FA-61360 / Options payoff and settlement / Member archive

Cash-settled expiry with exercise by exception: assigned short positions receive the settlement amount · case 05

Short holders are credited instead of debited on assignment.

Member previewVariant 5 · 3 implementations · 8 checks per implementation

Case contract

Inputs kind C/P, strike, settlement price, signed contracts (+long, -short), multiplier, a minimum in-the-money amount and a long-holder instruction (auto, exercise, dnx). Work in integer cents. Intrinsic is max(0, S-K) for calls, max(0, K-S) for puts. The automatic rule exercises when intrinsic >= threshold. Longs follow their instruction (exercise always exercises, dnx never, auto uses the rule); shorts are assigned by the automatic rule. Cash = intrinsic*multiplier*|contracts| if exercised, negative for shorts. Return [exercised, cash in currency units].

Why this case matters

Option expiry, exercise and settlement engines move cash and shares; a wrong branch misstates obligations.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
regression short settlement sign 1	`[true, 1225.0]`	`[true, -1225.0]`	Failed

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