Brent settled above $100 for the first time since May after Houthi attacks on two Saudi tankers

Brent crude settled at $100.69 a barrel on Thursday, up 7 percent, and it was the first settlement above $100 since May 26. US West Texas Intermediate settled at $92.19, up 6 percent. Both benchmarks finished at their highest levels since before the United States and Iran reached an agreement last month to end their war, CNBC reported.

Two events came first. Yemen's Houthi forces, which are backed by Tehran, claimed they had attacked two Saudi oil tankers in the Red Sea. President Donald Trump then wrote on Truth Social that from that point forward, every time Iran fires on a ship in the Strait of Hormuz, the United States will "bomb and destroy ONE BRIDGE OR POWER PLANT," including targets in or beside Tehran. Later on Thursday, Axios reported that Trump said he was "considering a massive attack" on Iran and that it would be "bigger than ever before." He told Axios he was close to a decision, and he set no deadline.

The bond market moved with the oil price. The Treasury Department's daily par yield curve put the 10-year at 4.71 percent on Thursday, against 4.67 percent on Wednesday, and the 2-year at 4.37 percent, against 4.31 percent. The 30-year finished at 5.17 percent. On Treasury's published series, 4.71 percent is the highest 10-year reading of 2026, and the last day at or above it was January 14, 2025.

Rate expectations turned with the curve. Fed funds futures put the probability of a Federal Reserve rate increase at the September meeting at 82 percent and at the December meeting at 92 percent, according to the CME FedWatch tool cited by CNBC. A week earlier the September reading was 52 percent.

US equities closed lower. The Dow Jones Industrial Average lost 506.93 points, or 0.97 percent, to end at 51,711.65. The S&P 500 fell 1.21 percent to 7,408.30, and the Nasdaq Composite fell 2.15 percent to 25,137.69. Alphabet finished down 7 percent and Tesla down 14 percent, both after reporting results.