One Cancels the Other Order (OCO)

A one-cancels-the-other (OCO) order is a pair of conditional orders placed together, in which the execution of one automatically cancels the other. The most common version combines a limit order to take profit above the current price with a stop order to cut losses below it. Whichever price is reached first triggers its order, and the platform withdraws the remaining one so the trader does not end up with an unwanted second trade.

OCO orders are offered by many stock brokers, futures platforms and cryptocurrency exchanges. They are part of a wider family of conditional instructions that includes bracket orders and one-triggers-the-other orders, and they are used mostly by active traders who want to set exits in advance rather than watch the screen. An OCO order is a tool for executing a plan; it does not by itself make a trade more or less likely to succeed.

Imagine leaving two instructions with a shop assistant before going on holiday: "If someone offers 120 for my bike, sell it. If the price of bikes drops to 80, sell it anyway so I don't lose more." Once one of those sales happens, the other instruction no longer makes sense, because there is no bike left to sell. An OCO order tells the platform to tear up the second instruction automatically.

The benefit is peace of mind. The trader decides in calm conditions where they will take a gain and where they will accept a loss, and the system carries it out even if they are asleep or away.

A typical OCO order to close a long position has three settings:

• Limit price. The take-profit level above the market, at which the asset should be sold if the price rises.
• Stop price. The trigger level below the market. When the price trades at or through it, a sell order is activated.
• Stop-limit price (optional). On many exchanges the triggered stop becomes a limit order at a set price rather than a market order, which controls the worst acceptable price but risks not being filled.

To open a position, traders can reverse the logic: for example, a buy order above the market to catch a breakout and another below it to buy on a dip, with whichever fills first cancelling the other. If one leg is only partly filled, platforms usually reduce or cancel the other leg in proportion, but the exact rule depends on the venue.

A trader buys one unit of a cryptocurrency at 60,000 and places an OCO sell order with a take-profit limit at 66,000 and a stop at 57,000. The potential gain is 66,000 − 60,000 = 6,000, and the potential loss is 60,000 − 57,000 = 3,000, so the reward is twice the risk, a ratio of 2 to 1.

If the price climbs to 66,000, the limit order sells the unit for a 6,000 gain and the stop order is cancelled. If instead the price falls to 57,000, the stop triggers a sale, limiting the loss to about 3,000 before fees and any slippage, and the take-profit order is cancelled. In both cases the trader is left with no open order that could reopen an unintended position.

• Risk management. An OCO order turns a planned exit into an instruction, a core habit in risk management and in setting a position size so that one loss does not wipe out an account.
• Volatile markets. In crypto, which trades around the clock, OCO orders let traders protect positions overnight or over weekends.
• Breakout trading. Traders who expect a sharp move but not its direction can place entry orders on both sides of a range.
• Leveraged positions. On margin or futures accounts, a stop leg can help close a position before it reaches liquidation, though it does not guarantee that outcome.

An OCO order does not guarantee a price. In fast markets, or when prices gap over a weekend or after news, a stop can be filled well below its trigger, or a stop-limit leg can fail to fill at all, leaving the position open. Prices can also briefly spike through a stop level and then recover, so a trader may be stopped out just before the market moves in their favour. Setting levels too close together can make the order trigger on ordinary noise, which links OCO use closely to an understanding of volatility. Finally, features vary across brokers and exchanges: some do not support OCO for every product, some charge fees on each leg, and some cancel open orders during maintenance. Reading the venue's rules on how an order book handles conditional orders is part of using them safely. Related instructions include the standalone stop-loss order.