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Cash-Secured Put Calculator
Cash required, break-even, max profit, and return on capital for a CSP.
How the calculation works
Cash secured defaults to strike × multiplier × contracts. Max profit is the premium credit. Break-even is strike minus premium. Max loss assumes the underlying goes to zero after the credit. Return on capital is max profit ÷ cash secured.
Formula & example
Cash ≈ strike × mult × contracts; BE = strike − premium; Max profit = premium × mult × contracts
Sell 1× $40 put for $1.10 → cash ≈ $4,000, BE $38.90, max profit $110, ROC 2.75%.
Why use this calculator
Premium alone overstates attractiveness; ROC versus cash locked matters for comparing CSPs.
When to use it
Use when selling puts you are willing to be assigned on and you want the cash set-aside and ROC before entry.
Tips for accurate results
- Broker cash requirements can differ from strike × 100.
- Assignment delivers long stock at the strike — plan the stock risk.
FAQ
Is max loss realistic?
It is the educational floor (underlying → $0). Real losses are usually smaller but can still be large.
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