Define Fixed Target as a measurable rule
Fixed Target is best treated as a rule with inputs that do not change after they are set. To measure it, you need to specify what remains fixed (the target level) and when it is considered fixed (the timestamp of when the rule is created or last updated).
A measurable definition usually includes:
- Target level: the price (or derived level) the exit is intended to reach.
- Target-side rule: for example, whether the condition is “price reaches or exceeds” (buy-side style) or “reaches or falls below” (sell-side style).
- Reference price source: what “price” means in practice (for instance, the venue quote, last traded price, or execution price).
- Time boundary: the timestamp when the fixed target is placed and any timestamp when it is modified.
Identify the measurable fields you will record
To measure Fixed Target consistently, record fields in a way that allows independent checking. The key fields are:
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Setup timestamp (T0)
- The moment the fixed target is created or confirmed by the system you are using.
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Fixed target value (P )*
- The target price level written at T0. If the platform stores it as a limit/stop parameter, record the stored value.
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Order/trigger identifiers
- Any unique IDs that let you tie the target to later events.
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Modification timestamps (if any)
- If the target can be amended, record the times and the new values. Measurement becomes ambiguous if you do not know whether “fixed” stayed fixed.
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Fill or close outcomes
- The execution price(s) and execution time(s), including partial fills if they occur.
- The “hit” outcome should be determined by an agreed rule (see below).
Use an explicit “hit” rule for comparison
A common measurement step is to decide whether the target was “hit.” For example, you might define a hit as: at least one execution occurred at a price that satisfies the target-side rule relative to P. Without this explicit rule, two people can measure different results from the same raw data.
Perform comparisons with transparent assumptions
Because you are not relying on real-time market data, measurement should use what you can record:
- Outcome-based check: Compare the execution prices to the fixed target using your hit rule.
- Timing-based check: Verify that the relevant event happened after T0 and after any modifications.
If you want a simple numeric metric, one option is:
- Target achievement flag: 1 if hit per your rule, else 0.
- Distance-to-target at fill (optional): the difference between each execution price and P.
Provide an example with stated assumptions
Assume:
- T0 is when the system confirms the fixed target.
- P* is the stored target level.
- A “hit” occurs when at least one execution price meets the target-side condition.
- Costs are ignored for the achievement flag, but recorded separately.
Measurement steps:
- Record T0 and P*.
- Record execution(s): price(s) and time(s).
- Apply the hit rule to the execution prices.
- Conclude “hit” or “not hit,” and report the supporting fields (T0, P*, execution details).
This makes the measurement independently verifiable because another reader can re-run the comparison using the same recorded values.
Limitations and failure modes you must account for
Even with careful fields and timestamps, Fixed Target measurement can fail in at least these ways:
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Ambiguous price reference Different systems may use different definitions of “price” (quote versus execution). If you do not record the reference, comparisons can conflict.
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Delayed or out-of-order events Execution and order confirmation times may not line up perfectly across logs. If timestamps are inconsistent, you may misclassify whether the target was still “fixed.”
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Partial fills A target rule may generate multiple executions. If your hit rule is unclear (e.g., whether one acceptable partial fill counts), measurement can become inconsistent.
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Cost and slippage effects Your target level might be met on the way in theory, but actual execution can differ due to costs, spreads, and execution variability. Even if you keep the target fixed, the realized outcome can differ.
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Historical similarity does not predict future results Past executions that matched a target do not establish that future executions will match, since outcomes vary with market conditions and execution behavior.