A number of factors comprise an investor’s concept of the "best execution" of an order to buy or sell securities. For some, it is the best price, but others may value quick execution, anonymity, and certainty of execution. This conference, the third in AEI’s series on the securities market structure, will review a survey of over 100 institutional investors, which provides the first comprehensive view of what this particular class of investors considers "best execution." This study was prepared by Greenwich Associates at the request of Instinet, an electronic trading venue.