Stan ChoeUpdated May 19, 2026 — 6:41am,first published 5:17amOil prices and stock markets worldwide swung through a shaky Monday with uncertainty about what will happen with the Iran war.The S&P 500 swivelled between gains and losses before finishing with a dip of 0.1 per cent, its second loss since setting an all-time high last week. The Dow Jones added 159 points, or 0.3 per cent, and the Nasdaq composite fell 0.5 per cent after both indexes likewise yo-yoed.Wall Street has had an unsteady session to start the week. APThe Australian sharemarket is set to recover the bulk of the previous session’s heavy losses, with futures at 6.24am AEST pointing to a gain of 96 points, or 1.1 per cent, at the open. The ASX slumped by 1.5 per cent on Monday. The Australian dollar was trading at US71.65¢.US stock prices moved in the opposite direction of oil prices, which have been twitchy because of uncertainty about how long the Iran war will keep the Strait of Hormuz closed and prevent oil tankers from delivering crude. The price for a barrel of Brent crude oil, the international standard, went from a high of $US112 overnight to below $US107 in the morning before turning back higher.After settling at $US112.10 per barrel, Brent’s price then fell back below $US109 after President Donald Trump said late in the day that he would hold off on a military attack on Iran planned for Tuesday, at the request of allies in the region. That kept alive hopes that a deal to open the Strait of Hormuz may still be possible.The moves for oil prices have helped make the world’s bond markets the centre of the action recently. Climbing yields there have cranked up the pressure on economies and stock markets worldwide.Higher yields make it more expensive for households and businesses to borrow, which US homebuyers know because of higher mortgage rates. Higher interest rates could also make it more difficult for companies to borrow to build data centres for artificial-intelligence technology, which has been driving much of the US economy’s growth.In the bond market, the yield on the 10-year Treasury got as high as 4.63 per cent before falling back to 4.59 per cent, where it was late on Friday. The yield on the 10-year Japanese government bond rallied toward its highest level since the late 1990s.Yields worldwide have been climbing on fears about higher inflation caused by higher oil prices, which could push central banks not only to abandon the possibility of cutting interest rates but also consider hiking rates. Higher rates would slow inflation at the cost of hurting the economy and dragging on prices for stocks and other investments.Several solid reports on the US economy recently, along with worries about the US government’s huge and growing debt problem, are also pushing upward on yields.On Wall Street, Regeneron Pharmaceuticals dropped 9.8 per cent to help lead the US stock market lower after reporting discouraging data from a trial of a treatment for melanoma.NextEra Energy fell 4.6 per cent after agreeing to buy Dominion Energy in an all-stock deal to create the world’s largest regulated electric utility by market value. Dominion rallied 9.4 per cent.Delta Air Lines finished essentially flat after swinging up and down through the day because of oil prices. It got a boost early following news that Berkshire Hathaway bought more than $US2.6 billion ($3.6 billion) of the airline’s stock. Berkshire Hathaway built a reputation as a value investor able to buy stocks at low prices under its former leader, Warren Buffett.Boston Scientific was another winner and climbed 6.2 per cent after saying it would spend $US2 billion of its previously announced $US5 billion stock buyback program by the end of June. Such purchases send cash directly to investors and boost the company’s per-share earnings.All told, the S&P 500 fell 5.45 points to 7,403.05. The Dow Jones Industrial Average added 159.95 to 49,686.12, and the Nasdaq composite fell 134.41 to 26,090.73.This upcoming week will offer little in terms of data on the US economy, but a heavily anticipated report on Nvidia’s latest quarterly results will arrive Wednesday. The chip company has routinely blown past analysts’ expectations each quarter, while forecasting even bigger growth than Wall Street had thought. It will likely need to keep up such momentum to keep AI stocks driving the market to more records.Target, Home Depot and Walmart will also report their latest quarterly results this week.In stock markets abroad, indexes fell in much of Asia but reversed losses in Europe to finish higher. Japan’s Nikkei 225 sank 1 per cent, but Germany’s DAX returned 1.5 per cent for two of the world’s bigger moves.APThe Market Recap newsletter is a wrap of the day’s trading. Get it each weekday afternoon.From our partners