Typically the bid tightens 5 to 10 minutes prior to the open. But occasionally/rarely it doesn't. The wide spread prior to the open is to catch new investors off guard. It happens when a new investor places a market order to buy or sell prior to the open.

For example, say I place a market order to sell and the stock has been trading at $1.00 for the past month. My intention is to sell at a dollar but since the order is market my stock sells at the bid price. Oops - moral of the story - always place limit orders.