FYI- Noticed Market Maker games/pattern on Level 2 for awhile there, with high size values on the ASK and smaller size value on the BID. Every time that happens, the PPS gravitates down to the BID, (the price you get if you sell). That high ASK size creates a wall/roadblock on the PPS. That ASK price and large size represents a large amount of stock for sale at the given ASK, these could be borrowed shares being sold Short, the price drops every time.
For the PPS to rise, we need to see a growing size on the BID and a small ASK size (a lower amount for sale on the ASK). Nearly every time I see that, the PPS moves higher.
OTCMarkets site Level 2 illustrates this where you can predict the very short term movement in the PPS. -- just food for thought.