Route order to best destination based on price.
IB's intelligent order routing software always routes to the destination with the best price, and considers the AMEX, BOX, ISE, CBOE, PHLX, and PSE. To ensure a speedy execution, only destinations with Autoexecution turned on will be considered in the routing decision process, unless Autoexecution is turned off at ALL exchanges. In this case, all venues will be considered. Additionally, in a fast market all non-ISE exchanges are ignored to prevent execution problems. In the case of numerous tied best prices, preference will be given to those destinations where Timber Hill is a specialist or market maker. When a destination is considered and does not execute an order, it is removed from routing consideration (for that order) until all venues have been visited. After all destinations have been considered, those already visited become re-eligible for routing consideration.

The options exchanges require 15 seconds to elapse between executions on same side orders (buy call/sell put or sell call/buy put) on the same underlying. To comply with this rule, venues to which the order has been routed will be removed from consideration until 15 seconds have elapsed.

To accommodate system latency, orders are withheld from routing to AMEX until 9:35 am ET.