US equity indexes rose after midday Monday amid strong gains in communications services, while a slide in government bond yields accompanied a drop in crude oil futures.
The Nasdaq Composite jumped 2.2% to 25,923.9, with the S&P 500 up 1.4% to 7,596.8 and the Dow Jones Industrial Average higher by 1.1% to 53,071.2.
Communication services surged 4.5%, topping sector charts, followed by a rise in consumer discretionary and technology. Energy, healthcare and consumer staples led decliners.
"Iranian Leadership is unbelievably duplicitous!" President Donald Trump said in a social media post Monday, reverting to lashing out at Iran after canceling a planned attack against the Islamic Republic last Saturday because the "perimeters of a deal has been agreed to."
"Nothing gets through to Iran unless we want it to, and nothing will get through unless a Deal, or Total Surrender, is accomplished," the US president said, referring to the US blockade of Iranian ports. "Whether Iran wants to admit it or not, we are, in fact, talking of a solution to a problem that they have caused, for decades."
Iran's Foreign Ministry Spokesman Esmaeil Baghaei said no negotiations with the US were underway and no meetings were scheduled, Reuters reported.
Oman and Iran have been negotiating over a new maritime route through the Strait of Hormuz, which borders both their territorial waters, Al Jazeera, a Middle Eastern broadcaster, reported. Sunday night, Iran's Foreign Minister Abbas Araghchi told the Iranian cabinet in a report that negotiations between Tehran and Muscat were "on the way to being finalized".
The front-month US West Texas Intermediate crude oil slumped 5.4% to $80.08 a barrel, and global benchmark North Sea Brent dropped 4.9% to $83.66 a barrel.
Most US Treasury yields declined, with the 10-year trading down 5.5 basis points to 4.69%, retreating from the 52-week high touched late last week. The two-year yield dropped 3.1 basis points to 4.26%.
In precious metal markets, gold futures slipped 0.4% to $4,090.5, while silver futures were unchanged at $57.77.
In economic news, the Institute for Supply Management's US manufacturing index rose to 55.6 in July from 53.3 in June, compared with expectations for 53.9 in a Bloomberg-compiled survey. This is the highest reading since May 2022, ISM said.
The S&P Global US manufacturing index for July was revised upward to 53.9 from the flash reading of 53.8, compared with expectations for no revision in a survey compiled by Bloomberg.
In company news, Alibaba (BABA) launched Qwen3.8-Max, its latest large language model, and plans to release the model's open weights next week alongside Qwen3.8-27B.
Bristol Myers Squibb (BMY) is in talks with AstraZeneca (AZN) about a potential combination that would create a pharmaceutical company valued at nearly $400 billion, the Financial Times reported.
Marriott International (MAR) reported Q2 revenue below estimates amid headwinds from the Middle East conflict, and offered a downbeat Q3 earnings outlook. Shares slumped 6.3%, among the worst performers on the Nasdaq and the S&P 500.