Quote from Batman28:
so what is the 'fastest' and most 'reliable'?
the only thing ECNs offer is cutting the middlement (brokers/dealers/specialists) and offer out of hours trading (cons&pros).
Inet is by far the biggest as I am aware.
obvious option is to have a platform that gives access to more than 1 of them.
edit: for larger orders, specialists will almost certainly get you the BEST price and complete the trade most efficiently.
and as far as getting filled goes, MMs on exchanges should also complete trades fast.