Shares of iRobot (IRBT -19.77%) fell 19.8% late Wednesday after Politico reported Amazon.com (AMZN 1.56%) will not offer concessions to European Union (E.U.) antitrust regulators as it works to clear its impending acquisition of the home robotics specialist. Amazon isn't backing down from antitrust regulators Citing two people familiar with the situation late this afternoon, Politico says Amazon and iRobot have until the end of the day today to present offers to the European Commission (EC) to make changes ...