Facebook timeline

Feb. 1: Facebook files papers with the Securities and Exchange Commission for the largest ever initial public stock offering for a U.S. Internet company. The company says it has 845 million users around the globe.

March 7: Facebook adds 25 underwriters to the original six for the IPO.

April 9: Facebook agrees to buy 18-month-old mobile photo-sharing site Instagram for $1 billion.

April 23: Facebook releases disappointing first-quarter results showing signs of slowing growth. It says it has 901 million users around the world.

May 3: Facebook sets a price range of $28 to $35 a share, raising as much as $11.8 billion for the social network and targeting a valuation as high as $96 billion, the highest for the public debut of a U.S. company.

May 4: Facebook executives attend meetings on Wall Street ahead of the IPO “roadshow.” Morgan Stanley hangs a Facebook flag from its headquarters.

May 7: Facebook executives kick off the cross-country roadshow, starting in New York with Mark Zuckerberg in his trademark hoodie pitching buttoned-up financiers on shares of his company. They field questions about the company’s mobile advertising strategy.

May 9: Facebook warns investors that its advertising business is not keeping up with the accelerating shift to mobile devices, a troubling admission as Facebook heads into the final stretch before its IPO.

May 14: Underwriters begin warning select institutional investors that they have revised downward their financial forecasts.

May 15: Facebook raises the price range to $34 to $38 a share, and increases the number of shares it’s offering to 421 million. General Motors says it is pulling its advertising from Facebook, raising new questions about the site’s ability to make money.

May 16: In a filing, Facebook reveals that some of its biggest investors plan to unload as much as half of their stakes in the IPO.

May 17: Facebook prices its shares at $38 per share, which valued the company at $104 billion, the richest valuation for a U.S. company at the time of its IPO.

May 18: Mark Zuckerberg rings the Nasdaq opening bill from Facebook’s Menlo Park, Calif., headquarters. Trading is scheduled to begin at 11 a.m. but is delayed by trading glitches. Facebook rises 11% but within 20 minutes falls back to its offering price. The underwriters prop up the shares to keep them from falling under the offering price. About 580 million shares trade hands, the most of any IPO. Investors fume that they waited hours for their orders to go through. Facebook shares close at $38.23.

May 19: Zuckerberg weds longtime girlfriend Priscilla Chan. Zuckerberg updates his status to “married.”

May 20: Nasdaq acknowledges technical glitches hampered the IPO.

May 21: Facebook shares open below the offering price and close the day down 11%.

May 22: Nasdaq says it would have stopped the Facebook IPO if it had known about the technical glitches in its systems. Securities regulators say they are investigating reports that Facebook’s lead underwriter, Morgan Stanley, may have withheld negative projections of the stock from some investors. Facebook shares fall another 9% to $31.

--Jessica Guynn and Scott J. Wilson