At-The-Opening Order: An order which specifies execution at the opening of the market or else it is cancelled.

Buy on Opening: To buy at the beginning of a trading session at a price within the opening range.

Opening Call: A period at the opening of a futures market in which the price for each contract is established by outcry.

Wide Opening: Refers to an unusually large spread between the bid and asked prices.

Opening Transaction: A trade which adds to the net position of an investor. An opening buy transaction adds more long securities to the account. An opening sell transaction adds more short securities. An opening option transaction increases that option's open interest.

Opening Purchase: A transaction in which the purchaser's intention is to create or increase a long position in a given series of options.

Opening Price: The range of prices at which the first bids and offers were made or first transactions were completed.