Trading Ahead
A trade transacted from a specialist's account even though there is a public order that offsets the trade.
Investopedia Commentary
Trading ahead is a violation of a specialist's negative obligation to NYSE customers. By trading from his or her own account rather than letting public orders match one another, the specialist is robbing the public of its opportunity to transact the security.
Related Links
Electronic Trading Tutorial
The Tale Of Two Exchanges: NYSE And Nasdaq
See also: Affirmative Obligation, Negative Obligation, NYSE, Principal, Specialist, Trade