Factbox: Facebook's IPO: who gets rich? SAN FRANCISCO (Reuters) - The rich are going to get richer when Silicon Valley's biggest IPO starts trading on Friday. Facebook this week raised the number of shares it intends to float by 25 percent to 421 million shares, and lifted the target price range to $34-$38 per share as investors clamored for a slice of the third-largest IPO in U.S. history. As a result, the No. 1 social network and its shareholders will now collectively reap more than $15 billion from the initial public offering - a $5 billion hike from early May, when Facebook sought an IPO of roughly $11 billion. ...