FORTUNE — Twitter this afternoon started the clock on its IPO, publicly filing to raise $1 billion.

The company did not indicate which stock exchange it has selected, but says that it will trade under ticker symbol TWTR. Goldman Sachs GS is listed as lead underwriter, with Morgan Stanley MS and J.P. Morgan JPM also are listed on the top line, while four other banks also are listed.

It reports a $69 million net loss on in $253 million revenue for the first half of 2013, compared to a $49 million net loss on $122 million revenue for the year-earlier period. The company also says that it had 218 million monthly active users in June 2013, compared to 151 million in June 2012 (and 204 million in May 2013).

Twitter co-founder Ev Williams is listed as the company’s largest single shareholder, with a 12% position. Fellow co-founder and current chairman Jack Dorsey has a 4.9% stake, while CEO Dick Costolo has a 1.6% stake. The company’s third co-founder, Biz Stone, is not listed as a 5% shareholder.

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Five institutions have at least 5% positions: Benchmark Capital (6.7%), Rizvi Traverse, Spark Capital, Union Square Ventures and DST Global.

Costolo earned approximately $11.5 million last year, including $200,000 in salary. In August his salary was reduced to just $14,000.

Twitter previously disclosed that it had filed confidentially with the Securities and Exchange Commission, but had not publicly disclosed any details. By making its filing public today, the company is on track to list by November 9. There is, however, a possibility that the government shutdown could hamper those plans. The SEC currently is operating at full strength, but may have to cut back on certain services were the funding to not be fully restored within the next few weeks. In that case, Twitter could have trouble getting amended filings approved (including the one where it lists anticipated pricing terms).

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