US sanctions Iran, markets mixed

On August 25, 2026, U.S. Treasury Secretary Scott Bessent announced fresh sanctions against Iran, warning that countries continuing to do business with Iran would face retaliation. This action, part of ongoing tensions following the war with Iran that began in late February, contributed to a record low for the Iran — Iranian rial against the U.S. dollar. Oil prices remained elevated, with Brent Crude near $90.51 per barrel and West Texas Intermediate at $85.10, well above pre-war levels. Asian markets were mostly lower, with the Nikkei 225 gaining 0.4%, while the KOSPI, Hang Seng Index, and Shanghai Stock Exchange Composite Index fell. U.S. stocks had a mixed session on Monday, with the S&P 500 slipping 0.3%, the Dow Jones Industrial Average adding 0.3%, and the Nasdaq Composite falling 0.8%, led by declines in tech stocks including Nvidia, Micron Technology, and Broadcom. The United States — United States Department of the Treasury's increased buybacks of Treasurys helped ease 10-year Treasury yields to 4.71%, but analysts noted this does not address fundamental issues of high debt and oil prices. United States — Federal Reserve Chairman Kevin Warsh is scheduled to speak at Jackson Hole on Friday, with markets watching for signals on inflation.