Stock markets rallied worldwide, and oil prices eased after the United States and Iran reached a tentative deal to get the global flow of crude going again.The S&P 500 rose 1.7% Monday 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 0.9%, and the Nasdaq composite jumped 3.1%. Brent crude’s price fell 4.8%, helping stocks of companies with big fuel bills to lead the market. AI stocks also rallied following their sharp swings over the last couple weeks. On Monday:The S&P 500 rose 122.83 points, or 1.7%, to 7,554.29.The Dow Jones Industrial Average rose 468.77 points, or 0.9%, to 51,671.03.The Nasdaq composite rose 795.10 points, or 3.1%, to 26,683.94.The Russell 2000 index of smaller companies rose 21.10 points, or 0.7% to 2,965.09.For the year:The S&P 500 is up 708.79 points, or 10.4%.The Dow is up 3,607.74 points, or 7.5%.The Nasdaq is up 3,441.95 points, or 14.8%.The Russell 2000 is up 483.18 points, or 19.5%.