An order that allows traders/ investors to pursue a more aggressive price than the National Best Bid and Offer (NBBO). The price (at which execution would take place) is dynamically determined on a combined basis: the best bid-ask and an offset amount (defined by the trader).

In practice, the order is placed as a limit order and then adjusted to exceed the NBBO for a sell order (or fall short of it for a buy order) until it is filled or otherwise cancelled.

It is also referred to as a relative order.