What Is a Cash-Secured Put?
A cash-secured put is an options strategy where you sell (write) a put option while setting aside enough cash to buy the underlying stock if the option is assigned. This strategy is popular among income-focused traders and is often the first leg of the Wheel Strategy, where traders alternate between selling cash-secured puts and covered calls to generate consistent premium income.
When you sell a cash-secured put, you receive a premium upfront in exchange for the obligation to buy 100 shares per contract at the strike price if the stock falls below that level. Your maximum profit is limited to the premium received, while your maximum loss occurs if the stock drops to zero — though the premium received reduces your effective cost basis.
How to Calculate Cash-Secured Put Profit and Loss
Understanding the math behind a cash-secured put is essential for evaluating whether a trade is worth taking. Here are the key formulas:
- Maximum Profit: Premium Received × Number of Contracts × 100. This occurs when the stock price stays at or above the strike price at expiration.
- Maximum Loss: (Strike Price − Premium Received) × Number of Contracts × 100. This occurs if the stock drops to $0.
- Breakeven Price: Strike Price − Premium Received. Below this price, the trade becomes unprofitable at expiration.
- Collateral Required: Strike Price × 100 × Number of Contracts. This is the cash you must hold to secure the put.
- Return on Capital: (Premium Received × 100 × Contracts) / Collateral Required × 100%.
How to Use This Cash-Secured Put Calculator
- Enter the Current Stock Price: Input the current market price of the underlying stock you are considering.
- Set the Strike Price: Choose the strike price for your put option. A strike below the current stock price (OTM) gives you a buffer before assignment.
- Input the Premium Received: Enter the price per share you would receive for selling the put option contract.
- Specify Contracts: Enter the number of option contracts (each contract controls 100 shares).
- Set Days to Expiration: Enter how many days remain until the option expires. This affects time value and the Black-Scholes estimate.
- Adjust Implied Volatility: Set the IV percentage. Higher IV increases the premium you receive but also increases the risk of assignment.
- Review Results: The calculator instantly displays max profit, max loss, breakeven, collateral, Greeks, and an interactive payoff diagram showing both expiry and current P/L curves.
Why Use Our Cash-Secured Put Calculator?
Interactive Payoff Diagram
Visualize profit and loss at expiration and before expiry on a single chart. See exactly where your breakeven lies.
Black-Scholes Pricing
Estimate the theoretical put option value before expiry using the Black-Scholes model with implied volatility and time decay.
Full Greeks Display
View Delta, Gamma, Theta, Vega, and Rho for your short put position to understand how it responds to price, time, and volatility changes.
Completely Free
No registration, no limits. Use our cash-secured put calculator as many times as you need — 100% free.
Choosing the Best Strike Price for a Cash-Secured Put
Strike selection is one of the most important decisions when selling cash-secured puts. Here is how different strike prices affect your trade:
- Out-of-the-Money (OTM): Strike below the current stock price. Lower premium but lower probability of assignment. This gives you a buffer — the stock must fall to the strike before you are obligated to buy.
- At-the-Money (ATM): Strike near the current stock price. Higher premium but approximately 50% chance of assignment. Best for traders who are comfortable owning the stock at the current price.
- In-the-Money (ITM): Strike above the current stock price. Highest premium but very high probability of assignment. Rarely used for cash-secured puts unless the trader specifically wants to acquire the stock.
How Implied Volatility Affects Cash-Secured Puts
Implied volatility (IV) measures the market's expectation of future price movement. For cash-secured put sellers, IV has a significant impact:
- High IV Environment: Options premiums are higher, meaning you collect more premium. This is generally favorable for put sellers, but it also signals higher expected price movement.
- Falling IV: Decreases the put option's value, benefiting the seller. This is measured by Vega. Selling puts before earnings and benefiting from IV crush is a common strategy.
- Rising IV: Increases the put option's value, working against the seller. The position loses money even if the stock price stays the same.
Time Decay and Cash-Secured Puts
Time decay (Theta) works in favor of cash-secured put sellers. As expiration approaches, the time value portion of the option premium erodes, benefiting the seller. Key points to remember:
- Time decay accelerates in the final 30 days before expiration, which is why many put sellers target 30–45 day expirations.
- Shorter-dated options decay faster but may need to be rolled more frequently.
- ATM options have the highest time value and therefore benefit most from theta decay.
- Consider selling puts with 30–45 days to expiration and closing at 50% profit to maximize theta capture while managing risk.