OCO Order (One-Cancels-the-Other)

An OCO order is two orders bundled into one. Most commonly, it's a stop loss and a take profit on the same position. When price hits the stop, the take profit is cancelled. When price hits the take profit, the stop is cancelled. You can't end up with both orders left in the market by accident. OCO is also used for breakout trading. You can set a buy stop above resistance AND a sell stop below support, both linked as an OCO pair. Whichever direction price breaks first, the order on that side fills and the opposite order cancels. You're guaranteed to enter in the breakout direction without having to monitor the chart. Most modern broker platforms support OCO natively. If yours doesn't, you can simulate it manually but you have to remember to cancel the other order yourself.