All or None

All or none refers to a buy or sell order indicating that no partial transaction will be executed. The full order must be completed, or none at all.

An experienced, competent financial manager might advise you to issue an all or none order in certain instances. At the same time, it might serve your purpose and the goals of your portfolio to sell only part of your holdings in a particular investment or purchase only part of a block of shares at a select time.