Iran's Foreign Minister announced the Strait of Hormuz is fully open to all commercial vessels during the ceasefire, causing crude oil to plunge 14% to $81/barrel. Airlines and cruise lines surged as fuel costs declined, while energy and chemical companies fell sharply. The S&P 500 reached record highs with the Nasdaq 100 on its 13th consecutive gaining session.

Seven major energy stocks are trading at historically low valuations (7x-11x forward P/E) despite oil prices above $90/barrel due to the Strait of Hormuz crisis. The sector has underperformed crude oil gains, creating a potential opportunity if the supply disruption persists, though risks remain if a ceasefire rapidly brings prices back down to $65-70.

Gasoline prices surged 21.2% in March 2026, the largest monthly increase since 1967, driven by disruptions to oil flows through the Strait of Hormuz due to the Iran war. National average gas prices jumped from $2.98 to $4.15 per gallon in six weeks. Goldman Sachs upgraded several refiner stocks as beneficiaries of elevated crack spreads and tighter energy supply chains, while economists debate whether this represents a temporary shock or a sustained inflationary regime.

U.S. gasoline prices surged to $4.02 per gallon and diesel hit $5.45, driven by Iran war disruptions at the Strait of Hormuz. Oil refiners are capitalizing on widened crack spreads (now ~$47/barrel vs. $20 pre-war), with refiner stocks posting exceptional gains. The VanEck Oil Refiners ETF (CRAK) is up 29% YTD on a 14-week winning streak, while individual refiners like Par Pacific and PBF Energy gained 50% and 41% in March respectively. Analysts raised price targets on Valero Energy, citing potential structural shifts in refining profitability.

Congressman David Taylor (R-Ohio) sold Chevron and Marathon Petroleum stocks at all-time highs following his public support for President Trump's military action against Iran. Taylor sold Chevron shares trading between $186-$198 and Marathon Petroleum shares, realizing gains of 19-33% at the time of sale. The timing of the stock sales shortly after his vocal support for the Iran strike raises concerns about potential conflicts of interest.

Gas prices have surged to $3.98/gallon, nearly double Trump's $2 promise, due to the Iran war. Diesel has jumped 43% to $5.38 nationally and over $7 in California. Consumer sentiment has declined sharply as inflation expectations rise. Energy companies and refiners are posting strong gains, with SM Energy up 44% and PBF Energy up 40% month-to-date, benefiting from wider profit margins.

While the S&P 500 has fallen 4.5% since a Middle East war began, three sectors remain resilient: energy stocks are surging due to spiked oil and gas prices; computer hardware and data storage companies continue benefiting from strong AI infrastructure demand; and cybersecurity firms are gaining as geopolitical tensions drive demand for security products.

Three weeks into the Iran war, markets are repositioning for a prolonged conflict lasting months rather than days. A 32-percentage-point divergence has emerged between stocks benefiting from a closed Strait of Hormuz (energy, defense, drones) which are up 17.55% on average, and those needing it open (airlines, cruise lines, logistics) which are down 15.35% on average. Prediction markets assign only a 26% probability of normal traffic returning by April 30, suggesting at least six more weeks of disruption.

Diesel prices have surged above $5 per gallon for the first time since 2022, with Goldman Sachs warning that the real energy crisis lies in refined products rather than crude oil. Middle East supply disruptions and refinery outages are constraining global diesel and jet fuel supplies, creating record-wide refining margins. U.S. refiners are positioned to benefit significantly from these elevated crack spreads.

Despite oil prices surging to nearly $100/barrel following the Iran conflict, MPLX has declined 1% because it operates a volume-based logistics business with limited direct commodity price exposure. Higher oil prices could actually reduce volumes flowing through its crude infrastructure. The company's primary growth driver is natural gas and NGL services, not crude oil, making it better suited as a durable income investment yielding 7%+ rather than a play on rising oil prices.

The Iran conflict has created a historic earnings boom for U.S. oil refiners as the 3-2-1 crack spread surges to approximately $40 per barrel—roughly double pre-conflict normalized margins. With global refining capacity declining and the U.S. operating the world's largest refining complex, the industry could see theoretical gross refining margins reach nearly $240 billion annually. Five major independent refiners are positioned to capture significant windfall profits from this structural advantage.

The Iran-U.S. conflict has triggered conditions for a refiner earnings supercycle, with diesel crack spreads at 78% of the all-time record and climbing 60% month-to-date. Historical precedent from 2004-2005 and 2022 shows refining stocks can deliver extraordinary returns during such periods. The article identifies five refiners positioned to benefit from widening crack spreads and potential $260+ billion in annualized gross refining margins.