President Trump’s naval blockade of Iran took effect Monday, risking further disruption to a global economy already battered by weeks of war, the WSJ’s Georgi Kantchev, Mike Cherney and Junko Fukutome write.

More than 15 U.S. warships were in place to support the operation. An advisory to mariners from U.K. Maritime Trade Operations said maritime-access restrictions were being enforced for Iranian ports and coastal areas along the Persian Gulf, Gulf of Oman and parts of the Arabian Sea.

It wasn’t clear how ships could satisfy both U.S. and Iranian conditions on leaving the Gulf. Tehran says international ships need to pay to get through the Strait of Hormuz, but Trump said he told the Navy to interdict vessels that pay a toll. Shipowners and brokers said they won’t transit the chokepoint unless America and Iran both guarantee safe passage.

Oil prices rose on Monday, with the blockade set to remove 2 million barrels of daily Iranian exports from a market already navigating a historic supply crunch. Aluminum prices surged to a four-year high amid fears of prolonged supply squeeze.

Meanwhile, Iran and its No. 1 oil customer, China, could be able to withstand a blockade for weeks or even months, the Journal’s Carol Ryan writes. Iran has been exporting more crude than usual during the war, and has built up a stockpile of around 160 million barrels of oil on ships at sea outside the Persian Gulf.

• Saudi Arabia is pressing the U.S. to drop its blockade and return to the negotiating table, fearing the move could lead Iran to escalate and disrupt other vital shipping routes. (WSJ)
• U.S. sanctions on “shadow fleet” tankers generally don’t confer sufficient legal authority to permit the seizure of those vessels at sea, legal experts say. (WSJ)

U.S. home sales fell 3.6% in March, getting the crucial spring selling season off to a poor start as the high cost of housing and economic doubts held buyers back, the Journal’s Nicole Friedman writes. Sales of existing homes fell last month to a seasonally adjusted annual rate of 3.98 million, the lowest level since June 2025, the National Association of Realtors said.

Real-estate agents and homebuilders had hoped falling mortgage rates would spur activity. Mortgage rates dipped below 6% in late February for the first time since 2022, but started rising again after the start of the Iran war. The average rate on a 30-year fixed mortgage was 6.37% last week, according to Freddie Mac. Meanwhile, the national median existing-home price in March rose to $408,800, up 1.4%.

Buyers’ concerns about high prices and mortgage rates are driving homebuilders to look everywhere for ways to slash costs, the WSJ’s Nicholas G. Miller writes. They are finding them in cheaper materials and rejiggered designs. Particle board cabinets are in. Hardwood is out. Countertops are getting thinner. Walls have smaller and fewer windows.

Builders say this makes homeownership more attainable, and that the lower-cost materials are solid and durable. Still, the approach has left first-time buyers wrestling with how much to give up in exchange for a good deal.

A producer of MSG and a maker of high-end toilets are catching the eyes of investors looking to cash in on the AI boom, the WSJ’s Yang Jie writes. Japan’s Ajinomoto—which means “essence of flavor”—also produces an insulating material essential for semiconductor packaging, while commode producer Toto makes specialized ceramics used in advanced chip making.

These products attracted activist investor Palliser Capital, which has built stakes in both companies, and describes them as overlooked and undervalued. The U.K.-based firm proposed that umami pioneer Ajinomoto raise its prices, because its dominance in its niche gives it influence over the chip supply chain. The MSG maker says it is ramping up production capacity for its Ajinomoto Build-up Film, as demand for the substrates that connect AI chips to devices soars.

• The local union for thousands of beef-plant workers in Colorado reached a labor agreement with JBS a week after employees agreed to return to work following a three-week strike. (WSJ)
• Oil-field services company Baker Hughes agreed to sell its materials-testing business Waygate Technologies to Sweden’s Hexagon for around $1.45 billion in cash. (WSJ)
• Volkswagen Group vehicle deliveries fell 4% to 2.05 million in the first quarter, driven by declines in the U.S. and China. (WSJ)
• Conagra hired J.M. Smucker and Procter & Gamble veteran John Brase as its next CEO. (WSJ)
• GFL Environmental agreed to buy waste-management and energy-infrastructure company Secure Waste Infrastructure in a deal with a $4.62 billion enterprise value. (WSJ)
• Mediterranean Shipping Co.—known as MSC—said its founder, Gianluigi Aponte, transferred ownership of the privately held company to his two children in the last quarter of 2025. (Reuters)
• The tonnage of freight shipped globally by air fell 4% in March from a year earlier, with the Mideast and South Asia posting a 21% drop, according to WorldACD. (Air Cargo News)
• Traton unit International Motors sold 13,300 trucks and buses in the first quarter, down 21% from a year earlier. (Transport Topics)
• Private-equity firm STG said in a news release that it acquired Carrier Logistics, a provider of transportation-management software for less-than-truckload carriers.
• United Parcel Service is closing a facility in Louisville, Ky., eliminating 61 positions. (Louisville Business First)
• Swiss commodities-trading giant Glencore said it acquired a 45% stake in an aluminum recycling plant in South Carolina operated by Alumicore. (Recycling Today)

Mark R. Long is editor of WSJ Logistics Report. Reach him at mark.long@wsj.com. Follow the WSJ Logistics Report team on LinkedIn: Mark R. Long, Liz Young and Paul Berger.