Glossary: O

These are common terms used in the financial services industry

OCO (one cancels the other)

Lets you place a sell limit and sell stop order on the same stock at the same time. When either order is executed the other will automatically be cancelled. Also applies to a buy limit and buy stop order.


A current market price is made up of a level at which you can sell and a level at which you can buy. The level at which you can buy is always the higher of the two prices and is called the offer.

Offer price

The price at which the seller is willing to sell at.

Online trading

The act of buying or selling financial instruments via the internet using a broker like CMC Markets’ online trading platform.

Open position

A long or short position which has not been closed out by an equal and opposite position.


The right, but not the obligation, to buy (‘call option’) or sell (‘put option’) a specific amount of a given stock, commodity, currency, or index at a specified price (the ‘strike price’) during a specified period of time. For the holder, the potential loss is limited to the price paid to acquire the option. When an option is not exercised, it expires.

Order / order to open

An instruction by a customer to a broker/trader to buy or sell should a specified price be reached. The order remains valid until executed or cancelled by the customer.

Order book

When bid and offer prices match, new incoming orders are automatically logged against orders on the book. FTSE 100 stocks have been traded on an electronic order book since 20 October 1997


A leading indicator in chart analysis which shows a potential trend reversal before it occurs.


Refers to trading outside the main opening hours of major markets, for example on indices like the UK 100 or US 30.

Over-the-counter market (OTC)

Refers to trading that is carried out directly between two parties, without any supervision of an exchange.

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