Groupon capitalization, the biggest online discount service in the world, has lost over 50% since it had been carried out by IPO Company in November last year, - Bloomberg says. The shares of Groupon lost 3.3% marking down its price to 9.97 dollars per share, that has become a minimal indicator after the service entered the stock exchange. During the IPO which has become the major one among the US Internet companies Groupon issued 35 million shares at 20 dollars per share. At the first session after placement, the company’s papers ticked up in price by 40 points, however later the quotes were impacted negatively by the financial results of Groupon for the fourth quarter 2011. At the beginning of 2012 Groupon has revised figures for October-November last year and reported that quarterly revenue amounted to 492.2 million dollars, by 14.3 million lower than supposed earlier. The net loss of Groupon in the fourth quarter reached 65 million dollars versus 10.6 million in the third quarter. At the beginning of April one of Groupon shareholders Fan Zhang lodged a complaint against the company, blaming its management in concealment of real financial performance of the service. The size of compensation required by Fan Zhang is not reported. In the mid April one more complaint against Groupon was made by Hagens Berman Sobol Shapiro Company representing interests of a few investors.