Is there a bubble in LinkedIn's stock price?
  Recent academic work has developed a method to determine, in real time, if a given stock is exhibiting a price bubble. Currently there is speculation in the financial press concerning the existence of a price bubble in the aftermath of the recent IPO of LinkedIn. We analyze stock price tick data from the short lifetime of this stock through May 24, 2011, and we find that LinkedIn has a price bubble. 
Robert Jarrow, Younes Kchia and Philip Protter
q-fin.RM q-fin.ST