Reference · Order Execution
Limit Order: Price Protection and Non-Fill Risk
Understand buy and sell limit conditions, including an illustrative price table, partial execution and reasons a chart touch may not produce a fill.
Published Updated
Published by FxTrusts, a supplier of brokerage and prop firm technology. Prepared with AI-assisted research and drafting; reviewed against the cited public sources. Examples are illustrative. Product links describe our services.
What is Limit order?
A buy limit specifies the highest acceptable purchase price; a sell limit specifies the lowest acceptable sale price. A limit order can remain unfilled or partially filled. Reaching a displayed chart price does not by itself prove that executable quantity was available for that order.
The limit controls price, not a guaranteed result
For a conventional buy limit at 25.00, execution must be at 25.00 or lower. A conventional sell limit at 25.00 requires 25.00 or higher. The order can receive a better price when the venue’s rules allow it. Those price conditions do not guarantee when execution will occur, how much will execute or whether the instruction will be accepted by the account and instrument configuration.
A chart touch is not the complete execution record
A chart may display bid, ask or last-trade data, while the order is evaluated against a different side or trigger basis. Even the relevant side touching the limit does not establish sufficient quantity or priority. Another resting order may consume the available amount first. On an OTC platform, the source and execution policy also matter. Reconstruct the appropriate quote and order history rather than treating a candle low as decisive proof.
An aggressive limit can execute immediately
A limit order is not always an instruction to wait for a future price. A buy limit above the current available ask can be marketable, while still setting a maximum price. It may fill immediately up to available eligible quantity and leave a remainder according to its lifetime and fill policy. Some interfaces restrict where pending orders may be placed, so check the actual platform behavior before applying a securities-market example to a different product.
Specify how the unfilled quantity is handled
Quantity left after a partial fill may remain active, be canceled or follow another supported policy. Expiry also determines how long the price condition remains relevant. Record the limit price, original quantity, cumulative fills, remaining quantity and expiry together. A changed instruction should preserve its relationship to the original order, especially when a fill can arrive while an amendment is being processed.
Eligible prices under a simple limit rule
This synthetic table assumes the stated prices are executable and ignores queue priority, fees and quantity limits. Eligibility is a necessary price condition, not a promise that a fill happens. A customer-facing explanation should retain that distinction and identify the actual order lifetime.
| Instruction | Available opposite-side price | Price condition |
|---|---|---|
| Buy limit 25.00 | Ask 24.95 | Eligible at a better price |
| Buy limit 25.00 | Ask 25.10 | Not eligible |
| Sell limit 25.00 | Bid 25.05 | Eligible at a better price |
| Sell limit 25.00 | Bid 24.90 | Not eligible |
Implementation checklist
- Confirm whether the order is evaluated against bid, ask, last or another documented basis.
- Check executable quantity and order priority, not only a chart touch.
- Record expiry and partial-fill policy.
- Preserve amendment and execution history for an accurate support review.
Sources
These documents support the reference. Check the original publication for current requirements and the limits of its scope.
- Investor.gov types of orderswww.investor.gov
- MetaTrader 5 trading principleswww.metatrader5.com
- MetaTrader 5 price datawww.metatrader5.com
Continue with the broader guides
Connect this reference to platform selection and the wider operating workflow.