Somtimes market makers stack the bid like that just like they create walls on the ask for one purpose and one purpose only, trying to get shares on the bid from profit takers and or jelly beans........ It works both ways, up and down.
Plus, as an added bonus, the precentage of shorts is coming down on the daily reg sho list which tells me that they preping their house to go long and toss in the towel. I think a cover beginning is imminent personally speaking........... ;-)