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Buy to close, explained: the order that ends a short option

Buy to close is the order you use to end an option you sold. You buy the same option back, and your promise is gone. Whether that's a gain or a loss depends on one thing: what you pay to buy it back compared with what you sold it for.

Options guide · 8-minute read · Updated 2026-10-27

The short answer

When you sell an option, your broker records it as a short position: you've made a promise. Buy to close buys back that same option, with the same strike and expiry. The two cancel out, and the promise ends.

Your result is simple:

• Bought back for less than you sold it for → a gain.
• Bought back for more → a loss.

It's the order behind taking profits early, closing for pennies before expiry, getting out before an event, and the first leg of every roll.

What it does to your account

After a buy-to-close order fills:

• The obligation is gone. You can no longer be assigned on that option.
• For a cash-secured put, the cash your broker held is freed for other uses.
• For a covered call, your shares are no longer promised. You can sell them, or sell a new call.
• The gain or loss is realized on that option. It shows up in your account history.

How fast freed cash shows as available varies a little by broker. Check how yours displays it.

The worked example (an illustration, not a trade idea)

You sold one $45 put on a made-up stock, XYZ, for $1.00. You collected $100. Here are four days you might buy it back:

Same order, four results. The order itself is neutral. It just ends the trade at today's price.

The last row is the one to plan for. If XYZ keeps falling, the cost to close keeps rising. At some point, closing for a known loss is better than waiting. Many sellers set that line before the trade.

Getting a fair fill

Options have two prices: the bid (what buyers pay) and the ask (what sellers want). When you buy to close, you're the buyer. A market order usually pays the ask, or worse if the quote moves.

Say the put shows $0.35 bid / $0.45 ask. The middle is $0.40.

1. Use a limit order. Start at the middle, $0.40.
2. Wait a minute. Many orders fill at or near the middle on actively traded options.
3. Step up a cent or two if it doesn't fill. Stop at the ask.
4. Watch the spread. On thinly traded options, the gap can be wide. A $0.20 gap on a 1-contract close is $20. Our options chain guide shows where to look.

On very cheap options, some brokers cut or waive the fee for buy-to-close orders. Check your broker's current fee page.

When sellers use it

To take a profit early. Many sellers place a good-till-cancelled buy-to-close order right after selling, often at about half the premium. If the option decays that far, it closes on its own. Theta does the work; the order collects it.

To close for pennies before expiry. An option worth $0.05 still carries a small risk of a late move. Paying $5 to end it can be cheap insurance. See letting an option expire worthless.

To get out before an event. If earnings or other news falls before expiry, closing removes the gap risk.

To exit a trade that broke your rules. If the stock fell through your loss line, buy to close and take the known loss.

As the first leg of a roll. A roll is buy to close plus sell to open. See how to place a roll order.

All of these fit inside the wheel strategy: sell, wait, then end each option on your terms.

Not the same as these orders

The common mix-up is choosing buy to open when you mean buy to close. That adds a new long option instead of ending your short one. Most brokers flag it, but read the preview. It should say "close" and show your existing position.

Questions