The official opening cross, yes. ARCA has their own auction style opening print but its a complete shitshow and I would advise not using it. I speak from experience.
thanks for answer. What direct access trading software do you use (I am using realtick III) Are there any more good platforms to participate in the cross (i am not sure but maybe Laser/Genesis also has this option and Lavatrading).
Doesn't the order have to be flagged for the cross in order to distinguish it from regular orders? Or is any order submitted to SM before 09:30 automatically become part of the opening cross or cancelled if not filled?
Regular DAY LIMIT orders placed on SM can participate in the cross (no flag needed), but theres a distinction between placing before 9:28am and after 9:28am http://www.nasdaqtrader.com/trader/openclose/openfaqs.pdf