Update: US Equity Indexes Fall in Midday Trading as Treasury Yields Rise Amid US-Iran Deadlock

01:38 PM EDT, 09/28/2026 (MT Newswires) -- (Updates with index/price action, macroeconomic data, corporate developments, and geopolitical news from the first paragraph.) US equity indexes fell after midday trading on Monday as Treasury yields rose after US President Donald Trump turned down Iran's settlement proposal, raising doubts over striking a deal in the near term. Iranian officials have privately expressed doubts about closing a deal with the US to end the conflict and reopen the Strait of Hormuz before the November US midterm elections, Bloomberg reported Monday, citing people with knowledge of the matter. Trump had mentioned on Sunday that he expects US negotiators to engage in more talks with Iran this week, Axios reported, citing a conversation with the president. "They want to make a deal, but it is not the deal that I want to make. It is what we would have maybe agreed to a year ago. They overplayed their hand," Trump said, according to the media outlet. The Nasdaq Composite fell 0.6% to 26,901.6. The Dow Jones Industrial Average fell 0.4% to 51,617, while the S&P 500 declined by 0.5% to 7,702.1. Communication services and consumer discretionary sectors led decliners, while the health sector led the gainers. The US West Texas Intermediate crude oil contract fell 0.3% to $92.16 per barrel. The majority of US Treasury yields rose intraday, with the 10-year yield edging up 5.5 basis points to 5.24% and the 30-year rate 6.4 basis points to 5.57%. In economic news, the Dallas Fed's monthly manufacturing index declined to 9.8 in September from 11.6 in the month prior, compared with Bloomberg-survey expectations for a larger decrease to 7.8. The print for the company outlook fell to 8.7 from 19.2 in August. In company news, Nvidia's (NVDA) board approved an additional $150 billion under its share repurchase program, boosting the total remaining authorization to $235 billion, the company said Monday. The company added that it expects to carry out the remaining buybacks under the program through fiscal 2028. Nvidia shares were up 2.4%. MongoDB (MDB) said Monday that chief executive officer and president Chirantan CJ Desai will step down from his roles, effective immediately, to pursue a role at Meta Platforms (META). The company appointed Dev Ittycheria as interim president and CEO, effective immediately. Ittycheria previously served as MongoDB CEO from 2014 to 2025, the company said. MongoDB shares were down 17.2%. SpaceX (SPCX) said Monday in a post on X that its Starship rocket entered Earth's orbit for the first time after performing an orbital insertion burn. SpaceX shares were down 1.2%.