NEW YORK — Stock markets rallied worldwide Monday, and oil prices eased after the United States and Iran reached a tentative deal to extend their ceasefire and reopen the Strait of Hormuz to get the global flow of crude going again.

The S&P 500 rose 1.7% on hopes that this time, the announcement of an Iran-U.S. agreement will mean a long-term fix to a conflict that has worsened inflation around the world. The Dow Jones Industrial Average climbed 468 points, or 0.9%, to a record, and the Nasdaq composite jumped 3.1%.

Stocks got a lift after the price for a barrel of Brent crude oil fell 4.8% to $83.17, back to where it was in early March. While that’s still above its price of roughly $70 from before the war, it’s lower than the $100 plus it cost just a few weeks ago. The hope is that lower oil prices will take pressure off households and businesses, which have had to pay higher prices for everything from food to fuel to fertilizer because of the war with Iran.

Iran confirmed the deal, but it does not include a final agreement on issues like Iran’s nuclear program. Negotiations on that are expected to continue over the next 60 days, which leaves opportunity for hiccups that could derail the agreement. And even if the Strait of Hormuz does fully reopen on Friday as expected, it will likely take months for the energy industry to get back to full speed.

For now, though, relief swept through financial markets worldwide.

On Wall Street, stocks of companies with big fuel bills were instant winners. United Airlines flew 3.9% higher, and cruise operator Royal Caribbean Group rose 6.6%.