Aon

n. American corporation headquartered in Illinois, holding company which operates several insurance and finance companies worldwide

Aon or AON may refer to:Aon (mythology), son of Poseidon in Greek mythologyAon Corporation, an insurance corporationAon (Fantasy Universe), name of the fantasy universe in which the Lone Wolf series of role-playing gamebooks is setThe Aon Center, the name of two buildingsAon Center (Chicago)Aon Center (Los Angeles)Alton railway station, from its National Rail codeAngolan kwanza, from its ISO currency codeApplication-oriented networking, a computer networking technologyAll-optical network, see Synchronous optical networkingAll or none (finance), a condition to fulfil an investor's order in its entirety or cancel it.
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n. aeon, immeasurably long period of time, age, eternity; (Geology) longest measure of time (made up of two or more eras)

[Greek] A Greek hero, son of Poseidon, who was venerated particularly in Boeotia. Boeotia was also known as Aonia, named after him.

Used in context of general equities. A limited price order that is to be executed in its entirety or not at all (no partial transaction), and thus is testing the strength/conviction of the counterparty. Unlike an FOK order , an AON order is not to be treated as cancelled if not executed as soon as it is represented in the trading crowd , but instead remains alive until executed or cancelled. The making of "all or none" bids or offers in stocks is prohibited, and the making of "all or none" bids or offers in bonds is subject to the restrictions of Rule 61. AON orders are not shown on the specialist's book because they cannot be traded in pieces. Antithesis of any-part-of order . See: FOK order .