Could somebody please explain how a sweep to fill order is any different than just using SMART routing by itself. Sort of seems like the same thing. I'm clueless on this one.
Say you want to by 10K shares. ISLD shows the best offer for 200 shares. SMART may route to ISLD and show your full size and let other hit it. Sweep will see 200 at ISLD and 5000 at INST and 400 at X and then 2000 at ISLD at the next price and so on and submit the orders simultaneously.