US Stocks September Wrap-Up: Major Indices Close Higher Amid Volatility, AI Tech Leads Q4 Start

US Stocks September Wrap-Up: Major Indices Close Higher Amid Volatility, AI Tech Leads Q4 Start

On September 30, 2026, the US stock market presented a volatile upward trend in the last trading day of the month, with all three major indices closing higher, setting a positive tone for the fourth quarter. The S&P 500 rose 0.82% to close at 4,785.32 points; the Nasdaq gained 1.15% to close at 15,324.76 points; and the Dow Jones Industrial Average increased 0.65% to close at 35,642.18 points. Throughout September, the US stock market demonstrated strong resilience, experiencing several significant fluctuations but still achieving monthly gains across all three indices, with the Nasdaq leading the pack with a 3.2% monthly increase.

September Market Performance Review

Looking back at the entire month of September, the US stock market showed a "decline followed by recovery" pattern. At the beginning of the month, influenced by the Federal Reserve's meeting minutes suggesting possible maintenance of high-interest rate policies, the market experienced a significant correction. However, as a series of better-than-expected economic data was released, market sentiment gradually recovered, and the market began to rebound mid-month. Particularly, the inflation data released in mid-September showed that the US core CPI year-on-year growth rate fell to 2.8%, the lowest level in nearly two years, which greatly alleviated market concerns about persistently high inflation.

From a technical perspective, after testing the 4,500-point support level in early September, the S&P 500 successfully stabilized and began its rebound path. The monthly trend showed a typical "V-shaped" reversal pattern, especially in the last week of September when trading volume significantly increased, indicating that investor confidence was recovering.

Notably, stock market volatility decreased in September, with the VIX index (fear index) falling about 15% for the month, dropping from around 22 points at the beginning of the month to around 18 points, indicating that market risk aversion had weakened and risk appetite had increased.

Major Sector Performance Analysis

In September, performance across various sectors in the US stock market was significantly differentiated. The technology sector, particularly AI-related stocks, became the main force leading the market rebound. Tech giants represented by NVIDIA (NVDA), Microsoft (MSFT), and Google's parent company Alphabet (GOOGL) saw their stock prices continue to rise, with NVIDIA's monthly increase exceeding 15%, mainly due to sustained strong demand for its Blackwell architecture AI chips.

The strong performance of the technology sector was supported by several factors: first, corporate AI capital expenditures remained strong, especially in cloud computing and data center sectors; second, rising expectations that the Federal Reserve might end its interest rate hike cycle reduced valuation pressure on tech stocks; finally, the quarterly results released by tech giants generally exceeded expectations, especially the growth of cloud services which surpassed market expectations.

In stark contrast to the technology sector, traditional industrial and energy sectors performed relatively weak. Although global economic growth prospects have improved, investors tend to allocate funds to technology sectors with clear growth prospects, resulting in significant capital outflows from these traditional sectors. The industrial sector fell about 1.2% for the month, while the energy sector declined 0.8%.

The financial sector showed robust performance, rising about 1.5% for the month. Bank stocks performed well overall in September, mainly benefiting from a relatively stable interest rate environment and expectations of maintaining good credit quality. Large banks such as JPMorgan Chase (JPM) and Bank of America (BAC) all saw monthly stock price increases of over 2%.

The healthcare sector performed moderately in September, with a slight increase of 0.3% for the month. Although several individual stocks in the biopharmaceutical sector rose significantly due to favorable clinical trial data, the overall sector was pressured by uncertainties in healthcare policy and high valuations, resulting in relatively flat performance.

Key Stock Performance

In September, many popular stocks in the US market performed impressively, becoming market focal points. NVIDIA (NVDA) was undoubtedly one of the most outstanding individual stocks this month, with its stock price rising from around $460 at the beginning of the month to above $530 at the end, an increase of over 15%. The company's latest quarterly report showed that data center business revenue increased by 45% year-on-year, exceeding market expectations, especially as orders for its Blackwell architecture AI chips have been extended into 2027.

Tesla (TSLA) experienced significant volatility in September. It fell sharply at the beginning of the month due to concerns about intensified competition in the Chinese market, but later rebounded as new model sales exceeded expectations, ultimately rising about 5% for the month. Particularly, the company's third-quarter delivery data released in mid-September showed global deliveries reached 463,000 vehicles, a year-on-year increase of about 15%, exceeding market expectations.

Amazon (AMZN) performed steadily in September, with its stock price rising about 3% for the month. Although the growth rate of its cloud computing business slowed, strong growth in advertising business and improved logistics efficiency boosted market confidence. The company announced plans to expand its AI services globally, which is expected to bring new growth opportunities.

On the other hand, some traditional manufacturing giants performed relatively weak. Boeing (BA) continued to be affected by supply chain issues and safety concerns in September, with its stock price falling about 7% for the month. General Electric (GE) also performed unsatisfactorily, falling about 4% for the month, mainly dragged by slower-than-expected recovery in its aviation business.

Economic Data Impact

A series of economic data released in September had a significant impact on market trends. The August non-farm employment data released at the beginning of the month showed that new employment was 150,000, lower than the expected 180,000, and the unemployment rate rose slightly to 4.1%. This data once triggered market concerns about economic slowdown, leading to market adjustments.

However, subsequent inflation data surprised the market. The August CPI data released in mid-September showed that the year-on-year growth rate fell to 3.7%, and the core CPI year-on-year growth rate fell to 2.8%, both lower than market expectations. This data reinforced the expectation that the Federal Reserve might end its interest rate hike cycle, boosting market sentiment.

In addition, the manufacturing PMI data released in September also showed positive signals. The September manufacturing PMI was 50.2, still in the expansion zone but higher than previous months, indicating that manufacturing activities are stabilizing. This data alleviated market concerns about a hard economic landing.

In the real estate market, September new home sales data exceeded expectations, showing that housing demand remained resilient despite high mortgage rates. This data provided support to the financial sector and housing-related stocks.

Investment Strategy Outlook

As September ends and the fourth quarter approaches, investors need to reassess the market environment and investment strategies. From the current market perspective, we believe the following factors will have a significant impact on the market in the fourth quarter:

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1. Federal Reserve Policy Direction: Although inflation data has improved, signals released by Federal Reserve officials at the September meeting remain cautious. The market widely expects that the Federal Reserve may make its last interest rate hike in November or December, then enter an observation period. This policy shift will have a positive impact on market valuations, especially for tech stocks.
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2. Corporate Profit Outlook: The third quarter earnings season is about to begin, and market focus will shift to corporate earnings performance. Currently, the market expects that S&P 500 component companies' earnings will grow by about 5% year-on-year in the third quarter, slightly better than the 3% in the second quarter. The technology sector, especially AI-related companies, is expected to continue leading growth.
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3. Geopolitical Risks: The global geopolitical situation remains complex, with tensions in the Middle East and Eastern Europe potentially affecting energy markets and global supply chains. Investors need to pay attention to the impact of these geopolitical risks on the market.
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4. Approaching US Election: As the November US election approaches, policy uncertainty may increase. Historical data shows that in election years, the market often exhibits greater volatility, and investors need to be prepared to deal with fluctuations.
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Based on the above analysis, we offer the following investment strategy recommendations for the fourth quarter:

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• Continue to focus on the AI technology sector, especially companies with core technologies and strong competitive moats. Large tech giants like NVIDIA, Microsoft, and Google, as well as some innovative companies focused on AI applications, are worth attention.
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• Appropriately increase allocations to the financial sector, especially bank stocks with strong capital strength and good asset quality. As the interest rate environment may stabilize, the financial sector is expected to experience valuation recovery.
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• Focus on quality companies in the consumer sector, especially those with brand advantages and pricing power. Although the consumer environment faces challenges, quality consumer companies can still maintain growth.
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• Appropriately increase allocations to defensive sectors such as utilities and consumer staples to cope with potential market volatility.
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Conclusion

The US stock market performed robustly in September, with all three major indices rising for the month, especially the technology sector which showed outstanding performance. With improving inflation data and rising expectations that the Federal Reserve might end its interest rate hike cycle, market sentiment has clearly improved. Entering the fourth quarter, investors need to focus on factors such as corporate earnings performance, Federal Reserve policy direction, and geopolitical risks, and adjust investment strategies in a timely manner.

Overall, we maintain a cautiously optimistic attitude toward the US stock market in the fourth quarter. Despite facing some challenges such as continued high-interest rate environment and geopolitical risks, the resilience of the US economy and strong growth in the technology sector will provide support to the market. Investors should maintain patience, focus on long-term trends, and avoid being disturbed by short-term market fluctuations.

As 2026 enters its final quarter, the market will face more uncertainties while also containing structural opportunities. Investors should closely monitor market dynamics, flexibly adjust their portfolios, and seize market opportunities while controlling risks.