Selling cash-secured puts (CSPs) is a popular income strategy, but calculating your potential returns requires understanding several key metrics. This guide explains how to calculate CSP profits, losses, breakeven points, and return on capital—plus a free calculator to do the math for you.
What is a Cash-Secured Put?
A cash-secured put (CSP) is when you sell a put option while holding enough cash to buy 100 shares if assigned. You collect premium upfront and either:
- Keep the premium if the stock stays above the strike (expires worthless)
- Buy shares at the strike if assigned (stock drops below strike)
The "cash-secured" part means you have the capital to cover assignment—unlike naked puts which use margin.
Key CSP Calculations
Maximum Profit
Your max profit on a CSP is the premium you collect. This happens when the put expires worthless (stock stays above strike).
Max Profit = Premium × 100 × Number of Contracts
Example: Sell 1 AAPL $170 put for $3.50 premium
Max Profit = $3.50 × 100 × 1 = $350
Maximum Loss
Theoretical max loss is if the stock goes to $0. In practice, you'd likely close the position before this happens.
Max Loss = (Strike Price × 100 × Contracts) - Premium Received
Example: $170 strike, $3.50 premium
Max Loss = ($170 × 100) - $350 = $16,650
Breakeven Price
Breakeven is where you neither make nor lose money (excluding commissions).
Breakeven = Strike Price - Premium Received (per share)
Example: $170 strike, $3.50 premium
Breakeven = $170 - $3.50 = $166.50
If assigned at $170 but your cost basis is $166.50, you're not in the red until the stock drops below that price.
Return on Capital
This is the most important metric—what return you're getting on your secured cash.
Return on Capital = (Premium / (Strike × 100)) × 100%
Example: $170 strike, $3.50 premium, 30 days to expiration
Return on Capital = ($350 / $17,000) × 100 = 2.06%
Annualized = 2.06% × (365 / 30) = 25.1%
Try Our Free CSP Calculator
Use our Options Profit Calculator to instantly calculate:
- Maximum profit
- Maximum loss
- Breakeven price
- Return on capital
Just select "Cash-Secured Put," enter your strike, premium, and contracts.
Factors Affecting CSP Returns
Strike Selection
Lower strikes = less premium but lower assignment risk. Higher strikes = more premium but higher assignment risk.
Common approach: Sell at 80-90% of current stock price (10-20% out of the money).
Days to Expiration (DTE)
Shorter DTE = higher annualized return but less absolute premium. Longer DTE = more absolute premium but lower annualized return.
Sweet spot for many traders: 30-45 days to expiration.
Implied Volatility
Higher IV = higher premiums. Sell CSPs when IV is elevated (but be careful—high IV often means something's happening with the stock).
CSP Return Scenarios
Scenario 1: Put Expires Worthless
Best case. You keep 100% of the premium, no shares acquired.
Return = Premium collected
Scenario 2: Assigned but Stock Recovers
You get assigned shares, but if the stock bounces back above your cost basis, you can sell for a profit or sell covered calls.
This is the start of a "wheel" cycle.
Scenario 3: Assigned and Stock Drops Further
Worst case. You now own shares at a loss. Options:
- Hold and sell covered calls to reduce cost basis
- Sell shares and realize the loss
- Hold long-term if you believe in the company
Tracking Your CSP Returns
To properly track CSP performance over time, record:
- Entry and exit dates
- Strike price and premium
- Capital deployed
- Outcome (expired, closed early, assigned)
- Return on capital
Options Tracker does this automatically—enter the trade once, and all metrics are calculated for you.
Common CSP Mistakes
1. Selling on Stocks You Don't Want to Own
Only sell CSPs on stocks you'd happily own at the strike price. Assignment should feel like a buying opportunity, not a disaster.
2. Ignoring Return on Capital
A $500 premium sounds great, but if it ties up $50,000, that's only 1% return. Always calculate ROC.
3. Over-Leveraging
Don't sell more contracts than you can afford to be assigned on. Use our Position Size Calculator to stay within your risk limits.
Conclusion
Calculating CSP returns is straightforward once you know the formulas. The key metrics are max profit (premium), max loss (strike × 100 - premium), breakeven (strike - premium), and return on capital (premium / collateral).
Use our free CSP calculator to run the numbers on your next trade, and sign up for Options Tracker to automatically track all your CSP positions and returns.