An order to simultaneously transact two or more option trades. Typically, one option would be bought while another would simultaneously be sold. Spread orders may be limit orders, not held orders, or orders with discretion. They cannot be stop orders, however.
See Also:
Order: A ticket or voucher representing long or short securities and options.
Spread: A trade in which two related contracts/stocks/bonds/options are traded to exploit the relative difference in price change between the two. A trading strategy in which a trader offsets the purchase of one trading unit against another.