A covered call is a sale of upside, not free income

strategyPublished 20 October 20262 min readequities

Key points

• The premium is received because the upside is sold.
• Below the strike, the shares drive the loss. The premium only offsets a slice of it.
• The payoff calculator draws the result at expiry from inputs you type. It is not the value of the contract tomorrow.

What is going on

At expiry, a covered call keeps the shares and the premium if the share price finishes below the strike, and it can be assigned if the price finishes above the strike, so the gain above that strike is not yours. Before expiry the contract’s value also moves with time and with implied volatility. Those are not in the expiry diagram. Early assignment, where the contract allows it, can arrive before the picture you drew. The Options Clearing Corporation describes contract terms. A brochure that calls the premium income has skipped the cap and the remaining downside.

Why it matters

If the shares fall by more than the premium, the position loses money. If the shares rise far through the strike, the position gains less than the shares alone. Comparing only the premium with a dividend confuses a one-off sale of an option with a distribution from the company. Costs include the spread on the contract and any commission. Liquidity in the strike you want may be poor.

What to watch

Write the strike, the expiry, the premium you would actually receive after the spread, and what you will do if assigned. Match the number of shares to the contract size. Do not describe the premium as a return on the shares without subtracting the path of the shares.

Risks

The downside of the shares remains. A halt, a gap, or an early assignment can change the timetable. This note does not quote a live premium.

Expiry is not tomorrow

An expiry diagram is the contract’s settlement shape if it is held to that date. Before then, the price you could close at depends on volatility, time and the share price. The calculator on this site draws the expiry shape you specify. It does not forecast the mark tomorrow.