Under Armour shares fell 13 in premarket trading on Friday, according to Reuters. The company forecast second-quarter revenue to decline 6 to 7, steeper than analysts’ expected 2.9 drop. The sportswear maker cited inflation and uncertainty over Trump-era tariffs as key factors pressuring demand in North America. First-quarter revenue declined 4 to $1.13 billion, meeting estimates, while adjusted earnings per share of 2 cents missed the 3-cent forecast. Under Armour warned of a 340 to 360 basis point decline in gross margin this quarter, driven by tariff-related supply chain disruptions. Pricing and currency benefits may offset some losses. The company sources 45 of its merchandise from Vietnam and Indonesia and faces direct exposure to new tariffs of up to 20.