Checklist · Copy Trading and Allocation
Allocation Caps: Per-Strategy and Per-Account Limits
Test strategy and shared account limits using a synthetic multi-subscription example, with clear units, concurrent checks and exception ownership.
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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.
Quick answer
An allocation cap limits a defined measure within a defined scope, such as one strategy, one instrument or an entire account. Several individually valid subscriptions can exceed a shared cap together. State the measure, aggregation rule and action taken when the projected state would exceed it.
Define what the cap measures
A cap might apply to lots, units, notional exposure, allocated cash or another quantity. Those are not interchangeable risk measures. A one-lot limit across unlike contracts is not meaningful without normalization. Decide whether positions are aggregated gross or net and whether pending requests count. Keep the instrument and currency scope explicit, especially when multiple strategies share an account or when contract sizes differ between sources.
Evaluate the shared account, not each strategy alone
A strategy-level limit protects only its declared scope. If three subscriptions each stay below their own limit, their combined requests can still exceed an account-level policy. The system needs a consistent view of current exposure and relevant in-flight requests. Two simultaneous checks against the same remaining capacity can both pass independently and exceed the total when committed together, so concurrency belongs in the acceptance test.
Specify the response to an excess
Possible policies include rejecting a new request, accepting an authorized smaller amount or stopping further signals pending review. The correct choice comes from the agreement and operating design. Silently resizing a copied trade changes its relationship to the source. A triggered limit also does not guarantee a final equity or closing price: cTrader’s documented equity-stop behavior, for example, includes execution risk. Quantity caps and equity triggers should remain separate concepts.
Review changes and recovery states
A withdrawal, new strategy, mapping change or manual position can alter available capacity. Record who may change limits and when the new value takes effect. Reconcile the current account after a reconnect before accepting more requests. If the system cannot establish its actual exposure, follow the approved degraded-state policy rather than treating unknown quantity as zero. The worksheet is a design test, not a claim that a particular FxTrusts engine already applies these controls.
Three subscriptions under one fictional gross cap
Assume all values refer to long EUR/USD lots under the same contract, an account cap of 1.00 lot and a reject-on-excess policy. Existing exposure is 0.40 from A and 0.35 from B, totaling 0.75. C requests 0.30, which would produce 1.05. Although C’s own 0.50 limit is satisfied, the shared limit is exceeded by 0.05, so the example rejects C’s request.
| Scope | Current/requested quantity | Limit result |
|---|---|---|
| Strategy C alone | 0.30 requested; 0.50 cap | Within its own cap |
| Existing shared account | 0.40 + 0.35 = 0.75 | 0.25 remaining |
| Projected shared account | 0.75 + 0.30 = 1.05 | Exceeds 1.00 cap |
| Declared response | Reject request and record reason | No silent reduction |
Implementation checklist
- Define units, scope, gross/net rule and pending-request treatment.
- Test concurrent requests against shared capacity.
- State rejection or authorized resizing behavior explicitly.
- Reconcile exposure after account changes, reconnects and manual interventions.
Sources
These documents support the reference. Check the original publication for current requirements and the limits of its scope.
- cTrader Copy investing and stopping behaviorhelp.ctrader.com
- MQL5 symbol propertieswww.mql5.com
- Interactive Brokers default allocationswww.ibkrguides.com
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