Update: US Equity Indexes Drop as Semiconductor Sell-Off Sinks Technology Sector, Crude Oil Soars

05:08 PM EDT, 10/08/2026 (MT Newswires) -- (Updates with index/price moves and company/geopolitical news from the first paragraph.) US equity indexes fell as a sell-off in semiconductor mega-caps pushed technology to the bottom of sector charts, and as crude oil jumped after Iran warned tankers about using the Strait of Hormuz. The Nasdaq Composite dropped 1.3% to 27,193.34, and the S&P 500 declined 0.5% to 7,765.36 on Thursday. The Dow Jones Industrial Average rose 0.1% to 51,231.64, after trading lower for most of the day. Energy and consumer staples led gainers. OpenAI told investors that it has clocked roughly $50 billion in annualized revenue at the end of September, below the $68 billion the media speculated late last month, CNBC reported Thursday, after the Financial Times first disclosed the sales figure. A person familiar with the matter told CNBC that $68 billion included gross revenue from OpenAI's partners, helping investors make like-for-like comparisons with Anthropic. Anthropic's revenue was $4.6 billion in 2025 as the company incurred a net loss of $42 billion, Reuters recently reported, citing a leaked copy of the company's prospectus. Among stocks with market capitalization exceeding $200 billion, the top 10 names were all technology companies, with eight either from the semiconductor industry or related sub-sectors, according to data compiled by Finviz. The three worst performers in this mega-cap category were Arm (ARM), Oracle (ORCL), and Intel (INTC), down at least 5.3% each. OpenAI signed a contract with Oracle to purchase $300 billion in computing power over roughly five years, according to media reports last year. In geopolitical news, tankers face a higher risk of attacks and intimidation as they try to get critical shipments through the Strait of Hormuz after Iran issued new warnings that it would block routes that it has not authorized, sources told Reuters. Tropical storm Isaias continues to strengthen ahead of landfall on the northern Gulf Coast by this weekend, CNN reported. The storm rapidly intensified into the Atlantic season's first hurricane on Wednesday night, the news report added. Chevron (CVX) has begun shut-in procedures for production at four Gulf of America facilities and is evacuating workers as Isaias approaches, the company said. Front-month US West Texas Intermediate crude oil contract advanced 3.8% to $91.67 per barrel, and global benchmark Brent jumped 4.3% to $104.51 per barrel even after President Donald Trump reportedly said Thursday that the US will not attack Iran before the mid-term elections in early November while pointing out "productive discussions" with Tehran. Treasury yields were mixed, with the 10-year down five basis points to 5.23% and the 30-year lower by 5.7 basis points to 5.60%. Both the 10- and 30-year yields traded higher earlier in the session, close to their highest levels since 2002. The two-year rate was steady at 4.76%. The US borrowing costs at Treasury auctions continued to rise on Thursday. An auction of $22 billion of 30-year bonds hit a high yield of 5.618%, up from 5.308% in the previous auction. The bid-to-cover ratio, which measures demand, declined to 2.54 from 2.61 in the previous auction. On Wednesday, a 10-year bond auction saw a sequential surge in the high yield paid to investors.