The majority of the volume today were sells at 2.  The bid/ask held strong at 2/3 the whole day.  If you look at the trading action today when most of the 2's were being sold, the bid was still showing 18 million on L2 (I believe this was the lowest the bid got all day).  Once those 2's finished selling the bid at 2 began to grow again, but I am not sure how high it got or what it ended on.

It didn't look like they were intentionally trying to lower the PPS though as most of the sells were not back to back and the size of the sells decreased after the initial 9mil block and 8mil and change block.  I would have to look at the trades to give you the timeframe, but at the time it seemed the sells were coming in slow and decreasing in size.