Cash-Secured Put calculator

Max profit on a cash-secured put is the premium you collected per share, realised whenever the stock closes at or above the strike at expiry. Below the strike you're assigned at the strike price, so your effective cost basis is strike − premium, and any further drop becomes an unrealised loss on the assigned shares.

The break-even is the strike price minus the premium received per share — also called the effective buy price. If the stock closes there at expiry, you've offset the entire premium against the assignment loss and finish flat.

A cash-secured put requires the full assignment cash sitting in your account: strike × 100 per contract. If the strike is $95, the broker earmarks $9,500 per contract until the trade closes or you get assigned.

Annualised yield projects what the premium would earn on the cash collateral if you could repeat the same trade every period for a year. The formula is (premium / strike) × (365 / days to expiry) × 100 — a 30-day trade collecting 2% becomes ~24% annualised on collateral.

Yes. The premium softens the first few dollars of a stock decline, but if the stock falls well below your strike you're assigned the shares at a price above the market and have an unrealised loss on the position. The maximum loss is the strike minus the premium, hit if the stock goes to zero.