The S&P 500 erased early losses and briefly turned positive on April 13 after the U.S. enforced a naval blockade targeting Iranian ports at the Strait of Hormuz. Equity futures had initially dipped overnight due to failed peace talks between Washington and Tehran, but markets quickly absorbed the shock.

Crude oil prices jumped above $104 per barrel as the blockade raised concerns over tightened global supply. Iran had been exporting over 2 million barrels daily prior to the restriction. U.S. gasoline prices are now projected to exceed $4.25 per gallon, with Iran's parliamentary speaker warning of further spikes: "Enjoy the current pump figures. With the so-called 'blockade,' soon you’ll be nostalgic for $4–$5 gas."

The equity rebound followed the S&P 500's strongest weekly gain since November, climbing 3.6% prior to the geopolitical escalation. Energy markets remain fixated on potential disruptions at the critical chokepoint, which handles 21% of global oil transit.