MY, HOW TIME FLIES

March 2006 -- Twitter co-founder Jack Dorsey, working at a podcasting startup called Odeo, develops Twitter as an in-house messaging service. On March 21 Dorsey publishes the first tweet ever: "just setting up my twttr." Later in 2006, Odeo co-founder Evan Williams creates a new company called Obvious and buys Odeo and all of its assets -- including Twitter -- from investors.

July 2006 -- Twitter is launched to the general public.

April 2007 -- Twitter is spun off into its own company with Jack Dorsey as CEO, Evan Williams as chairman and Biz Stone as creative director.

March 2008 -- Twitter has 1.3 million registered users.

October 2008 -- Dorsey steps down as CEO and becomes chairman; co-founder Williams replaces Dorsey.

September 2009 -- The company notches a $100 million funding round that includes Wall Street players T. Rowe Price and Morgan Stanley.

April 2010 -- Twitter has more than 100 million registered users.

October 2010 -- Williams steps down as CEO. Dick Costolo, formerly Twitter's chief operating officer, becomes CEO.

December 2010 -- Kleiner Perkins Caufield and Byers leads a $200 million venture funding round.

March 2011 -- Dorsey rejoins Twitter as executive chairman, focusing on product development.

August 2011 -- Breaking a record for venture capital deals, Twitter sews up $400 million from Russia's DST Global, which spends another $400 million buying Twitter shares from employees and prior investors.

June 2013 -- Twitter has 218 million monthly active users, up from 151 million a year earlier.

Sept. 12 -- The company uses its own Twitter account to announce it has filed a confidential IPO plan.

Oct. 3 -- SEC filings reveal that Twitter hopes to raise $1 billion in its IPO.

Oct. 15 -- Twitter chooses to list its shares on the New York Stock Exchange rather than the Nasdaq.

Oct. 24 -- Twitter announces the initial public offering could value the company at nearly $11 billion and says it hopes to raise up to $1.4 billion from the IPO, significantly more than it had projected.

Wednesday -- Signaling strong investor interest in its shares, Twitter increases its IPO price above its earlier range, to $26 a share.

Thursday -- Trading in TWTR begins on the New York Stock Exchange; shares close at $44.90.

Source: Thomson Reuters; Crunchbase; Mercury News research