A put sold with the cash to buy the shares set aside: the yield on that cash, annualised, the breakeven and the price you effectively pay if assigned.
| Price at expiry | Profit or loss at expiry |
|---|---|
| $40.26 | -$384.00 |
| $44.10 | $0.00 |
| $45.00 | $90.00 |
| $48.00 | $90.00 |
| $51.84 | $90.00 |
Selling a put obliges you to buy 100 shares per contract at the strike if the put is exercised. Setting aside the strike times 100 in cash is what makes it cash-secured, and that cash is the base the yield is measured against.
If the stock stays above the strike the put expires and the premium is the whole result. If it ends below, you buy the shares at the strike, and because the premium was already received the price you have really paid is the strike less the premium.
The premium divided by the strike, which is the cash per share set aside. Annualised here means that yield times 365 over the days to expiry, without compounding.
How an assigned put's premium enters the share basis · every calculator
Every price here is one you typed; nothing is fetched and nothing is stored. The numbers travel in the address of this page, so a result can be linked to. Results are at expiry for one structure, before commissions and fees, and assume no early assignment. An illustration of the arithmetic, not advice.