
Facebook founder and CEO Mark Zuckerberg speaks at a conference on Sept. 11, 2012, in San Francisco.
Facebook stock ended trading Monday 9.1% lower at $20.79 a share, as investors reacted to reports of a security bug and renewed their worries about the company’s future.
Read also:
Facebook's Slump Triggers Short-Sale Restriction (Wall Street Journal (blog))
Barron's slams Facebook, stock falls (Businessweek)
Facebook stock falls after Barron's says it's 'still too pricey' (Washington Post)
Explore: 443 additional articles.