Because one day a bundle of stock hits the market or over a period of time it comes out. And everyone thinks they are holding on to a tightly held stock and its not so. Over a period of 3 months in 2004 CTKH the S/O went from about 1 billion to 3 billion shares. Remember these shares are not Registered like some of the REGDEX shares are not registered. Read that IrishBull post real good about Reg S shares.
Market Data 
Markets 
AI
