Here's the tweet. Here's the S-1. It plans to use ticker symbol "TWTR." No stock exchange specified. The S-1 states a $1 billion fundraising target, which the NYT explains is "a pro forma number meant to calculate listing fees." The company says its revenue increased from $106 million in 2011 to $316.9 in 2012, with a net loss for 2012 of $79 million.