Buy to Open vs Buy to Close - The Four Options Order Actions
Reviewed by Leon Moyer - Published October 9, 2026 - Last reviewed October 9, 2026
In this lesson
Choose the right order action (buy to open, sell to close, sell to open or buy to close) for a trade, and read every field on an options order ticket.
Buy to open starts a new long option position, and buy to close ends a short option position you sold earlier. Together with sell to open and sell to close, these four order actions tell your broker whether an order adds a position or removes one, and every options order uses one of them.
The opening or closing designation tells the broker how the trade changes your position. Some interfaces infer it from your holdings. Stock orders draw a similar line between selling shares you own and selling short.
What do buy to open, sell to close, sell to open and buy to close mean?
FINRA's options guide for investors uses the formal names for the same four actions: an opening purchase, an opening sale, a closing sale and a closing purchase. Your broker's order screen may use either set of words.
How do opening and closing orders pair up?
Every opening order has one matching closing order. The first word tells you the direction; the second tells you whether the order starts or ends the position.
- A long trade starts with buy to open and ends with sell to close.
- A short trade starts with sell to open and ends with buy to close.
Every opening order has a matching closing order
The profit on a long option you close is the closing price minus the opening price, times 100 shares per contract. The profit on a short option you close is the opening price minus the closing price, times 100.
The difference matters beyond bookkeeping. Open interest counts outstanding contracts in a particular option series. For each contract traded, it rises by one if both parties open, falls by one if both close, and stays unchanged if one opens while the other closes. Your action alone does not determine the change. Opening a short option also needs the appropriate options trading level; buying back a standalone short option removes its obligation.
What is on an options order ticket?
Beyond the four parts that identify the contract (the underlying, call or put, the strike price and the expiration), an order ticket asks for:
- Action: one of the four above.
- Quantity: the number of contracts, each normally covering 100 shares.
- Order type: most often market (fill now at the best available price) or limit (fill only at your price or better). The next lesson, Limit Order vs Market Order for Options, covers how to choose.
- Limit price: for a limit order, the most you will pay or the least you will accept, per share.
- Time in force: day orders expire at the close if unfilled; good-til-canceled (GTC) orders stay working until they fill or you cancel them, often up to a limit the broker sets.
Before you submit, check the complete contract identifier: underlying, call or put, strike and expiration date. The example ticket below uses a hypothetical October 16, 2026 expiration; the date is part of the contract, not a time-in-force setting.
What an options order ticket asks for
ONE CONTRACT
XYZ Oct 16 2026 50 Call
Action
Buy to open
Quantity
1 contract
Order type
Limit $2.00
Time in force
Day
$2.00 limit x 100 shares = up to $200, plus fees
Most brokers show a summary line before you submit, such as "Buy to open 1 XYZ Oct 16, 2026 50 call, limit $2.00, day". Read it every time. It is the last chance to catch a wrong strike, a wrong expiration or a wrong action. Then confirm the filled quantity and price before treating the position as open.
Worked example
Two round trips, one in each direction
A long call. You buy to open one XYZ 50 call at $2.00, paying $200. Two weeks later the premium is $3.10, and you sell to close.
- You receive $3.10 x 100 = $310.
- Profit: ($3.10 - $2.00) x 100 = $110 before fees.
A short put. You sell to open one XYZ 45 put at $1.00, receiving $100, with $4,500 in cash set aside in case you are assigned. Later the put is worth $0.30, and you buy to close to end the obligation early.
- You pay $0.30 x 100 = $30.
- Profit: ($1.00 - $0.30) x 100 = $70 before fees, and no more risk of assignment.
Closing part of a position. If you had bought two of the 50 calls, selling to close one of them would leave the other open. Quantity works the same way in both directions.
Illustrative and hypothetical. The ticker and prices are invented for teaching, and the figures exclude commissions, fees, margin interest and taxes, which reduce real results. Past or hypothetical outcomes do not indicate future results.
A short option can lose far more than its premium. If XYZ had gone to zero instead, the short 45 put would have lost the strike x 100 minus the premium: $4,500 - $100 = $4,400. A short call sold without shares to cover it has unlimited risk, because the stock has no price ceiling.
One long call, from opening order to closing order
Buy to open
1 XYZ 50 call at $2.00: pay $200
Position
Long 1 XYZ 50 call
Sell to close
At $3.10: receive $310
Result
$110 profit before fees
What happens if you choose the wrong order action?
The action tells the broker which position you mean to change, so a mistake can do more than fail. Choosing sell to open when you meant sell to close, for example, asks to create a short option instead of ending a long one. That order needs the approval level and collateral for a short option, and the broker may reject it if your account lacks them. Beyond that, brokers handle mismatched actions differently, which is why checking the summary line before you submit is the reliable safeguard.
Do you have to close an option before expiration?
No. Closing is one of several ways a position can end. A long option can also be exercised or left to expire, and a short option can be held until it expires or is assigned. Still, closing is the most common exit: according to the OCC's Options Industry Council, historically more than 72% of option contracts are closed before expiration, about 22% expire worthless and about 6% are exercised. These are aggregate historical figures, not the probability that your particular contract will be assigned.
Rolling Options Explained covers when to close, roll or hold, and What Happens When Options Expire? covers the last day.
Check your understanding
You sold a covered call last month and want to end the obligation today. Which order action do you use?
Show answer
Buy to close. You opened the position with sell to open, so the matching closing order is buy to close.
You buy to open three XYZ 50 calls at $1.50 and later sell to close all three at $2.40. What is your profit before fees?
Show answer
$270: ($2.40 - $1.50) x 100 shares x 3 contracts.
Why do brokers restrict sell to open more than sell to close?
Show answer
Sell to open creates a new obligation to buy or deliver shares if assigned, which can lose far more than the premium. Sell to close ends a long you already own. Closing a standalone long reduces exposure, but removing a hedge can increase risk elsewhere.
Key takeaways
- Every options order is one of four actions: buy to open, sell to close, sell to open or buy to close.
- Long trades go buy to open, then sell to close; short trades go sell to open, then buy to close.
- An order ticket also needs a quantity, an order type, a limit price for limit orders and a time in force.
- Read the order summary before you submit: the action, strike and expiration are easy to get wrong.
Common questions
What does buy to open mean?
Buy to open means buying an option to start a new long position, or to add to one. You pay the premium and own the right the contract gives. You later end the position with a sell to close order, by exercising it, or by letting it expire.
What is sell to open in options?
Sell to open means selling an option you do not own, which starts a new short position. You receive the premium and take on the obligation to buy or deliver shares if assigned. Your broker must approve your account for the strategy, and the tier needed depends on the strategy and its collateral.
What is the difference between sell to open and sell to close?
Sell to close ends a long option you bought earlier, turning it back into cash. Sell to open starts a new short option you did not own. Closing a standalone long removes its exposure; opening a short adds an obligation. Selling a protective long leg can increase the remaining position's risk.
Can you exercise an option instead of selling to close it?
Yes. A long option can be exercised, or left to expire, instead of sold to close. Selling usually returns more before expiration, because exercising gives up the option's remaining extrinsic value, which is one reason most options are closed rather than exercised.