As the technology press has been predicting in recent weeks, social media/microblogging company Twitter has filed for its initial public offering (IPO) with the Securities Exchange Commission (SEC (News - Alert)). The company, which was founded in 2006 by Ev Williams and Biz Stone and will trade under the ticker "TWTR,” expects the IPO to occur in December of this year. Goldman Sachs Group Inc. is rumored to be the lead underwriter for the IPO.

"We believe that there is a significant opportunity to expand our user base. Industry sources estimate that as of 2012 there were 2.4 billion Internet users and 1.2 billion smartphone users, of which only 215 million are monthly active users of Twitter (News - Alert),” said the company in a statement announcing the filing (which may be found here.)

Twitter, which was recently valued at $10.5 billion by one of its investors, GSV Capital Corp. (GSVC), may turn out to be one of the largest IPOs since Facebook, though the company still isn’t nearly as large as Mark Zuckerberg’s (News - Alert) empire, which is valued at about $109 billion. Twitter has about 218 million monthly users, compared to Facebook’s one billion-plus users. Investors have pumped $1.16 billion into Twitter since it was founded, and all of them are likely see major returns, but current numbers show the company has room to grow.

Our colleague, Tony Rizzo (News - Alert), has provided his thoughts and insights on the next steps in Twitter’s future as a public company. At the time, he opted not to mention which Twitter insiders noted in Twitter’s S1 filing who stand to benefit the most from the IPO. Given how large the event is likely to be, however, it’s of interest to note who these individuals are and what they stand to gain from the offering. Even more interesting, there are some early Twitter insiders who stand to make precisely zero dollars from the transaction.

Individuals who will benefit most from the Twitter IPO, start with the company’s executive chairman Jack Dorsey and CEO Jack Costolo and founder Williams (who is the largest single stakeholder at 12 percent).  In addition, it’s expected to put money into the pockets of Series G holders Yuri Milner’s DST, T Rowe Price and Chris Sacca; Union Square Ventures; Benchmark Capital; board members Peter Currie, Peter Chernan and David Rosenblatt (News - Alert); and Series C and D holders Rizvi Traverse and Spark Capital.

Early insiders in Twitter who stand to make nothing from the IPO include Biz Stone, who oddly enough was not listed in the S1 filing; early founder Noah Glass who reached a settlement with Twitter for an undisclosed sum some months ago; and Christopher Fry, the company’s SVP of engineering, who holds only restricted stock.