Futures IOC/FAK vs. FOK Orders Explained
Learn how immediate-or-cancel or fill-and-kill futures instructions differ from fill-or-kill, including partial fills, remaining quantity, limits, and venue naming.
Direct answer
Immediate partial-fill and fill-or-kill instructions solve different problems. IOC or FAK-style handling can fill available quantity and cancel the rest, while FOK requires the specified quantity immediately or cancels.
Start with the execution condition, not the acronym
Order labels can vary by venue and platform.
CME Globex documentation uses Fill and Kill, or FAK, for an order that can fill immediately in whole or in part at the specified price or better, with remaining quantity eliminated.
Fill or Kill, or FOK, requires the specified minimum quantity to fill immediately at the specified price or better or the order is canceled.
Some platforms use IOC, Immediate or Cancel, for the same practical idea as immediate partial execution plus cancellation of the unfilled balance.
Check the venue's exact definition before treating the acronyms as interchangeable.
Worked example: 10 contracts but only 6 are available
Suppose you want to buy 10 futures contracts with a limit of 5,000.00.
Assume only 6 contracts are immediately available at 5,000.00 or better.
Under a partial-immediate instruction such as FAK or a platform's IOC, 6 can fill and the remaining 4 can be canceled.
The result is:
Under an FOK instruction for all 10, the order does not satisfy its immediate full-quantity condition.
The result is 0 filled and 10 canceled.
- 6 contracts executed
- 4 contracts canceled
- position increases by 6, not 10
FOK protects quantity completeness, not a future fill
FOK does not mean the venue waits for the missing quantity to appear.
The immediate condition is the point.
If the required quantity cannot be matched immediately under the order's price condition, the order is canceled.
That makes FOK different from a resting Day or GTC limit order.
Futures Day versus GTC orders explains instructions that can remain working over time.
FOK also does not remove the limit-price rule when used with a limit order. Quantity completeness and price boundary are separate constraints.
Partial-immediate orders create real position risk
A partial fill is a completed trade for the quantity that executed.
If you wanted 10 contracts but received 6, your account now has exposure from 6 contracts.
Do not assume the entire order failed just because the full requested quantity was unavailable.
Check filled quantity and leaves quantity before submitting another order.
Otherwise, replacing the original 10 can accidentally produce 16 contracts if the earlier 6 were already filled.
Why futures orders fill at multiple prices explains how execution records and remaining quantity should be reconciled.
Price boundary and time condition are separate choices
Market, limit, stop, and stop-limit describe price or trigger behavior.
Day, GTC, FAK, IOC, and FOK describe how long or under what immediate condition an order remains eligible.
A platform can combine only the order types and duration qualifiers that its venue and product support.
Do not assume every product supports every combination.
Futures market orders versus limit orders explains the price side of the instruction.
The broker's ticket and final exchange acknowledgement determine what was actually submitted. [!TRYMARK] Compare two immediate orders Assume 10 contracts are requested and only 6 are immediately available within the price limit. Write the filled, canceled, and final position quantity for a partial-immediate order and for FOK.
Use an immediate-order checklist
Confirm the exact venue, product, and contract month.
Read the platform's definition of IOC, FAK, and FOK.
Confirm whether partial execution is permitted.
Confirm the required minimum or full quantity.
Check the limit price or other price condition separately.
Record every execution and the canceled remainder.
Verify final position quantity before sending a replacement.
Do not infer order behavior from the acronym alone.
This guide explains order mechanics. It does not recommend an immediate-order instruction.
Common questions
What is the difference between IOC and FOK in futures?
IOC-style handling can permit an immediate partial fill and cancel the remainder. FOK requires the specified quantity immediately or cancels the order without the required fill.
Is CME FAK the same as IOC?
They can describe similar immediate-partial-fill behavior, but terminology is venue-specific. CME Globex documentation uses FAK, while some platforms use IOC. Read the exact venue definition.
Can a futures FOK order partially fill?
A true FOK instruction requires its specified minimum quantity immediately. If that requirement is the full order quantity and cannot be met, the order is canceled rather than partially completed.
Does IOC or FAK mean my remaining quantity keeps working?
No under the immediate-cancel behavior described here. The executable portion can trade immediately and the remaining balance is canceled. Verify the final order report.