If this follows a typical a post-FDA positive decision the same as I haveseen in the past and POZN does open for Pre-Market trading, I would expect a very rapid overshooting and then a correction of about 30% of the pre-market rise, then on market opening it will shoot higher again (130% of the premarket rise) and then drop about 30% of the raise again and then begin a slow climb in stock price for the rest of Monday and Tuesday.
ie Pre-market open = $16.00 Premarket high = 18.50 Premarket close = 17.00 Market open = 17.00 market high (first hour) = 20.00 markt correction (2nd hour) = 18.20 market close = $20 - $22
All figures are just my guess, and what dollar values they achieve will be different.