I don't know. Really.
I am not a Level 2 expert, there are others whom I think are - they have watched it for so long they can look at it at tell one exactly what is going on. I swing traded on the Big Boards for 7 years now, that's more my thing - research and technicals. Plus, I am not always able to be at my computer through the day.
But even a newbie like me can see purpose in how the pps is down. I remember on a day off in early September I watched it all day long. We hit the ask and raised the pps up to around .0135 (I believe) on the day before. The next day small trades (3k, 2k, 5k, etc.) brought the bid down to .009 and the ask to .01 - THEN some large bids went through at .009. When the bid dropped to .008, it stopped, some small hits at the ask for an hour or so, the bid & ask raised then BOOM, more sells (100k per sell) at .009.
On other days I saw the same type of action - only I was not able to watch all day because I was in & out of the computer all day because of work.
When a stock trades like that repeatedly - it is obvious there is design/purpose/intent in that pattern. Stocks, when moving on their 'own,' don't trade that way - whether in the pennies or on the Big Boards.
But I don't know who is doing this, or why, or if they are done yet. If they are, the posters here are correct, our bids are contributing to the pressure holding us back. 4 other times I thought the downward pressure was done and I was wrong; so I'm just wary and don't believe it is over yet - with no proof at all.
All The Best