Under Armour is trading 4.06% down at $4.25 on September 28, 2026; no clear company-specific catalyst appeared in available search results. - President Trump rejected Iran’s proposal, pushing oil prices higher and renewing inflation concerns. - Reuters reported falling U.S. stock futures and rising Treasury yields, reflecting a risk-off backdrop. - That macro pressure is a plausible explanation for the decline, but available sources do not directly link it to Under Armour.