FA-61389 / Options payoff and settlement / Member archive

Contract adjustment for splits and special dividends: any forward split is treated as an integral ratio · case 04

A 3-for-2 split leaves strike and contracts unchanged and the deliverable unadjusted.

Member previewVariant 4 · 3 implementations · 8 checks per implementation

Case contract

Inputs strike, contracts, deliverable, action and value. split [new, old]: if new is a multiple of old (ratio r), strike becomes strike/r rounded half-up to cents and contracts become contracts*r; otherwise the deliverable becomes floor(deliverable*new/old) with strike and contracts unchanged. special_div of at least 0.125 per share reduces the strike by the amount (rounded half-up to cents). Other actions, including ordinary_div, change nothing. Return [strike, contracts, deliverable].

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 integral ratio detection 1	`[101.01, 1, 100]`	`[101.01, 1, 125]`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.