How a covered call works
You own at least 100 shares of a stock. You sell one call contract against them and collect a premium immediately. In exchange, you accept an obligation: if the stock is above the strike price at expiration, your shares are sold at that strike.
The word covered matters. Because you already hold the shares, you can always meet the obligation. This is what separates a covered call from a naked short call, where a rising stock creates theoretically unlimited losses.
A worked example
You own 100 shares of a stock trading at $50, bought at $50. You sell one call with a $55 strike expiring in 35 days and collect $1.50 per share, which is $150.
Three regions matter on that chart:
| Stock at expiration | What happens | Your result |
|---|---|---|
| Below $48.50 | Call expires worthless, you keep shares | A loss, cushioned by $150 |
| $48.50 to $55.00 | Call expires worthless, you keep shares | Profit up to $650 |
| Above $55.00 | Shares called away at $55 | Capped at $650 |
Whether the stock finishes at $56 or $96, your outcome is the same $650. That flat line to the right is the entire cost of the strategy, and it is why covered calls suit stocks you expect to drift rather than stocks you expect to run.
Computing the return
Two numbers describe a covered call, and both belong in the decision.
In the example, the return if the stock goes nowhere is $1.50 ÷ $50, or 3.0% over 35 days. Annualizing that by multiplying by 365/35 gives roughly 31%, which is the figure covered call advertising tends to lead with. The return if called is ($1.50 + $55 − $50) ÷ $50, or 13% over the same 35 days.
Choosing a strike
Strike selection is the strategy's only real decision, and delta is the cleanest way to think about it. A call with 0.30 delta has roughly a 30% chance of finishing in the money, which is roughly the chance your shares get called away.
| Strike choice | Premium | Assignment odds | Best when |
|---|---|---|---|
| Deep out of the money (0.15 delta) | Small | Low | You want to keep the shares |
| Moderately out (0.30 delta) | Moderate | Moderate | The common balance |
| At the money (0.50 delta) | Large | High | You are happy to sell at that price |
A useful discipline: pick a strike you would genuinely be pleased to sell at. If assignment at that price would feel like a mistake, the strike is too low, and no premium fully compensates for the regret of watching a stock run away from you.
The two ways it goes wrong
The stock falls hard. The premium cushions the first $1.50 of decline and nothing after that. If the stock drops to $40, you lose $1,000 on shares and keep $150, for a net loss of $850. Covered calls are not downside protection; they are a small discount on an unchanged downside.
The stock runs. Your shares are called away at $55 and the stock continues to $70. You made $650 and forfeited $1,500 more. This hurts most on exactly the positions you most wanted to own, which is the strategy's central irony: selling upside works best on stocks that go nowhere, and the stocks that go nowhere are rarely the ones you want to hold.
Managing the position
Most covered call writers do one of three things as expiration approaches.
- Let it expire. If the stock is below the strike, the call dies worthless, you keep the shares and the premium, and you can sell another call.
- Accept assignment. If the stock is above the strike, deliver the shares at your predetermined price and book the planned maximum profit.
- Roll the call. Buy back the short call and sell a later, often higher, strike. Rolling can avoid assignment, but rolling a deeply in-the-money call frequently requires paying more to close than the new premium collects, turning an income trade into a bet on a reversal.
Before you place any of these trades, run the exact contract through the options profit calculator to see the position at every price and date, not just at expiration.