Time-in-Force

A limit order needs one more instruction: how long should it wait, and what should happen if only part of it can fill? That instruction is time-in-force. This chapter walks through the four you’ll use, with an example of each.

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What Is Time-in-Force?

Time-in-force tells the exchange how long your order should stay active and what to do if it can’t fill completely. Think of it as instructions on a delivery package:

• “Deliver anytime” (GTC)
• “Deliver now or return it” (IOC / FAK)
• “Deliver the whole thing now or don’t bother” (FOK)
• “Deliver before Friday or return it” (GTD)

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GTC — Good Till Cancelled

“Keep my order open until I cancel it.” Your order rests on the book for as long as it takes. It stays there until it gets filled or you manually cancel it. This is the most common time-in-force for limit orders.

You: Buy 100 shares at $0.50, GTC Exchange: Got it. I’ll keep this open. …3 hours later, someone sells at $0.50… Exchange: Filled! 100 shares at $0.50

Use when: You’re patient and want to wait for your price.

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IOC / FAK — Immediate or Cancel (Fill and Kill)

“Fill whatever you can right now. Cancel the rest.” IOC and FAK mean the same thing — different exchanges just use different names. The exchange tries to fill as much of your order as possible instantly. Anything left over gets cancelled — it does not rest on the book.

You: Buy 100 shares at $0.55, IOC Book: 60 shares available at $0.55 Result: 60 filled, 40 cancelled

Use when: You want to grab what’s available without leaving an order sitting around.

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FOK — Fill or Kill

“Fill the entire order right now, or cancel the whole thing.” It’s all or nothing. If the exchange can’t fill your complete order instantly, nothing happens.

You: Buy 100 at $0.55, FOK — only 60 available Result: Entire order cancelled. No fill at all.

You: Buy 100 at $0.55, FOK — 150 available Result: 100 shares filled at $0.55

Use when: You need the full amount or nothing — partial fills would mess up your strategy.

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GTD — Good Till Date

“Keep my order open until a specific date/time.” Like GTC, but with an expiration. Your order rests on the book and automatically cancels if it hasn’t filled by the deadline you set.

You: Buy 100 shares at $0.45, GTD March 15 …March 15 arrives, no fill… Exchange: Time’s up. Order cancelled.

Use when: You want to wait for your price, but only up to a certain point — like before a market resolves or an event happens.

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Side-by-Side Comparison

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How to Choose

Next: Execution & Slippage — what actually happens to your order once it reaches the book.