(Updates with index/price moves, macroeconomic data, and company/geopolitical news from the first paragraph.)
US equity indexes fell while crude oil prices rose as President Donald Trump signaled more attacks on Iran amid threats from the Tehran-backed Houthi group to Saudi Arabian crude oil supplies.
The Nasdaq slipped less than 0.1% to 25,508.07 on Monday, giving up intraday gains of more than 1%. The S&P 500 fell 0.2% to 7,443.28 after trading in positive territory earlier in the session. The Dow Jones Industrial Average slid 0.6% to 51,839.26, ending the day close to the session low.
Health care, materials, and industrials led decliners. Communication services, energy, and technology were the only gainers.
President Donald Trump warned Iran "will pay" for three US troop deaths over the past few days, CNN reported. The US is increasing the number of fighter jets in the Middle East as Trump considers how to proceed in the fight against Iran, CNN cited an official.
The US military strategy seems to be to attack Iran's offensive and defensive assets until it surrenders its claims on the Strait of Hormuz, according to a Macquarie note. "As for the US's long-term strategic plans, it is clear that they are about diminishing reliance on the Strait over time, by supporting the build-out of alternative oil transportation modalities."
Meanwhile, the Tehran-backed Houthi group in Yemen said Monday they were imposing a naval blockade on Saudi Arabia, Reuters reported. The full closure of the Bab el-Mandeb strait would reduce global oil supply by 7% as it would leave most of Saudi oil exports unable to leave the region, the news report said. The disruption would add to the reduction in oil flows from the war, which has already cut shipments by 10% of global supply, it added.
The front-month US West Texas Intermediate rose 0.6% to $83.01 a barrel, while global benchmark North Sea Brent climbed 0.9% to $88.88 a barrel, after both crude types traded lower earlier in the session.
Most US Treasury yields rose, with the 10-year advancing 5.3 basis points to 4.59%. The two-year jumped 3.9 basis points to 4.21%.
In precious metal markets, gold futures slipped 0.2% to $4,013.5, while silver futures climbed 1.3% to $57.06.
In economic news, the Conference Board's measure of leading indicators declined by 0.2% in June, larger than the 0.1% decrease expected in a Bloomberg-compiled survey, following a 0.1% increase in May.
"Consumer spending is weakening, but strong business investment related to AI is expected to support economic activity while inflation continues to improve," said Justyna Zabinska-La Monica, Senior Manager of Business Cycle Indicators. "The Conference Board raised its forecast from 1.8% to 1.9% year-over-year GDP growth for 2026."
In company news, Alphabet's (GOOG, GOOGL) Google is working on a new server chip that will allow it to serve its AI models to users more efficiently, The Information reported Monday, citing two people with direct knowledge of the matter. Shares of Google's parent rose 1.5%.