Twitter has announced that it has filed for its IPO.

Since Twitter was able to submit confidentially, this indicated that it had annual revenue of less than $1 billion in its most recent fiscal year. The JOBS Act allows for “emerging growth” companies with less than $1 billion in annual gross revenue to file in secret.

Goldman Sachs is believed to be the lead underwriter for the deal, and Twitter will reportedly list on the NYSE.

A recent SEC filing from Twitter investor GSV valued the company at nearly $10.5 billion, up from an estimate of roughly $9.8 billion earlier this year. Twitter, which turned seven this year, has raised over $1.16 billion in funding to date.

Twitter has been steadily preparing for a public offering with key hires and acquisitions. In May, it hired Morgan Stanley veteran Cynthia Gaylor to head up corporate development. Last December, the company brought on Mike Gupta as CFO and shuffled Ali Rowghani to COO. Recent acquisitions include the world’s largest mobile ad exchange MoPub and social data company Trendrr.

Having been through the process recently, Facebook CEO Mark Zuckerberg shared some advice for Twitter earlier this week, encouraging the company not to be afraid of an IPO. That means something, considering that shares of Facebook took over a year to climb back to IPO prices.

The filing also puts new weight to activist investor Carl Icahn’s comments from earlier this week that he is “excited” about Twitter.

Twitter, for its part, is trying to keep a low profile on the move. The company got right back to work after making the announcement:

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