(Updates with market moves at the end of the day, and other changes, if any.)
The Nasdaq Composite and the S&P 500 fell Monday as the US unveiled a global sanctions plan targeting countries that have an economic relationship with Iran.
The Nasdaq shed 0.8% to close at 25,980.19, while the S&P 500 declined 0.3% to 7,652.86. The Dow Jones Industrial Average rose 0.3% to 53,417.16. Technology led the laggards, while most sectors were in the green, led by consumer staples.
The Treasury Department on Monday launched a campaign to close all financial resources that support Iran.
"We are launching an economic onslaught against Iran's financial connections around the globe," Treasury Secretary Scott Bessent said in a statement. "Our objective is to sever every economic lifeline that sustains this tyrannical regime until Tehran stands alone."
Countries doing business with Iran will be given deadlines to shut down Iran-related activities, according to the statement. Entities aiding money laundering or sanctions evasion on behalf of Iran could be cut off from the US financial system.
China, Russia, India, Pakistan, Qatar and Turkey, among others, still trade with Tehran, Axios reported.
"No one is above the reach of US sanctions," Bessent said Monday in response to a question at a press conference on whether the Trump administration would target Chinese banks, CNBC reported.
West Texas Intermediate crude oil was down 2.3% at $85.07 a barrel in Monday late-afternoon trade, while Brent dropped 2.5% to $92.06.
Iran's state-controlled Persian Gulf Strait Authority warned on X that vessels breaching its protocols in the Strait of Hormuz could face restrictions on future passages.
US Treasury yields were mixed, with the 10-year yield down 3.2 basis points at 4.71%, while the two-year yield was little changed at 4.24%.
Federal Reserve Chair Kevin Warsh's debut Jackson Hole speech on Friday is unlikely to help clear up investor confusion over the Treasury Department's bond market intervention, Morgan Stanley said in a note sent Monday. The firm's economists view the expansion in bond buybacks announced last week as evidence that the Treasury had become uncomfortable with a rise in long-term interest rates.
Markets are currently pricing in a 58% probability that the Fed will keep its benchmark rate steady in September, with the remaining odds in favor of a 25-basis-point hike, according to the CME FedWatch tool.
In company news, Nvidia (NVDA) shares fell 2.9%, the worst performer on the Dow. The technology bellwether is scheduled to release its latest quarterly earnings on Wednesday.
Some Nvidia customers are facing price increases of over 15% on servers equipped with its artificial intelligence chips due to rising memory costs, Bloomberg News reported Saturday, citing people familiar with the matter.
Chip-related stocks were among the notable laggards on the S&P 500, with SanDisk (SNDK) down 6.5%, the second-steepest decline on the index. Micron Technology (MU), Super Micro Computer (SMCI) and Western Digital (WDC) shed more than 5% each.
Marvell Technology (MRVL), CrowdStrike (CRWD), Salesforce (CRM) and Intuit (INTU) are also slated to post their results this week.
Spot gold rose 1.1% to $4,654.89 per troy ounce, while silver lost 1% to $69.65 per ounce.
