Assignment handling

Definition

Assignment handling is the pre-declared plan for what happens when a short option is exercised against the account — shares delivered (short put) or called away (short call), converting an options position into a stock position, sometimes mid-strategy and sometimes overnight. On this platform every strategy carrying short American-style options MUST declare its assignment plan at entry; assignment is a scheduled mechanic, not an emergency.

How it works / structure

• When assignment arrives: mostly at expiration for ITM shorts (automatic exercise thresholds — ms-expiration-exercise-assignment); early for calls ahead of ex-dividend dates when remaining extrinsic < dividend (dividend_vs_extrinsic, event-dividends-ex-dates); early for deep-ITM puts when carry favors exercise; randomly allocated by the OCC to short holders.
• Plan options (engine-executable, per strategy): KEEP — accept the shares as a planned acquisition (strategy-cash-secured-put and strategy-wheel build this in); CLOSE — liquidate the delivered stock immediately at market open rules; CONVERT — re-establish the options structure (e.g. re-sell the call — the wheel’s next spoke); UNWIND-PAIR — for spreads assigned on one leg, exercise or close the other leg the same day (leg risk window minimized).
• Spread leg risk: assignment on a spread’s short leg leaves the long leg plus a stock position overnight — margin and direction both change (acct-margin-rules); the same-day pairing rule bounds it.
• Cash/margin readiness: put assignment requires the cash or margin capacity for the shares — checked at position entry, not discovery time.

When it applies

Always, for short American-style options: income programs (planned acceptance), spreads (leg-risk protocol), calls over ex-dates (the calendar check at entry). Cash-settled index options have no assignment dimension (ms-settlement) — one reason defined structures on indexes carry less mechanical load.

Risk profile & failure modes

• Overnight exposure jump: assignment converts bounded option risk into full stock exposure between sessions; unaware accounts discover it at the margin call.
• Dividend capture against you: short calls through ex-dates are assigned with high frequency when extrinsic < dividend — the seller keeps a dead call’s premium and owes the stock’s dividend move; the calendar check is mandatory.
• Panic unwind pricing: unplanned assignment handled at the open pays stress spreads; a declared plan executes mechanics instead of reacting.
• Tax surprises: assignment realizes stock gains/losses and interacts with holding periods and wash sales (acct-assignment-tax).

Evidence & limits

Assignment mechanics, allocation, and exercise-by-exception thresholds are OCC/FINRA-documented rules, not empirics. Early-assignment frequency around dividends follows the extrinsic-vs-dividend arithmetic — an exercise rationality result, observable in assignment statistics. There is no “edge” here to claim: this entry is plumbing, and its value is that plans made at entry are cheaper than decisions made at 9:31 the morning after.

Falsifiable-thesis examples

Illustrations only, not signals:

• “This short call (extrinsic > expected dividend at every ex-date in its life) will not be assigned early” — falsified by an early assignment.
• “The wheel program’s assignment-acceptance branch will show cost basis (strike − cumulative premium) below the market price at each assignment this quarter” — falsified by the recorded pairs.

Cross-references

• The mechanics underneath: ms-expiration-exercise-assignment, ms-settlement
• Strategies with built-in plans: strategy-cash-secured-put, strategy-covered-call, strategy-wheel
• The dividend trigger: event-dividends-ex-dates, dividend_vs_extrinsic concept
• Aftermath: acct-assignment-tax, acct-margin-rules, mgmt-rolling (the pre-assignment alternative)