price.
Maker vs taker
A maker adds liquidity by placing an order that rests on the book and is later matched. A taker removes liquidity by matching against an order already on the book. A Limit/GTD or GTC order can be maker if it rests first, but it becomes taker if your price crosses the spread and fills immediately. FAK and FOK are usually taker-style because they try to execute immediately.
Why maker and taker matters
Maker/taker status affects cost, execution certainty, and price quality. Taker orders usually fill faster but may pay higher fees and cross the spread. Maker orders can earn better prices or lower builder fees when they rest and fill later, but they may not fill before expiry. Polycopy shows the applicable trading fee before confirmation; Polymarket can also apply taker fees on fee-enabled markets.
Which behavior to choose
Use Limit with 10-minute expiry for most copied trades when you want a balance between fill rate and price protection. Use FAK when you want an immediate attempt and no open order. Use FOK only when partial fills are unacceptable. If a market is thin, a smaller order, wider slippage tolerance, or a resting limit order can improve the chance of getting filled.