Longtime deal app Groupon issued a “going concern” warning during a tepid first quarter earnings report this week, signaling the company could be insolvent within a year. "Groupon also disclosed it was terminating the lease at its massive River North headquarters next January — two years early," per the Chicago Tribune. "In 2010, Groupon moved into its headquarters at 600 W. Chicago Ave., becoming one the largest tenants at the former Montgomery Ward catalog warehouse and leasing more than 300,000 square feet through January 2026. All of the space is listed for sublease."