U.S. stock indexes saw mixed results on Monday as gains in broad market sectors were offset by declines in large technology firms, including Apple and Nvidia. The S&P 500 fell 0.5% after erasing an earlier 1.1% gain, while the Nasdaq composite dropped 1.1%. In contrast, the Dow Jones Industrial Average rose 0.4%, supported by a majority of stocks within the S&P 500 that benefited from a decline in oil prices.
The market movements follow recent earnings reports and economic data. A report from the Institute for Supply Management indicated that U.S. manufacturing improved last month beyond economist expectations, while a measure of inflation in the survey showed prices rising at a slower pace. However, uncertainty regarding artificial intelligence investments and higher memory costs affected the technology sector. Brent crude prices closed Monday at $104.77 per barrel following a 7.6% drop, which provided relief to companies with high fuel expenses, such as United Airlines and Carnival.
Apple shares fell 3% in after-hours trading on Monday despite reporting record September-quarter iPhone revenue and a 12% overall revenue increase to $114.5 billion. The company warned of a margin squeeze, forecasting that gross margins would contract to between 45% and 46% in the December quarter due to rising memory costs and expenses related to AI-integrated Siri services. Alphabet and Nvidia also experienced volatility, with Nvidia dropping 1.3% on Monday following a 4.2% decline the previous Friday.
The fluctuations in technology stocks reflect broader concerns about the return on investment for the hundreds of billions of dollars currently being spent on artificial intelligence data centers. In the hardware sector, memory chipmakers such as SK Hynix and Samsung Electronics saw their share prices decline by 3.6% and 2.9% respectively in Tuesday trading in Seoul, following the U.S. sell-off. In Australia, the Reserve Bank raised its benchmark interest rate by 0.25 percentage points to 4.85% on Tuesday, citing persistent inflation driven in part by Middle East conflict and AI-related technology investments.
Market participants are now looking toward the December quarter for clearer signs of consumer demand and corporate profitability. Apple has indicated it expects a record holiday season for revenue, though supply-chain constraints have already pushed delivery dates for its new foldable Duo phone into January. Investors will continue to track whether the U.S. economy can maintain growth despite high interest rates and the ongoing volatility in global energy markets. The next major indicators include upcoming earnings reports and further updates on international trade and manufacturing output.