Iran's joint military command has reportedly ordered the closure of the Strait of Hormuz — the world's most critical oil chokepoint — citing continued Israeli military operations in Lebanon. The strait handles roughly 20% of global seaborne crude and LNG, meaning any sustained closure would sharply tighten global energy supply. The timing is notable: VP Vance is en route to Switzerland for talks, suggesting the closure may be partly a pressure tactic ahead of negotiations.

The immediate setup is a spike in crude and energy names, but the key question is duration and credibility — Iran has threatened Hormuz closures before without full execution. Markets will watch whether tanker traffic actually halts, how Gulf producers (Saudi, UAE) respond, and whether Vance's talks produce any de-escalation signal within hours. Defense and domestic energy names are likely to catch a bid while refiners with Middle East crude exposure face margin compression.