What's my maximum possible loss if I sell a put and the stock goes to zero?

How this is calculated

• Selling a put obligates you to buy 100 shares per contract at the strike price if you're assigned.
• If the stock falls all the way to zero, your maximum loss per share equals the strike price minus the premium you collected. Multiply by 100 shares per contract, then by your contract count, for the total maximum loss.
• Unlike buying a put or a call, where the most you can lose is what you paid, a short put's loss is large but technically capped, since a stock cannot trade below zero.
• This is a worst-case model that assumes the stock goes to zero and you are assigned. It does not predict what the stock will actually do, and most assigned puts do not go to zero.
• If this is a cash-secured put, you've already set aside the capital to buy the shares. If it's a naked put on margin, confirm your account actually has enough buying power to cover assignment, that's a separate risk worth planning for before selling naked puts.