Mhmmm I explained my problem not exactly. I meant no broker, but ECN. I'm sorry.
By this time I've not known that my broker must offer it...I thought that it's no matter of broker but only matter of routing individual ECN's.
so.......Must I ask my broker for offer it?
Imagine this situation:
Bid Ask
Nyse 6.25 100 Nyse 6.26 100
Arca 6.24 40 Nasd 6.26 50
Nasd 6.24 500 NSX 6.26 10
And I would like to buy shares from NSX and I wouldn't buy shares from Nasd and Nyse.
(Sorry for my bad...