This question is addressed to anyone familiar with the ARCA ECN and Nasdaq trading. The market is 20.00 x 20.01. I have an offer on ARCA at 20.01 for 1000 shares. Now let's say there are no ISLD or INCA offers anywhere on their books. Now an ISLD or INCA order comes in to buy 1000 at 20.10. What happens to my ARCA order? Does my order get filled at 20.10,20.01, or not filled at all?