LinkedIn Corp., an online professional network, was one of the first well-known social media companies to go public. Its first day of trading was May 19, 2011.
Pricing: $45 per share
First-day close: $94.25, more than double IPO price
Friday's close: $75.11, up 67 percent from IPO price
Trading range since IPO: $55.98 to $122.70