Both yesterday and today, PSUN has gone down precipitously early in the day, but on virtually no volume. I think the market maker might be taking advantage of the extremely thin trading in this stock. It looks to me like they're just dropping the price, and then slowly buying up any stock they can find at those levels. Of course they wouldn't be able to do this if there were other buyers out there willing to take advantage of the lower price, but clearly that is not the case right now.
IMHO based on my own experience the market maker appears not to be interested in increasing liquidity by selling. I'm basing this on the length of time it took to partially fill a limit buy order (with the limit set at the most recent market price prior to the order) last week, and the minute amount of shares that were filled in that time.