OCO order (one cancels the other)

What an OCO order means

An OCO order, short for one cancels the other, is a pair of linked orders placed together. When one of them is executed, the other is cancelled automatically. The most common version combines a take-profit order at a better price with a stop-loss order at a worse price, so that whichever level the market reaches first closes the position and removes the opposite instruction.

Traders use OCO orders to plan an exit in advance, rather than watching the screen. They can also use them for entries: for example, placing a buy stop above a resistance level and a sell stop below a support level before a news release, so that a break in either direction opens a position and cancels the other.

Not every broker or platform supports OCO orders under that name. Some offer bracket orders, attached stop and limit orders, or similar linked-order functions that behave in comparable ways. The details of how they work can differ, so the specific platform documentation is the guide.

How it works

The platform stores two orders with a link between them. The link is the key: it ensures the two orders cannot both be active as separate, independent instructions.

1. You open a position or decide on a price range.
2. You set one order on the profit side, usually a limit order, and one on the protective side, usually a stop order.
3. Both orders sit in the system as working orders.
4. When one triggers and fills, the system cancels the remaining order.
5. If an order only partly fills, the platform's rules decide how the linked order is adjusted; some reduce its size, others keep it until the first order is complete.

The orders can be valid for the day or until cancelled. For protective exits, a good-til-cancelled setting is common, so the pair stays in place across sessions.

A stop order within an OCO usually becomes a market order when triggered, so the fill price may differ from the stop level in fast markets. Some platforms allow a stop-limit leg, which controls the price but may not fill.

A worked example

The numbers are illustrative. A trader buys 100 shares at 50.00. They want to risk no more than 2.00 per share and aim for a 4.00 gain.

• Stop-loss leg: sell stop at 48.00.
• Take-profit leg: sell limit at 54.00.
• The two are submitted as an OCO order.

Scenario A: The price rises to 54.00. The limit leg fills, selling 100 shares for 5,400. The stop leg is cancelled. Gross gain = (54.00 - 50.00) x 100 = 400.

Scenario B: The price falls to 48.00. The stop leg triggers and sells at about 48.00, giving a loss of (50.00 - 48.00) x 100 = 200 before costs. The limit leg is cancelled.

The ratio of potential gain to risk is 400 ÷ 200 = 2 to 1. Without the OCO link, a trader could be left with a live limit order after the stop had already sold the position, which could open an unwanted new short position.

Why it matters

OCO orders help enforce a plan. They remove the need for constant monitoring and reduce the chance of an emotional decision at the wrong moment. They also protect against having two conflicting orders executing at once.

They matter most for people who cannot watch markets all day, and for trading around events where the direction is unclear. The linked-cancel feature saves effort, though it does not make the exit safe from slippage or gaps.

Platforms and brokers differ in how OCO orders are implemented, in which instruments allow them, and whether they stay active outside trading hours.

How to use it in practice

1. Check that your platform supports OCO or bracket orders for the instrument you trade.
2. Set the stop level where your trade idea is invalid, and the target where you plan to take profit.
3. Compare the distances to confirm that the risk-reward ratio is acceptable after spread and fees.
4. Choose the validity period, such as day or good-til-cancelled.
5. Know whether the stop leg becomes a market order or a limit order.
6. Review what happens if your connection drops; server-side orders stay active, but platform-side orders may not.

Common mistakes and misconceptions

• Assuming the stop will fill exactly at its level. In a gap or fast market it can fill worse.
• Placing both legs too close together, so ordinary noise triggers one.
• Forgetting to cancel or adjust a leg when you change position size.
• Believing every platform treats partial fills the same way.
• Mixing up OCO with OTO, where one order triggers another rather than cancelling it.
• Leaving an OCO active through a news event without checking spreads.

Risks and limitations

OCO orders reduce management effort, not market risk. Stops can slip, limit orders may not fill, and thin markets can behave unpredictably. With leveraged products, losses can exceed expectations quickly. Availability and rules differ between brokers, so test on a demo account first.

How Brokeli looks at it

When reviewing a platform we look at which order types are offered, including linked orders such as OCO and bracket orders, and whether they are available on all products. We record this from published research snapshots and platform documentation. It helps readers judge whether a platform supports their exit planning, not whether to trade.