Originally posted by dlincke
Unless you send a PNP order ARCA will preference your order out to other exchanges (NYSE, AMEX, regionals, Nasdaq Intermarket dealers) if they display superior prices to what is available on the book. PNP orders won't let you actively cross the market though. Instinet may be your best choice as it works analogous to ISLD. Or head right to Chicago which is the best solution in terms ot ease of use, speed, and liquidity.