FILE - In this May 18, 2012 file photo provided by Facebook, Facebook founder, Chairman and CEO Mark Zuckerberg, center, rings the Nasdaq opening bell from Facebook headquarters in Menlo Park, Calif. ... more 
FILE - In this May 18, 2012 file photo provided by Facebook, Facebook founder, Chairman and CEO Mark Zuckerberg, center, rings the Nasdaq opening bell from Facebook headquarters in Menlo Park, Calif. Robert Greifeld, second from right, CEO of the Nasdaq-OMX Stock Market, Inc., said Sunday, May 20, the stock exchange is "humbly embarrassed" by its bungling of Facebook's debut. Facebook's stock was expected to start trading at 11 a.m. Friday, but didn't open until 11:32 a.m., and some investors didn't learn for hours whether their orders went through. (AP Photo/Nasdaq via Facebook, Zef Nikolla, File) less 
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Associated Press | Photo By Nasdaq via Facebook, Zef Nikolla, File
Tue, May 22, 2012 1:14 AM EDT