The purpose of this tool is to inquire whether a particular trade is a potential trade-through based on SIP data and the details of an execution as indicated below. Note that the side is the one taken by the executing venue and the quote window surrounds the given execution time to account for flickering quotes. Roughly 6 months of historical SIP quotes up to the previous business day are available.

Currently, execution details are given for an IBM trade on September 16, 2008 at 1:01:1 PM ET. Change the contents of these cells based on the trade you are interested in testing.

For each market center offering protected quotes, the most inferior price in force on the executing side within the quote window is selected. If the trade price is inferior to the selected quote for any market center, a potential trade-through has occurred and the violated venues are colored orange.