Twitter took to its own network to announce it has filed a "confidential" S-1, an SEC document companies use to register for an initial public offering.
The company's tweet announcing its IPO went out to more than 23 million followers, and certainly many, many more in retweets:
We’ve confidentially submitted an S-1 to the SEC for a planned IPO. This Tweet does not constitute an offer of any securities for sale.— Twitter (@twitter) September 12, 2013
The one thing we can say about Twitter based on this development comes from recently revised SEC rules that allow confidential filings. To qualify for confidential status, Twitter's "total annual gross revenues" in its most recently completed fiscal year must have been less than $1 billion.