United Parcel Service Inc. (NYSE:UPS) and FedEx Corp. (NYSE:FDX) are bracing for fresh turbulence as the end of U.S. de minimis exemptions tightens trade flows, threatening parcel volumes and raising costs just as the critical peak shipping season approaches. Bank of America Securities downgraded both carriers on Thursday, citing weakening demand, higher costs, and mounting uncertainty around the industry's most critical quarter. Analyst Ken Hoexter cut UPS to Underperform from Neutral and lowered FedEx to ...