Can I bid GE on island or arca 35.501 or even 35.5001 to be first to fill above large queue of 35.50 bidders ?
No, but i do always see shave prints like that. Anyone who actually knows would be great. Some awesome fills out there in between the spread, i refer to them as 'magic prints'.
if you see any prints between the bid and offer on arca (P) then they are crossed orders (that's an order type...) those other magic prints as szeven said in my experience are either someone trying to hit the bid/ask on via TRIM( and getting micro price improvement) or AUTO (I used to see those prints all the time 2 one hundredths above the bid/below the offer...) I'm sure there are other places that give this micro type of price improvement... most of them print as D (third market...) cheers! - mnx