Day trading pre-market open August 26, page-47

There is often a surplus of volume that overlaps during the auction periods. In this instance, ‘priority’ is given to the buyers who bid the highest price, and to the sellers who ask for the lowest price.Therefore, if you are wondering why some people bid for shares at a higher price than the indicative opening or closing price, or offer to sell shares at a price that is well below the expected auction price, it is due to the way overlapping volume is matched.By placing an order at the front of either the buy or sell ‘queues’, the first trades executed will involve these bids or offers. The trade does not necessarily occur at the price that a buyer or seller has submitted. Instead, the trade price occurs at the mid-point where buy and sell volume overlap.