I can't help but wonder why there is often a stock trade near the end of the day which sets the price back to where it was at the start of the day.
Then there's the downward stair-step over several months, each after several weeks at a "stable" price.
It would seem to suggest manipulation (no, I am not an expert, I just have a suspicious mind). Who has access to actual purchasers?
http://finance.yahoo.com/q/bc?s=PTSC.OB&t=6m&l=on&z=l&q=l&c= (6 month)
http://finance.yahoo.com/q/bc?s=PTSC.OB&t=5d&l=on&z=l&q=l&c= (1 day)