Under Armour Inc UAA.N slumped 9.5% after warning that its profit margin would be under pressure in the current quarter. By Bansari Mayur Kamdar Feb 11 (Reuters) - Wall Street's main indexes were mixed on Friday as investors digested hot inflation data that caused a sharp selloff in the previous session on fears about quicker interest rate hikes. Meanwhile, a University of Michigan survey showed U.S. consumer sentiment fell to its lowest level in more than a decade in early February amid expectations that inflation would continue to rise in the near term.