DEFINITION of 'At Best'
An order to fill a transaction at the most desirable price available, and as quickly as possible. At-best transactions can either be applied to equities or currencies where the trader would attempt to get the best possible price or rate respectively.
BREAKING DOWN 'At Best'
This type of order is generally executed faster than a conditional order, such as a limit order. Because the ultimate price a trader receives for a share is subject to the current market price, the trader may wind up paying more (for a buy order) or receiving less (for a sell order) than expected.