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…