Cash-secured put calculator
Selling a cash-secured put means you get paid now and agree to buy 100 shares at the strike if you are assigned. Enter the strike and premium to see how much cash it ties up and what happens at expiration.
New to this? Read Cash-secured puts explained.
Worked example
Example numbers
You sell 1 put at the $30 strike for $0.90, with cash set aside to buy the shares.
At expiration: stock at $32 → the put expires worthless, you keep +$90. Stock at $28 → you are likely assigned and buy 100 shares at $30 ($3,000). They are worth $2,800, so you are down $200 on the shares, plus $90 premium = −$110 (still holding the shares).
How the math works
- Cash set aside = strike × 100 × contracts.
- Max gain = premium × 100 × contracts (minus fees).
- Breakeven / effective buy price = strike − premium.
- Max loss = (strike − premium) × 100 × contracts, if the stock fell to $0.
FAQ
How much cash do I need for a cash-secured put?
The strike times 100 for each contract. A $30 put needs $3,000 set aside. The premium you receive can lower your net cash outlay, depending on how your broker counts it.
What is the breakeven on a cash-secured put?
The strike minus the premium. Selling the $30 put for $0.90 gives a breakeven of $29.10.
What is the max loss on a cash-secured put?
If the stock went to $0 you would still have to buy the shares at the strike, so the max loss is (strike − premium) × 100 per contract. In the example that is $2,910.
What happens if I get assigned?
You buy 100 shares per contract at the strike price, using the cash you set aside. You keep the premium either way.
Educational only. This page explains order mechanics with example numbers. It is not investment advice, not a recommendation to buy or sell anything, and not a broker. Check your own broker’s rules, fees and assignment terms before you trade.