When you sell, every sign flips
Selling an option reverses the sign of every Greek. A short call is negative delta, negative gamma, positive theta and negative vega. The two that matter are the pair: you are always long theta and short gamma at the same time, and that combination is what premium selling actually is.
Most options education is written for buyers. Every Greek gets explained from the long side, and then people who only ever sell have to invert the whole thing in their heads, live, while holding a position.
The same contract, both ways
The UBER October 17 $72.50 call, 42 days out, stock at $68.40.
| Greek | Long the call | Short the call | What the short version means |
|---|---|---|---|
| Delta | +0.331 | -0.331 | you lose $33 per dollar the stock rises |
| Gamma | +0.0488 | -0.0488 | your delta worsens in both directions |
| Theta | -$3.45/day | +$3.45/day | time works for you |
| Vega | +$8.41 | -$8.41 | rising volatility costs you |
| Rho | +$2.43 | -$2.43 | rising rates cost you, barely |
The pair that defines the strategy
Look at theta and gamma together. Positive theta, negative gamma. That combination is not a coincidence and it cannot be separated.
Every option is a trade between them. The buyer pays theta for gamma: they bleed daily in exchange for a position that gets better fast when they are right. You take the other side. You collect the bleed and accept a position that gets worse fast when you are wrong.
Nobody has ever found a way to be long theta and long gamma at the same time. If somebody offers you one, they are selling you something with a hidden leg.
Which means the honest description of a premium seller is: paid a little every day, occasionally run over. The magnitude of the running over grows as expiry approaches, and that is the whole risk-management problem in one sentence.
The four positions, sorted
- Short call: negative delta, wants the stock flat or down. Negative gamma, positive theta, negative vega.
- Short put: positive delta, wants the stock flat or up. Negative gamma, positive theta, negative vega. The positive delta is the sign that catches people, because selling a put feels like a bearish act and is not.
- Long call: positive delta, positive gamma, negative theta, positive vega.
- Long put: negative delta, positive gamma, negative theta, positive vega.
Notice that both short positions share three of four signs. Whether you sold a call or a put, you are short gamma, long theta and short vega. Only delta distinguishes them. That is why the wheel feels like one strategy even though it alternates between puts and calls: three quarters of the risk profile never changes.
The covered call, composed
The position is 100 shares plus one short call. Shares have a delta of exactly 1.00 each and no other Greeks at all.
- Delta: +100 from the shares, -33.1 from the call. Net +66.9 share-equivalents.
- Gamma: -0.0488. All of it from the call. The shares contribute nothing.
- Theta: +$3.45 a day. All from the call.
- Vega: -$8.41. All from the call.
So a covered call is a two thirds stock position with a small daily income and a short volatility bet stapled to it. That is a genuinely different animal from 100 shares, and describing it as "owning the stock and getting paid extra" hides three of the four lines above.
Watch what happens if UBER rallies to $75. The call goes deep in the money, its delta climbs toward 1.00, and the composite delta falls toward zero. Your position stops participating in the rally entirely. That is not a malfunction. It is the upside you sold, showing up as a Greek.
Three habits this suggests
- Write the signs down when you open. Short 1 call: delta -33, gamma -0.05, theta +$3.45, vega -$8.41. Doing it once per position stops the sign errors that produce hedges pointing the wrong way.
- Read your platform carefully. Some show Greeks per share, some per contract, some already signed for your position and some for the contract as if you were long. A theta of 0.0345 and a theta of 3.45 are the same number and one of them will mislead you at speed.
- Total the book, not the trade. Five short puts across five tickers are five negative gamma, short vega positions that will all reprice together. The aggregate is the position you actually hold.
OptionsKing scores every candidate strike on a deterministic 0 to 100 scale, blends that score with the return on the capital the trade ties up, and shows you the highest-ranked handful. There is no minimum score. How it works covers what the ranking does and does not tell you.
Questions people actually ask
What are the Greeks of a short call?
Negative delta, negative gamma, positive theta and negative vega. On the worked contract that is delta -0.331, gamma -0.0488, theta +$3.45 a day and vega -$8.41 per volatility point.
Is a short put positive delta?
Yes. Selling a put is a bullish position that profits when the stock rises or stays put, which surprises people because puts feel bearish. It shares its other three Greek signs with a short call.
Can I be long theta and long gamma at once?
No. Every option trades one against the other. Buyers pay time decay for convexity and sellers collect time decay while accepting a delta that worsens in both directions. That trade-off is what an option is.
What is the delta of a covered call?
100 from the shares minus the call delta. With a 0.331 delta short call that is 66.9 share-equivalents, so the position captures about two thirds of the stock movement and stops participating entirely if the call goes deep in the money.
Sources
Rules and thresholds above were checked against these documents on August 4, 2026. Exchange and broker rules change. Confirm anything you are about to act on with your own broker.
Keep reading
Do the math on your own trade
Every price in this article is an illustrative worked example, not a quote. Read The Greeks for the rest of the series, and the disclaimer before you act on any of it. Selling options carries real risk of loss, and the loss can be far larger than the premium you collected.