The 200,000,000 shares represents the "IPO offering". The day that a moviestock is IPOed (for the first time) the price is frozen either until the IPO offering shares are sold out or at the next reset (whichever happens first).
In the case of STAR9, if it had sold those 200,000,000 shares before reset yesterday then the IPO would be over and it would behave like a regular stock and the price would be unfrozen.
Each moviestock has an unlimited amount of shares with no cap. Each player does have a 100,000 max share limit that they can invest in in either direction but there are unlimited shares available for each stock.