Quote from kiwi_trader:
Imagine the scenario. There is 1 seller at 50.50 and 3 sellers at 51 and 5 sellers at 53 (theres a gap there for some reason)
You have a buy order at 51 but 6 other orders or even just one large enough to absorb all the available sellers is in front of yours in the queue.
They fill.
Quote from trade4succes:
it all depends at which market center your order is resting, and if opening auctions are reg nms protected or not (i don't know, but maybe someone else knows).
Quote from speculatus:
Please correct me if I'm wrong, but AFAIK, opening and closing trades are not "covered orders" (since thy require special handling) and thus exempt from RegNMS.
Quote from trade4succes:
ah ok, so in this case, if the order is resting on a certain marketcenter, and another marketcenter's opening auction prints $0.50 below your price, there is nothing you can do. but if the order was on that marketcenter which had the opening auction priced $0.50 below, you would have gotten that $0.50 below price.