On this page
Choose the side before calculating
The original one-unit put pays a premium of 5 from holder to writer. At expiry price 90 and strike 100, the holder payoff is 10. The holder’s two movements are −5 and +10; the writer’s are +5 and −10.
Reconcile the position pair
Simple holder profit is +5 and writer profit −5. Their settlement amounts and premiums each sum to zero. This is an accounting check within the supplied no-cost contract, not a statement about other brokerage cash flows.
| Movement | Holder | Writer |
|---|---|---|
| Premium | −5 | +5 |
| Expiry settlement | +10 | −10 |
| Simple profit | +5 | −5 |
Do not reverse the contract type
Selling a put is not the same as buying a call. The writer’s put settlement is −max(K−S,0), whereas a call holder receives max(S−K,0). Opposite directional intuition does not make their payoff functions identical.
Retain real contract administration separately
These signs describe expiry cash-equivalent amounts. Margin, assignment, early exercise and physical delivery need their own contract records. No trading permission or margin estimate is supplied by this introductory sign table.