Twitter says it is looking to sell its shares for $17 to $20 each in its upcoming public offering. If the company sells at the top end of its range, it would raise $1.6 billion in its IPO, and value the company around $11 billion. That $20 figure is significant because it’s less than the $20.62 value Twitter assigned to its shares on August 5, the last time the company went through a valuation before letting the public take a look at its financials