Update: US Equity Indexes Fall as Iran Talks Stall, Fed Governor Points to Higher Rates, Inflation

04:21 PM EDT, 09/28/2026 (MT Newswires) -- (Updates with index/price action, macroeconomic data, corporate developments, company/geopolitical news from the first paragraph.) US equity indexes fell on Monday as Treasury yields rose after President Donald Trump rejected Iran's settlement proposal, and Fed Governor Lisa Cook guided for higher inflationary pressures amid the AI buildout and Middle East tensions. Iranian officials have privately expressed doubts about striking a deal with the US before the November US midterm elections, Bloomberg reported Monday, citing people with knowledge of the matter. Trump said on Sunday after scrapping Iran's proposal that he expects US negotiators to engage in more talks with Iran this week, Axios reported, citing a conversation with the president. The Nasdaq Composite fell 0.9% to 26,820.3. The Dow Jones Industrial Average fell 0.6% to 51,481.7, while the S&P 500 declined by 0.7% to 7,683.9. Communication services and consumer discretionary sectors led decliners. Fed Governor Lisa Cook said she expects further upward inflation pressure from the AI buildout, elevated oil prices, and Middle East-related supply chain disruptions, while highlighting that the labor market is "well-positioned to handle an increase in rates." Fed Governor Michael Barr had also recently said that further rate increases will likely be needed to bring down inflation and restore price stability. The majority of US Treasury yields rose, with the 10-year yield rising 5.1 basis points to 5.232% and the 30-year rate 4.8 basis points to 5.55%. The US West Texas Intermediate crude oil contract rose 0.6% to $92.96 per barrel. In economic news, the Dallas Fed's monthly manufacturing index declined to 9.8 in September from 11.6 in the prior month, 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 (NVDA) said Monday its board approved an additional $150 billion under its share buyback program, boosting the total remaining authorization to $235 billion. The company also launched the Open Agent Safety Platform to help AI developers enforce guardrails on agents. Nvidia shares rose 1.6% on Monday. Kodiak Sciences (KOD) said Monday its experimental eye drugs, Zenkuda and tabirafusp-ted, met primary endpoints in a phase 3 trial in patients with wet age-related macular degeneration. Kodiak Sciences shares were up 177.9%. DataMeds AI (MEDS) and Tollo Health announced the launch of the Health Lives Here mobile application to help patients using GLP-1 medications. Shares rose 22.5%.