In October, the United States stock market surprised many people. Usually, October is a month that makes traders nervous because big market crashes happened in 1929 and 1987 during this time. Some traders even call it “Octoberphobia.” But this year, October turned out to be strong and positive, especially because of the fast growth of artificial intelligence, or AI.
The S&P 500, which is a major index that shows how the top 500 U.S. companies are doing, went up by 2.3% in October. Many traders who thought the market would fall were disappointed, because the opposite happened. Another big index, the Nasdaq Composite, did even better. The Nasdaq is known for having many technology companies, and it rose by 4.7% in the same month. This rise shows that technology, especially AI, played a very big role in the market’s success.
One reason for this strong month was Amazon. On Friday, Amazon’s stock price jumped 9.6%. This happened because Amazon’s cloud business grew very well, and its CEO Andy Jassy talked about “strong demand in AI and core infrastructure.” When Amazon’s shares went up, other AI-related companies such as Palantir and Oracle also saw their stocks rise. This shows how one company’s success, especially in AI, can push up others too.
AI did not help the market only in one day. Throughout October, AI companies kept showing strong progress. The biggest example is Nvidia. Nvidia reached a huge milestone when it became the first company to reach a value of $5 trillion. Its CEO, Jensen Huang, explained AI’s growth by saying the technology has created a “virtuous cycle.” According to him, when more people use AI, companies invest more money into AI. That investment makes AI even better, and because it becomes better, even more people start using it. This cycle repeats and helps AI grow continuously.
During the last week of October, many big technology companies announced their earnings. These reports showed that tech companies are now spending huge amounts of money on capital expenses, and a large part of this money is going into building AI systems and infrastructure. This is a sign that AI is not just a temporary trend. It is becoming a major long-term part of the technology world.
The excitement around AI feels different compared to earlier technology booms that sometimes faded quickly. Some experts compared it to the difference between eating a candy bar and eating a pumpkin full of fiber. A candy bar gives fast energy but does not last long. A fiber-rich pumpkin, on the other hand, gives steady energy that stays with you. This means AI is giving steady, long-term growth, not just quick excitement.
Apart from the U.S., other countries also saw important economic changes in October. For example, new numbers from China showed that factory activity slowed down. China’s Manufacturing PMI for October was 50.6, which was lower than September’s 51.2. Although the number is still above 50 — meaning the factories are still growing — it shows that growth is becoming slower. Experts expected the number to be a little higher at 50.9, so this small drop was surprising.
There was also big news from Baidu, the Chinese technology company. Baidu’s robotaxi service, Apollo Go, reported that it had reached 250,000 robotaxi rides per week. This is the same number of weekly driverless rides that Waymo had earlier in the year. It shows that self-driving technology is growing fast, not only in the U.S. but also in China.
Another important update came from Berkshire Hathaway, the company run by famous investor Warren Buffett. Berkshire Hathaway’s operating profit increased by 34% compared to last year, reaching $13.485 billion. The company now has $381.6 billion in cash — the largest amount it has ever held. Even with this huge amount of money, the company is not planning to buy back its own stock yet.
At the end of the month, U.S. markets closed on a strong note. On Sunday night in the U.S., futures tied to the major American stock indexes did not change much, but earlier on Monday, stock markets in Asia rose. Japan’s Nikkei 225 and South Korea’s Kospi both went up by more than 2%. This shows that good news in the U.S. market often spreads to the rest of the world.
As November begins, the S&P 500 is already more than 16% higher for the year. Even though the market is doing well, investors still need to pay attention to important events coming up. One key event is a Supreme Court case about Trump-era tariffs, which could affect international trade. Investors are also watching for earnings reports from companies like Advanced Micro Devices and Palantir. Since these companies are deeply involved in AI, their performance could again influence the whole market.
In simple words, October showed how powerful AI has become in the business world. It helped big companies grow, lifted the whole stock market, and changed the way investors look at the future. Technology companies are spending more money to build stronger AI, robotaxi services are becoming more common, and countries all over the world are feeling the effects of new technology.
Even though some parts of the global economy, like China’s factory activity, are slowing down, AI continues to give markets energy and confidence. It is becoming clear that AI is not just another tool. It is becoming the center of new business growth. Companies, big and small, are trying hard to understand it, use it, and invest in it.
