An order for 100 shares is not evidence that 100 shares executed. To understand a partial fill, separate the original request from the execution records—and then check what happened to the unfilled quantity.
A useful receipt answers several questions rather than compressing everything into one number: How many shares filled? At which prices? What was the average execution price? What fees are recorded? What is the remainder’s status?
First, identify the order type
The supplied Polymarket predictions changelog describes these international order mechanics:
- FAK: permits partial execution, with cancellation of the unfilled remainder.
- FOK: requires full immediate execution or cancellation.
The distinction matters. A partial-execution example should not be labeled FOK, and the FAK remainder rule should not be generalized to every order type.
For a real order, distinguish the documented rule from evidence of that order’s final status. Knowing the rule does not replace checking the record.
A fictional, annotated FAK receipt
Hypothetical teaching example—not a real trade, venue receipt or TickBetter interface. All quantities and prices below are invented for arithmetic. The example assumes that the execution records and final remainder status have been confirmed. It does not model fee deductions or net account balances.
| Field | Fictional value | How to read it |
|---|---|---|
| Side and order type | Buy, FAK | Establishes which remainder rule applies |
| Requested size | 100 shares | The intended quantity, not the executed quantity |
| Fill 1 | 30 shares at $0.40 per share | One execution component |
| Fill 2 | 20 shares at $0.42 per share | Another execution component |
| Total filled | 50 shares | The sum of the executed quantities |
| Weighted average execution price | $0.408 per share, before fees | Weights each price by its filled quantity |
| Fill-price subtotal | $20.40, before fees | Sum of quantity × price across the fills |
| Execution fees | Unknown; not supplied in this example | Missing information is not a zero fee |
| Unfilled remainder | 50 shares | Requested quantity minus filled quantity |
| Remainder status | Canceled, assumed confirmed for this example | A status separate from the filled amount |
| Later rebate | Unknown; none assumed | Not deducted from the immediate subtotal |
The receipt says 50 shares filled, not 100. It also says the remaining 50 were canceled in this fictional FAK case. Those are two separate facts.
Calculate the average from the fills
The average execution price should reflect the number of shares executed at each price:
Weighted average = sum of (filled quantity × fill price) ÷ total filled quantity
For this example:
- 30 × $0.40 = $12.00
- 20 × $0.42 = $8.40
- Total: $20.40 for 50 filled shares
- $20.40 ÷ 50 = $0.408 per share, before fees
Simply averaging $0.40 and $0.42 would give $0.41. That would ignore the unequal quantities in the two fills.
Dividing the $20.40 subtotal by the 100 requested shares would also be wrong: half of those requested shares never executed in this example.
Keep fees and later rebates separate
The fill-price subtotal is not a complete statement of trading costs when the execution fee is unknown. Preserve that uncertainty rather than labeling $20.40 as the final all-in cost.
The supplied trading-fees article provides historical background for distinguishing execution fees from later rebates. It is not evidence of a new fee change this week, and this example does not apply a current fee rate.
If a rebate is later confirmed, record it separately with its confirmed amount. Do not subtract a hypothetical rebate from the immediate trading cost or present an expected rebate as money already received.
Check the remainder, not just the total
Subtracting filled shares from requested shares gives the unfilled quantity. It does not, by itself, establish that quantity’s status.
In this fictional FAK example, the final status is assumed confirmed as canceled. In a real record with no final status available, write “remainder status unknown” rather than converting the order-type rule into a claim that cancellation has been verified.
For a different order type, use its documented handling instead of borrowing the FAK rule.
A practical receipt-reading checklist
- Identify the request: side, order type and requested quantity.
- Read each fill: executed quantity and execution price.
- Reconcile the total: add filled quantities; do not substitute requested size.
- Check the average: weight prices by executed quantities and label whether fees are excluded.
- Record fees separately: unknown is not zero.
- Resolve the remainder: distinguish its quantity from its confirmed status.
- Keep later rebates separate: include only confirmed information, not an assumed discount.
This is a guide to ordinary international execution records—not tax treatment, outage recovery or cash-out valuation. The goal is simple: make the record show what actually executed, what did not, and what is still unknown.