Groupon Files for $750 Million IPOGroupon Inc., the Chicago-based social coupon website, is filing for an initial public offering (IPO) of stock.SavePrintA screenshot of www.groupon.comAntonio Perez6/2/2011|Updated: 10/1/2015We had a problem loading this article. Please enable javascript or use a different browser. If the issue persists, please visit our help center.