People walk past a sign welcoming Facebook at the NASDAQ stock exchange in New York. The company's shares extended their slump after a much-hyped public offering earlier this month, shedding more than... more 

People walk past a sign welcoming Facebook at the NASDAQ stock exchange in New York. The company's shares extended their slump after a much-hyped public offering earlier this month, shedding more than seven percent as markets reopened following a US holiday weekend less