1.Take Facebook as an example, it debuted with 421 million shares at IPO and now it has 2.8 billion shares. It hasn't made any stock split since IPO so does its number of shares outstanding increase because of new share issuance only, or is there any other factor? How to know when the company issues new shares or how the company issues new shares after IPO? (since I can't find any sources/news to justify in Facebook case)
2.After IPO, if the company wants to issue more stocks, does it issue at the market value?
3.When the company goes public (IPO), how do shareholders keep their company ownership with such tremendous participation from the public?