Graywolf,My understanding (and this is only my understanding) is...

Graywolf,

My understanding (and this is only my understanding) is that legally the order is real but at the same time uncommitted by virtue of its reaction time.

i.e. as soon as the algo sees an order coming in, it adjusts its own order virtually simultaneously (within microseconds - my understanding is that they have a massive speed advantage as its feed is right next to the exchange, but I could be wrong) and pushes itself to the end of the queue or in some cases disappears.

Therefore IMHO it is 'false' or 'fake' or 'mispresentative of the real picture' as it reacts to other genuine orders being placed before anyone else can see what is going on.

Bigjig,

To answer your question I am not aware of any midpoint trading for ABU i.e. 2.65c, or indeed if this is allowed. I don know that I am not able to place an order at this price (via etrade pro) but others maybe able to elaborate?

Note: my opinion is mine only and in no way am I offering advice of any kind. Please DYOR.