Can someone please help me to understand why the answer for the below question is Order 2, as per my understanding I thought that it would be Order 1 since the order is fully displayed and the other two orders are partially displayed.
Three orders arrive at the exchange with the same price.
Order 1 arrives at 11:01:00, buy 400 shares.
Order 2 arrives at 11:00:00, buy 1000 shares - display 400
Order 3 arrives at 11:00:30, buy 1000 shares - display 600