Originally posted by PnL Rally
the specialists can disable the NX, and the 30 second rule only applies to the same stock.......specialists can also show only 100 shares on the bid or ask to effectively disable NX
Right. The specialist can 'freeze the book' at his discretion, thereby disabling NX. No alert of any kind is necessary. Normally, the size will revert to 1X1 and nothing will happen for a time...
An NX order not filled goes straight to the book, which is <I>order purgatory</i>, and of course the specialist is a minor deity.
An electronically entered order, including an NX that has been booked, can be ignored for 30 seconds (though it often is ignored for longer, and this is not, to my knowledge, the '30 second NX rule'), while the crowd finds itself in no such trading Siberia.
Think of NX this way: a percentage -- I deduce that it's the majority -- of shares sent NX wind up on the book. The book is the man's edge, and therefore, despite being touted as the great equalizer for the average investor, NX is effectively an <i>order flow generator</i> for the specialist. And the specialist, as principal, will use that order flow to his own advantage.
Of course, the NX order that gets filled is a nice thing to experience...unless you tried to cancel, which, interestingly, is not allowed to happen 'instantaneously' like an NX fill is (unless it's to the advantage of the market maker).
I wish I could say that your conclusion isn't correct, Bung, but I have too many reasons to believe it may be. Sounds like you are starting to understand the mind of your adversary.
Trendsetter, I don't know where you trade, but if it's a prop firm, then all the traders may be aggregated into one account for NX purposes which means you are competing with the other traders for the fill on any particular stock. If your NX button is ineffective, if might be because someone at the firm has hit the specialist and invoked the 30 second rule on that stock which applies to the firm's account, even if a thousand traders work it.
Elredge, I agree. If you're in a position, and the specialist freezes the book, it's a sign (usually) either of strong continuation or of reversal. That can be useful information.
The specialist is a 'market maker' (and sometime market faker) and he's human so of course he is going to behave in ways similar to the OTC variety, using any and all rules and loopholes therein for his own benefit.
NX, like SOES, is awesome in theory, but limited in practice.
PS. There have been several good threads on NX, so for more info try the search feature.