Most probably, like other days when there is a drive to acquire early in the day, the MM's who have to sell at their ask price may not have the shares to cover the purchase. They sell short for the day and since many companies do not allow their MM's to hold a short position in BB/penny stocks stocks overnight, they have to cover their sales from the higher price during the day and and try to buy back late in the day for at least a half- cent less then they sold for. It happens a lot and usually occurs from around 3:15 to 3:45 of the trading day. After they make themselves "whole' and are not holding any short positions, then they back off and those still interested in buying, esp. when they see the price pull back some, jump in and the result is usally a small blip upwards the last 15 minutes or so.

Doesn't happen all the time but happens enough to see their pattern.