What Is Buy to Close in Options Trading on Pluang?

Buy to Close is the order you place to exit a short options position by repurchasing the exact contract you originally sold, ending your obligation before it expires or gets assigned. When you open a position by selling an option (a short call or short put), you collect a premium upfront; Buy to Close reverses that trade, and your profit or loss is simply the premium you originally received minus the premium you pay to buy the contract back. Traders place a Buy to Close order for two main reasons: to lock in a profit once the premium has fallen (take profit), or to cut a loss and remove further downside if the premium has risen against them (cut loss). Because Pluang's US Stock Options are American-style, the buyer of your contract can exercise it at any time before expiry — not only on the expiry date — which makes Buy to Close the main tool short sellers use to control assignment risk while a position is still open.

How the profit/loss is calculated

The formula is the same whether you're closing a short call or a short put:

`Premium received (when you sold) − Premium paid (when you Buy to Close) = Profit or Loss per share`

Multiply the per-share result by 100 (one standard options contract represents 100 shares of the underlying) to get the total dollar amount per contract.

Example — closing a short call:

• You sell a call and receive a premium of $5 per share.
• If the underlying stays relatively stable and the premium falls to $2 per share, Buy to Close locks in $5 − $2 = $3 per share, or $300 profit per contract.
• If the underlying instead moves against your position and the premium rises to $8 per share, Buy to Close at that point locks in $5 − $8 = −$3 per share, or a $300 loss per contract.

Example — closing a short put:

• You sell a put and receive a premium of $10 per share.
• If the underlying stays stable or rises and the premium falls to $4 per share, Buy to Close locks in $10 − $4 = $6 per share, or $600 profit per contract.
• If the underlying falls toward or below the strike price and the premium rises to $15 per share, Buy to Close at that point locks in $10 − $15 = −$5 per share, or a $500 loss per contract.

In both cases, the trade is only final once the Buy to Close order actually fills — until then, the position stays open and exposed to further price movement and, for American-style contracts, ongoing assignment risk.

Related questions:

Q: What's the difference between Buy to Close and Sell to Close?
Buy to Close exits a short position — one you opened by selling a contract — while Sell to Close exits a long position — one you opened by buying a contract. Both are closing orders that reverse your original trade, but they apply to opposite starting positions: Buy to Close always follows an initial sell, and Sell to Close always follows an initial buy. Picking the correct one matters because placing the wrong closing order type can fail to close your actual position.

Q: Can I place a Buy to Close order before the options contract expires?
Yes — Buy to Close can be placed at any point while the market is open for that contract, right up until expiry. Most traders close early rather than waiting, specifically to lock in a profit while the premium is favorable or to cut a loss before it grows. Because assignment on Pluang's American-style contracts can happen before expiry, waiting until the last moment adds unnecessary risk for a short position that's already in trouble.

Q: What happens if I never Buy to Close a losing short position?
The position stays open and exposed to further losses, and — since Pluang's options are American-style — it also stays exposed to early assignment at any point before expiry. If the contract is never closed and remains in the money at expiry, it will be handled through Pluang's expiry-day process rather than through a voluntary Buy to Close. Leaving a losing short position open does not limit or cap the loss on its own.

Q: Does a Buy to Close order use the same order types as opening the position?
Yes — a Buy to Close order can be placed as either a limit or a market order, the same choice available when you originally sold the contract. A limit order lets you set the maximum premium you're willing to pay to close, while a market order fills immediately at the best available premium. Which one fits best depends on how urgently you need the position closed versus how much price control you want.