A covered call is a stock position with a ceiling on it. You own the shares, you sell someone the right to buy them at a fixed price, and you keep the cash for that right whether or not it is exercised. Most of the way it goes wrong is settled before the order is placed, in the strike and in the basis you measure the yield against.
The examples use round numbers and one stock so the share-count arithmetic stays visible. They are illustrative; the arithmetic is exact.
What the trade is
One contract covers 100 shares. Selling a call against 100 shares you own is what makes it covered: if the call is exercised, the shares deliver and the short position closes itself. The same order against shares you do not own is naked, with margin requirements and a loss profile that has no upper bound.
Put the strike at or above your cost basis. When the stock is called away at a strike above what you paid, the trade closes with the share gain and the premium both realized. A strike below basis means assignment books a loss on the shares, and the premium only reduces its size.
The premium arrives in the account the next business day. It pays for an obligation that lasts until you buy the call back or it expires. Assignment can happen any time the call is in the money, though in practice it clusters when little time value is left or a dividend is due; the glossary covers the terms.
The accounting is two lines. Max profit per share is the premium plus the distance from basis to strike. Break-even on the combined position is basis minus premium. Everything else about the trade is a variation on those two numbers.
What you collect and what you give up
Take an illustrative position: 100 shares bought at 48.00, and one 50 call sold against them for 1.20 with 30 days to expiry. The premium is 120 dollars, the net cost of the position is 4,680, the most the position can produce is 320, and the stock can fall to 46.80 before the trade loses a dollar.
Three bands matter at expiry.
| Stock at expiry | Result on the 100 shares | Result on the call | Net on the position |
|---|---|---|---|
| 46.00 | −200 | +120 | −80 |
| 49.00 | +100 | +120 | +220 |
| 52.00 | +200 | +120 | +320 |
At 46.00 the shares lose 200 and the 120 collected cuts that to 80. The call expires and the shares stay in the account. At 49.00 the shares gain 100, the call expires worthless, and the position keeps the whole 220. At 52.00 the call is exercised, the shares leave at 50.00, and the position books 200 on the shares plus the 120 premium. It still booked 320. The extra 2.00 the stock gained above the strike, 200 dollars, went to the call buyer.
Choosing the strike and expiry
Delta is the fastest filter on a chain. A short call at 0.20 to 0.30 delta sits far enough out that ordinary movement does not reach it, and it pays for the distance the market expects the stock might travel. Move to 0.45 delta and the strike sits near spot while the credit grows by half again; on a 48.00 stock the 50 and 49 calls can differ by a point and by most of a dollar. Take the smaller credit and keep the point. The options guide covers the greeks behind that choice.
Expiry is a trade between decay rate and decision count. Weekly calls decay faster per day, which helps the seller, and they hand you a decision every Friday plus a spread to pay on every roll. A monthly cycle gives you four rolls a year instead of fifty and a strike that stays out of reach for longer.
Two calendar events matter. An earnings date inside the option's life can gap the stock through the strike overnight, before you can roll, and the position is assigned at a price you did not choose. A dividend date creates early exercise: a call that is in the money with less time value left than the dividend is worth gets exercised the day before the stock goes ex, because the holder wants the dividend more than the remaining time. If you want the shares, keep short calls away from ex-dates while the strike is close.
Far strikes carry wide markets. A strike twenty points out might quote 0.10 bid to 0.30 ask. You sell at the bid and collect ten dollars on a contract the mid prices at twenty, so the spread took half the premium. Near strikes trade a penny wide across hundreds of contracts.
The two outcomes that hurt
The first is the stock running. The position above returns 320 on 4,680, about 6.8%, and it returns that whether the stock finishes at 50.00 or 58.00. The trade was sized for a move and the structure sells off the tail of it. Where the thesis was a 15% advance in three months, the covered call turns it into a 6.8% advance plus a decision about whether to rebuy higher.
The second is the stock falling. The premium rebates 2.5% on a 48.00 stock, and a 10% decline is 4.80 a share. Below 46.80 the position loses dollar for dollar with the shares. The most it makes is 320, the capital exposed is 4,680, and the premium covers the first 120 of any decline and nothing after that. If a 15% drawdown in the stock would force a sale, the covered call has not changed the risk of the position; it moved the entry by 2.5%, which is smaller than position sizing would fix. The risk material covers the sizing side.
Rolling and defending
Rolling up and out means buying back the call that is about to be exercised and selling a later one at a higher strike. Once the stock has moved, the near call is almost all intrinsic, so buying it back is expensive. With the stock at 53.00 and three weeks left, the 50 call costs about 3.10, or 310 dollars. A 55 call 45 days out might sell for 1.80. That roll is a 130 dollar debit for the right to keep 200 dollars of further gain between 53 and 55. If the stock stalls at 53, the 130 is gone and your effective cost on the shares is higher.
A roll is a new trade at the new price. It moves the cap to a later date and a higher strike; the shares are still capped. Every roll pays another spread, and a series of rolls turns a capped gain into a running cost.
Rolling down is not a defence. With the stock at 53.00, buying back the 50 call for 310 and selling the 48 call for 540 produces a 230 credit and lowers the exit from 50 to 48. A 50 call 45 days out is worth about 5.00 against a 53.00 stock, so the roll to 48 collects 40 dollars more than a roll to 50 and gives up 200 dollars of ceiling. If the stock holds above 50 the account ends 160 worse off. The trade only works if the stock falls back under 48 and the call expires. That is a directional bet on a bounce, sold to yourself as a defensive roll.
Where the yield claims go wrong
Monthly premium times twelve is the most common bad number in covered call marketing. The position collects 120 on 4,800 of stock, 2.5% in thirty days and 30% annualized, provided the stock does not move, implied volatility stays where it is, and every month prices the same. None of those hold. Volatility falls and the same strike pays less; the stock falls and the share loss dwarfs the credit.
Assignment is the second omission. The quoted yield assumes the position keeps producing premium. Assignment ends it, realizes the share gain, and forces a decision about redeploying the capital. The basis is the third: a position 20% under water still collects a respectable premium percentage, and that percentage says nothing about whether the position is profitable.
The denominator is the fourth. Premium divided by the strike is not the return on the trade when you paid 48 for shares struck at 50. The capital actually at risk is what the shares are worth today, because that is what a decline takes away. Divide the premium by that. On why the same strike pays different amounts in different months, see how implied volatility sets the premium.
Covered calls after a run-up
The basis problem appears when the stock has doubled. Bought at 30.00, now 60.00, and you sell the 60 call for 1.50. On the 3,000 you paid that is 5% for the month and the trade looks better than it is. The 6,000 the shares are worth today is the capital that goes into the next decision, and the premium is 2.5% of it.
If the call is exercised, a gain held for years becomes cash, and whether to rebuy at 60.00 is the real question. Answer it before you sell the call. If you would buy these shares at today's price with today's cash, the short call caps a position you still want. If you would not, the call is a way of selling part of the position at a fixed price, which is a legitimate exit, and the premium is what you were paid for taking it.
Realizing the gain has a tax or reporting consequence that varies by account and jurisdiction. Work that out on its own, because the call decision is about the stock at today's price. Selling the same call month after month, and the cash-secured put that pairs with it, is the structure described in the options wheel.
Questions
What makes a call covered?
You own at least 100 shares for every contract you sell. If the call is exercised, those shares deliver at the strike and the short position closes itself. Selling the same call without the shares is naked, which carries margin requirements and a loss profile with no upper bound.
How is the maximum profit calculated?
Premium plus the distance from your basis to the strike, multiplied by 100. Buy at 48.00, sell the 50 call for 1.20, and the ceiling is 120 plus 200, or 320 dollars. The stock can finish at 50.00 or 58.00 and the position still returns those 320 dollars.
Where does the position break even?
Basis minus the premium per share. Paid 48.00 and collected 1.20, the position breaks even at 46.80. Below that price the shares lose dollar for dollar, and the call expiring worthless changes nothing. Assignment ends the position earlier, at the strike, and the break-even calculation stops applying.
Which delta should the short call sit at?
Most sellers work between 0.20 and 0.30 delta, where a strike sits far enough from spot to survive a normal week and still pays something. Higher delta pays more and gives up more room. Avoid expiry dates that span earnings or sit just after an ex-dividend date if assignment would be unwelcome.
What are the two ways a covered call hurts?
The stock runs and the gain stops at the strike, so a 15% move becomes a 6.8% result. Or the stock falls further than the premium covers, and you hold a falling position with a small rebate attached. The premium pays for the first part of a decline and none of the rest.
Does rolling the call rescue the trade?
It buys time, at a price. Rolling up and out pays a debit to raise the ceiling, and the debit is lost if the stock stalls. Rolling down to a lower strike collects a credit because you surrender more upside, and if the stock keeps rising that credit is smaller than what you gave up.
Why is annualizing one month's premium misleading?
It assumes the stock does not move, implied volatility holds, and every month prices the same. It also ignores assignment, which ends the position, and the basis, which decides whether the position is profitable at all. Divide the premium by the current value of the shares instead of the strike.
Should you sell calls on a stock that has doubled?
Price the trade against today's capital. Bought at 30.00 with the stock at 60.00, a 1.50 credit is 5% of your basis and 2.5% of the 6,000 now exposed. If you would not buy the shares at 60.00, the call is an exit at a fixed price, and that is a different decision from income.
